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Diffstat (limited to 'src/include/librdkafka/rdkafka.h')
| -rw-r--r-- | src/include/librdkafka/rdkafka.h | 4190 |
1 files changed, 4190 insertions, 0 deletions
diff --git a/src/include/librdkafka/rdkafka.h b/src/include/librdkafka/rdkafka.h new file mode 100644 index 0000000..16770dc --- /dev/null +++ b/src/include/librdkafka/rdkafka.h @@ -0,0 +1,4190 @@ +/* + * librdkafka - Apache Kafka C library + * + * Copyright (c) 2012-2013 Magnus Edenhill + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +/** + * @file rdkafka.h + * @brief Apache Kafka C/C++ consumer and producer client library. + * + * rdkafka.h contains the public API for librdkafka. + * The API is documented in this file as comments prefixing the function, type, + * enum, define, etc. + * + * @sa For the C++ interface see rdkafkacpp.h + * + * @tableofcontents + */ + + +/* @cond NO_DOC */ +#pragma once + +#include <stdio.h> +#include <inttypes.h> +#include <sys/types.h> + +#ifdef __cplusplus +extern "C" { +#if 0 +} /* Restore indent */ +#endif +#endif + +#ifdef _MSC_VER +#include <basetsd.h> +#ifndef WIN32_MEAN_AND_LEAN +#define WIN32_MEAN_AND_LEAN +#endif +#include <Winsock2.h> /* for sockaddr, .. */ +typedef SSIZE_T ssize_t; +#define RD_UNUSED +#define RD_INLINE __inline +#define RD_DEPRECATED __declspec(deprecated) +#undef RD_EXPORT +#ifdef LIBRDKAFKA_STATICLIB +#define RD_EXPORT +#else +#ifdef LIBRDKAFKA_EXPORTS +#define RD_EXPORT __declspec(dllexport) +#else +#define RD_EXPORT __declspec(dllimport) +#endif +#ifndef LIBRDKAFKA_TYPECHECKS +#define LIBRDKAFKA_TYPECHECKS 0 +#endif +#endif + +#else +#include <sys/socket.h> /* for sockaddr, .. */ + +#define RD_UNUSED __attribute__((unused)) +#define RD_INLINE inline +#define RD_EXPORT +#define RD_DEPRECATED __attribute__((deprecated)) + +#ifndef LIBRDKAFKA_TYPECHECKS +#define LIBRDKAFKA_TYPECHECKS 1 +#endif +#endif + + +/** + * @brief Type-checking macros + * Compile-time checking that \p ARG is of type \p TYPE. + * @returns \p RET + */ +#if LIBRDKAFKA_TYPECHECKS +#define _LRK_TYPECHECK(RET,TYPE,ARG) \ + ({ if (0) { TYPE __t RD_UNUSED = (ARG); } RET; }) + +#define _LRK_TYPECHECK2(RET,TYPE,ARG,TYPE2,ARG2) \ + ({ \ + if (0) { \ + TYPE __t RD_UNUSED = (ARG); \ + TYPE2 __t2 RD_UNUSED = (ARG2); \ + } \ + RET; }) + +#define _LRK_TYPECHECK3(RET,TYPE,ARG,TYPE2,ARG2,TYPE3,ARG3) \ + ({ \ + if (0) { \ + TYPE __t RD_UNUSED = (ARG); \ + TYPE2 __t2 RD_UNUSED = (ARG2); \ + TYPE3 __t3 RD_UNUSED = (ARG3); \ + } \ + RET; }) +#else +#define _LRK_TYPECHECK(RET,TYPE,ARG) (RET) +#define _LRK_TYPECHECK2(RET,TYPE,ARG,TYPE2,ARG2) (RET) +#define _LRK_TYPECHECK3(RET,TYPE,ARG,TYPE2,ARG2,TYPE3,ARG3) (RET) +#endif + +/* @endcond */ + + +/** + * @name librdkafka version + * @{ + * + * + */ + +/** + * @brief librdkafka version + * + * Interpreted as hex \c MM.mm.rr.xx: + * - MM = Major + * - mm = minor + * - rr = revision + * - xx = pre-release id (0xff is the final release) + * + * E.g.: \c 0x000801ff = 0.8.1 + * + * @remark This value should only be used during compile time, + * for runtime checks of version use rd_kafka_version() + */ +#define RD_KAFKA_VERSION 0x000b01ff + +/** + * @brief Returns the librdkafka version as integer. + * + * @returns Version integer. + * + * @sa See RD_KAFKA_VERSION for how to parse the integer format. + * @sa Use rd_kafka_version_str() to retreive the version as a string. + */ +RD_EXPORT +int rd_kafka_version(void); + +/** + * @brief Returns the librdkafka version as string. + * + * @returns Version string + */ +RD_EXPORT +const char *rd_kafka_version_str (void); + +/**@}*/ + + +/** + * @name Constants, errors, types + * @{ + * + * + */ + + +/** + * @enum rd_kafka_type_t + * + * @brief rd_kafka_t handle type. + * + * @sa rd_kafka_new() + */ +typedef enum rd_kafka_type_t { + RD_KAFKA_PRODUCER, /**< Producer client */ + RD_KAFKA_CONSUMER /**< Consumer client */ +} rd_kafka_type_t; + + +/** + * @enum Timestamp types + * + * @sa rd_kafka_message_timestamp() + */ +typedef enum rd_kafka_timestamp_type_t { + RD_KAFKA_TIMESTAMP_NOT_AVAILABLE, /**< Timestamp not available */ + RD_KAFKA_TIMESTAMP_CREATE_TIME, /**< Message creation time */ + RD_KAFKA_TIMESTAMP_LOG_APPEND_TIME /**< Log append time */ +} rd_kafka_timestamp_type_t; + + + +/** + * @brief Retrieve supported debug contexts for use with the \c \"debug\" + * configuration property. (runtime) + * + * @returns Comma-separated list of available debugging contexts. + */ +RD_EXPORT +const char *rd_kafka_get_debug_contexts(void); + +/** + * @brief Supported debug contexts. (compile time) + * + * @deprecated This compile time value may be outdated at runtime due to + * linking another version of the library. + * Use rd_kafka_get_debug_contexts() instead. + */ +#define RD_KAFKA_DEBUG_CONTEXTS \ + "all,generic,broker,topic,metadata,feature,queue,msg,protocol,cgrp,security,fetch,interceptor,plugin,consumer" + + +/* @cond NO_DOC */ +/* Private types to provide ABI compatibility */ +typedef struct rd_kafka_s rd_kafka_t; +typedef struct rd_kafka_topic_s rd_kafka_topic_t; +typedef struct rd_kafka_conf_s rd_kafka_conf_t; +typedef struct rd_kafka_topic_conf_s rd_kafka_topic_conf_t; +typedef struct rd_kafka_queue_s rd_kafka_queue_t; +/* @endcond */ + + +/** + * @enum rd_kafka_resp_err_t + * @brief Error codes. + * + * The negative error codes delimited by two underscores + * (\c RD_KAFKA_RESP_ERR__..) denotes errors internal to librdkafka and are + * displayed as \c \"Local: \<error string..\>\", while the error codes + * delimited by a single underscore (\c RD_KAFKA_RESP_ERR_..) denote broker + * errors and are displayed as \c \"Broker: \<error string..\>\". + * + * @sa Use rd_kafka_err2str() to translate an error code a human readable string + */ +typedef enum { + /* Internal errors to rdkafka: */ + /** Begin internal error codes */ + RD_KAFKA_RESP_ERR__BEGIN = -200, + /** Received message is incorrect */ + RD_KAFKA_RESP_ERR__BAD_MSG = -199, + /** Bad/unknown compression */ + RD_KAFKA_RESP_ERR__BAD_COMPRESSION = -198, + /** Broker is going away */ + RD_KAFKA_RESP_ERR__DESTROY = -197, + /** Generic failure */ + RD_KAFKA_RESP_ERR__FAIL = -196, + /** Broker transport failure */ + RD_KAFKA_RESP_ERR__TRANSPORT = -195, + /** Critical system resource */ + RD_KAFKA_RESP_ERR__CRIT_SYS_RESOURCE = -194, + /** Failed to resolve broker */ + RD_KAFKA_RESP_ERR__RESOLVE = -193, + /** Produced message timed out*/ + RD_KAFKA_RESP_ERR__MSG_TIMED_OUT = -192, + /** Reached the end of the topic+partition queue on + * the broker. Not really an error. */ + RD_KAFKA_RESP_ERR__PARTITION_EOF = -191, + /** Permanent: Partition does not exist in cluster. */ + RD_KAFKA_RESP_ERR__UNKNOWN_PARTITION = -190, + /** File or filesystem error */ + RD_KAFKA_RESP_ERR__FS = -189, + /** Permanent: Topic does not exist in cluster. */ + RD_KAFKA_RESP_ERR__UNKNOWN_TOPIC = -188, + /** All broker connections are down. */ + RD_KAFKA_RESP_ERR__ALL_BROKERS_DOWN = -187, + /** Invalid argument, or invalid configuration */ + RD_KAFKA_RESP_ERR__INVALID_ARG = -186, + /** Operation timed out */ + RD_KAFKA_RESP_ERR__TIMED_OUT = -185, + /** Queue is full */ + RD_KAFKA_RESP_ERR__QUEUE_FULL = -184, + /** ISR count < required.acks */ + RD_KAFKA_RESP_ERR__ISR_INSUFF = -183, + /** Broker node update */ + RD_KAFKA_RESP_ERR__NODE_UPDATE = -182, + /** SSL error */ + RD_KAFKA_RESP_ERR__SSL = -181, + /** Waiting for coordinator to become available. */ + RD_KAFKA_RESP_ERR__WAIT_COORD = -180, + /** Unknown client group */ + RD_KAFKA_RESP_ERR__UNKNOWN_GROUP = -179, + /** Operation in progress */ + RD_KAFKA_RESP_ERR__IN_PROGRESS = -178, + /** Previous operation in progress, wait for it to finish. */ + RD_KAFKA_RESP_ERR__PREV_IN_PROGRESS = -177, + /** This operation would interfere with an existing subscription */ + RD_KAFKA_RESP_ERR__EXISTING_SUBSCRIPTION = -176, + /** Assigned partitions (kafka_rebalance_cb) */ + RD_KAFKA_RESP_ERR__ASSIGN_PARTITIONS = -175, + /** Revoked partitions (rebalance_cb) */ + RD_KAFKA_RESP_ERR__REVOKE_PARTITIONS = -174, + /** Conflicting use */ + RD_KAFKA_RESP_ERR__CONFLICT = -173, + /** Wrong state */ + RD_KAFKA_RESP_ERR__STATE = -172, + /** Unknown protocol */ + RD_KAFKA_RESP_ERR__UNKNOWN_PROTOCOL = -171, + /** Not implemented */ + RD_KAFKA_RESP_ERR__NOT_IMPLEMENTED = -170, + /** Authentication failure*/ + RD_KAFKA_RESP_ERR__AUTHENTICATION = -169, + /** No stored offset */ + RD_KAFKA_RESP_ERR__NO_OFFSET = -168, + /** Outdated */ + RD_KAFKA_RESP_ERR__OUTDATED = -167, + /** Timed out in queue */ + RD_KAFKA_RESP_ERR__TIMED_OUT_QUEUE = -166, + /** Feature not supported by broker */ + RD_KAFKA_RESP_ERR__UNSUPPORTED_FEATURE = -165, + /** Awaiting cache update */ + RD_KAFKA_RESP_ERR__WAIT_CACHE = -164, + /** Operation interrupted (e.g., due to yield)) */ + RD_KAFKA_RESP_ERR__INTR = -163, + /** Key serialization error */ + RD_KAFKA_RESP_ERR__KEY_SERIALIZATION = -162, + /** Value serialization error */ + RD_KAFKA_RESP_ERR__VALUE_SERIALIZATION = -161, + /** Key deserialization error */ + RD_KAFKA_RESP_ERR__KEY_DESERIALIZATION = -160, + /** Value deserialization error */ + RD_KAFKA_RESP_ERR__VALUE_DESERIALIZATION = -159, + /** Partial response */ + RD_KAFKA_RESP_ERR__PARTIAL = -158, + /** Modification attempted on read-only object */ + RD_KAFKA_RESP_ERR__READ_ONLY = -157, + /** No such entry / item not found */ + RD_KAFKA_RESP_ERR__NOENT = -156, + /** Read underflow */ + RD_KAFKA_RESP_ERR__UNDERFLOW = -155, + + /** End internal error codes */ + RD_KAFKA_RESP_ERR__END = -100, + + /* Kafka broker errors: */ + /** Unknown broker error */ + RD_KAFKA_RESP_ERR_UNKNOWN = -1, + /** Success */ + RD_KAFKA_RESP_ERR_NO_ERROR = 0, + /** Offset out of range */ + RD_KAFKA_RESP_ERR_OFFSET_OUT_OF_RANGE = 1, + /** Invalid message */ + RD_KAFKA_RESP_ERR_INVALID_MSG = 2, + /** Unknown topic or partition */ + RD_KAFKA_RESP_ERR_UNKNOWN_TOPIC_OR_PART = 3, + /** Invalid message size */ + RD_KAFKA_RESP_ERR_INVALID_MSG_SIZE = 4, + /** Leader not available */ + RD_KAFKA_RESP_ERR_LEADER_NOT_AVAILABLE = 5, + /** Not leader for partition */ + RD_KAFKA_RESP_ERR_NOT_LEADER_FOR_PARTITION = 6, + /** Request timed out */ + RD_KAFKA_RESP_ERR_REQUEST_TIMED_OUT = 7, + /** Broker not available */ + RD_KAFKA_RESP_ERR_BROKER_NOT_AVAILABLE = 8, + /** Replica not available */ + RD_KAFKA_RESP_ERR_REPLICA_NOT_AVAILABLE = 9, + /** Message size too large */ + RD_KAFKA_RESP_ERR_MSG_SIZE_TOO_LARGE = 10, + /** StaleControllerEpochCode */ + RD_KAFKA_RESP_ERR_STALE_CTRL_EPOCH = 11, + /** Offset metadata string too large */ + RD_KAFKA_RESP_ERR_OFFSET_METADATA_TOO_LARGE = 12, + /** Broker disconnected before response received */ + RD_KAFKA_RESP_ERR_NETWORK_EXCEPTION = 13, + /** Group coordinator load in progress */ + RD_KAFKA_RESP_ERR_GROUP_LOAD_IN_PROGRESS = 14, + /** Group coordinator not available */ + RD_KAFKA_RESP_ERR_GROUP_COORDINATOR_NOT_AVAILABLE = 15, + /** Not coordinator for group */ + RD_KAFKA_RESP_ERR_NOT_COORDINATOR_FOR_GROUP = 16, + /** Invalid topic */ + RD_KAFKA_RESP_ERR_TOPIC_EXCEPTION = 17, + /** Message batch larger than configured server segment size */ + RD_KAFKA_RESP_ERR_RECORD_LIST_TOO_LARGE = 18, + /** Not enough in-sync replicas */ + RD_KAFKA_RESP_ERR_NOT_ENOUGH_REPLICAS = 19, + /** Message(s) written to insufficient number of in-sync replicas */ + RD_KAFKA_RESP_ERR_NOT_ENOUGH_REPLICAS_AFTER_APPEND = 20, + /** Invalid required acks value */ + RD_KAFKA_RESP_ERR_INVALID_REQUIRED_ACKS = 21, + /** Specified group generation id is not valid */ + RD_KAFKA_RESP_ERR_ILLEGAL_GENERATION = 22, + /** Inconsistent group protocol */ + RD_KAFKA_RESP_ERR_INCONSISTENT_GROUP_PROTOCOL = 23, + /** Invalid group.id */ + RD_KAFKA_RESP_ERR_INVALID_GROUP_ID = 24, + /** Unknown member */ + RD_KAFKA_RESP_ERR_UNKNOWN_MEMBER_ID = 25, + /** Invalid session timeout */ + RD_KAFKA_RESP_ERR_INVALID_SESSION_TIMEOUT = 26, + /** Group rebalance in progress */ + RD_KAFKA_RESP_ERR_REBALANCE_IN_PROGRESS = 27, + /** Commit offset data size is not valid */ + RD_KAFKA_RESP_ERR_INVALID_COMMIT_OFFSET_SIZE = 28, + /** Topic authorization failed */ + RD_KAFKA_RESP_ERR_TOPIC_AUTHORIZATION_FAILED = 29, + /** Group authorization failed */ + RD_KAFKA_RESP_ERR_GROUP_AUTHORIZATION_FAILED = 30, + /** Cluster authorization failed */ + RD_KAFKA_RESP_ERR_CLUSTER_AUTHORIZATION_FAILED = 31, + /** Invalid timestamp */ + RD_KAFKA_RESP_ERR_INVALID_TIMESTAMP = 32, + /** Unsupported SASL mechanism */ + RD_KAFKA_RESP_ERR_UNSUPPORTED_SASL_MECHANISM = 33, + /** Illegal SASL state */ + RD_KAFKA_RESP_ERR_ILLEGAL_SASL_STATE = 34, + /** Unuspported version */ + RD_KAFKA_RESP_ERR_UNSUPPORTED_VERSION = 35, + /** Topic already exists */ + RD_KAFKA_RESP_ERR_TOPIC_ALREADY_EXISTS = 36, + /** Invalid number of partitions */ + RD_KAFKA_RESP_ERR_INVALID_PARTITIONS = 37, + /** Invalid replication factor */ + RD_KAFKA_RESP_ERR_INVALID_REPLICATION_FACTOR = 38, + /** Invalid replica assignment */ + RD_KAFKA_RESP_ERR_INVALID_REPLICA_ASSIGNMENT = 39, + /** Invalid config */ + RD_KAFKA_RESP_ERR_INVALID_CONFIG = 40, + /** Not controller for cluster */ + RD_KAFKA_RESP_ERR_NOT_CONTROLLER = 41, + /** Invalid request */ + RD_KAFKA_RESP_ERR_INVALID_REQUEST = 42, + /** Message format on broker does not support request */ + RD_KAFKA_RESP_ERR_UNSUPPORTED_FOR_MESSAGE_FORMAT = 43, + /** Isolation policy volation */ + RD_KAFKA_RESP_ERR_POLICY_VIOLATION = 44, + /** Broker received an out of order sequence number */ + RD_KAFKA_RESP_ERR_OUT_OF_ORDER_SEQUENCE_NUMBER = 45, + /** Broker received a duplicate sequence number */ + RD_KAFKA_RESP_ERR_DUPLICATE_SEQUENCE_NUMBER = 46, + /** Producer attempted an operation with an old epoch */ + RD_KAFKA_RESP_ERR_INVALID_PRODUCER_EPOCH = 47, + /** Producer attempted a transactional operation in an invalid state */ + RD_KAFKA_RESP_ERR_INVALID_TXN_STATE = 48, + /** Producer attempted to use a producer id which is not + * currently assigned to its transactional id */ + RD_KAFKA_RESP_ERR_INVALID_PRODUCER_ID_MAPPING = 49, + /** Transaction timeout is larger than the maximum + * value allowed by the broker's max.transaction.timeout.ms */ + RD_KAFKA_RESP_ERR_INVALID_TRANSACTION_TIMEOUT = 50, + /** Producer attempted to update a transaction while another + * concurrent operation on the same transaction was ongoing */ + RD_KAFKA_RESP_ERR_CONCURRENT_TRANSACTIONS = 51, + /** Indicates that the transaction coordinator sending a + * WriteTxnMarker is no longer the current coordinator for a + * given producer */ + RD_KAFKA_RESP_ERR_TRANSACTION_COORDINATOR_FENCED = 52, + /** Transactional Id authorization failed */ + RD_KAFKA_RESP_ERR_TRANSACTIONAL_ID_AUTHORIZATION_FAILED = 53, + /** Security features are disabled */ + RD_KAFKA_RESP_ERR_SECURITY_DISABLED = 54, + /** Operation not attempted */ + RD_KAFKA_RESP_ERR_OPERATION_NOT_ATTEMPTED = 55, + + RD_KAFKA_RESP_ERR_END_ALL, +} rd_kafka_resp_err_t; + + +/** + * @brief Error code value, name and description. + * Typically for use with language bindings to automatically expose + * the full set of librdkafka error codes. + */ +struct rd_kafka_err_desc { + rd_kafka_resp_err_t code;/**< Error code */ + const char *name; /**< Error name, same as code enum sans prefix */ + const char *desc; /**< Human readable error description. */ +}; + + +/** + * @brief Returns the full list of error codes. + */ +RD_EXPORT +void rd_kafka_get_err_descs (const struct rd_kafka_err_desc **errdescs, + size_t *cntp); + + + + +/** + * @brief Returns a human readable representation of a kafka error. + * + * @param err Error code to translate + */ +RD_EXPORT +const char *rd_kafka_err2str (rd_kafka_resp_err_t err); + + + +/** + * @brief Returns the error code name (enum name). + * + * @param err Error code to translate + */ +RD_EXPORT +const char *rd_kafka_err2name (rd_kafka_resp_err_t err); + + +/** + * @brief Returns the last error code generated by a legacy API call + * in the current thread. + * + * The legacy APIs are the ones using errno to propagate error value, namely: + * - rd_kafka_topic_new() + * - rd_kafka_consume_start() + * - rd_kafka_consume_stop() + * - rd_kafka_consume() + * - rd_kafka_consume_batch() + * - rd_kafka_consume_callback() + * - rd_kafka_consume_queue() + * - rd_kafka_produce() + * + * The main use for this function is to avoid converting system \p errno + * values