README more specific about tcmalloc space benefits

[redis.git] / src / object.c

diff --git a/src/object.c b/src/object.c
index 21268340c6d4e7e3b43766e5f405f51e5dfe8751..b1eae96329ebe59a4cdc7366d8ca0d393ed27761 100644 (file)
--- a/src/object.c
+++ b/src/object.c
@@ -19,14 +19,19 @@ robj *createObject(int type, void *ptr) {
     o->encoding = REDIS_ENCODING_RAW;
     o->ptr = ptr;
     o->refcount = 1;
-    if (server.vm_enabled) {
-        /* Note that this code may run in the context of an I/O thread
-         * and accessing server.lruclock in theory is an error
-         * (no locks). But in practice this is safe, and even if we read
-         * garbage Redis will not fail. */
-        o->lru = server.lruclock;
-        o->storage = REDIS_VM_MEMORY;
-    }
+    /* Set the LRU to the current lruclock (minutes resolution).
+     * We do this regardless of the fact VM is active as LRU is also
+     * used for the maxmemory directive when Redis is used as cache.
+     *
+     * Note that this code may run in the context of an I/O thread
+     * and accessing server.lruclock in theory is an error
+     * (no locks). But in practice this is safe, and even if we read
+     * garbage Redis will not fail. */
+    o->lru = server.lruclock;
+    /* The following is only needed if VM is active, but since the conditional
+     * is probably more costly than initializing the field it's better to
+     * have every field properly initialized anyway. */
+    o->storage = REDIS_VM_MEMORY;
     return o;
 }
 
@@ -74,7 +79,16 @@ robj *createZiplistObject(void) {
 
 robj *createSetObject(void) {
     dict *d = dictCreate(&setDictType,NULL);
-    return createObject(REDIS_SET,d);
+    robj *o = createObject(REDIS_SET,d);
+    o->encoding = REDIS_ENCODING_HT;
+    return o;
+}
+
+robj *createIntsetObject(void) {
+    intset *is = intsetNew();
+    robj *o = createObject(REDIS_SET,is);
+    o->encoding = REDIS_ENCODING_INTSET;
+    return o;
 }
 
 robj *createHashObject(void) {
@@ -115,7 +129,16 @@ void freeListObject(robj *o) {
 }
 
 void freeSetObject(robj *o) {
-    dictRelease((dict*) o->ptr);
+    switch (o->encoding) {
+    case REDIS_ENCODING_HT:
+        dictRelease((dict*) o->ptr);
+        break;
+    case REDIS_ENCODING_INTSET:
+        zfree(o->ptr);
+        break;
+    default:
+        redisPanic("Unknown set encoding type");
+    }
 }
 
 void freeZsetObject(robj *o) {
@@ -222,8 +245,12 @@ robj *tryObjectEncoding(robj *o) {
      * range and if this is the main thread, since when VM is enabled we
      * have the constraint that I/O thread should only handle non-shared
      * objects, in order to avoid race conditions (we don't have per-object
-     * locking). */
-    if (value >= 0 && value < REDIS_SHARED_INTEGERS &&
+     * locking).
+     *
+     * Note that we also avoid using shared integers when maxmemory is used
+     * because very object needs to have a private LRU field for the LRU
+     * algorithm to work well. */
+    if (server.maxmemory == 0 && value >= 0 && value < REDIS_SHARED_INTEGERS &&
         pthread_equal(pthread_self(),server.mainthread)) {
         decrRefCount(o);
         incrRefCount(shared.integers[value]);
@@ -336,9 +363,9 @@ int getDoubleFromObjectOrReply(redisClient *c, robj *o, double *target, const ch
     double value;
     if (getDoubleFromObject(o, &value) != REDIS_OK) {
         if (msg != NULL) {
-            addReplySds(c, sdscatprintf(sdsempty(), "-ERR %s\r\n", msg));
+            addReplyError(c,(char*)msg);
         } else {
-            addReplySds(c, sdsnew("-ERR value is not a double\r\n"));
+            addReplyError(c,"value is not a double");
         }
         return REDIS_ERR;
     }
@@ -358,6 +385,8 @@ int getLongLongFromObject(robj *o, long long *target) {
         if (o->encoding == REDIS_ENCODING_RAW) {
             value = strtoll(o->ptr, &eptr, 10);
             if (eptr[0] != '\0') return REDIS_ERR;
+            if (errno == ERANGE && (value == LLONG_MIN || value == LLONG_MAX))
+                return REDIS_ERR;
         } else if (o->encoding == REDIS_ENCODING_INT) {
             value = (long)o->ptr;
         } else {
@@ -365,7 +394,7 @@ int getLongLongFromObject(robj *o, long long *target) {
         }
     }
 
-    *target = value;
+    if (target) *target = value;
     return REDIS_OK;
 }
 
@@ -373,9 +402,9 @@ int getLongLongFromObjectOrReply(redisClient *c, robj *o, long long *target, con
     long long value;
     if (getLongLongFromObject(o, &value) != REDIS_OK) {
         if (msg != NULL) {
-            addReplySds(c, sdscatprintf(sdsempty(), "-ERR %s\r\n", msg));
+            addReplyError(c,(char*)msg);
         } else {
-            addReplySds(c, sdsnew("-ERR value is not an integer\r\n"));
+            addReplyError(c,"value is not an integer or out of range");
         }
         return REDIS_ERR;
     }
@@ -390,9 +419,9 @@ int getLongFromObjectOrReply(redisClient *c, robj *o, long *target, const char *
     if (getLongLongFromObjectOrReply(c, o, &value, msg) != REDIS_OK) return REDIS_ERR;
     if (value < LONG_MIN || value > LONG_MAX) {
         if (msg != NULL) {
-            addReplySds(c, sdscatprintf(sdsempty(), "-ERR %s\r\n", msg));
+            addReplyError(c,(char*)msg);
         } else {
-            addReplySds(c, sdsnew("-ERR value is out of range\r\n"));
+            addReplyError(c,"value is out of range");
         }
         return REDIS_ERR;
     }
@@ -409,6 +438,18 @@ char *strEncoding(int encoding) {
     case REDIS_ENCODING_ZIPMAP: return "zipmap";
     case REDIS_ENCODING_LINKEDLIST: return "linkedlist";
     case REDIS_ENCODING_ZIPLIST: return "ziplist";
+    case REDIS_ENCODING_INTSET: return "intset";
     default: return "unknown";
     }
 }
+
+/* Given an object returns the min number of seconds the object was never
+ * requested, using an approximated LRU algorithm. */
+unsigned long estimateObjectIdleTime(robj *o) {
+    if (server.lruclock >= o->lru) {
+        return (server.lruclock - o->lru) * REDIS_LRU_CLOCK_RESOLUTION;
+    } else {
+        return ((REDIS_LRU_CLOCK_MAX - o->lru) + server.lruclock) *
+                    REDIS_LRU_CLOCK_RESOLUTION;
+    }
+}