#include "redis.h"
-#include <pthread.h>
#include <math.h>
robj *createObject(int type, void *ptr) {
- robj *o;
-
- if (server.vm_enabled) pthread_mutex_lock(&server.obj_freelist_mutex);
- if (listLength(server.objfreelist)) {
- listNode *head = listFirst(server.objfreelist);
- o = listNodeValue(head);
- listDelNode(server.objfreelist,head);
- if (server.vm_enabled) pthread_mutex_unlock(&server.obj_freelist_mutex);
- } else {
- if (server.vm_enabled) pthread_mutex_unlock(&server.obj_freelist_mutex);
- o = zmalloc(sizeof(*o));
- }
+ robj *o = zmalloc(sizeof(*o));
o->type = type;
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. */
return o;
}
robj *createStringObjectFromLongLong(long long value) {
robj *o;
- if (value >= 0 && value < REDIS_SHARED_INTEGERS &&
- pthread_equal(pthread_self(),server.mainthread)) {
+ if (value >= 0 && value < REDIS_SHARED_INTEGERS) {
incrRefCount(shared.integers[value]);
o = shared.integers[value];
} else {
robj *createZsetObject(void) {
zset *zs = zmalloc(sizeof(*zs));
+ robj *o;
zs->dict = dictCreate(&zsetDictType,NULL);
zs->zsl = zslCreate();
- return createObject(REDIS_ZSET,zs);
+ o = createObject(REDIS_ZSET,zs);
+ o->encoding = REDIS_ENCODING_SKIPLIST;
+ return o;
+}
+
+robj *createZsetZiplistObject(void) {
+ unsigned char *zl = ziplistNew();
+ robj *o = createObject(REDIS_ZSET,zl);
+ o->encoding = REDIS_ENCODING_ZIPLIST;
+ return o;
}
void freeStringObject(robj *o) {
}
void freeZsetObject(robj *o) {
- zset *zs = o->ptr;
-
- dictRelease(zs->dict);
- zslFree(zs->zsl);
- zfree(zs);
+ zset *zs;
+ switch (o->encoding) {
+ case REDIS_ENCODING_SKIPLIST:
+ zs = o->ptr;
+ dictRelease(zs->dict);
+ zslFree(zs->zsl);
+ zfree(zs);
+ break;
+ case REDIS_ENCODING_ZIPLIST:
+ zfree(o->ptr);
+ break;
+ default:
+ redisPanic("Unknown sorted set encoding");
+ }
}
void freeHashObject(robj *o) {
void decrRefCount(void *obj) {
robj *o = obj;
- /* Object is a swapped out value, or in the process of being loaded. */
- if (server.vm_enabled &&
- (o->storage == REDIS_VM_SWAPPED || o->storage == REDIS_VM_LOADING))
- {
- vmpointer *vp = obj;
- if (o->storage == REDIS_VM_LOADING) vmCancelThreadedIOJob(o);
- vmMarkPagesFree(vp->page,vp->usedpages);
- server.vm_stats_swapped_objects--;
- zfree(vp);
- return;
- }
-
if (o->refcount <= 0) redisPanic("decrRefCount against refcount <= 0");
- /* Object is in memory, or in the process of being swapped out.
- *
- * If the object is being swapped out, abort the operation on
- * decrRefCount even if the refcount does not drop to 0: the object
- * is referenced at least two times, as value of the key AND as
- * job->val in the iojob. So if we don't invalidate the iojob, when it is
- * done but the relevant key was removed in the meantime, the
- * complete jobs handler will not find the key about the job and the
- * assert will fail. */
- if (server.vm_enabled && o->storage == REDIS_VM_SWAPPING)
- vmCancelThreadedIOJob(o);
- if (--(o->refcount) == 0) {
+ if (o->refcount == 1) {
switch(o->type) {
case REDIS_STRING: freeStringObject(o); break;
case REDIS_LIST: freeListObject(o); break;
case REDIS_HASH: freeHashObject(o); break;
default: redisPanic("Unknown object type"); break;
}
- o->ptr = NULL; /* defensive programming. We'll see NULL in traces. */
- if (server.vm_enabled) pthread_mutex_lock(&server.obj_freelist_mutex);
- if (listLength(server.objfreelist) > REDIS_OBJFREELIST_MAX ||
- !listAddNodeHead(server.objfreelist,o))
- zfree(o);
- if (server.vm_enabled) pthread_mutex_unlock(&server.obj_freelist_mutex);
+ zfree(o);
+ } else {
+ o->refcount--;
}
}
+/* This function set the ref count to zero without freeing the object.