to rd_kafka_resp_err_t codes for legacy APIs. + * + * @remark The last error is stored per-thread, if multiple rd_kafka_t handles + * are used in the same application thread the developer needs to + * make sure rd_kafka_last_error() is called immediately after + * a failed API call. + * + * @remark errno propagation from librdkafka is not safe on Windows + * and should not be used, use rd_kafka_last_error() instead. + */ +RD_EXPORT +rd_kafka_resp_err_t rd_kafka_last_error (void); + + +/** + * @brief Converts the system errno value \p errnox to a rd_kafka_resp_err_t + * error code upon failure from the following functions: + * - rd_kafka_topic_new() + * - rd_kafka_consume_start() + * - rd_kafka_consume_stop() + * - rd_kafka_consume() + * - rd_kafka_consume_batch() + * - rd_kafka_consume_callback() + * - rd_kafka_consume_queue() + * - rd_kafka_produce() + * + * @param errnox System errno value to convert + * + * @returns Appropriate error code for \p errnox + * + * @remark A better alternative is to call rd_kafka_last_error() immediately + * after any of the above functions return -1 or NULL. + * + * @deprecated Use rd_kafka_last_error() to retrieve the last error code + * set by the legacy librdkafka APIs. + * + * @sa rd_kafka_last_error() + */ +RD_EXPORT RD_DEPRECATED +rd_kafka_resp_err_t rd_kafka_errno2err(int errnox); + + +/** + * @brief Returns the thread-local system errno + * + * On most platforms this is the same as \p errno but in case of different + * runtimes between library and application (e.g., Windows static DLLs) + * this provides a means for exposing the errno librdkafka uses. + * + * @remark The value is local to the current calling thread. + * + * @deprecated Use rd_kafka_last_error() to retrieve the last error code + * set by the legacy librdkafka APIs. + */ +RD_EXPORT RD_DEPRECATED +int rd_kafka_errno (void); + + + +/** + * @brief Topic+Partition place holder + * + * Generic place holder for a Topic+Partition and its related information + * used for multiple purposes: + * - consumer offset (see rd_kafka_commit(), et.al.) + * - group rebalancing callback (rd_kafka_conf_set_rebalance_cb()) + * - offset commit result callback (rd_kafka_conf_set_offset_commit_cb()) + */ + +/** + * @brief Generic place holder for a specific Topic+Partition. + * + * @sa rd_kafka_topic_partition_list_new() + */ +typedef struct rd_kafka_topic_partition_s { + char *topic; /**< Topic name */ + int32_t partition; /**< Partition */ + int64_t offset; /**< Offset */ + void *metadata; /**< Metadata */ + size_t metadata_size; /**< Metadata size */ + void *opaque; /**< Application opaque */ + rd_kafka_resp_err_t err; /**< Error code, depending on use. */ + void *_private; /**< INTERNAL USE ONLY, + * INITIALIZE TO ZERO, DO NOT TOUCH */ +} rd_kafka_topic_partition_t; + + +/** + * @brief Destroy a rd_kafka_topic_partition_t. + * @remark This must not be called for elements in a topic partition list. + */ +RD_EXPORT +void rd_kafka_topic_partition_destroy (rd_kafka_topic_partition_t *rktpar); + + +/** + * @brief A growable list of Topic+Partitions. + * + */ +typedef struct rd_kafka_topic_partition_list_s { + int cnt; /**< Current number of elements */ + int size; /**< Current allocated size */ + rd_kafka_topic_partition_t *elems; /**< Element array[] */ +} rd_kafka_topic_partition_list_t; + + +/** + * @brief Create a new list/vector Topic+Partition container. + * + * @param size Initial allocated size used when the expected number of + * elements is known or can be estimated. + * Avoids reallocation and possibly relocation of the + * elems array. + * + * @returns A newly allocated Topic+Partition list. + * + * @remark Use rd_kafka_topic_partition_list_destroy() to free all resources + * in use by a list and the list itself. + * @sa rd_kafka_topic_partition_list_add() + */ +RD_EXPORT +rd_kafka_topic_partition_list_t *rd_kafka_topic_partition_list_new (int size); + + +/** + * @brief Free all resources used by the list and the list itself. + */ +RD_EXPORT +void +rd_kafka_topic_partition_list_destroy (rd_kafka_topic_partition_list_t *rkparlist); + +/** + * @brief Add topic+partition to list + * + * @param rktparlist List to extend + * @param topic Topic name (copied) + * @param partition Partition id + * + * @returns The object which can be used to fill in additionals fields. + */ +RD_EXPORT +rd_kafka_topic_partition_t * +rd_kafka_topic_partition_list_add (rd_kafka_topic_partition_list_t *rktparlist, + const char *topic, int32_t partition); + + +/** + * @brief Add range of partitions from \p start to \p stop inclusive. + * + * @param rktparlist List to extend + * @param topic Topic name (copied) + * @param start Start partition of range + * @param stop Last partition of range (inclusive) + */ +RD_EXPORT +void +rd_kafka_topic_partition_list_add_range (rd_kafka_topic_partition_list_t + *rktparlist, + const char *topic, + int32_t start, int32_t stop); + + + +/** + * @brief Delete partition from list. + * + * @param rktparlist List to modify + * @param topic Topic name to match + * @param partition Partition to match + * + * @returns 1 if partition was found (and removed), else 0. + * + * @remark Any held indices to elems[] are unusable after this call returns 1. + */ +RD_EXPORT +int +rd_kafka_topic_partition_list_del (rd_kafka_topic_partition_list_t *rktparlist, + const char *topic, int32_t partition); + + +/** + * @brief Delete partition from list by elems[] index. + * + * @returns 1 if partition was found (and removed), else 0. + * + * @sa rd_kafka_topic_partition_list_del() + */ +RD_EXPORT +int +rd_kafka_topic_partition_list_del_by_idx ( + rd_kafka_topic_partition_list_t *rktparlist, + int idx); + + +/** + * @brief Make a copy of an existing list. + * + * @param src The existing list to copy. + * + * @returns A new list fully populated to be identical to \p src + */ +RD_EXPORT +rd_kafka_topic_partition_list_t * +rd_kafka_topic_partition_list_copy (const rd_kafka_topic_partition_list_t *src); + + + + +/** + * @brief Set offset to \p offset for \p topic and \p partition + * + * @returns RD_KAFKA_RESP_ERR_NO_ERROR on success or + * RD_KAFKA_RESP_ERR__UNKNOWN_PARTITION if \p partition was not found + * in the list. + */ +RD_EXPORT +rd_kafka_resp_err_t rd_kafka_topic_partition_list_set_offset ( + rd_kafka_topic_partition_list_t *rktparlist, + const char *topic, int32_t partition, int64_t offset); + + + +/** + * @brief Find element by \p topic and \p partition. + * + * @returns a pointer to the first matching element, or NULL if not found. + */ +RD_EXPORT +rd_kafka_topic_partition_t * +rd_kafka_topic_partition_list_find (rd_kafka_topic_partition_list_t *rktparlist, + const char *topic, int32_t partition); + + +/** + * @brief Sort list using comparator \p cmp. + * + * If \p cmp is NULL the default comparator will be used that + * sorts by ascending topic name and partition. + * + */ +RD_EXPORT void +rd_kafka_topic_partition_list_sort (rd_kafka_topic_partition_list_t *rktparlist, + int (*cmp) (const void *a, const void *b, + void *opaque), + void *opaque); + + +/**@}*/ + + + +/** + * @name Var-arg tag types + * @{ + * + */ + +/** + * @enum rd_kafka_vtype_t + * + * @brief Var-arg tag types + * + * @sa rd_kafka_producev() + */ +typedef enum rd_kafka_vtype_t { + RD_KAFKA_VTYPE_END, /**< va-arg sentinel */ + RD_KAFKA_VTYPE_TOPIC, /**< (const char *) Topic name */ + RD_KAFKA_VTYPE_RKT, /**< (rd_kafka_topic_t *) Topic handle */ + RD_KAFKA_VTYPE_PARTITION, /**< (int32_t) Partition */ + RD_KAFKA_VTYPE_VALUE, /**< (void *, size_t) Message value (payload)*/ + RD_KAFKA_VTYPE_KEY, /**< (void *, size_t) Message key */ + RD_KAFKA_VTYPE_OPAQUE, /**< (void *) Application opaque */ + RD_KAFKA_VTYPE_MSGFLAGS, /**< (int) RD_KAFKA_MSG_F_.. flags */ + RD_KAFKA_VTYPE_TIMESTAMP, /**< (int64_t) Milliseconds since epoch UTC */ + RD_KAFKA_VTYPE_HEADER, /**< (const char *, const void *, ssize_t) + * Message Header */ + RD_KAFKA_VTYPE_HEADERS, /**< (rd_kafka_headers_t *) Headers list */ +} rd_kafka_vtype_t; + + +/** + * @brief Convenience macros for rd_kafka_vtype_t that takes the + * correct arguments for each vtype. + */ + +/*! + * va-arg end sentinel used to terminate the variable argument list + */ +#define RD_KAFKA_V_END RD_KAFKA_VTYPE_END + +/*! + * Topic name (const char *) + */ +#define RD_KAFKA_V_TOPIC(topic) \ + _LRK_TYPECHECK(RD_KAFKA_VTYPE_TOPIC, const char *, topic), \ + (const char *)topic +/*! + * Topic object (rd_kafka_topic_t *) + */ +#define RD_KAFKA_V_RKT(rkt) \ + _LRK_TYPECHECK(RD_KAFKA_VTYPE_RKT, rd_kafka_topic_t *, rkt), \ + (rd_kafka_topic_t *)rkt +/*! + * Partition (int32_t) + */ +#define RD_KAFKA_V_PARTITION(partition) \ + _LRK_TYPECHECK(RD_KAFKA_VTYPE_PARTITION, int32_t, partition), \ + (int32_t)partition +/*! + * Message value/payload pointer and length (void *, size_t) + */ +#define RD_KAFKA_V_VALUE(VALUE,LEN) \ + _LRK_TYPECHECK2(RD_KAFKA_VTYPE_VALUE, void *, VALUE, size_t, LEN), \ + (void *)VALUE, (size_t)LEN +/*! + * Message key pointer and length (const void *, size_t) + */ +#define RD_KAFKA_V_KEY(KEY,LEN) \ + _LRK_TYPECHECK2(RD_KAFKA_VTYPE_KEY, const void *, KEY, size_t, LEN), \ + (void *)KEY, (size_t)LEN +/*! + * Message opaque pointer (void *) + * Same as \c produce(.., msg_opaque), and \c rkmessage->_private . + */ +#define RD_KAFKA_V_OPAQUE(opaque) \ + _LRK_TYPECHECK(RD_KAFKA_VTYPE_OPAQUE, void *, opaque), \ + (void *)opaque +/*! + * Message flags (int) + * @sa RD_KAFKA_MSG_F_COPY, et.al. + */ +#define RD_KAFKA_V_MSGFLAGS(msgflags) \ + _LRK_TYPECHECK(RD_KAFKA_VTYPE_MSGFLAGS, int, msgflags), \ + (int)msgflags +/*! + * Timestamp (int64_t) + */ +#define RD_KAFKA_V_TIMESTAMP(timestamp) \ + _LRK_TYPECHECK(RD_KAFKA_VTYPE_TIMESTAMP, int64_t, timestamp), \ + (int64_t)timestamp +/*! + * Add Message Header (const char *NAME, const void *VALUE, ssize_t LEN). + * @sa rd_kafka_header_add() + * @remark RD_KAFKA_V_HEADER() and RD_KAFKA_V_HEADERS() MUST NOT be mixed + * in the same call to producev(). + */ +#define RD_KAFKA_V_HEADER(NAME,VALUE,LEN) \ + _LRK_TYPECHECK3(RD_KAFKA_VTYPE_HEADER, const char *, NAME, \ + const void *, VALUE, ssize_t, LEN), \ + (const char *)NAME, (const void *)VALUE, (ssize_t)LEN + +/*! + * Message Headers list (rd_kafka_headers_t *). + * The message object will assume ownership of the headers (unless producev() + * fails). + * Any existing headers will be replaced. + * @sa rd_kafka_message_set_headers() + * @remark RD_KAFKA_V_HEADER() and RD_KAFKA_V_HEADERS() MUST NOT be mixed + * in the same call to producev(). + */ +#define RD_KAFKA_V_HEADERS(HDRS) \ + _LRK_TYPECHECK(RD_KAFKA_VTYPE_HEADERS, rd_kafka_headers_t *, HDRS), \ + (rd_kafka_headers_t *)HDRS + + +/**@}*/ + + +/** + * @name Message headers + * @{ + * + * @brief Message headers consist of a list of (string key, binary value) pairs. + * Duplicate keys are supported and the order in which keys were + * added are retained. + * + * Header values are considered binary and may have three types of + * value: + * - proper value with size > 0 and a valid pointer + * - empty value with size = 0 and any non-NULL pointer + * - null value with size = 0 and a NULL pointer + * + * Headers require Apache Kafka broker version v0.11.0.0 or later. + * + * Header operations are O(n). + */ + +typedef struct rd_kafka_headers_s rd_kafka_headers_t; + +/** + * @brief Create a new headers list. + * + * @param initial_count Preallocate space for this number of headers. + * Any number of headers may be added, updated and + * removed regardless of the initial count. + */ +RD_EXPORT rd_kafka_headers_t *rd_kafka_headers_new (size_t initial_count); + +/** + * @brief Destroy the headers list. The object and any returned value pointers + * are not usable after this call. + */ +RD_EXPORT void rd_kafka_headers_destroy (rd_kafka_headers_t *hdrs); + +/** + * @brief Make a copy of headers list \p src. + */ +RD_EXPORT rd_kafka_headers_t * +rd_kafka_headers_copy (const rd_kafka_headers_t *src); + +/** + * @brief Add header with name \p name and value \p val (copied) of size + * \p size (not including null-terminator). + * + * @param name Header name. + * @param name_size Header name size (not including the null-terminator). + * If -1 the \p name length is automatically acquired using + * strlen(). + * @param value Pointer to header value, or NULL (set size to 0 or -1). + * @param value_size Size of header value. If -1 the \p value is assumed to be a + * null-terminated string and the length is automatically + * acquired using strlen(). + * + * @returns RD_KAFKA_RESP_ERR__READ_ONLY if the headers are read-only, + * else RD_KAFKA_RESP_ERR_NO_ERROR. + */ +RD_EXPORT rd_kafka_resp_err_t +rd_kafka_header_add (rd_kafka_headers_t *hdrs, + const char *name, ssize_t name_size, + const void *value, ssize_t value_size); + +/** + * @brief Remove all headers for the given key (if any). + * + * @returns RD_KAFKA_RESP_ERR__READ_ONLY if the headers are read-only, + * RD_KAFKA_RESP_ERR__NOENT if no matching headers were found, + * else RD_KAFKA_RESP_ERR_NO_ERROR if headers were removed. + */ +RD_EXPORT rd_kafka_resp_err_t +rd_kafka_header_remove (rd_kafka_headers_t *hdrs, const char *name); + + +/** + * @brief Find last header in list \p hdrs matching \p name. + * + * @param name Header to find (last match). + * @param valuep (out) Set to a (null-terminated) const pointer to the value + * (may be NULL). + * @param sizep (out) Set to the value's size (not including null-terminator). + * + * @returns RD_KAFKA_RESP_ERR_NO_ERROR if an entry was found, else + * RD_KAFKA_RESP_ERR__NOENT. + * + * @remark The returned pointer in \p valuep includes a trailing null-terminator + * that is not accounted for in \p sizep. + * @remark The returned pointer is only valid as long as the headers list and + * the header item is valid. + */ +RD_EXPORT rd_kafka_resp_err_t +rd_kafka_header_get_last (const rd_kafka_headers_t *hdrs, + const char *name, const void **valuep, size_t *sizep); + +/** + * @brief Iterator for headers matching \p name. + * + * Same semantics as rd_kafka_header_get_last() + * + * @param hdrs Headers to iterate. + * @param idx Iterator index, start at 0 and increment by one for each call + * as long as RD_KAFKA_RESP_ERR_NO_ERROR is returned. + * @param name Header name to match. + * @param valuep (out) Set to a (null-terminated) const pointer to the value + * (may be NULL). + * @param sizep (out) Set to the value's size (not including null-terminator). + */ +RD_EXPORT rd_kafka_resp_err_t +rd_kafka_header_get (const rd_kafka_headers_t *hdrs, size_t idx, + const char *name, const void **valuep, size_t *sizep); + + +/** + * @brief Iterator for all headers. + * + * Same semantics as rd_kafka_header_get() + * + * @sa rd_kafka_header_get() + */ +RD_EXPORT rd_kafka_resp_err_t +rd_kafka_header_get_all (const rd_kafka_headers_t *hdrs, size_t idx, + const char **namep, + const void **valuep, size_t *sizep); + + + +/**@}*/ + + + +/** + * @name Kafka messages + * @{ + * + */ + + + +// FIXME: This doesn't show up in docs for some reason +// "Compound rd_kafka_message_t is not documented." + +/** + * @brief A Kafka message as returned by the \c rd_kafka_consume*() family + * of functions as well as provided to the Producer \c dr_msg_cb(). + * + * For the consumer this object has two purposes: + * - provide the application with a consumed message. (\c err == 0) + * - report per-topic+partition consumer errors (\c err != 0) + * + * The application must check \c err to decide what action to take. + * + * When the application is finished with a message it must call + * rd_kafka_message_destroy() unless otherwise noted. + */ +typedef struct rd_kafka_message_s { + rd_kafka_resp_err_t err; /**< Non-zero for error signaling. */ + rd_kafka_topic_t *rkt; /**< Topic */ + int32_t partition; /**< Partition */ + void *payload; /**< Producer: original message payload. + * Consumer: Depends on the value of \c err : + * - \c err==0: Message payload. + * - \c err!=0: Error string */ + size_t len; /**< Depends on the value of \c err : + * - \c err==0: Message payload length + * - \c err!=0: Error string length */ + void *key; /**< Depends on the value of \c err : + * - \c err==0: Optional message key */ + size_t key_len; /**< Depends on the value of \c err : + * - \c err==0: Optional message key length*/ + int64_t offset; /**< Consume: + * - Message offset (or offset for error + * if \c err!