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#include "redis.h"
#include <pthread.h>
#include <math.h>
robj *createObject(int type, void *ptr) {
robj *o = zmalloc(sizeof(*o));
o->type = type;
o->encoding = REDIS_ENCODING_RAW;
o->ptr = ptr;
o->refcount = 1;
/* 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;
}
robj *createStringObject(char *ptr, size_t len) {
return createObject(REDIS_STRING,sdsnewlen(ptr,len));
}
robj *createStringObjectFromLongLong(long long value) {
robj *o;
if (value >= 0 && value < REDIS_SHARED_INTEGERS &&
pthread_equal(pthread_self(),server.mainthread)) {
incrRefCount(shared.integers[value]);
o = shared.integers[value];
} else {
if (value >= LONG_MIN && value <= LONG_MAX) {
o = createObject(REDIS_STRING, NULL);
o->encoding = REDIS_ENCODING_INT;
o->ptr = (void*)((long)value);
} else {
o = createObject(REDIS_STRING,sdsfromlonglong(value));
}
}
return o;
}
robj *dupStringObject(robj *o) {
redisAssert(o->encoding == REDIS_ENCODING_RAW);
return createStringObject(o->ptr,sdslen(o->ptr));
}
robj *createListObject(void) {
list *l = listCreate();
robj *o = createObject(REDIS_LIST,l);
listSetFreeMethod(l,decrRefCount);
o->encoding = REDIS_ENCODING_LINKEDLIST;
return o;
}
robj *createZiplistObject(void) {
unsigned char *zl = ziplistNew();
robj *o = createObject(REDIS_LIST,zl);
o->encoding = REDIS_ENCODING_ZIPLIST;
return o;
}
robj *createSetObject(void) {
dict *d = dictCreate(&setDictType,NULL);
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) {
/* All the Hashes start as zipmaps. Will be automatically converted
* into hash tables if there are enough elements or big elements
* inside. */
unsigned char *zm = zipmapNew();
robj *o = createObject(REDIS_HASH,zm);
o->encoding = REDIS_ENCODING_ZIPMAP;
return o;
}
robj *createZsetObject(void) {
zset *zs = zmalloc(sizeof(*zs));
robj *o;
zs->dict = dictCreate(&zsetDictType,NULL);
zs->zsl = zslCreate();
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) {
if (o->encoding == REDIS_ENCODING_RAW) {
sdsfree(o->ptr);
}
}
void freeListObject(robj *o) {
switch (o->encoding) {
case REDIS_ENCODING_LINKEDLIST:
listRelease((list*) o->ptr);
break;
case REDIS_ENCODING_ZIPLIST:
zfree(o->ptr);
break;
default:
redisPanic("Unknown list encoding type");
}
}
void freeSetObject(robj *o) {
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) {
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) {
switch (o->encoding) {
case REDIS_ENCODING_HT:
dictRelease((dict*) o->ptr);
break;
case REDIS_ENCODING_ZIPMAP:
zfree(o->ptr);
break;
default:
redisPanic("Unknown hash encoding type");
break;
}
}
void incrRefCount(robj *o) {
o->refcount++;
}
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 == 1) {
switch(o->type) {
case REDIS_STRING: freeStringObject(o); break;
case REDIS_LIST: freeListObject(o); break;
case REDIS_SET: freeSetObject(o); break;
case REDIS_ZSET: freeZsetObject(o); break;
case REDIS_HASH: freeHashObject(o); break;
default: redisPanic("Unknown object type"); break;
}
zfree(o);
} else {
o->refcount--;
}
}
int checkType(redisClient *c, robj *o, int type) {
if (o->type != type) {
addReply(c,shared.wrongtypeerr);
return 1;
}
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;
sds s = o->ptr;
if (o->encoding != REDIS_ENCODING_RAW)
return o; /* Already encoded */
/* It's not safe to encode shared objects: shared objects can be shared
* everywhere in the "object space" of Redis. Encoded objects can only
* appear as "values" (and not, for instance, as keys) */
if (o->refcount > 1) return o;
/* Currently we try to encode only strings */
redisAssert(o->type == REDIS_STRING);
/* Check if we can represent this string as a long integer */
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).
*
* 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]);
return shared.integers[value];
} else {
o->encoding = REDIS_ENCODING_INT;
sdsfree(o->ptr);
o->ptr = (void*) value;
return o;
}
}
/* Get a decoded version of an encoded object (returned as a new object).