+ * It is useful in order to pass a new object to functions incrementing
+ * the ref count of the received object. Example:
+ *
+ * functionThatWillIncrementRefCount(resetRefCount(CreateObject(...)));
+ *
+ * Otherwise you need to resort to the less elegant pattern:
+ *
+ * *obj = createObject(...);
+ * functionThatWillIncrementRefCount(obj);
+ * decrRefCount(obj);
+ */
+robj *resetRefCount(robj *obj) {
+ obj->refcount = 0;
+ return obj;
+}
+
int checkType(redisClient *c, robj *o, int type) {
if (o->type != type) {
addReply(c,shared.wrongtypeerr);
return 0;
}
+int isObjectRepresentableAsLongLong(robj *o, long long *llval) {
+ redisAssert(o->type == REDIS_STRING);
+ if (o->encoding == REDIS_ENCODING_INT) {
+ if (llval) *llval = (long) o->ptr;
+ return REDIS_OK;
+ } else {
+ return string2ll(o->ptr,sdslen(o->ptr),llval) ? REDIS_OK : REDIS_ERR;
+ }
+}
+
/* Try to encode a string object in order to save space */
robj *tryObjectEncoding(robj *o) {
long value;
redisAssert(o->type == REDIS_STRING);
/* Check if we can represent this string as a long integer */
- if (isStringRepresentableAsLong(s,&value) == REDIS_ERR) return o;
+ if (!string2l(s,sdslen(s),&value)) return o;
/* Ok, this object can be encoded...
*
* Can I use a shared object? Only if the object is inside a given
- * 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 &&
- pthread_equal(pthread_self(),server.mainthread)) {
+ * range and if the back end in use is in-memory. For disk store every
+ * object in memory used as value should be independent.
+ *
+ * Note that we also avoid using shared integers when maxmemory is used
+ * because every 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) {
decrRefCount(o);
incrRefCount(shared.integers[value]);
return shared.integers[value];
case REDIS_ENCODING_LINKEDLIST: return "linkedlist";
case REDIS_ENCODING_ZIPLIST: return "ziplist";
case REDIS_ENCODING_INTSET: return "intset";
+ case REDIS_ENCODING_SKIPLIST: return "skiplist";
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;
+ }
+}
+
+/* This is an helper function for the DEBUG command. We need to lookup keys
+ * without any modification of LRU or other parameters. */
+robj *objectCommandLookup(redisClient *c, robj *key) {
+ dictEntry *de;
+
+ if ((de = dictFind(c->db->dict,key->ptr)) == NULL) return NULL;
+ return (robj*) dictGetEntryVal(de);
+}
+
+robj *objectCommandLookupOrReply(redisClient *c, robj *key, robj *reply) {
+ robj *o = objectCommandLookup(c,key);
+
+ if (!o) addReply(c, reply);
+ return o;
+}
+
+/* Object command allows to inspect the internals of an Redis Object.
+ * Usage: OBJECT <verb> ... arguments ... */
+void objectCommand(redisClient *c) {
+ robj *o;
+
+ if (!strcasecmp(c->argv[1]->ptr,"refcount") && c->argc == 3) {
+ if ((o = objectCommandLookupOrReply(c,c->argv[2],shared.nullbulk))
+ == NULL) return;
+ addReplyLongLong(c,o->refcount);
+ } else if (!strcasecmp(c->argv[1]->ptr,"encoding") && c->argc == 3) {
+ if ((o = objectCommandLookupOrReply(c,c->argv[2],shared.nullbulk))
+ == NULL) return;
+ addReplyBulkCString(c,strEncoding(o->encoding));
+ } else if (!strcasecmp(c->argv[1]->ptr,"idletime") && c->argc == 3) {
+ if ((o = objectCommandLookupOrReply(c,c->argv[2],shared.nullbulk))
+ == NULL) return;
+ addReplyLongLong(c,estimateObjectIdleTime(o));
+ } else {
+ addReplyError(c,"Syntax error. Try OBJECT (refcount|encoding|idletime)");
+ }
+}
+
projects / redis.git / blobdiff