=0 if applicable). + * - dr_msg_cb: + * Message offset assigned by broker. + * If \c produce.offset.report is set then + * each message will have this field set, + * otherwise only the last message in + * each produced internal batch will + * have this field set, otherwise 0. */ + void *_private; /**< Consume: + * - rdkafka private pointer: DO NOT MODIFY + * - dr_msg_cb: + * msg_opaque from produce() call */ +} rd_kafka_message_t; + + +/** + * @brief Frees resources for \p rkmessage and hands ownership back to rdkafka. + */ +RD_EXPORT +void rd_kafka_message_destroy(rd_kafka_message_t *rkmessage); + + + + +/** + * @brief Returns the error string for an errored rd_kafka_message_t or NULL if + * there was no error. + * + * @remark This function MUST NOT be used with the producer. + */ +static RD_INLINE const char * +RD_UNUSED +rd_kafka_message_errstr(const rd_kafka_message_t *rkmessage) { + if (!rkmessage->err) + return NULL; + + if (rkmessage->payload) + return (const char *)rkmessage->payload; + + return rd_kafka_err2str(rkmessage->err); +} + + + +/** + * @brief Returns the message timestamp for a consumed message. + * + * The timestamp is the number of milliseconds since the epoch (UTC). + * + * \p tstype (if not NULL) is updated to indicate the type of timestamp. + * + * @returns message timestamp, or -1 if not available. + * + * @remark Message timestamps require broker version 0.10.0 or later. + */ +RD_EXPORT +int64_t rd_kafka_message_timestamp (const rd_kafka_message_t *rkmessage, + rd_kafka_timestamp_type_t *tstype); + + + +/** + * @brief Returns the latency for a produced message measured from + * the produce() call. + * + * @returns the latency in microseconds, or -1 if not available. + */ +RD_EXPORT +int64_t rd_kafka_message_latency (const rd_kafka_message_t *rkmessage); + + +/** + * @brief Get the message header list. + * + * The returned pointer in \p *hdrsp is associated with the \p rkmessage and + * must not be used after destruction of the message object or the header + * list is replaced with rd_kafka_message_set_headers(). + * + * @returns RD_KAFKA_RESP_ERR_NO_ERROR if headers were returned, + * RD_KAFKA_RESP_ERR__NOENT if the message has no headers, + * or another error code if the headers could not be parsed. + * + * @remark Headers require broker version 0.11.0.0 or later. + * + * @remark As an optimization the raw protocol headers are parsed on + * the first call to this function. + */ +RD_EXPORT rd_kafka_resp_err_t +rd_kafka_message_headers (const rd_kafka_message_t *rkmessage, + rd_kafka_headers_t **hdrsp); + + +/** + * @brief Replace the message's current headers with a new list. + * + * @param hdrs New header list. The message object assumes ownership of + * the list, the list will be destroyed automatically with + * the message object. + * The new headers list may be updated until the message object + * is passed or returned to librdkafka. + * + * @remark The existing headers object, if any, will be destroyed. + */ +RD_EXPORT +void rd_kafka_message_set_headers (rd_kafka_message_t *rkmessage, + rd_kafka_headers_t *hdrs); + + +/** + * @brief Returns the number of header key/value pairs + * + * @param hdrs Headers to count + */ +RD_EXPORT size_t rd_kafka_header_cnt (const rd_kafka_headers_t *hdrs); + + +/**@}*/ + + +/** + * @name Configuration interface + * @{ + * + * @brief Main/global configuration property interface + * + */ + +/** + * @enum rd_kafka_conf_res_t + * @brief Configuration result type + */ +typedef enum { + RD_KAFKA_CONF_UNKNOWN = -2, /**< Unknown configuration name. */ + RD_KAFKA_CONF_INVALID = -1, /**< Invalid configuration value. */ + RD_KAFKA_CONF_OK = 0 /**< Configuration okay */ +} rd_kafka_conf_res_t; + + +/** + * @brief Create configuration object. + * + * When providing your own configuration to the \c rd_kafka_*_new_*() calls + * the rd_kafka_conf_t objects needs to be created with this function + * which will set up the defaults. + * I.e.: + * @code + * rd_kafka_conf_t *myconf; + * rd_kafka_conf_res_t res; + * + * myconf = rd_kafka_conf_new(); + * res = rd_kafka_conf_set(myconf, "socket.timeout.ms", "600", + * errstr, sizeof(errstr)); + * if (res != RD_KAFKA_CONF_OK) + * die("%s\n", errstr); + * + * rk = rd_kafka_new(..., myconf); + * @endcode + * + * Please see CONFIGURATION.md for the default settings or use + * rd_kafka_conf_properties_show() to provide the information at runtime. + * + * The properties are identical to the Apache Kafka configuration properties + * whenever possible. + * + * @returns A new rd_kafka_conf_t object with defaults set. + * + * @sa rd_kafka_conf_set(), rd_kafka_conf_destroy() + */ +RD_EXPORT +rd_kafka_conf_t *rd_kafka_conf_new(void); + + +/** + * @brief Destroys a conf object. + */ +RD_EXPORT +void rd_kafka_conf_destroy(rd_kafka_conf_t *conf); + + +/** + * @brief Creates a copy/duplicate of configuration object \p conf + * + * @remark Interceptors are NOT copied to the new configuration object. + * @sa rd_kafka_interceptor_f_on_conf_dup + */ +RD_EXPORT +rd_kafka_conf_t *rd_kafka_conf_dup(const rd_kafka_conf_t *conf); + + +/** + * @brief Same as rd_kafka_conf_dup() but with an array of property name + * prefixes to filter out (ignore) when copying. + */ +RD_EXPORT +rd_kafka_conf_t *rd_kafka_conf_dup_filter (const rd_kafka_conf_t *conf, + size_t filter_cnt, + const char **filter); + + + +/** + * @brief Sets a configuration property. + * + * \p conf must have been previously created with rd_kafka_conf_new(). + * + * Fallthrough: + * Topic-level configuration properties may be set using this interface + * in which case they are applied on the \c default_topic_conf. + * If no \c default_topic_conf has been set one will be created. + * Any sub-sequent rd_kafka_conf_set_default_topic_conf() calls will + * replace the current default topic configuration. + * + * @returns \c rd_kafka_conf_res_t to indicate success or failure. + * In case of failure \p errstr is updated to contain a human readable + * error string. + */ +RD_EXPORT +rd_kafka_conf_res_t rd_kafka_conf_set(rd_kafka_conf_t *conf, + const char *name, + const char *value, + char *errstr, size_t errstr_size); + + +/** + * @brief Enable event sourcing. + * \p events is a bitmask of \c RD_KAFKA_EVENT_* of events to enable + * for consumption by `rd_kafka_queue_poll()`. + */ +RD_EXPORT +void rd_kafka_conf_set_events(rd_kafka_conf_t *conf, int events); + + +/** + @deprecated See rd_kafka_conf_set_dr_msg_cb() +*/ +RD_EXPORT +void rd_kafka_conf_set_dr_cb(rd_kafka_conf_t *conf, + void (*dr_cb) (rd_kafka_t *rk, + void *payload, size_t len, + rd_kafka_resp_err_t err, + void *opaque, void *msg_opaque)); + +/** + * @brief \b Producer: Set delivery report callback in provided \p conf object. + * + * The delivery report callback will be called once for each message + * accepted by rd_kafka_produce() (et.al) with \p err set to indicate + * the result of the produce request. + * + * The callback is called when a message is succesfully produced or + * if librdkafka encountered a permanent failure, or the retry counter for + * temporary errors has been exhausted. + * + * An application must call rd_kafka_poll() at regular intervals to + * serve queued delivery report callbacks. + */ +RD_EXPORT +void rd_kafka_conf_set_dr_msg_cb(rd_kafka_conf_t *conf, + void (*dr_msg_cb) (rd_kafka_t *rk, + const rd_kafka_message_t * + rkmessage, + void *opaque)); + + +/** + * @brief \b Consumer: Set consume callback for use with rd_kafka_consumer_poll() + * + */ +RD_EXPORT +void rd_kafka_conf_set_consume_cb (rd_kafka_conf_t *conf, + void (*consume_cb) (rd_kafka_message_t * + rkmessage, + void *opaque)); + +/** + * @brief \b Consumer: Set rebalance callback for use with + * coordinated consumer group balancing. + * + * The \p err field is set to either RD_KAFKA_RESP_ERR__ASSIGN_PARTITIONS + * or RD_KAFKA_RESP_ERR__REVOKE_PARTITIONS and 'partitions' + * contains the full partition set that was either assigned or revoked. + * + * Registering a \p rebalance_cb turns off librdkafka's automatic + * partition assignment/revocation and instead delegates that responsibility + * to the application's \p rebalance_cb. + * + * The rebalance callback is responsible for updating librdkafka's + * assignment set based on the two events: RD_KAFKA_RESP_ERR__ASSIGN_PARTITIONS + * and RD_KAFKA_RESP_ERR__REVOKE_PARTITIONS but should also be able to handle + * arbitrary rebalancing failures where \p err is neither of those. + * @remark In this latter case (arbitrary error), the application must + * call rd_kafka_assign(rk, NULL) to synchronize state. + * + * Without a rebalance callback this is done automatically by librdkafka + * but registering a rebalance callback gives the application flexibility + * in performing other operations along with the assinging/revocation, + * such as fetching offsets from an alternate location (on assign) + * or manually committing offsets (on revoke). + * + * @remark The \p partitions list is destroyed by librdkafka on return + * return from the rebalance_cb and must not be freed or + * saved by the application. + * + * The following example shows the application's responsibilities: + * @code + * static void rebalance_cb (rd_kafka_t *rk, rd_kafka_resp_err_t err, + * rd_kafka_topic_partition_list_t *partitions, + * void *opaque) { + * + * switch (err) + * { + * case RD_KAFKA_RESP_ERR__ASSIGN_PARTITIONS: + * // application may load offets from arbitrary external + * // storage here and update \p partitions + * + * rd_kafka_assign(rk, partitions); + * break; + * + * case RD_KAFKA_RESP_ERR__REVOKE_PARTITIONS: + * if (manual_commits) // Optional explicit manual commit + * rd_kafka_commit(rk, partitions, 0); // sync commit + * + * rd_kafka_assign(rk, NULL); + * break; + * + * default: + * handle_unlikely_error(err); + * rd_kafka_assign(rk, NULL); // sync state + * break; + * } + * } + * @endcode + */ +RD_EXPORT +void rd_kafka_conf_set_rebalance_cb ( + rd_kafka_conf_t *conf, + void (*rebalance_cb) (rd_kafka_t *rk, + rd_kafka_resp_err_t err, + rd_kafka_topic_partition_list_t *partitions, + void *opaque)); + + + +/** + * @brief \b Consumer: Set offset commit callback for use with consumer groups. + * + * The results of automatic or manual offset commits will be scheduled + * for this callback and is served by rd_kafka_consumer_poll(). + * + * If no partitions had valid offsets to commit this callback will be called + * with \p err == RD_KAFKA_RESP_ERR__NO_OFFSET which is not to be considered + * an error. + * + * The \p offsets list contains per-partition information: + * - \c offset: committed offset (attempted) + * - \c err: commit error + */ +RD_EXPORT +void rd_kafka_conf_set_offset_commit_cb ( + rd_kafka_conf_t *conf, + void (*offset_commit_cb) (rd_kafka_t *rk, + rd_kafka_resp_err_t err, + rd_kafka_topic_partition_list_t *offsets, + void *opaque)); + + +/** + * @brief Set error callback in provided conf object. + * + * The error callback is used by librdkafka to signal critical errors + * back to the application. + * + * If no \p error_cb is registered then the errors will be logged instead. + */ +RD_EXPORT +void rd_kafka_conf_set_error_cb(rd_kafka_conf_t *conf, + void (*error_cb) (rd_kafka_t *rk, int err, + const char *reason, + void *opaque)); + +/** + * @brief Set throttle callback. + * + * The throttle callback is used to forward broker throttle times to the + * application for Produce and Fetch (consume) requests. + * + * Callbacks are triggered whenever a non-zero throttle time is returned by + * the broker, or when the throttle time drops back to zero. + * + * An application must call rd_kafka_poll() or rd_kafka_consumer_poll() at + * regular intervals to serve queued callbacks. + * + * @remark Requires broker version 0.9.0 or later. + */ +RD_EXPORT +void rd_kafka_conf_set_throttle_cb (rd_kafka_conf_t *conf, + void (*throttle_cb) ( + rd_kafka_t *rk, + const char *broker_name, + int32_t broker_id, + int throttle_time_ms, + void *opaque)); + + +/** + * @brief Set logger callback. + * + * The default is to print to stderr, but a syslog logger is also available, + * see rd_kafka_log_print and rd_kafka_log_syslog for the builtin alternatives. + * Alternatively the application may provide its own logger callback. + * Or pass \p func as NULL to disable logging. + * + * This is the configuration alternative to the deprecated rd_kafka_set_logger() + * + * @remark The log_cb will be called spontaneously from librdkafka's internal + * threads unless logs have been forwarded to a poll queue through + * \c rd_kafka_set_log_queue(). + * An application MUST NOT call any librdkafka APIs or do any prolonged + * work in a non-forwarded \c log_cb. + */ +RD_EXPORT +void rd_kafka_conf_set_log_cb(rd_kafka_conf_t *conf, + void (*log_cb) (const rd_kafka_t *rk, int level, + const char *fac, const char *buf)); + + +/** + * @brief Set statistics callback in provided conf object. + * + * The statistics callback is triggered from rd_kafka_poll() every + * \c statistics.interval.ms (needs to be configured separately). + * Function arguments: + * - \p rk - Kafka handle + * - \p json - String containing the statistics data in JSON format + * - \p json_len - Length of \p json string. + * - \p opaque - Application-provided opaque. + * + * If the application wishes to hold on to the \p json pointer and free + * it at a later time it must return 1 from the \p stats_cb. + * If the application returns 0 from the \p stats_cb then librdkafka + * will immediately free the \p json pointer. + */ +RD_EXPORT +void rd_kafka_conf_set_stats_cb(rd_kafka_conf_t *conf, + int (*stats_cb) (rd_kafka_t *rk, + char *json, + size_t json_len, + void *opaque)); + + + +/** + * @brief Set socket callback. + * + * The socket callback is responsible for opening a socket + * according to the supplied \p domain, \p type and \p protocol. + * The socket shall be created with \c CLOEXEC set in a racefree fashion, if + * possible. + * + * Default: + * - on linux: racefree CLOEXEC + * - others : non-racefree CLOEXEC + * + * @remark The callback will be called from an internal librdkafka thread. + */ +RD_EXPORT +void rd_kafka_conf_set_socket_cb(rd_kafka_conf_t *conf, + int (*socket_cb) (int domain, int type, + int protocol, + void *opaque)); + + + +/** + * @brief Set connect callback. + * + * The connect callback is responsible for connecting socket \p sockfd + * to peer address \p addr. + * The \p id field contains the broker identifier. + * + * \p connect_cb shall return 0 on success (socket connected) or an error + * number (errno) on error. + * + * @remark The callback will be called from an internal librdkafka thread. + */ +RD_EXPORT void +rd_kafka_conf_set_connect_cb (rd_kafka_conf_t *conf, + int (*connect_cb) (int sockfd, + const struct sockaddr *addr, + int addrlen, + const char *id, + void *opaque)); + +/** + * @brief Set close socket callback. + * + * Close a socket (optionally opened with socket_cb()). + * + * @remark The callback will be called from an internal librdkafka thread. + */ +RD_EXPORT void +rd_kafka_conf_set_closesocket_cb (rd_kafka_conf_t *conf, + int (*closesocket_cb) (int sockfd, + void *opaque)); + + + +#ifndef _MSC_VER +/** + * @brief Set open callback. + * + * The open callback is responsible for opening the file specified by + * pathname, flags and mode. + * The file shall be opened with \c CLOEXEC set in a racefree fashion, if + * possible. + * + * Default: + * - on linux: racefree CLOEXEC + * - others : non-racefree CLOEXEC + * + * @remark The callback will be called from an internal librdkafka thread. + */ +RD_EXPORT +void rd_kafka_conf_set_open_cb (rd_kafka_conf_t *conf, + int (*open_cb) (const char *pathname, + int flags, mode_t mode, + void *opaque)); +#endif + +/** + * @brief Sets the application's opaque pointer that will be passed to callbacks + */ +RD_EXPORT +void rd_kafka_conf_set_opaque(rd_kafka_conf_t *conf, void *opaque); + +/** + * @brief Retrieves the opaque pointer previously set with rd_kafka_conf_set_opaque() + */ +RD_EXPORT +void *rd_kafka_opaque(const rd_kafka_t *rk); + + + +/** + * Sets the default topic configuration to use for automatically + * subscribed topics (e.g., through pattern-matched topics). + * The topic config object is not usable after this call. + */ +RD_EXPORT +void rd_kafka_conf_set_default_topic_conf (rd_kafka_conf_t *conf, + rd_kafka_topic_conf_t *tconf); + + + +/** + * @brief Retrieve configuration value for property \p name. + * + * If \p dest is non-NULL the value will be written to \p dest with at + * most \p dest_size. + * + * \p *dest_size is updated to the full length of the value, thus if + * \p *dest_size initially is smaller than the full length the application + * may reallocate \p dest to fit the returned \p *dest_size and try again. + * + * If \p dest is NULL only the full length of the value is returned. + * + * Fallthrough: + * Topic-level configuration properties from the \c default_topic_conf + * may be retrieved using this interface. + * + * @returns \p RD_KAFKA_CONF_OK if the property name matched, else + * \p RD_KAFKA_CONF_UNKNOWN. + */ +RD_EXPORT +rd_kafka_conf_res_t rd_kafka_conf_get (const rd_kafka_conf_t *conf, + const char *name, + char *dest, size_t *dest_size); + + +/** + * @brief Retrieve topic configuration value for property \p name. + * + * @sa rd_kafka_conf_get() + */ +RD_EXPORT +rd_kafka_conf_res_t rd_kafka_topic_conf_get (const rd_kafka_topic_conf_t *conf, + const char *name, + char *dest, size_t *dest_size); + + +/** + * @brief Dump the configuration properties and values of \p conf to an array + * with \"key\", \"value\" pairs. + * + * The number of entries in the array is returned in \p *cntp. + * + * The dump must be freed with `rd_kafka_conf_dump_free()`. + */ +RD_EXPORT +const char **rd_kafka_conf_dump(rd_kafka_conf_t *conf, size_t *cntp); + + +/** + * @brief Dump the topic configuration properties and values of \p conf + * to an array with \"key\", \"value\" pairs. + * + * The number of entries in the array is returned in \p *cntp. + * + * The dump must be freed with `rd_kafka_conf_dump_free()`. + */ +RD_EXPORT +const char **rd_kafka_topic_conf_dump(rd_kafka_topic_conf_t *conf, + size_t *cntp); + +/** + * @brief Frees a configuration dump returned from `rd_kafka_conf_dump()` or + * `rd_kafka_topic_conf_dump(). + */ +RD_EXPORT +void rd_kafka_conf_dump_free(const char **arr, size_t cnt); + +/** + * @brief Prints a table to \p fp of all supported configuration properties, + * their default values as well as a description. + */ +RD_EXPORT +void rd_kafka_conf_properties_show(FILE *fp); + +/**@}*/ + + +/** + * @name Topic configuration + * @{ + * + * @brief Topic configuration property interface + * + */ + + +/** + * @brief Create topic configuration object + * + * @sa Same semantics as for rd_kafka_conf_new(). + */ +RD_EXPORT +rd_kafka_topic_conf_t *rd_kafka_topic_conf_new(void); + + +/** + * @brief Creates a copy/duplicate of topic configuration object \p conf. + */ +RD_EXPORT +rd_kafka_topic_conf_t *rd_kafka_topic_conf_dup(const rd_kafka_topic_conf_t + *conf); + +/** + * @brief Creates a copy/duplicate of \p rk 's default topic configuration + * object. + */ +RD_EXPORT +rd_kafka_topic_conf_t *rd_kafka_default_topic_conf_dup (rd_kafka_t *rk); + + +/** + * @brief Destroys a topic conf object. + */ +RD_EXPORT +void rd_kafka_topic_conf_destroy(rd_kafka_topic_conf_t *topic_conf); + + +/** + * @brief Sets a single rd_kafka_topic_conf_t value by property name. + * + * \p topic_conf should have been previously set up + * with `rd_kafka_topic_conf_new()`. + * + * @returns rd_kafka_conf_res_t to indicate success or failure. + */ +RD_EXPORT +rd_kafka_conf_res_t rd_kafka_topic_conf_set(rd_kafka_topic_conf_t *conf, + const char *name, + const char *value, + char *errstr, size_t errstr_size); + +/** + * @brief Sets the application's opaque pointer that will be passed to all topic + * callbacks as the \c rkt_opaque argument. + */ +RD_EXPORT +void rd_kafka_topic_conf_set_opaque(rd_kafka_topic_conf_t *conf, void *opaque); + + +/** + * @brief \b Producer: Set partitioner callback in provided topic conf object. + * + * The partitioner may be called in any thread at any time, + * it may be called multiple times for the same message/key. + * + * Partitioner function constraints: + * - MUST NOT call any rd_kafka_*() functions except: + * rd_kafka_topic_partition_available() + * - MUST NOT block or execute for prolonged periods of time. + * - MUST return a value between 0 and partition_cnt-1, or the + * special \c RD_KAFKA_PARTITION_UA value if partitioning + * could not be performed. + */ +RD_EXPORT +void +rd_kafka_topic_conf_set_partitioner_cb (rd_kafka_topic_conf_t *topic_conf, + int32_t (*partitioner) ( + const rd_kafka_topic_t *rkt, + const void *keydata, + size_t keylen, + int32_t partition_cnt, + void *rkt_opaque, + void *msg_opaque)); + + +/** + * @brief \b Producer: Set message queueing order comparator callback. + * + * The callback may be called in any thread at any time, + * it may be called multiple times for the same message. + * + * Ordering comparator function constraints: + * - MUST be stable sort (same input gives same output). + * - MUST NOT call any rd_kafka_*() functions. + * - MUST NOT block or execute for prolonged periods of time. + * + * The comparator shall compare the two messages and return: + * - < 0 if message \p a should be inserted before message \p b. + * - >=0 if message \p a should be inserted after message \p b. + * + * @remark Insert sorting will be used to enqueue the message in the + * correct queue position, this comes at a cost of O(n). + * + * @remark If `queuing.strategy=fifo` new messages are enqueued to the + * tail of the queue regardless of msg_order_cmp, but retried messages + * are still affected by msg_order_cmp. + * + * @warning THIS IS AN EXPERIMENTAL API, SUBJECT TO CHANGE OR REMOVAL, + * DO NOT USE IN PRODUCTION. + */ +RD_EXPORT void +rd_kafka_topic_conf_set_msg_order_cmp (rd_kafka_topic_conf_t *topic_conf, + int (*msg_order_cmp) ( + const rd_kafka_message_t *a, + const rd_kafka_message_t *b)); + + +/** + * @brief Check if partition is available (has a leader broker). + * + * @returns 1 if the partition is available, else 0. + * + * @warning This function must only be called from inside a partitioner function + */ +RD_EXPORT +int rd_kafka_topic_partition_available(const rd_kafka_topic_t *rkt, + int32_t partition); + + +/******************************************************************* + * * + * Partitioners provided by rdkafka * + * * + *******************************************************************/ + +/** + * @brief Random partitioner. + * + * Will try not to return unavailable partitions. + * + * @returns a random partition between 0 and \p partition_cnt - 1. + * + */ +RD_EXPORT +int32_t rd_kafka_msg_partitioner_random(const rd_kafka_topic_t *rkt, + const void *key, size_t keylen, + int32_t partition_cnt, + void *opaque, void *msg_opaque); + +/** + * @brief Consistent partitioner. + * + * Uses consistent hashing to map identical keys onto identical partitions. + * + * @returns a \"random\" partition between 0 and \p partition_cnt - 1 based on + * the CRC value of the key + */ +RD_EXPORT +int32_t rd_kafka_msg_partitioner_consistent (const rd_kafka_topic_t *rkt, + const void *key, size_t keylen, + int32_t partition_cnt, + void *opaque, void *msg_opaque); + +/** + * @brief Consistent-Random partitioner. + * + * This is the default partitioner. + * Uses consistent hashing to map identical keys onto identical partitions, and + * messages without keys will be assigned via the random partitioner. + * + * @returns a \"random\" partition between 0 and \p partition_cnt - 1 based on + * the CRC value of the key (if provided) + */ +RD_EXPORT +int32_t rd_kafka_msg_partitioner_consistent_random (const rd_kafka_topic_t *rkt, + const void *key, size_t keylen, + int32_t partition_cnt, + void *opaque, void *msg_opaque); + + +/** + * @brief Murmur2 partitioner (Java compatible). + * + * Uses consistent hashing to map identical keys onto identical partitions + * using Java-compatible Murmur2 hashing. + * + * @returns a partition between 0 and \p partition_cnt - 1. + */ +RD_EXPORT +int32_t rd_kafka_msg_partitioner_murmur2 (const rd_kafka_topic_t *rkt, + const void *key, size_t keylen, + int32_t partition_cnt, + void *rkt_opaque, + void *msg_opaque); + +/** + * @brief Consistent-Random Murmur2 partitioner (Java compatible). + * + * Uses consistent hashing to map identical keys onto identical partitions + * using Java-compatible Murmur2 hashing. + * Messages without keys will be assigned via the random partitioner. + * + * @returns a partition between 0 and \p partition_cnt - 1. + */ +RD_EXPORT +int32_t rd_kafka_msg_partitioner_murmur2_random (const rd_kafka_topic_t *rkt, + const void *key, size_t keylen, + int32_t partition_cnt, + void *rkt_opaque, + void *msg_opaque); + + +/**@}*/ + + + +/** + * @name Main Kafka and Topic object handles + * @{ + * + * + */ + + + + +/** + * @brief Creates a new Kafka handle and starts its operation according to the + * specified \p type (\p RD_KAFKA_CONSUMER or \p RD_KAFKA_PRODUCER). + * + * \p conf is an optional struct created with `rd_kafka_conf_new()` that will + * be used instead of the default configuration. + * The \p conf object is freed by this function on success and must not be used + * or destroyed by the application sub-sequently. + * See `rd_kafka_conf_set()` et.al for more information. + * + * \p errstr must be a pointer to memory of at least size \p errstr_size where + * `rd_kafka_new()` may write a human readable error message in case the + * creation of a new handle fails. In which case the function returns NULL. + * + * @remark \b RD_KAFKA_CONSUMER: When a new \p RD_KAFKA_CONSUMER + * rd_kafka_t handle is created it may either operate in the + * legacy simple consumer mode using the rd_kafka_consume_start() + * interface, or the High-level KafkaConsumer API. + * @remark An application must only use one of these groups of APIs on a given + * rd_kafka_t RD_KAFKA_CONSUMER handle. + + * + * @returns The Kafka handle on success or NULL on error (see \p errstr) + * + * @sa To destroy the Kafka handle, use rd_kafka_destroy(). + */ +RD_EXPORT +rd_kafka_t *rd_kafka_new(rd_kafka_type_t type, rd_kafka_conf_t *conf, + char *errstr, size_t errstr_size); + + +/** + * @brief Destroy Kafka handle. + * + * @remark This is a blocking operation. + */ +RD_EXPORT +void rd_kafka_destroy(rd_kafka_t *rk); + + + +/** + * @brief Returns Kafka handle name. + */ +RD_EXPORT +const char *rd_kafka_name(const rd_kafka_t *rk); + + +/** + * @brief Returns Kafka handle type. + */ +RD_EXPORT +rd_kafka_type_t rd_kafka_type(const rd_kafka_t *rk); + + +/** + * @brief Returns this client's broker-assigned group member id + * + * @remark This currently requires the high-level KafkaConsumer + * + * @returns An allocated string containing the current broker-assigned group + * member id, or NULL if not available. + * The application must free the string with \p free() or + * rd_kafka_mem_free() + */ +RD_EXPORT +char *rd_kafka_memberid (const rd_kafka_t *rk); + + + +/** + * @brief Returns the ClusterId as reported in broker metadata. + * + * @param timeout_ms If there is no cached value from metadata retrieval + * then this specifies the maximum amount of time + * (in milliseconds) the call will block waiting + * for metadata to be retrieved. + * Use 0 for non-blocking calls. + + * @remark Requires broker version >=0.10.0 and api.version.request=true. + * + * @remark The application must free the returned pointer + * using rd_kafka_mem_free(). + * + * @returns a newly allocated string containing the ClusterId, or NULL + * if no ClusterId could be retrieved in the allotted timespan. + */ +RD_EXPORT +char *rd_kafka_clusterid (rd_kafka_t *rk, int timeout_ms); + + +/** + * @brief Creates a new topic handle for topic named \p topic. + * + * \p conf is an optional configuration for the topic created with + * `rd_kafka_topic_conf_new()` that will be used instead of the default + * topic configuration. + * The \p conf object is freed by this function and must not be used or + * destroyed by the application sub-sequently. + * See `rd_kafka_topic_conf_set()` et.al for more information. + * + * Topic handles are refcounted internally and calling rd_kafka_topic_new() + * again with the same topic name will return the previous topic handle + * without updating the original handle's configuration. + * Applications must eventually call rd_kafka_topic_destroy() for each + * succesfull call to rd_kafka_topic_new() to clear up resources. + * + * @returns the new topic handle or NULL on error (use rd_kafka_errno2err() + * to convert system \p errno to an rd_kafka_resp_err_t error code. + * + * @sa rd_kafka_topic_destroy() + */ +RD_EXPORT +rd_kafka_topic_t *rd_kafka_topic_new(rd_kafka_t *rk, const char *topic, + rd_kafka_topic_conf_t *conf); + + + +/** + * @brief Loose application's topic handle refcount as previously created + * with `rd_kafka_topic_new()`. + * + * @remark Since topic objects are refcounted (both internally and for the app) + * the topic object might not actually be destroyed by this call, + * but the application must consider the object destroyed. + */ +RD_EXPORT +void rd_kafka_topic_destroy(rd_kafka_topic_t *rkt); + + +/** + * @brief Returns the topic name. + */ +RD_EXPORT +const char *rd_kafka_topic_name(const rd_kafka_topic_t *rkt); + + +/** + * @brief Get the \p rkt_opaque pointer that was set in the topic configuration. + */ +RD_EXPORT +void *rd_kafka_topic_opaque (const rd_kafka_topic_t *rkt); + + +/** + * @brief Unassigned partition. + * + * The unassigned partition is used by the producer API for messages + * that should be partitioned using the configured or default partitioner. + */ +#define RD_KAFKA_PARTITION_UA ((int32_t)-1) + + +/** + * @brief Polls the provided kafka handle for events. + * + * Events will cause application provided callbacks to be called. + * + * The \p timeout_ms argument specifies the maximum amount of time + * (in milliseconds) that the call will block waiting for events. + * For non-blocking calls, provide 0 as \p timeout_ms. + * To wait indefinately for an event, provide -1. + * + * @remark An application should make sure to call poll() at regular + * intervals to serve any queued callbacks waiting to be called. + * + * Events: + * - delivery report callbacks (if dr_cb/dr_msg_cb is configured) [producer] + * - error callbacks (rd_kafka_conf_set_error_cb()) [all] + * - stats callbacks (rd_kafka_conf_set_stats_cb()) [all] + * - throttle callbacks (rd_kafka_conf_set_throttle_cb()) [all] + * + * @returns the number of events served. + */ +RD_EXPORT +int rd_kafka_poll(rd_kafka_t *rk, int timeout_ms); + + +/** + * @brief Cancels the current callback dispatcher (rd_kafka_poll(), + * rd_kafka_consume_callback(), etc). + * + * A callback may use this to force an immediate return to the calling + * code (caller of e.g. rd_kafka_poll()) without processing any further + * events. + * + * @remark This function MUST ONLY be called from within a librdkafka callback. + */ +RD_EXPORT +void rd_kafka_yield (rd_kafka_t *rk); + + + + +/** + * @brief Pause producing or consumption for the provided list of partitions. + * + * Success or error is returned per-partition \p err in the \p partitions list. + * + * @returns RD_KAFKA_RESP_ERR_NO_ERROR + */ +RD_EXPORT rd_kafka_resp_err_t +rd_kafka_pause_partitions (rd_kafka_t *rk, + rd_kafka_topic_partition_list_t *partitions); + + + +/** + * @brief Resume producing consumption for the provided list of partitions. + * + * Success or error is returned per-partition \p err in the \p partitions list. + * + * @returns RD_KAFKA_RESP_ERR_NO_ERROR + */ +RD_EXPORT rd_kafka_resp_err_t +rd_kafka_resume_partitions (rd_kafka_t *rk, + rd_kafka_topic_partition_list_t *partitions); + + + + +/** + * @brief Query broker for low (oldest/beginning) and high (newest/end) offsets + * for partition. + * + * Offsets are returned in \p *low and \p *high respectively. + * + * @returns RD_KAFKA_RESP_ERR_NO_ERROR on success or an error code on failure. + */ +RD_EXPORT rd_kafka_resp_err_t +rd_kafka_query_watermark_offsets (rd_kafka_t *rk, + const char *topic, int32_t partition, + int64_t *low, int64_t *high, int timeout_ms); + + +/** + * @brief Get last known low (oldest/beginning) and high (newest/end) offsets + * for partition. + * + * The low offset is updated periodically (if statistics.interval.ms is set) + * while the high offset is updated on each fetched message set from the broker. + * + * If there is no cached offset (either low or high, or both) then + * RD_KAFKA_OFFSET_INVALID will be returned for the respective offset. + * + * Offsets are returned in \p *low and \p *high respectively. + * + * @returns RD_KAFKA_RESP_ERR_NO_ERROR on success or an error code on failure. + * + * @remark Shall only be used with an active consumer instance. + */ +RD_EXPORT rd_kafka_resp_err_t +rd_kafka_get_watermark_offsets (rd_kafka_t *rk, + const char *topic, int32_t partition, + int64_t *low, int64_t *high); + + + +/** + * @brief Look up the offsets for the given partitions by timestamp. + * + * The returned offset for each partition is the earliest offset whose + * timestamp is greater than or equal to the given timestamp in the + * corresponding partition. + * + * The timestamps to query are represented as \c offset in \p offsets + * on input, and \c offset will contain the offset on output. + * + * The function will block for at most \p timeout_ms milliseconds. + * + * @remark Duplicate Topic+Partitions are not supported. + * @remark Per-partition errors may be returned in \c rd_kafka_topic_partition_t.err + * + * @returns RD_KAFKA_RESP_ERR_NO_ERROR if offsets were be queried (do note + * that per-partition errors might be set), + * RD_KAFKA_RESP_ERR__TIMED_OUT if not all offsets could be fetched + * within \p timeout_ms, + * RD_KAFKA_RESP_ERR__INVALID_ARG if the \p offsets list is empty, + * RD_KAFKA_RESP_ERR__UNKNOWN_PARTITION if all partitions are unknown, + * RD_KAFKA_RESP_ERR_LEADER_NOT_AVAILABLE if unable to query leaders + * for the given partitions. + */ +RD_EXPORT rd_kafka_resp_err_t +rd_kafka_offsets_for_times (rd_kafka_t *rk, + rd_kafka_topic_partition_list_t *offsets, + int timeout_ms); + + +/** + * @brief Free pointer returned by librdkafka + * + * This is typically an abstraction for the free(3) call and makes sure + * the application can use the same memory allocator as librdkafka for + * freeing pointers returned by librdkafka. + * + * In standard setups it is usually not necessary to use this interface + * rather than the free(3) functione. + * + * @remark rd_kafka_mem_free() must only be used for pointers returned by APIs + * that explicitly mention using this function for freeing. + */ +RD_EXPORT +void rd_kafka_mem_free (rd_kafka_t *rk, void *ptr); + + +/**@}*/ + + + + + +/** + * @name Queue API + * @{ + * + * Message queues allows the application to re-route consumed messages + * from multiple topic+partitions into one single queue point. + * This queue point containing messages from a number of topic+partitions + * may then be served by a single rd_kafka_consume*_queue() call, + * rather than one call per topic+partition combination. + */ + + +/** + * @brief Create a new message queue. + * + * See rd_kafka_consume_start_queue(), rd_kafka_consume_queue(), et.al. + */ +RD_EXPORT +rd_kafka_queue_t *rd_kafka_queue_new(rd_kafka_t *rk); + +/** + * Destroy a queue, purging all of its enqueued messages. + */ +RD_EXPORT +void rd_kafka_queue_destroy(rd_kafka_queue_t *rkqu); + + +/** + * @returns a reference to the main librdkafka event queue. + * This is the queue served by rd_kafka_poll(). + * + * Use rd_kafka_queue_destroy() to loose the reference. + */ +RD_EXPORT +rd_kafka_queue_t *rd_kafka_queue_get_main (rd_kafka_t *rk); + + +/** + * @returns a reference to the librdkafka consumer queue. + * This is the queue served by rd_kafka_consumer_poll(). + * + * Use rd_kafka_queue_destroy() to loose the reference. + * + * @remark rd_kafka_queue_destroy() MUST be called on this queue + * prior to calling rd_kafka_consumer_close(). + */ +RD_EXPORT +rd_kafka_queue_t *rd_kafka_queue_get_consumer (rd_kafka_t *rk); + +/** + * @returns a reference to the partition's queue, or NULL if + * partition is invalid. + * + * Use rd_kafka_queue_destroy() to loose the reference. + * + * @remark rd_kafka_queue_destroy() MUST be called on this queue + * + * @remark This function only works on consumers. + */ +RD_EXPORT +rd_kafka_queue_t *rd_kafka_queue_get_partition (rd_kafka_t *rk, + const char *topic, + int32_t partition); + +/** + * @brief Forward/re-route queue \p src to \p dst. + * If \p dst is \c NULL the forwarding is removed. + * + * The internal refcounts for both queues are increased. + * + * @remark Regardless of whether \p dst is NULL or not, after calling this + * function, \p src will not forward it's fetch queue to the consumer + * queue. + */ +RD_EXPORT +void rd_kafka_queue_forward (rd_kafka_queue_t *src, rd_kafka_queue_t *dst); + +/** + * @brief Forward librdkafka logs (and debug) to the specified queue + * for serving with one of the ..poll() calls. + * + * This allows an application to serve log callbacks (\c log_cb) + * in its thread of choice. + * + * @param rkqu Queue to forward logs to. If the value is NULL the logs + * are forwarded to the main queue. + * + * @remark The configuration property \c log.queue MUST also be set to true. + * + * @remark librdkafka maintains its own reference to the provided queue. + * + * @returns RD_KAFKA_RESP_ERR_NO_ERROR on success or an error code on error. + */ +RD_EXPORT +rd_kafka_resp_err_t rd_kafka_set_log_queue (rd_kafka_t *rk, + rd_kafka_queue_t *rkqu); + + +/** + * @returns the current number of elements in queue. + */ +RD_EXPORT +size_t rd_kafka_queue_length (rd_kafka_queue_t *rkqu); + + +/** + * @brief Enable IO event triggering for queue. + * + * To ease integration with IO based polling loops this API + * allows an application to create a separate file-descriptor + * that librdkafka will write \p payload (of size \p size) to + * whenever a new element is enqueued on a previously empty queue. + * + * To remove event triggering call with \p fd = -1. + * + * librdkafka will maintain a copy of the \p payload. + * + * @remark When using forwarded queues the IO event must only be enabled + * on the final forwarded-to (destination) queue. + */ +RD_EXPORT +void rd_kafka_queue_io_event_enable (rd_kafka_queue_t *rkqu, int fd, + const void *payload, size_t size); + +/**@}*/ + +/** + * + * @name Simple Consumer API (legacy) + * @{ + * + */ + + +#define RD_KAFKA_OFFSET_BEGINNING -2 /**< Start consuming from beginning of + * kafka partition queue: oldest msg */ +#define RD_KAFKA_OFFSET_END -1 /**< Start consuming from end of kafka + * partition queue: next msg */ +#define RD_KAFKA_OFFSET_STORED -1000 /**< Start consuming from offset retrieved + * from offset store */ +#define RD_KAFKA_OFFSET_INVALID -1001 /**< Invalid offset */ + + +/** @cond NO_DOC */ +#define RD_KAFKA_OFFSET_TAIL_BASE -2000 /* internal: do not use */ +/** @endcond */ + +/** + * @brief Start consuming \p CNT messages from topic's current end offset. + * + * That is, if current end offset is 12345 and \p CNT is 200, it will start + * consuming from offset \c 12345-200 = \c 12145. */ +#define RD_KAFKA_OFFSET_TAIL(CNT) (RD_KAFKA_OFFSET_TAIL_BASE - (CNT)) + +/** + * @brief Start consuming messages for topic \p rkt and \p partition + * at offset \p offset which may either be an absolute \c (0..N) + * or one of the logical offsets: + * - RD_KAFKA_OFFSET_BEGINNING + * - RD_KAFKA_OFFSET_END + * - RD_KAFKA_OFFSET_STORED + * - RD_KAFKA_OFFSET_TAIL + * + * rdkafka will attempt to keep \c queued.min.messages (config property) + * messages in the local queue by repeatedly fetching batches of messages + * from the broker until the threshold is reached. + * + * The application shall use one of the `rd_kafka_consume*()` functions + * to consume messages from the local queue, each kafka message being + * represented as a `rd_kafka_message_t *` object. + * + * `rd_kafka_consume_start()` must not be called multiple times for the same + * topic and partition without stopping consumption first with + * `rd_kafka_consume_stop()`. + * + * @returns 0 on success or -1 on error in which case errno is set accordingly: + * - EBUSY - Conflicts with an existing or previous subscription + * (RD_KAFKA_RESP_ERR__CONFLICT) + * - EINVAL - Invalid offset, or incomplete configuration (lacking group.id) + * (RD_KAFKA_RESP_ERR__INVALID_ARG) + * - ESRCH - requested \p partition is invalid. + * (RD_KAFKA_RESP_ERR__UNKNOWN_PARTITION) + * - ENOENT - topic is unknown in the Kafka cluster. + * (RD_KAFKA_RESP_ERR__UNKNOWN_TOPIC) + * + * Use `rd_kafka_errno2err()` to convert sytem \c errno to `rd_kafka_resp_err_t` + */ +RD_EXPORT +int rd_kafka_consume_start(rd_kafka_topic_t *rkt, int32_t partition, + int64_t offset); + +/** + * @brief Same as rd_kafka_consume_start() but re-routes incoming messages to + * the provided queue \p rkqu (which must have been previously allocated + * with `rd_kafka_queue_new()`. + * + * The application must use one of the `rd_kafka_consume_*_queue()` functions + * to receive fetched messages. + * + * `rd_kafka_consume_start_queue()` must not be called multiple times for the + * same topic and partition without stopping consumption first with + * `rd_kafka_consume_stop()`. + * `rd_kafka_consume_start()` and `rd_kafka_consume_start_queue()` must not + * be combined for the same topic and partition. + */ +RD_EXPORT +int rd_kafka_consume_start_queue(rd_kafka_topic_t *rkt, int32_t partition, + int64_t offset, rd_kafka_queue_t *rkqu); + +/** + * @brief Stop consuming messages for topic \p rkt and \p partition, purging + * all messages currently in the local queue. + * + * NOTE: To enforce synchronisation this call will block until the internal + * fetcher has terminated and offsets are committed to configured + * storage method. + * + * The application needs to be stop all consumers before calling + * `rd_kafka_destroy()` on the main object handle. + * + * @returns 0 on success or -1 on error (see `errno`). + */ +RD_EXPORT +int rd_kafka_consume_stop(rd_kafka_topic_t *rkt, int32_t partition); + + + +/** + * @brief Seek consumer for topic+partition to \p offset which is either an + * absolute or logical offset. + * + * If \p timeout_ms is not 0 the call will wait this long for the + * seek to be performed. If the timeout is reached the internal state + * will be unknown and this function returns `RD_KAFKA_RESP_ERR__TIMED_OUT`. + * If \p timeout_ms is 0 it will initiate the seek but return + * immediately without any error reporting (e.g., async). + * + * This call triggers a fetch queue barrier flush. + * + * @returns `RD_KAFKA_RESP_ERR__NO_ERROR` on success else an error code. + */ +RD_EXPORT +rd_kafka_resp_err_t rd_kafka_seek (rd_kafka_topic_t *rkt, + int32_t partition, + int64_t offset, + int timeout_ms); + + +/** + * @brief Consume a single message from topic \p rkt and \p partition + * + * \p timeout_ms is maximum amount of time to wait for a message to be received. + * Consumer must have been previously started with `rd_kafka_consume_start()`. + * + * @returns a message object on success or \c NULL on error. + * The message object must be destroyed with `rd_kafka_message_destroy()` + * when the application is done with it. + * + * Errors (when returning NULL): + * - ETIMEDOUT - \p timeout_ms was reached with no new messages fetched. + * - ENOENT - \p rkt + \p partition is unknown. + * (no prior `rd_kafka_consume_start()` call) + * + * NOTE: The returned message's \c ..->err must be checked for errors. + * NOTE: \c ..->err \c == \c RD_KAFKA_RESP_ERR__PARTITION_EOF signals that the + * end of the partition has been reached, which should typically not be + * considered an error. The application should handle this case + * (e.g., ignore). + * + * @remark on_consume() interceptors may be called from this function prior to + * passing message to application. + */ +RD_EXPORT +rd_kafka_message_t *rd_kafka_consume(rd_kafka_topic_t *rkt, int32_t partition, + int timeout_ms); + + + +/** + * @brief Consume up to \p rkmessages_size from topic \p rkt and \p partition + * putting a pointer to each message in the application provided + * array \p rkmessages (of size \p rkmessages_size entries). + * + * `rd_kafka_consume_batch()` provides higher throughput performance + * than `rd_kafka_consume()`. + * + * \p timeout_ms is the maximum amount of time to wait for all of + * \p rkmessages_size messages to be put into \p rkmessages. + * If no messages were available within the timeout period this function + * returns 0 and \p rkmessages remains untouched. + * This differs somewhat from `rd_kafka_consume()`. + * + * The message objects must be destroyed with `rd_kafka_message_destroy()` + * when the application is done with it. + * + * @returns the number of rkmessages added in \p rkmessages, + * or -1 on error (same error codes as for `rd_kafka_consume()`. + * + * @sa rd_kafka_consume() + * + * @remark on_consume() interceptors may be called from this function prior to + * passing message to application. + */ +RD_EXPORT +ssize_t rd_kafka_consume_batch(rd_kafka_topic_t *rkt, int32_t partition, + int timeout_ms, + rd_kafka_message_t **rkmessages, + size_t rkmessages_size); + + + +/** + * @brief Consumes messages from topic \p rkt and \p partition, calling + * the provided callback for each consumed messsage. + * + * `rd_kafka_consume_callback()` provides higher throughput performance + * than both `rd_kafka_consume()` and `rd_kafka_consume_batch()`. + * + * \p timeout_ms is the maximum amount of time to wait for one or more messages + * to arrive. + * + * The provided \p consume_cb function is called for each message, + * the application \b MUST \b NOT call `rd_kafka_message_destroy()` on the + * provided \p rkmessage. + * + * The \p opaque argument is passed to the 'consume_cb' as \p opaque. + * + * @returns the number of messages processed or -1 on error. + * + * @sa rd_kafka_consume() + * + * @remark on_consume() interceptors may be called from this function prior to + * passing message to application. + */ +RD_EXPORT +int rd_kafka_consume_callback(rd_kafka_topic_t *rkt, int32_t partition, + int timeout_ms, + void (*consume_cb) (rd_kafka_message_t + *rkmessage, + void *opaque), + void *opaque); + + +/** + * @name Simple Consumer API (legacy): Queue consumers + * @{ + * + * The following `..._queue()` functions are analogue to the functions above + * but reads messages from the provided queue \p rkqu instead. + * \p rkqu must have been previously created with `rd_kafka_queue_new()` + * and the topic consumer must have been started with + * `rd_kafka_consume_start_queue()` utilising the the same queue. + */ + +/** + * @brief Consume from queue + * + * @sa rd_kafka_consume() + */ +RD_EXPORT +rd_kafka_message_t *rd_kafka_consume_queue(rd_kafka_queue_t *rkqu, + int timeout_ms); + +/** + * @brief Consume batch of messages from queue + * + * @sa rd_kafka_consume_batch() + */ +RD_EXPORT +ssize_t rd_kafka_consume_batch_queue(rd_kafka_queue_t *rkqu, + int timeout_ms, + rd_kafka_message_t **rkmessages, + size_t rkmessages_size); + +/** + * @brief Consume multiple messages from queue with callback + * + * @sa rd_kafka_consume_callback() + */ +RD_EXPORT +int rd_kafka_consume_callback_queue(rd_kafka_queue_t *rkqu, + int timeout_ms, + void (*consume_cb) (rd_kafka_message_t + *rkmessage, + void *opaque), + void *opaque); + + +/**@}*/ + + + + +/** + * @name Simple Consumer API (legacy): Topic+partition offset store. + * @{ + * + * If \c auto.commit.enable is true the offset is stored automatically prior to + * returning of the message(s) in each of the rd_kafka_consume*() functions + * above. + */ + + +/** + * @brief Store offset \p offset for topic \p rkt partition \p partition. + * + * The offset will be committed (written) to the offset store according + * to \c `auto.commit.interval.ms` or manual offset-less commit() + * + * @remark \c `enable.auto.offset.store` must be set to "false" when using this API. + * + * @returns RD_KAFKA_RESP_ERR_NO_ERROR on success or an error code on error. + */ +RD_EXPORT +rd_kafka_resp_err_t rd_kafka_offset_store(rd_kafka_topic_t *rkt, + int32_t partition, int64_t offset); + + +/** + * @brief Store offsets for next auto-commit for one or more partitions. + * + * The offset will be committed (written) to the offset store according + * to \c `auto.commit.interval.ms` or