* If the object is already raw-encoded just increment the ref count. */
robj *getDecodedObject(robj *o) {
robj *dec;
if (o->encoding == REDIS_ENCODING_RAW) {
incrRefCount(o);
return o;
}
if (o->type == REDIS_STRING && o->encoding == REDIS_ENCODING_INT) {
char buf[32];
ll2string(buf,32,(long)o->ptr);
dec = createStringObject(buf,strlen(buf));
return dec;
} else {
redisPanic("Unknown encoding type");
}
}
/* Compare two string objects via strcmp() or alike.
* Note that the objects may be integer-encoded. In such a case we
* use ll2string() to get a string representation of the numbers on the stack
* and compare the strings, it's much faster than calling getDecodedObject().
*
* Important note: if objects are not integer encoded, but binary-safe strings,
* sdscmp() from sds.c will apply memcmp() so this function ca be considered
* binary safe. */
int compareStringObjects(robj *a, robj *b) {
redisAssert(a->type == REDIS_STRING && b->type == REDIS_STRING);
char bufa[128], bufb[128], *astr, *bstr;
int bothsds = 1;
if (a == b) return 0;
if (a->encoding != REDIS_ENCODING_RAW) {
ll2string(bufa,sizeof(bufa),(long) a->ptr);
astr = bufa;
bothsds = 0;
} else {
astr = a->ptr;
}
if (b->encoding != REDIS_ENCODING_RAW) {
ll2string(bufb,sizeof(bufb),(long) b->ptr);
bstr = bufb;
bothsds = 0;
} else {
bstr = b->ptr;
}
return bothsds ? sdscmp(astr,bstr) : strcmp(astr,bstr);
}
/* Equal string objects return 1 if the two objects are the same from the
* point of view of a string comparison, otherwise 0 is returned. Note that
* this function is faster then checking for (compareStringObject(a,b) == 0)
* because it can perform some more optimization. */
int equalStringObjects(robj *a, robj *b) {
if (a->encoding != REDIS_ENCODING_RAW && b->encoding != REDIS_ENCODING_RAW){
return a->ptr == b->ptr;
} else {
return compareStringObjects(a,b) == 0;
}
}
size_t stringObjectLen(robj *o) {
redisAssert(o->type == REDIS_STRING);
if (o->encoding == REDIS_ENCODING_RAW) {
return sdslen(o->ptr);
} else {
char buf[32];
return ll2string(buf,32,(long)o->ptr);
}
}
int getDoubleFromObject(robj *o, double *target) {
double value;
char *eptr;
if (o == NULL) {
value = 0;
} else {
redisAssert(o->type == REDIS_STRING);
if (o->encoding == REDIS_ENCODING_RAW) {
value = strtod(o->ptr, &eptr);
if (eptr[0] != '\0' || isnan(value)) return REDIS_ERR;
} else if (o->encoding == REDIS_ENCODING_INT) {
value = (long)o->ptr;
} else {
redisPanic("Unknown string encoding");
}
}
*target = value;
return REDIS_OK;
}
int getDoubleFromObjectOrReply(redisClient *c, robj *o, double *target, const char *msg) {
double value;
if (getDoubleFromObject(o, &value) != REDIS_OK) {
if (msg != NULL) {
addReplyError(c,(char*)msg);
} else {
addReplyError(c,"value is not a double");
}
return REDIS_ERR;
}
*target = value;
return REDIS_OK;
}
int getLongLongFromObject(robj *o, long long *target) {
long long value;
char *eptr;
if (o == NULL) {
value = 0;
} else {
redisAssert(o->type == REDIS_STRING);
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 {
redisPanic("Unknown string encoding");
}
}
if (target) *target = value;
return REDIS_OK;
}
int getLongLongFromObjectOrReply(redisClient *c, robj *o, long long *target, const char *msg) {
long long value;
if (getLongLongFromObject(o, &value) != REDIS_OK) {
if (msg != NULL) {
addReplyError(c,(char*)msg);
} else {
addReplyError(c,"value is not an integer or out of range");
}
return REDIS_ERR;
}
*target = value;
return REDIS_OK;
}
int getLongFromObjectOrReply(redisClient *c, robj *o, long *target, const char *msg) {
long long value;
if (getLongLongFromObjectOrReply(c, o, &value, msg) != REDIS_OK) return REDIS_ERR;
if (value < LONG_MIN || value > LONG_MAX) {
if (msg != NULL) {
addReplyError(c,(char*)msg);
} else {
addReplyError(c,"value is out of range");
}
return REDIS_ERR;
}
*target = value;
return REDIS_OK;
}
char *strEncoding(int encoding) {
switch(encoding) {
case REDIS_ENCODING_RAW: return "raw";
case REDIS_ENCODING_INT: return "int";
case REDIS_ENCODING_HT: return "hashtable";
case REDIS_ENCODING_ZIPMAP: return "zipmap";
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 (server.vm_enabled) lookupKeyRead(c->db,key);
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)");
}
}
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