sds size classes - memory optimization

src/Makefile

@@ -119,7 +119,7 @@ REDIS_SERVER_NAME=redis-server
 REDIS_SENTINEL_NAME=redis-sentinel
 REDIS_SERVER_OBJ=adlist.o quicklist.o ae.o anet.o dict.o redis.o sds.o zmalloc.o lzf_c.o lzf_d.o pqsort.o zipmap.o sha1.o ziplist.o release.o networking.o util.o object.o db.o replication.o rdb.o t_string.o t_list.o t_set.o t_zset.o t_hash.o config.o aof.o pubsub.o multi.o debug.o sort.o intset.o syncio.o cluster.o crc16.o endianconv.o slowlog.o scripting.o bio.o rio.o rand.o memtest.o crc64.o bitops.o sentinel.o notify.o setproctitle.o blocked.o hyperloglog.o latency.o sparkline.o redis-check-rdb.o
 REDIS_CLI_NAME=redis-cli
-REDIS_CLI_OBJ=anet.o sds.o adlist.o redis-cli.o zmalloc.o release.o anet.o ae.o crc64.o
+REDIS_CLI_OBJ=anet.o adlist.o redis-cli.o zmalloc.o release.o anet.o ae.o crc64.o
 REDIS_BENCHMARK_NAME=redis-benchmark
 REDIS_BENCHMARK_OBJ=ae.o anet.o redis-benchmark.o sds.o adlist.o zmalloc.o redis-benchmark.o
 REDIS_CHECK_RDB_NAME=redis-check-rdb

src/debug.c

@@ -423,7 +423,10 @@ void debugCommand(redisClient *c) {
         sizes = sdscatprintf(sizes,"bits:%d ", (sizeof(void*) == 8)?64:32);
         sizes = sdscatprintf(sizes,"robj:%d ", (int)sizeof(robj));
         sizes = sdscatprintf(sizes,"dictentry:%d ", (int)sizeof(dictEntry));
-        sizes = sdscatprintf(sizes,"sdshdr:%d", (int)sizeof(struct sdshdr));
+        sizes = sdscatprintf(sizes,"sdshdr8:%d", (int)sizeof(struct sdshdr8));
+        sizes = sdscatprintf(sizes,"sdshdr16:%d", (int)sizeof(struct sdshdr16));
+        sizes = sdscatprintf(sizes,"sdshdr32:%d", (int)sizeof(struct sdshdr32));
+        sizes = sdscatprintf(sizes,"sdshdr64:%d", (int)sizeof(struct sdshdr64));
         addReplyBulkSds(c,sizes);
     } else if (!strcasecmp(c->argv[1]->ptr,"jemalloc") && c->argc == 3) {
 #if defined(USE_JEMALLOC)

src/networking.c

@@ -33,21 +33,14 @@
 
 static void setProtocolError(redisClient *c, int pos);
 
-/* To evaluate the output buffer size of a client we need to get size of
- * allocated objects, however we can't used zmalloc_size() directly on sds
- * strings because of the trick they use to work (the header is before the
- * returned pointer), so we use this helper function. */
-size_t zmalloc_size_sds(sds s) {
-    return zmalloc_size(s-sizeof(struct sdshdr));
-}
 
