performance: enable uthash bloom filter

2 files changed, 12 insertions, 0 deletions

diff --git a/src/cells/heavy_keeper.c b/src/cells/heavy_keeper.c
index eff0c78..ee21c2a 100644
--- a/src/cells/heavy_keeper.c
+++ b/src/cells/heavy_keeper.c
@@ -19,6 +19,9 @@
             hashv = XXH3_64bits(keyptr, keylen); \
         } while (0)
 
+#define HASH_BLOOM 16 // https://troydhanson.github.io/uthash/userguide.html#_bloom_filter_faster_misses
+// Reasonable values for the size of the Bloom filter are 16-32 bits. Since heavy keeper often has items less than 1000, 16 bits is fairly enough.
+
 #include "uthash.h"
 
 #include "exdata.h"
diff --git a/src/cells/spread_sketch.c b/src/cells/spread_sketch.c
index c2dee92..8e98f80 100644
--- a/src/cells/spread_sketch.c
+++ b/src/cells/spread_sketch.c
@@ -6,6 +6,15 @@
 #include <assert.h>
 
 #include "xxhash/xxhash.h"
+
+// XXHASH is faster for long string keys
+#define HASH_FUNCTION(keyptr, keylen, hashv) \
+        do { \
+            hashv = XXH3_64bits(keyptr, keylen); \
+        } while (0)
+#define HASH_BLOOM 16 // https://troydhanson.github.io/uthash/userguide.html#_bloom_filter_faster_misses
+// Reasonable values for the size of the Bloom filter are 16-32 bits. Since cube often has items less than 1000, 16 bits is fairly enough.
+
 #include "uthash.h"
 
 #include "spread_sketch.h"