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authorbyte2016 <[email protected]>2018-06-12 19:55:38 +0800
committerbyte2016 <[email protected]>2018-06-12 19:55:38 +0800
commit76f2c13d7c27d7419af79ea0bdc7ab7717b6935b (patch)
treeaa2ca741501d40990b892d504a1cc3b7defe57aa /src/quicklist.h
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+/* quicklist.h - A generic doubly linked quicklist implementation
+ *
+ * Copyright (c) 2014, Matt Stancliff <[email protected]>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * * Redistributions of source code must retain the above copyright notice,
+ * this quicklist of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this quicklist of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * * Neither the name of Redis nor the names of its contributors may be used
+ * to endorse or promote products derived from this software without
+ * specific prior written permission.
+ *
+ * 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.
+ */
+
+#ifndef __QUICKLIST_H__
+#define __QUICKLIST_H__
+
+/* Node, quicklist, and Iterator are the only data structures used currently. */
+
+/* quicklistNode is a 32 byte struct describing a ziplist for a quicklist.
+ * We use bit fields keep the quicklistNode at 32 bytes.
+ * count: 16 bits, max 65536 (max zl bytes is 65k, so max count actually < 32k).
+ * encoding: 2 bits, RAW=1, LZF=2.
+ * container: 2 bits, NONE=1, ZIPLIST=2.
+ * recompress: 1 bit, bool, true if node is temporarry decompressed for usage.
+ * attempted_compress: 1 bit, boolean, used for verifying during testing.
+ * extra: 12 bits, free for future use; pads out the remainder of 32 bits */
+typedef struct quicklistNode {
+ struct quicklistNode *prev;
+ struct quicklistNode *next;
+ unsigned char *zl;
+ unsigned int sz; /* ziplist size in bytes */
+ unsigned int count : 16; /* count of items in ziplist */
+ unsigned int encoding : 2; /* RAW==1 or LZF==2 */
+ unsigned int container : 2; /* NONE==1 or ZIPLIST==2 */
+ unsigned int recompress : 1; /* was this node previous compressed? */
+ unsigned int attempted_compress : 1; /* node can't compress; too small */
+ unsigned int extra : 10; /* more bits to steal for future usage */
+} quicklistNode;
+
+/* quicklistLZF is a 4+N byte struct holding 'sz' followed by 'compressed'.
+ * 'sz' is byte length of 'compressed' field.
+ * 'compressed' is LZF data with total (compressed) length 'sz'
+ * NOTE: uncompressed length is stored in quicklistNode->sz.
+ * When quicklistNode->zl is compressed, node->zl points to a quicklistLZF */
+typedef struct quicklistLZF {
+ unsigned int sz; /* LZF size in bytes*/
+ char compressed[];
+} quicklistLZF;
+
+/* quicklist is a 32 byte struct (on 64-bit systems) describing a quicklist.
+ * 'count' is the number of total entries.
+ * 'len' is the number of quicklist nodes.
+ * 'compress' is: -1 if compression disabled, otherwise it's the number
+ * of quicklistNodes to leave uncompressed at ends of quicklist.
+ * 'fill' is the user-requested (or default) fill factor. */
+typedef struct quicklist {
+ quicklistNode *head;
+ quicklistNode *tail;
+ unsigned long count; /* total count of all entries in all ziplists */
+ unsigned int len; /* number of quicklistNodes */
+ int fill : 16; /* fill factor for individual nodes */
+ unsigned int compress : 16; /* depth of end nodes not to compress;0=off */
+} quicklist;
+
+typedef struct quicklistIter {
+ const quicklist *quicklist;
+ quicklistNode *current;
+ unsigned char *zi;
+ long offset; /* offset in current ziplist */
+ int direction;
+} quicklistIter;
+
+typedef struct quicklistEntry {
+ const quicklist *quicklist;
+ quicklistNode *node;
+ unsigned char *zi;
+ unsigned char *value;
+ long long longval;
+ unsigned int sz;
+ int offset;
+} quicklistEntry;
+
+#define QUICKLIST_HEAD 0
+#define QUICKLIST_TAIL -1
+
+/* quicklist node encodings */
+#define QUICKLIST_NODE_ENCODING_RAW 1
+#define QUICKLIST_NODE_ENCODING_LZF 2
+
+/* quicklist compression disable */
+#define QUICKLIST_NOCOMPRESS 0
+
+/* quicklist container formats */
+#define QUICKLIST_NODE_CONTAINER_NONE 1
+#define QUICKLIST_NODE_CONTAINER_ZIPLIST 2
+
+#define quicklistNodeIsCompressed(node) \
+ ((node)->encoding == QUICKLIST_NODE_ENCODING_LZF)
+
+/* Prototypes */
+quicklist *quicklistCreate(void);
+quicklist *quicklistNew(int fill, int compress);
+void quicklistSetCompressDepth(quicklist *quicklist, int depth);
+void quicklistSetFill(quicklist *quicklist, int fill);
+void quicklistSetOptions(quicklist *quicklist, int fill, int depth);
+void quicklistRelease(quicklist *quicklist);
+int quicklistPushHead(quicklist *quicklist, void *value, const size_t sz);
+int quicklistPushTail(quicklist *quicklist, void *value, const size_t sz);
+void quicklistPush(quicklist *quicklist, void *value, const size_t sz,
+ int where);
+void quicklistAppendZiplist(quicklist *quicklist, unsigned char *zl);
+quicklist *quicklistAppendValuesFromZiplist(quicklist *quicklist,
+ unsigned char *zl);
+quicklist *quicklistCreateFromZiplist(int fill, int compress,
+ unsigned char *zl);
+void quicklistInsertAfter(quicklist *quicklist, quicklistEntry *node,
+ void *value, const size_t sz);
+void quicklistInsertBefore(quicklist *quicklist, quicklistEntry *node,
+ void *value, const size_t sz);
+void quicklistDelEntry(quicklistIter *iter, quicklistEntry *entry);
+int quicklistReplaceAtIndex(quicklist *quicklist, long index, void *data,
+ int sz);
+int quicklistDelRange(quicklist *quicklist, const long start, const long stop);
+quicklistIter *quicklistGetIterator(const quicklist *quicklist, int direction);
+quicklistIter *quicklistGetIteratorAtIdx(const quicklist *quicklist,
+ int direction, const long long idx);
+int quicklistNext(quicklistIter *iter, quicklistEntry *node);
+void quicklistReleaseIterator(quicklistIter *iter);
+quicklist *quicklistDup(quicklist *orig);
+int quicklistIndex(const quicklist *quicklist, const long long index,
+ quicklistEntry *entry);
+void quicklistRewind(quicklist *quicklist, quicklistIter *li);
+void quicklistRewindTail(quicklist *quicklist, quicklistIter *li);
+void quicklistRotate(quicklist *quicklist);
+int quicklistPopCustom(quicklist *quicklist, int where, unsigned char **data,
+ unsigned int *sz, long long *sval,
+ void *(*saver)(unsigned char *data, unsigned int sz));
+int quicklistPop(quicklist *quicklist, int where, unsigned char **data,
+ unsigned int *sz, long long *slong);
+unsigned int quicklistCount(const quicklist *ql);
+int quicklistCompare(unsigned char *p1, unsigned char *p2, int p2_len);
+size_t quicklistGetLzf(const quicklistNode *node, void **data);
+
+#ifdef REDIS_TEST
+int quicklistTest(int argc, char *argv[]);
+#endif
+
+/* Directions for iterators */
+#define AL_START_HEAD 0
+#define AL_START_TAIL 1
+
+#endif /* __QUICKLIST_H__ */