 /* Return the amount of memory used by the sds string at object->ptr
  * for a string object. */
 size_t getStringObjectSdsUsedMemory(robj *o) {
     redisAssertWithInfo(NULL,o,o->type == REDIS_STRING);
     switch(o->encoding) {
-    case REDIS_ENCODING_RAW: return zmalloc_size_sds(o->ptr);
-    case REDIS_ENCODING_EMBSTR: return sdslen(o->ptr);
+    case REDIS_ENCODING_RAW: return sdsZmallocSize(o->ptr);
+    case REDIS_ENCODING_EMBSTR: return zmalloc_size(o)-sizeof(robj);
     default: return 0; /* Just integer encoding for now. */
     }
 }
@@ -235,10 +228,10 @@ void _addReplyObjectToList(redisClient *c, robj *o) {
             tail->encoding == REDIS_ENCODING_RAW &&
             sdslen(tail->ptr)+sdslen(o->ptr) <= REDIS_REPLY_CHUNK_BYTES)
         {
-            c->reply_bytes -= zmalloc_size_sds(tail->ptr);
+            c->reply_bytes -= sdsZmallocSize(tail->ptr);
             tail = dupLastObjectIfNeeded(c->reply);
             tail->ptr = sdscatlen(tail->ptr,o->ptr,sdslen(o->ptr));
-            c->reply_bytes += zmalloc_size_sds(tail->ptr);
+            c->reply_bytes += sdsZmallocSize(tail->ptr);
         } else {
             incrRefCount(o);
             listAddNodeTail(c->reply,o);
@@ -260,22 +253,22 @@ void _addReplySdsToList(redisClient *c, sds s) {
 
     if (listLength(c->reply) == 0) {
         listAddNodeTail(c->reply,createObject(REDIS_STRING,s));
-        c->reply_bytes += zmalloc_size_sds(s);
+        c->reply_bytes += sdsZmallocSize(s);
     } else {
         tail = listNodeValue(listLast(c->reply));
 
         /* Append to this object when possible. */
         if (tail->ptr != NULL && tail->encoding == REDIS_ENCODING_RAW &&
             sdslen(tail->ptr)+sdslen(s) <= REDIS_REPLY_CHUNK_BYTES)
         {
-            c->reply_bytes -= zmalloc_size_sds(tail->ptr);
+            c->reply_bytes -= sdsZmallocSize(tail->ptr);
             tail = dupLastObjectIfNeeded(c->reply);
             tail->ptr = sdscatlen(tail->ptr,s,sdslen(s));
-            c->reply_bytes += zmalloc_size_sds(tail->ptr);
+            c->reply_bytes += sdsZmallocSize(tail->ptr);
             sdsfree(s);
         } else {
             listAddNodeTail(c->reply,createObject(REDIS_STRING,s));
-            c->reply_bytes += zmalloc_size_sds(s);
+            c->reply_bytes += sdsZmallocSize(s);
         }
     }
     asyncCloseClientOnOutputBufferLimitReached(c);
@@ -298,10 +291,10 @@ void _addReplyStringToList(redisClient *c, const char *s, size_t len) {
         if (tail->ptr != NULL && tail->encoding == REDIS_ENCODING_RAW &&
             sdslen(tail->ptr)+len <= REDIS_REPLY_CHUNK_BYTES)
         {
-            c->reply_bytes -= zmalloc_size_sds(tail->ptr);
+            c->reply_bytes -= sdsZmallocSize(tail->ptr);
             tail = dupLastObjectIfNeeded(c->reply);
             tail->ptr = sdscatlen(tail->ptr,s,len);
-            c->reply_bytes += zmalloc_size_sds(tail->ptr);
+            c->reply_bytes += sdsZmallocSize(tail->ptr);
         } else {
             robj *o = createStringObject(s,len);
 
@@ -440,16 +433,16 @@ void setDeferredMultiBulkLength(redisClient *c, void *node, long length) {
     len = listNodeValue(ln);
     len->ptr = sdscatprintf(sdsempty(),"*%ld\r\n",length);
     len->encoding = REDIS_ENCODING_RAW; /* in case it was an EMBSTR. */
-    c->reply_bytes += zmalloc_size_sds(len->ptr);
+    c->reply_bytes += sdsZmallocSize(len->ptr);
     if (ln->next != NULL) {
         next = listNodeValue(ln->next);
 