manual offset-less commit(). + * + * Per-partition success/error status propagated through each partition's + * \c .err field. + * + * @remark \c `enable.auto.offset.store` must be set to "false" when using this API. + * + * @returns RD_KAFKA_RESP_ERR_NO_ERROR on success, or + * RD_KAFKA_RESP_ERR__UNKNOWN_PARTITION if none of the + * offsets could be stored, or + * RD_KAFKA_RESP_ERR__INVALID_ARG if \c enable.auto.offset.store is true. + */ +RD_EXPORT rd_kafka_resp_err_t +rd_kafka_offsets_store(rd_kafka_t *rk, + rd_kafka_topic_partition_list_t *offsets); +/**@}*/ + + + + +/** + * @name KafkaConsumer (C) + * @{ + * @brief High-level KafkaConsumer C API + * + * + * + */ + +/** + * @brief Subscribe to topic set using balanced consumer groups. + * + * Wildcard (regex) topics are supported by the librdkafka assignor: + * any topic name in the \p topics list that is prefixed with \c \"^\" will + * be regex-matched to the full list of topics in the cluster and matching + * topics will be added to the subscription list. + * + * @returns RD_KAFKA_RESP_ERR_NO_ERROR on success or + * RD_KAFKA_RESP_ERR__INVALID_ARG if list is empty, contains invalid + * topics or regexes. + */ +RD_EXPORT rd_kafka_resp_err_t +rd_kafka_subscribe (rd_kafka_t *rk, + const rd_kafka_topic_partition_list_t *topics); + + +/** + * @brief Unsubscribe from the current subscription set. + */ +RD_EXPORT +rd_kafka_resp_err_t rd_kafka_unsubscribe (rd_kafka_t *rk); + + +/** + * @brief Returns the current topic subscription + * + * @returns An error code on failure, otherwise \p topic is updated + * to point to a newly allocated topic list (possibly empty). + * + * @remark The application is responsible for calling + * rd_kafka_topic_partition_list_destroy on the returned list. + */ +RD_EXPORT rd_kafka_resp_err_t +rd_kafka_subscription (rd_kafka_t *rk, + rd_kafka_topic_partition_list_t **topics); + + + +/** + * @brief Poll the consumer for messages or events. + * + * Will block for at most \p timeout_ms milliseconds. + * + * @remark An application should make sure to call consumer_poll() at regular + * intervals, even if no messages are expected, to serve any + * queued callbacks waiting to be called. This is especially + * important when a rebalance_cb has been registered as it needs + * to be called and handled properly to synchronize internal + * consumer state. + * + * @returns A message object which is a proper message if \p ->err is + * RD_KAFKA_RESP_ERR_NO_ERROR, or an event or error for any other + * value. + * + * @remark on_consume() interceptors may be called from this function prior to + * passing message to application. + * + * @sa rd_kafka_message_t + */ +RD_EXPORT +rd_kafka_message_t *rd_kafka_consumer_poll (rd_kafka_t *rk, int timeout_ms); + +/** + * @brief Close down the KafkaConsumer. + * + * @remark This call will block until the consumer has revoked its assignment, + * calling the \c rebalance_cb if it is configured, committed offsets + * to broker, and left the consumer group. + * The maximum blocking time is roughly limited to session.timeout.ms. + * + * @returns An error code indicating if the consumer close was succesful + * or not. + * + * @remark The application still needs to call rd_kafka_destroy() after + * this call finishes to clean up the underlying handle resources. + * + */ +RD_EXPORT +rd_kafka_resp_err_t rd_kafka_consumer_close (rd_kafka_t *rk); + + + +/** + * @brief Atomic assignment of partitions to consume. + * + * The new \p partitions will replace the existing assignment. + * + * When used from a rebalance callback the application shall pass the + * partition list passed to the callback (or a copy of it) (even if the list + * is empty) rather than NULL to maintain internal join state. + + * A zero-length \p partitions will treat the partitions as a valid, + * albeit empty, assignment, and maintain internal state, while a \c NULL + * value for \p partitions will reset and clear the internal state. + */ +RD_EXPORT rd_kafka_resp_err_t +rd_kafka_assign (rd_kafka_t *rk, + const rd_kafka_topic_partition_list_t *partitions); + +/** + * @brief Returns the current partition assignment + * + * @returns An error code on failure, otherwise \p partitions is updated + * to point to a newly allocated partition list (possibly empty). + * + * @remark The application is responsible for calling + * rd_kafka_topic_partition_list_destroy on the returned list. + */ +RD_EXPORT rd_kafka_resp_err_t +rd_kafka_assignment (rd_kafka_t *rk, + rd_kafka_topic_partition_list_t **partitions); + + + + +/** + * @brief Commit offsets on broker for the provided list of partitions. + * + * \p offsets should contain \c topic, \c partition, \c offset and possibly + * \c metadata. + * If \p offsets is NULL the current partition assignment will be used instead. + * + * If \p async is false this operation will block until the broker offset commit + * is done, returning the resulting success or error code. + * + * If a rd_kafka_conf_set_offset_commit_cb() offset commit callback has been + * configured the callback will be enqueued for a future call to + * rd_kafka_poll(), rd_kafka_consumer_poll() or similar. + */ +RD_EXPORT rd_kafka_resp_err_t +rd_kafka_commit (rd_kafka_t *rk, const rd_kafka_topic_partition_list_t *offsets, + int async); + + +/** + * @brief Commit message's offset on broker for the message's partition. + * + * @sa rd_kafka_commit + */ +RD_EXPORT rd_kafka_resp_err_t +rd_kafka_commit_message (rd_kafka_t *rk, const rd_kafka_message_t *rkmessage, + int async); + + +/** + * @brief Commit offsets on broker for the provided list of partitions. + * + * See rd_kafka_commit for \p offsets semantics. + * + * The result of the offset commit will be posted on the provided \p rkqu queue. + * + * If the application uses one of the poll APIs (rd_kafka_poll(), + * rd_kafka_consumer_poll(), rd_kafka_queue_poll(), ..) to serve the queue + * the \p cb callback is required. \p opaque is passed to the callback. + * + * If using the event API the callback is ignored and the offset commit result + * will be returned as an RD_KAFKA_EVENT_COMMIT event. The \p opaque + * value will be available with rd_kafka_event_opaque() + * + * If \p rkqu is NULL a temporary queue will be created and the callback will + * be served by this call. + * + * @sa rd_kafka_commit() + * @sa rd_kafka_conf_set_offset_commit_cb() + */ +RD_EXPORT rd_kafka_resp_err_t +rd_kafka_commit_queue (rd_kafka_t *rk, + const rd_kafka_topic_partition_list_t *offsets, + rd_kafka_queue_t *rkqu, + void (*cb) (rd_kafka_t *rk, + rd_kafka_resp_err_t err, + rd_kafka_topic_partition_list_t *offsets, + void *opaque), + void *opaque); + + +/** + * @brief Retrieve committed offsets for topics+partitions. + * + * The \p offset field of each requested partition will either be set to + * stored offset or to RD_KAFKA_OFFSET_INVALID in case there was no stored + * offset for that partition. + * + * @returns RD_KAFKA_RESP_ERR_NO_ERROR on success in which case the + * \p offset or \p err field of each \p partitions' element is filled + * in with the stored offset, or a partition specific error. + * Else returns an error code. + */ +RD_EXPORT rd_kafka_resp_err_t +rd_kafka_committed (rd_kafka_t *rk, + rd_kafka_topic_partition_list_t *partitions, + int timeout_ms); + + + +/** + * @brief Retrieve current positions (offsets) for topics+partitions. + * + * The \p offset field of each requested partition will be set to the offset + * of the last consumed message + 1, or RD_KAFKA_OFFSET_INVALID in case there was + * no previous message. + * + * @returns RD_KAFKA_RESP_ERR_NO_ERROR on success in which case the + * \p offset or \p err field of each \p partitions' element is filled + * in with the stored offset, or a partition specific error. + * Else returns an error code. + */ +RD_EXPORT rd_kafka_resp_err_t +rd_kafka_position (rd_kafka_t *rk, + rd_kafka_topic_partition_list_t *partitions); + + +/**@}*/ + + + +/** + * @name Producer API + * @{ + * + * + */ + + +/** + * @brief Producer message flags + */ +#define RD_KAFKA_MSG_F_FREE 0x1 /**< Delegate freeing of payload to rdkafka. */ +#define RD_KAFKA_MSG_F_COPY 0x2 /**< rdkafka will make a copy of the payload. */ +#define RD_KAFKA_MSG_F_BLOCK 0x4 /**< Block produce*() on message queue full. + * WARNING: If a delivery report callback + * is used the application MUST + * call rd_kafka_poll() (or equiv.) + * to make sure delivered messages + * are drained from the internal + * delivery report queue. + * Failure to do so will result + * in indefinately blocking on + * the produce() call when the + * message queue is full. + */ + + + +/** + * @brief Produce and send a single message to broker. + * + * \p rkt is the target topic which must have been previously created with + * `rd_kafka_topic_new()`. + * + * `rd_kafka_produce()` is an asynch non-blocking API. + * + * \p partition is the target partition, either: + * - RD_KAFKA_PARTITION_UA (unassigned) for + * automatic partitioning using the topic's partitioner function, or + * - a fixed partition (0..N) + * + * \p msgflags is zero or more of the following flags OR:ed together: + * RD_KAFKA_MSG_F_BLOCK - block \p produce*() call if + * \p queue.buffering.max.messages or + * \p queue.buffering.max.kbytes are exceeded. + * Messages are considered in-queue from the point they + * are accepted by produce() until their corresponding + * delivery report callback/event returns. + * It is thus a requirement to call + * rd_kafka_poll() (or equiv.) from a separate + * thread when F_BLOCK is used. + * See WARNING on \c RD_KAFKA_MSG_F_BLOCK above. + * + * RD_KAFKA_MSG_F_FREE - rdkafka will free(3) \p payload when it is done + * with it. + * RD_KAFKA_MSG_F_COPY - the \p payload data will be copied and the + * \p payload pointer will not be used by rdkafka + * after the call returns. + * + * .._F_FREE and .._F_COPY are mutually exclusive. + * + * If the function returns -1 and RD_KAFKA_MSG_F_FREE was specified, then + * the memory associated with the payload is still the caller's + * responsibility. + * + * \p payload is the message payload of size \p len bytes. + * + * \p key is an optional message key of size \p keylen bytes, if non-NULL it + * will be passed to the topic partitioner as well as be sent with the + * message to the broker and passed on to the consumer. + * + * \p msg_opaque is an optional application-provided per-message opaque + * pointer that will provided in the delivery report callback (`dr_cb`) for + * referencing this message. + * + * @remark on_send() and on_acknowledgement() interceptors may be called + * from this function. on_acknowledgement() will only be called if the + * message fails partitioning. + * + * @returns 0 on success or -1 on error in which case errno is set accordingly: + * - ENOBUFS - maximum number of outstanding messages has been reached: + * "queue.buffering.max.messages" + * (RD_KAFKA_RESP_ERR__QUEUE_FULL) + * - EMSGSIZE - message is larger than configured max size: + * "messages.max.bytes". + * (RD_KAFKA_RESP_ERR_MSG_SIZE_TOO_LARGE) + * - ESRCH - requested \p partition is unknown in the Kafka cluster. + * (RD_KAFKA_RESP_ERR__UNKNOWN_PARTITION) + * - ENOENT - topic is unknown in the Kafka cluster. + * (RD_KAFKA_RESP_ERR__UNKNOWN_TOPIC) + * + * @sa Use rd_kafka_errno2err() to convert `errno` to rdkafka error code. + */ +RD_EXPORT +int rd_kafka_produce(rd_kafka_topic_t *rkt, int32_t partition, + int msgflags, + void *payload, size_t len, + const void *key, size_t keylen, + void *msg_opaque); + + +/** + * @brief Produce and send a single message to broker. + * + * The message is defined by a va-arg list using \c rd_kafka_vtype_t + * tag tuples which must be terminated with a single \c RD_KAFKA_V_END. + * + * @returns \c RD_KAFKA_RESP_ERR_NO_ERROR on success, else an error code. + * \c RD_KAFKA_RESP_ERR__CONFLICT is returned if _V_HEADER and + * _V_HEADERS are mixed. + * + * @sa rd_kafka_produce, RD_KAFKA_V_END + */ +RD_EXPORT +rd_kafka_resp_err_t rd_kafka_producev (rd_kafka_t *rk, ...); + + +/** + * @brief Produce multiple messages. + * + * If partition is RD_KAFKA_PARTITION_UA the configured partitioner will + * be run for each message (slower), otherwise the messages will be enqueued + * to the specified partition directly (faster). + * + * The messages are provided in the array \p rkmessages of count \p message_cnt + * elements. + * The \p partition and \p msgflags are used for all provided messages. + * + * Honoured \p rkmessages[] fields are: + * - payload,len Message payload and length + * - key,key_len Optional message key + * - _private Message opaque pointer (msg_opaque) + * - err Will be set according to success or failure. + * Application only needs to check for errors if + * return value != \p message_cnt. + * + * @returns the number of messages succesfully enqueued for producing. + * + * @remark This interface does NOT support setting message headers on + * the provided \p rkmessages. + */ +RD_EXPORT +int rd_kafka_produce_batch(rd_kafka_topic_t *rkt, int32_t partition, + int msgflags, + rd_kafka_message_t *rkmessages, int message_cnt); + + + + +/** + * @brief Wait until all outstanding produce requests, et.al, are completed. + * This should typically be done prior to destroying a producer instance + * to make sure all queued and in-flight produce requests are completed + * before terminating. + * + * @remark This function will call rd_kafka_poll() and thus trigger callbacks. + * + * @returns RD_KAFKA_RESP_ERR__TIMED_OUT if \p timeout_ms was reached before all + * outstanding requests were completed, else RD_KAFKA_RESP_ERR_NO_ERROR + */ +RD_EXPORT +rd_kafka_resp_err_t rd_kafka_flush (rd_kafka_t *rk, int timeout_ms); + + +/**@}*/ + + +/** +* @name Metadata API +* @{ +* +* +*/ + + +/** + * @brief Broker information + */ +typedef struct rd_kafka_metadata_broker { + int32_t id; /**< Broker Id */ + char *host; /**< Broker hostname */ + int port; /**< Broker listening port */ +} rd_kafka_metadata_broker_t; + +/** + * @brief Partition information + */ +typedef struct rd_kafka_metadata_partition { + int32_t id; /**< Partition Id */ + rd_kafka_resp_err_t err; /**< Partition error reported by broker */ + int32_t leader; /**< Leader broker */ + int replica_cnt; /**< Number of brokers in \p replicas */ + int32_t *replicas; /**< Replica brokers */ + int isr_cnt; /**< Number of ISR brokers in \p isrs */ + int32_t *isrs; /**< In-Sync-Replica brokers */ +} rd_kafka_metadata_partition_t; + +/** + * @brief Topic information + */ +typedef struct rd_kafka_metadata_topic { + char *topic; /**< Topic name */ + int partition_cnt; /**< Number of partitions in \p partitions*/ + struct rd_kafka_metadata_partition *partitions; /**< Partitions */ + rd_kafka_resp_err_t err; /**< Topic error reported by broker */ +} rd_kafka_metadata_topic_t; + + +/** + * @brief Metadata container + */ +typedef struct rd_kafka_metadata { + int broker_cnt; /**< Number of brokers in \p brokers */ + struct rd_kafka_metadata_broker *brokers; /**< Brokers */ + + int topic_cnt; /**< Number of topics in \p topics */ + struct rd_kafka_metadata_topic *topics; /**< Topics */ + + int32_t orig_broker_id; /**< Broker originating this metadata */ + char *orig_broker_name; /**< Name of originating broker */ +} rd_kafka_metadata_t; + + +/** + * @brief Request Metadata from broker. + * + * Parameters: + * - \p all_topics if non-zero: request info about all topics in cluster, + * if zero: only request info about locally known topics. + * - \p only_rkt only request info about this topic + * - \p metadatap pointer to hold metadata result. + * The \p *metadatap pointer must be released + * with rd_kafka_metadata_destroy(). + * - \p timeout_ms maximum response time before failing. + * + * Returns RD_KAFKA_RESP_ERR_NO_ERROR on success (in which case *metadatap) + * will be set, else RD_KAFKA_RESP_ERR__TIMED_OUT on timeout or + * other error code on error. + */ +RD_EXPORT +rd_kafka_resp_err_t +rd_kafka_metadata (rd_kafka_t *rk, int all_topics, + rd_kafka_topic_t *only_rkt, + const struct rd_kafka_metadata **metadatap, + int timeout_ms); + +/** + * @brief Release metadata memory. + */ +RD_EXPORT +void rd_kafka_metadata_destroy(const struct rd_kafka_metadata *metadata); + + +/**@}*/ + + + +/** +* @name