         /* Only glue when the next node is non-NULL (an sds in this case) */
         if (next->ptr != NULL) {
-            c->reply_bytes -= zmalloc_size_sds(len->ptr);
+            c->reply_bytes -= sdsZmallocSize(len->ptr);
             c->reply_bytes -= getStringObjectSdsUsedMemory(next);
             len->ptr = sdscatlen(len->ptr,next->ptr,sdslen(next->ptr));
-            c->reply_bytes += zmalloc_size_sds(len->ptr);
+            c->reply_bytes += sdsZmallocSize(len->ptr);
             listDelNode(c->reply,ln->next);
         }
     }

src/object.c

@@ -58,8 +58,8 @@ robj *createRawStringObject(const char *ptr, size_t len) {
  * an object where the sds string is actually an unmodifiable string
  * allocated in the same chunk as the object itself. */
 robj *createEmbeddedStringObject(const char *ptr, size_t len) {
-    robj *o = zmalloc(sizeof(robj)+sizeof(struct sdshdr)+len+1);
-    struct sdshdr *sh = (void*)(o+1);
+    robj *o = zmalloc(sizeof(robj)+sizeof(struct sdshdr8)+len+1);
+    struct sdshdr8 *sh = (void*)(o+1);
 
     o->type = REDIS_STRING;
     o->encoding = REDIS_ENCODING_EMBSTR;
@@ -68,7 +68,8 @@ robj *createEmbeddedStringObject(const char *ptr, size_t len) {
     o->lru = LRU_CLOCK();
 
     sh->len = len;
-    sh->free = 0;
+    sh->alloc = len;
+    sh->flags = SDS_TYPE_8;
     if (ptr) {
         memcpy(sh->buf,ptr,len);
         sh->buf[len] = '\0';
@@ -84,7 +85,7 @@ robj *createEmbeddedStringObject(const char *ptr, size_t len) {
  *
  * The current limit of 39 is chosen so that the biggest string object
  * we allocate as EMBSTR will still fit into the 64 byte arena of jemalloc. */
-#define REDIS_ENCODING_EMBSTR_SIZE_LIMIT 39
+#define REDIS_ENCODING_EMBSTR_SIZE_LIMIT 44
 robj *createStringObject(const char *ptr, size_t len) {
     if (len <= REDIS_ENCODING_EMBSTR_SIZE_LIMIT)
         return createEmbeddedStringObject(ptr,len);

src/redis-cli.c

@@ -46,8 +46,8 @@
 #include <limits.h>
 #include <math.h>
 
-#include "hiredis.h"
-#include "sds.h"
+#include <hiredis.h>
+#include <sds.h> /* use sds.h from hiredis, so that only one set of sds functions will be present in the binary */
 #include "zmalloc.h"
 #include "linenoise.h"
 #include "help.h"

src/scripting.c

@@ -265,14 +265,11 @@ int luaRedisGenericCommand(lua_State *lua, int raise_error) {
         if (j < LUA_CMD_OBJCACHE_SIZE && cached_objects[j] &&
             cached_objects_len[j] >= obj_len)
         {
-            char *s = cached_objects[j]->ptr;
-            struct sdshdr *sh = (void*)(s-(sizeof(struct sdshdr)));
-
+            sds s = cached_objects[j]->ptr;
             argv[j] = cached_objects[j];
             cached_objects[j] = NULL;
             memcpy(s,obj_s,obj_len+1);
-            sh->free += sh->len - obj_len;
-            sh->len = obj_len;
+            sdssetlen(s, obj_len);
         } else {
             argv[j] = createStringObject(obj_s, obj_len);
         }
@@ -422,11 +419,10 @@ int luaRedisGenericCommand(lua_State *lua, int raise_error) {
              o->encoding == REDIS_ENCODING_EMBSTR) &&
             sdslen(o->ptr) <= LUA_CMD_OBJCACHE_MAX_LEN)
         {
-            struct sdshdr *sh = (void*)(((char*)(o->ptr))-(sizeof(struct sdshdr)));
-
+            sds s = o->ptr;
             if (cached_objects[j]) decrRefCount(cached_objects[j]);
             cached_objects[j] = o;
-            cached_objects_len[j] = sh->free + sh->len;
+            cached_objects_len[j] = sdsalloc(s);
         } else {
             decrRefCount(o);
         }