Client group information +* @{ +* +* +*/ + + +/** + * @brief Group member information + * + * For more information on \p member_metadata format, see + * https://cwiki.apache.org/confluence/display/KAFKA/A+Guide+To+The+Kafka+Protocol#AGuideToTheKafkaProtocol-GroupMembershipAPI + * + */ +struct rd_kafka_group_member_info { + char *member_id; /**< Member id (generated by broker) */ + char *client_id; /**< Client's \p client.id */ + char *client_host; /**< Client's hostname */ + void *member_metadata; /**< Member metadata (binary), + * format depends on \p protocol_type. */ + int member_metadata_size; /**< Member metadata size in bytes */ + void *member_assignment; /**< Member assignment (binary), + * format depends on \p protocol_type. */ + int member_assignment_size; /**< Member assignment size in bytes */ +}; + +/** + * @brief Group information + */ +struct rd_kafka_group_info { + struct rd_kafka_metadata_broker broker; /**< Originating broker info */ + char *group; /**< Group name */ + rd_kafka_resp_err_t err; /**< Broker-originated error */ + char *state; /**< Group state */ + char *protocol_type; /**< Group protocol type */ + char *protocol; /**< Group protocol */ + struct rd_kafka_group_member_info *members; /**< Group members */ + int member_cnt; /**< Group member count */ +}; + +/** + * @brief List of groups + * + * @sa rd_kafka_group_list_destroy() to release list memory. + */ +struct rd_kafka_group_list { + struct rd_kafka_group_info *groups; /**< Groups */ + int group_cnt; /**< Group count */ +}; + + +/** + * @brief List and describe client groups in cluster. + * + * \p group is an optional group name to describe, otherwise (\p NULL) all + * groups are returned. + * + * \p timeout_ms is the (approximate) maximum time to wait for response + * from brokers and must be a positive value. + * + * @returns \c RD_KAFKA_RESP_ERR__NO_ERROR on success and \p grplistp is + * updated to point to a newly allocated list of groups. + * \c RD_KAFKA_RESP_ERR__PARTIAL if not all brokers responded + * in time but at least one group is returned in \p grplistlp. + * \c RD_KAFKA_RESP_ERR__TIMED_OUT if no groups were returned in the + * given timeframe but not all brokers have yet responded, or + * if the list of brokers in the cluster could not be obtained within + * the given timeframe. + * \c RD_KAFKA_RESP_ERR__TRANSPORT if no brokers were found. + * Other error codes may also be returned from the request layer. + * + * The \p grplistp remains untouched if any error code is returned, + * with the exception of RD_KAFKA_RESP_ERR__PARTIAL which behaves + * as RD_KAFKA_RESP_ERR__NO_ERROR (success) but with an incomplete + * group list. + * + * @sa Use rd_kafka_group_list_destroy() to release list memory. + */ +RD_EXPORT +rd_kafka_resp_err_t +rd_kafka_list_groups (rd_kafka_t *rk, const char *group, + const struct rd_kafka_group_list **grplistp, + int timeout_ms); + +/** + * @brief Release list memory + */ +RD_EXPORT +void rd_kafka_group_list_destroy (const struct rd_kafka_group_list *grplist); + + +/**@}*/ + + + +/** + * @name Miscellaneous APIs + * @{ + * + */ + + +/** + * @brief Adds one or more brokers to the kafka handle's list of initial + * bootstrap brokers. + * + * Additional brokers will be discovered automatically as soon as rdkafka + * connects to a broker by querying the broker metadata. + * + * If a broker name resolves to multiple addresses (and possibly + * address families) all will be used for connection attempts in + * round-robin fashion. + * + * \p brokerlist is a ,-separated list of brokers in the format: + * \c \<broker1\>,\<broker2\>,.. + * Where each broker is in either the host or URL based format: + * \c \<host\>[:\<port\>] + * \c \<proto\>://\<host\>[:port] + * \c \<proto\> is either \c PLAINTEXT, \c SSL, \c SASL, \c SASL_PLAINTEXT + * The two formats can be mixed but ultimately the value of the + * `security.protocol` config property decides what brokers are allowed. + * + * Example: + * brokerlist = "broker1:10000,broker2" + * brokerlist = "SSL://broker3:9000,ssl://broker2" + * + * @returns the number of brokers successfully added. + * + * @remark Brokers may also be defined with the \c metadata.broker.list or + * \c bootstrap.servers configuration property (preferred method). + */ +RD_EXPORT +int rd_kafka_brokers_add(rd_kafka_t *rk, const char *brokerlist); + + + + +/** + * @brief Set logger function. + * + * The default is to print to stderr, but a syslog logger is also available, + * see rd_kafka_log_(print|syslog) for the builtin alternatives. + * Alternatively the application may provide its own logger callback. + * Or pass 'func' as NULL to disable logging. + * + * @deprecated Use rd_kafka_conf_set_log_cb() + * + * @remark \p rk may be passed as NULL in the callback. + */ +RD_EXPORT RD_DEPRECATED +void rd_kafka_set_logger(rd_kafka_t *rk, + void (*func) (const rd_kafka_t *rk, int level, + const char *fac, const char *buf)); + + +/** + * @brief Specifies the maximum logging level produced by + * internal kafka logging and debugging. + * + * If the \p \"debug\" configuration property is set the level is automatically + * adjusted to \c LOG_DEBUG (7). + */ +RD_EXPORT +void rd_kafka_set_log_level(rd_kafka_t *rk, int level); + + +/** + * @brief Builtin (default) log sink: print to stderr + */ +RD_EXPORT +void rd_kafka_log_print(const rd_kafka_t *rk, int level, + const char *fac, const char *buf); + + +/** + * @brief Builtin log sink: print to syslog. + */ +RD_EXPORT +void rd_kafka_log_syslog(const rd_kafka_t *rk, int level, + const char *fac, const char *buf); + + +/** + * @brief Returns the current out queue length. + * + * The out queue contains messages waiting to be sent to, or acknowledged by, + * the broker. + * + * An application should wait for this queue to reach zero before terminating + * to make sure outstanding requests (such as offset commits) are fully + * processed. + * + * @returns number of messages in the out queue. + */ +RD_EXPORT +int rd_kafka_outq_len(rd_kafka_t *rk); + + + +/** + * @brief Dumps rdkafka's internal state for handle \p rk to stream \p fp + * + * This is only useful for debugging rdkafka, showing state and statistics + * for brokers, topics, partitions, etc. + */ +RD_EXPORT +void rd_kafka_dump(FILE *fp, rd_kafka_t *rk); + + + +/** + * @brief Retrieve the current number of threads in use by librdkafka. + * + * Used by regression tests. + */ +RD_EXPORT +int rd_kafka_thread_cnt(void); + + +/** + * @brief Wait for all rd_kafka_t objects to be destroyed. + * + * Returns 0 if all kafka objects are now destroyed, or -1 if the + * timeout was reached. + * + * @remark This function is deprecated. + */ +RD_EXPORT +int rd_kafka_wait_destroyed(int timeout_ms); + + +/** + * @brief Run librdkafka's built-in unit-tests. + * + * @returns the number of failures, or 0 if all tests passed. + */ +RD_EXPORT +int rd_kafka_unittest (void); + + +/**@}*/ + + + + +/** + * @name Experimental APIs + * @{ + */ + +/** + * @brief Redirect the main (rd_kafka_poll()) queue to the KafkaConsumer's + * queue (rd_kafka_consumer_poll()). + * + * @warning It is not permitted to call rd_kafka_poll() after directing the + * main queue with rd_kafka_poll_set_consumer(). + */ +RD_EXPORT +rd_kafka_resp_err_t rd_kafka_poll_set_consumer (rd_kafka_t *rk); + + +/**@}*/ + +/** + * @name Event interface + * + * @brief The event API provides an alternative pollable non-callback interface + * to librdkafka's message and event queues. + * + * @{ + */ + + +/** + * @brief Event types + */ +typedef int rd_kafka_event_type_t; +#define RD_KAFKA_EVENT_NONE 0x0 +#define RD_KAFKA_EVENT_DR 0x1 /**< Producer Delivery report batch */ +#define RD_KAFKA_EVENT_FETCH 0x2 /**< Fetched message (consumer) */ +#define RD_KAFKA_EVENT_LOG 0x4 /**< Log message */ +#define RD_KAFKA_EVENT_ERROR 0x8 /**< Error */ +#define RD_KAFKA_EVENT_REBALANCE 0x10 /**< Group rebalance (consumer) */ +#define RD_KAFKA_EVENT_OFFSET_COMMIT 0x20 /**< Offset commit result */ +#define RD_KAFKA_EVENT_STATS 0x40 /**< Stats */ + + +typedef struct rd_kafka_op_s rd_kafka_event_t; + + +/** + * @returns the event type for the given event. + * + * @remark As a convenience it is okay to pass \p rkev as NULL in which case + * RD_KAFKA_EVENT_NONE is returned. + */ +RD_EXPORT +rd_kafka_event_type_t rd_kafka_event_type (const rd_kafka_event_t *rkev); + +/** + * @returns the event type's name for the given event. + * + * @remark As a convenience it is okay to pass \p rkev as NULL in which case + * the name for RD_KAFKA_EVENT_NONE is returned. + */ +RD_EXPORT +const char *rd_kafka_event_name (const rd_kafka_event_t *rkev); + + +/** + * @brief Destroy an event. + * + * @remark Any references to this event, such as extracted messages, + * will not be usable after this call. + * + * @remark As a convenience it is okay to pass \p rkev as NULL in which case + * no action is performed. + */ +RD_EXPORT +void rd_kafka_event_destroy (rd_kafka_event_t *rkev); + + +/** + * @returns the next message from an event. + * + * Call repeatedly until it returns NULL. + * + * Event types: + * - RD_KAFKA_EVENT_FETCH (1 message) + * - RD_KAFKA_EVENT_DR (>=1 message(s)) + * + * @remark The returned message(s) MUST NOT be + * freed with rd_kafka_message_destroy(). + * + * @remark on_consume() interceptor may be called + * from this function prior to passing message to application. + */ +RD_EXPORT +const rd_kafka_message_t *rd_kafka_event_message_next (rd_kafka_event_t *rkev); + + +/** + * @brief Extacts \p size message(s) from the event into the + * pre-allocated array \p rkmessages. + * + * Event types: + * - RD_KAFKA_EVENT_FETCH (1 message) + * - RD_KAFKA_EVENT_DR (>=1 message(s)) + * + * @returns the number of messages extracted. + * + * @remark on_consume() interceptor may be called + * from this function prior to passing message to application. + */ +RD_EXPORT +size_t rd_kafka_event_message_array (rd_kafka_event_t *rkev, + const rd_kafka_message_t **rkmessages, + size_t size); + + +/** + * @returns the number of remaining messages in the event. + * + * Event types: + * - RD_KAFKA_EVENT_FETCH (1 message) + * - RD_KAFKA_EVENT_DR (>=1 message(s)) + */ +RD_EXPORT +size_t rd_kafka_event_message_count (rd_kafka_event_t *rkev); + + +/** + * @returns the error code for the event. + * + * Event types: + * - all + */ +RD_EXPORT +rd_kafka_resp_err_t rd_kafka_event_error (rd_kafka_event_t *rkev); + + +/** + * @returns the error string (if any). + * An application should check that rd_kafka_event_error() returns + * non-zero before calling this function. + * + * Event types: + * - all + */ +RD_EXPORT +const char *rd_kafka_event_error_string (rd_kafka_event_t *rkev); + + + +/** + * @returns the user opaque (if any) + * + * Event types: + * - RD_KAFKA_OFFSET_COMMIT + */ +RD_EXPORT +void *rd_kafka_event_opaque (rd_kafka_event_t *rkev); + + +/** + * @brief Extract log message from the event. + * + * Event types: + * - RD_KAFKA_EVENT_LOG + * + * @returns 0 on success or -1 if unsupported event type. + */ +RD_EXPORT +int rd_kafka_event_log (rd_kafka_event_t *rkev, + const char **fac, const char **str, int *level); + + +/** + * @brief Extract stats from the event. + * + * Event types: + * - RD_KAFKA_EVENT_STATS + * + * @returns stats json string. + * + * @remark the returned string will be freed automatically along with the event object + * + */ +RD_EXPORT +const char *rd_kafka_event_stats (rd_kafka_event_t *rkev); + + +/** + * @returns the topic partition list from the event. + * + * @remark The list MUST NOT be freed with rd_kafka_topic_partition_list_destroy() + * + * Event types: + * - RD_KAFKA_EVENT_REBALANCE + * - RD_KAFKA_EVENT_OFFSET_COMMIT + */ +RD_EXPORT rd_kafka_topic_partition_list_t * +rd_kafka_event_topic_partition_list (rd_kafka_event_t *rkev); + + +/** + * @returns a newly allocated topic_partition container, if applicable for the event type, + * else NULL. + * + * @remark The returned pointer MUST be freed with rd_kafka_topic_partition_destroy(). + * + * Event types: + * RD_KAFKA_EVENT_ERROR (for partition level errors) + */ +RD_EXPORT rd_kafka_topic_partition_t * +rd_kafka_event_topic_partition (rd_kafka_event_t *rkev); + + +/** + * @brief Poll a queue for an event for max \p timeout_ms. + * + * @returns an event, or NULL. + * + * @remark Use rd_kafka_event_destroy() to free the event. + */ +RD_EXPORT +rd_kafka_event_t *rd_kafka_queue_poll (rd_kafka_queue_t *rkqu, int timeout_ms); + +/** +* @brief Poll a queue for events served through callbacks for max \p timeout_ms. +* +* @returns the number of events served. +* +* @remark This API must only be used for queues with callbacks registered +* for all expected event types. E.g., not a message queue. +*/ +RD_EXPORT +int rd_kafka_queue_poll_callback (rd_kafka_queue_t *rkqu, int timeout_ms); + + +/**@}*/ + + +/** + * @name Plugin interface + * + * @brief A plugin interface that allows external runtime-loaded libraries + * to integrate with a client instance without modifications to + * the application code. + * + * Plugins are loaded when referenced through the `plugin.library.paths` + * configuration property and operates on the \c rd_kafka_conf_t + * object prior \c rd_kafka_t instance creation. + * + * @warning Plugins require the application to link librdkafka dynamically + * and not statically. Failure to do so will lead to missing symbols + * or finding symbols in another librdkafka library than the + * application was linked with. + */ + + +/** + * @brief Plugin's configuration initializer method called each time the + * library is referenced from configuration (even if previously loaded by + * another client instance). + * + * @remark This method MUST be implemented by plugins and have the symbol name + * \c conf_init + * + * @param conf Configuration set up to this point. + * @param plug_opaquep Plugin can set this pointer to a per-configuration + * opaque pointer. + * @param errstr String buffer of size \p errstr_size where plugin must write + * a human readable error string in the case the initializer + * fails (returns non-zero). + * + * @remark A plugin may add an on_conf_destroy() interceptor to clean up + * plugin-specific resources created in the plugin's conf_init() method. + * + * @returns RD_KAFKA_RESP_ERR_NO_ERROR on success or an error code on error. + */ +typedef rd_kafka_resp_err_t +(rd_kafka_plugin_f_conf_init_t) (rd_kafka_conf_t *conf, + void **plug_opaquep, + char *errstr, size_t errstr_size); + +/**@}*/ + + + +/** + * @name Interceptors + * + * @{ + * + * @brief A callback interface that allows message interception for both + * producer and consumer data pipelines. + * + * Except for the on_new(), on_conf_set(), on_conf_dup() and on_conf_destroy() + * interceptors, interceptors are added to the + * newly created rd_kafka_t client instance. These interceptors MUST only + * be added from on_new() and MUST NOT be added after rd_kafka_new() returns. + * + * The on_new(), on_conf_set(), on_conf_dup() and on_conf_destroy() interceptors + * are added to the configuration object which is later passed to + * rd_kafka_new() where on_new() is called to allow addition of + * other interceptors. + * + * Each interceptor reference consists of a display name (ic_name), + * a callback function, and an application-specified opaque value that is + * passed as-is to the callback. + * The ic_name must be unique for the interceptor implementation and is used + * to reject duplicate interceptor methods. + * + * Any number of interceptors can be added and they are called in the order + * they were added, unless otherwise noted. + * The list of registered interceptor methods are referred to as + * interceptor chains. + * + * @remark Contrary to the Java client the librdkafka interceptor interface + * does not support message key and value modification. + * Message mutability is discouraged in the Java client and the + * combination of serializers and headers cover most use-cases. + * + * @remark Interceptors are NOT copied to the new configuration on + * rd_kafka_conf_dup() since it would be hard for interceptors to + * track usage of the interceptor's opaque value. + * An interceptor should rely on the plugin, which will be copied + * in rd_kafka_conf_conf_dup(), to set up the initial interceptors. + * An interceptor should implement the on_conf_dup() method + * to manually set up its internal configuration on the newly created + * configuration object that is being copied-to based on the + * interceptor-specific configuration properties. + * conf_dup() should thus be treated the same as conf_init(). + * + * @remark Interceptors are keyed by the interceptor type (on_..()), the + * interceptor name (ic_name) and the interceptor method function. + * Duplicates are not allowed and the .._add_on_..() method will + * return RD_KAFKA_RESP_ERR__CONFLICT if attempting to add a duplicate + * method. + * The only exception is on_conf_destroy() which may be added multiple + * times by the same interceptor to allow proper cleanup of + * interceptor configuration state. + */ + + +/** + * @brief on_conf_set() is called from rd_kafka_*_conf_set() in the order + * the interceptors were added. + * + * @param ic_opaque The interceptor's opaque pointer specified in ..add..(). + * @param name The configuration property to set. + * @param val The configuration value to set, or NULL for reverting to default + * in which case the previous value should be freed. + * @param errstr A human readable error string in case the interceptor fails. + * @param errstr_size Maximum space (including \0) in \p errstr. + * + * @returns RD_KAFKA_CONF_RES_OK if the property was known and successfully + * handled by the interceptor, RD_KAFKA_CONF_RES_INVALID if the + * property was handled by the interceptor but the value was invalid, + * or RD_KAFKA_CONF_RES_UNKNOWN if the interceptor did not handle + * this property, in which case the property is passed on on the + * interceptor in the chain, finally ending up at the built-in + * configuration handler. + */ +typedef rd_kafka_conf_res_t +(rd_kafka_interceptor_f_on_conf_set_t) (rd_kafka_conf_t *conf, + const char *name, const char *val, + char *errstr, size_t errstr_size, + void *ic_opaque); + + +/** + * @brief on_conf_dup() is called from rd_kafka_conf_dup() in the + * order the interceptors were added and is used to let + * an interceptor re-register its conf interecptors with a new + * opaque value. + * The on_conf_dup() method is called prior to the configuration from + * \p old_conf being copied to \p new_conf. + * + * @param ic_opaque The interceptor's opaque pointer specified in ..add..(). + * + * @returns RD_KAFKA_RESP_ERR_NO_ERROR on success or an error code + * on failure (which is logged but otherwise ignored). + * + * @remark No on_conf_* interceptors are copied to the new configuration + * object on rd_kafka_conf_dup(). + */ +typedef rd_kafka_resp_err_t +(rd_kafka_interceptor_f_on_conf_dup_t) (rd_kafka_conf_t *new_conf, + const rd_kafka_conf_t *old_conf, + size_t filter_cnt, + const char **filter, + void *ic_opaque); + + +/** + * @brief on_conf_destroy() is called from rd_kafka_*_conf_destroy() in the + * order the interceptors were added. + * + * @param ic_opaque The interceptor's opaque pointer specified in ..add..(). + */ +typedef rd_kafka_resp_err_t +(rd_kafka_interceptor_f_on_conf_destroy_t) (void *ic_opaque); + + +/** + * @brief on_new() is called from rd_kafka_new() prior toreturning + * the newly created client instance to the application. + * + * @param rk The client instance. + * @param conf The client instance's final configuration. + * @param ic_opaque The interceptor's opaque pointer specified in ..add..(). + * @param errstr A human readable error string in case the interceptor fails. + * @param errstr_size Maximum space (including \0) in \p errstr. + * + * @returns an error code on failure, the error is logged but otherwise ignored. + * + * @warning The \p rk client instance will not be fully set up when this + * interceptor is called and the interceptor MUST NOT call any + * other rk-specific APIs than rd_kafka_interceptor_add..(). + * + */ +typedef rd_kafka_resp_err_t +(rd_kafka_interceptor_f_on_new_t) (rd_kafka_t *rk, const rd_kafka_conf_t *conf, + void *ic_opaque, + char *errstr, size_t errstr_size); + + +/** + * @brief on_destroy() is called from rd_kafka_destroy() or (rd_kafka_new() + * if rd_kafka_new() fails during initialization). + * + * @param rk The client instance. + * @param ic_opaque The interceptor's opaque pointer specified in ..add..(). + */ +typedef rd_kafka_resp_err_t +(rd_kafka_interceptor_f_on_destroy_t) (rd_kafka_t *rk, void *ic_opaque); + + + + +/** + * @brief on_send() is called from rd_kafka_produce*() (et.al) prior to + * the partitioner being called. + * + * @param rk The client instance. + * @param rkmessage The message being produced. Immutable. + * @param ic_opaque The interceptor's opaque pointer specified in ..add..(). + * + * @remark This interceptor is only used by producer instances. + * + * @remark The \p rkmessage object is NOT mutable and MUST NOT be modified + * by the interceptor. + * + * @remark If the partitioner fails or an unknown partition was specified, + * the on_acknowledgement() interceptor chain will be called from + * within the rd_kafka_produce*() call to maintain send-acknowledgement + * symmetry. + * + * @returns an error code on failure, the error is logged but otherwise ignored. + */ +typedef rd_kafka_resp_err_t +(rd_kafka_interceptor_f_on_send_t) (rd_kafka_t *rk, + rd_kafka_message_t *rkmessage, + void *ic_opaque); + +/** + * @brief on_acknowledgement() is called to inform interceptors that a message + * was succesfully delivered or permanently failed delivery. + * The interceptor chain is called from internal librdkafka background + * threads, or rd_kafka_produce*() if the partitioner failed. + * + * @param rk The client instance. + * @param rkmessage The message being produced. Immutable. + * @param ic_opaque The interceptor's opaque pointer specified in ..add..(). + * + * @remark This interceptor is only used by producer instances. + * + * @remark The \p rkmessage object is NOT mutable and MUST NOT be modified + * by the interceptor. + * + * @warning The on_acknowledgement() method may be called from internal + * librdkafka threads. An on_acknowledgement() interceptor MUST NOT + * call any librdkafka API's associated with the \p rk, or perform + * any blocking or prolonged work. + * + * @returns an error code on failure, the error is logged but otherwise ignored. + */ +typedef rd_kafka_resp_err_t +(rd_kafka_interceptor_f_on_acknowledgement_t) (rd_kafka_t *rk, + rd_kafka_message_t *rkmessage, + void *ic_opaque); + + +/** + * @brief on_consume() is called just prior to passing the message to the + * application in rd_kafka_consumer_poll(), rd_kafka_consume*(), + * the event interface, etc. + * + * @param rk The client instance. + * @param rkmessage The message being consumed. Immutable. + * @param ic_opaque The interceptor's opaque pointer specified in ..add..(). + * + * @remark This interceptor is only used by consumer instances. + * + * @remark The \p rkmessage object is NOT mutable and MUST NOT be modified + * by the interceptor. + * + * @returns an error code on failure, the error is logged but otherwise ignored. + */ +typedef rd_kafka_resp_err_t +(rd_kafka_interceptor_f_on_consume_t) (rd_kafka_t *rk, + rd_kafka_message_t *rkmessage, + void *ic_opaque); + +/** + * @brief on_commit() is called on completed or failed offset commit. + * It is called from internal librdkafka threads. + * + * @param rk The client instance. + * @param offsets List of topic+partition+offset+error that were committed. + * The error message of each partition should be checked for + * error. + * @param ic_opaque The interceptor's opaque pointer specified in ..add..(). + * + * @remark This interceptor is only used by consumer instances. + * + * @warning The on_commit() interceptor is called from internal + * librdkafka threads. An on_commit() interceptor MUST NOT + * call any librdkafka API's associated with the \p rk, or perform + * any blocking or prolonged work. + * + * + * @returns an error code on failure, the error is logged but otherwise ignored. + */ +typedef rd_kafka_resp_err_t +(rd_kafka_interceptor_f_on_commit_t) ( + rd_kafka_t *rk, + const rd_kafka_topic_partition_list_t *offsets, + rd_kafka_resp_err_t err, void *ic_opaque); + + +/** + * @brief on_request_sent() is called when a request has been fully written + * to a broker TCP connections socket. + * + * @param rk The client instance. + * @param sockfd Socket file descriptor. + * @param brokername Broker request is being sent to. + * @param brokerid Broker request is being sent to. + * @param ApiKey Kafka protocol request type. + * @param ApiVersion Kafka protocol request type version. + * @param Corrid Kafka protocol request correlation id. + * @param size Size of request. + * @param ic_opaque The interceptor's opaque pointer specified in ..add..(). + * + * @warning The on_request_sent() interceptor is called from internal + * librdkafka broker threads. An on_request_sent() interceptor MUST NOT + * call any librdkafka API's associated with the \p rk, or perform + * any blocking or prolonged work. + * + * @returns an error code on failure, the error is logged but otherwise ignored. + */ +typedef rd_kafka_resp_err_t +(rd_kafka_interceptor_f_on_request_sent_t) ( + rd_kafka_t *rk, + int sockfd, + const char *brokername, + int32_t brokerid, + int16_t ApiKey, + int16_t ApiVersion, + int32_t CorrId, + size_t size, + void *ic_opaque); + + + +/** + * @brief Append an on_conf_set() interceptor. + * + * @param conf Configuration object. + * @param ic_name Interceptor name, used in logging. + * @param on_conf_set Function pointer. + * @param ic_opaque Opaque value that will be passed to the function. + * + * @returns RD_KAFKA_RESP_ERR_NO_ERROR on success or RD_KAFKA_RESP_ERR__CONFLICT + * if an existing intercepted with the same \p ic_name and function + * has already been added to \p conf. + */ +RD_EXPORT rd_kafka_resp_err_t +rd_kafka_conf_interceptor_add_on_conf_set ( + rd_kafka_conf_t *conf, const char *ic_name, + rd_kafka_interceptor_f_on_conf_set_t *on_conf_set, + void *ic_opaque); + + +/** + * @brief Append an on_conf_dup() interceptor. + * + * @param conf Configuration object. + * @param ic_name Interceptor name, used in logging. + * @param on_conf_dup Function pointer. + * @param ic_opaque Opaque value that will be passed to the function. + * + * @returns RD_KAFKA_RESP_ERR_NO_ERROR on success or RD_KAFKA_RESP_ERR__CONFLICT + * if an existing intercepted with the same \p ic_name and function + * has already been added to \p conf. + */ +RD_EXPORT rd_kafka_resp_err_t +rd_kafka_conf_interceptor_add_on_conf_dup ( + rd_kafka_conf_t *conf, const char *ic_name, + rd_kafka_interceptor_f_on_conf_dup_t *on_conf_dup, + void *ic_opaque); + +/** + * @brief Append an on_conf_destroy() interceptor. + * + * @param conf Configuration object. + * @param ic_name Interceptor name, used in logging. + * @param on_conf_destroy Function pointer. + * @param ic_opaque Opaque value that will be passed to the function. + * + * @returns RD_KAFKA_RESP_ERR_NO_ERROR + * + * @remark Multiple on_conf_destroy() interceptors are allowed to be added + * to the same configuration object. + */ +RD_EXPORT rd_kafka_resp_err_t +rd_kafka_conf_interceptor_add_on_conf_destroy ( + rd_kafka_conf_t *conf, const char *ic_name, + rd_kafka_interceptor_f_on_conf_destroy_t *on_conf_destroy, + void *ic_opaque); + + +/** + * @brief Append an on_new() interceptor. + * + * @param conf Configuration object. + * @param ic_name Interceptor name, used in logging. + * @param on_send Function pointer. + * @param ic_opaque Opaque value that will be passed to the function. + * + * @remark Since the on_new() interceptor is added to the configuration object + * it may be copied by rd_kafka_conf_dup(). + * An interceptor implementation must thus be able to handle + * the same interceptor,ic_opaque tuple to be used by multiple + * client instances. + * + * @remark An interceptor plugin should check the return value to make sure it + * has not already been added. + * + * @returns RD_KAFKA_RESP_ERR_NO_ERROR on success or RD_KAFKA_RESP_ERR__CONFLICT + * if an existing intercepted with the same \p ic_name and function + * has already been added to \p conf. + */ +RD_EXPORT rd_kafka_resp_err_t +rd_kafka_conf_interceptor_add_on_new ( + rd_kafka_conf_t *conf, const char *ic_name, + rd_kafka_interceptor_f_on_new_t *on_new, + void *ic_opaque); + + + +/** + * @brief Append an on_destroy() interceptor. + * + * @param rk Client instance. + * @param ic_name Interceptor name, used in logging. + * @param on_destroy Function pointer. + * @param ic_opaque Opaque value that will be passed to the function. + * + * @returns RD_KAFKA_RESP_ERR_NO_ERROR on success or RD_KAFKA_RESP_ERR__CONFLICT + * if an existing intercepted with the same \p ic_name and function + * has already been added to \p conf. + */ +RD_EXPORT rd_kafka_resp_err_t +rd_kafka_interceptor_add_on_destroy ( + rd_kafka_t *rk, const char *ic_name, + rd_kafka_interceptor_f_on_destroy_t *on_destroy, + void *ic_opaque); + + +/** + * @brief Append an on_send() interceptor. + * + * @param rk Client instance. + * @param ic_name Interceptor name, used in logging. + * @param on_send Function pointer. + * @param ic_opaque Opaque value that will be passed to the function. + * + * @returns RD_KAFKA_RESP_ERR_NO_ERROR on success or RD_KAFKA_RESP_ERR__CONFLICT + * if an existing intercepted with the same \p ic_name and function + * has already been added to \p conf. + */ +RD_EXPORT rd_kafka_resp_err_t +rd_kafka_interceptor_add_on_send ( + rd_kafka_t *rk, const char *ic_name, + rd_kafka_interceptor_f_on_send_t *on_send, + void *ic_opaque); + +/** + * @brief Append an on_acknowledgement() interceptor. + * + * @param rk Client instance. + * @param ic_name Interceptor name, used in logging. + * @param on_acknowledgement Function pointer. + * @param ic_opaque Opaque value that will be passed to the function. + * + * @returns RD_KAFKA_RESP_ERR_NO_ERROR on success or RD_KAFKA_RESP_ERR__CONFLICT + * if an existing intercepted with the same \p ic_name and function + * has already been added to \p conf. + */ +RD_EXPORT rd_kafka_resp_err_t +rd_kafka_interceptor_add_on_acknowledgement ( + rd_kafka_t *rk, const char *ic_name, + rd_kafka_interceptor_f_on_acknowledgement_t *on_acknowledgement, + void *ic_opaque); + + +/** + * @brief Append an on_consume() interceptor. + * + * @param rk Client instance. + * @param ic_name Interceptor name, used in logging. + * @param on_consume Function pointer. + * @param ic_opaque Opaque value that will be passed to the function. + * + * @returns RD_KAFKA_RESP_ERR_NO_ERROR on success or RD_KAFKA_RESP_ERR__CONFLICT + * if an existing intercepted with the same \p ic_name and function + * has already been added to \p conf. + */ +RD_EXPORT rd_kafka_resp_err_t +rd_kafka_interceptor_add_on_consume ( + rd_kafka_t *rk, const char *ic_name, + rd_kafka_interceptor_f_on_consume_t *on_consume, + void *ic_opaque); + + +/** + * @brief Append an on_commit() interceptor. + * + * @param rk Client instance. + * @param ic_name Interceptor name, used in logging. + * @param on_commit() Function pointer. + * @param ic_opaque Opaque value that will be passed to the function. + * + * @returns RD_KAFKA_RESP_ERR_NO_ERROR on success or RD_KAFKA_RESP_ERR__CONFLICT + * if an existing intercepted with the same \p ic_name and function + * has already been added to \p conf. + */ +RD_EXPORT rd_kafka_resp_err_t +rd_kafka_interceptor_add_on_commit ( + rd_kafka_t *rk, const char *ic_name, + rd_kafka_interceptor_f_on_commit_t *on_commit, + void *ic_opaque); + + +/** + * @brief Append an on_request_sent() interceptor. + * + * @param rk Client instance. + * @param ic_name Interceptor name, used in logging. + * @param on_request_sent() Function pointer. + * @param ic_opaque Opaque value that will be passed to the function. + * + * @returns RD_KAFKA_RESP_ERR_NO_ERROR on success or RD_KAFKA_RESP_ERR__CONFLICT + * if an existing intercepted with the same \p ic_name and function + * has already been added to \p conf. + */ +RD_EXPORT rd_kafka_resp_err_t +rd_kafka_interceptor_add_on_request_sent ( + rd_kafka_t *rk, const char *ic_name, + rd_kafka_interceptor_f_on_request_sent_t *on_request_sent, + void *ic_opaque); + + + + +/**@}*/ + + +#ifdef __cplusplus +} +#endif |