src/object.c

#include "redis.h"
#include <pthread.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));
    }
    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;
    }
    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) {
        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));

    zs->dict = dictCreate(&zsetDictType,NULL);
    zs->zsl = zslCreate();
    return createObject(REDIS_ZSET,zs);
}

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 = o->ptr;

    dictRelease(zs->dict);
    zslFree(zs->zsl);
    zfree(zs);
}

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) == 0) {
        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;
        }
        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);
    }
}

int checkType(redisClient *c, robj *o, int type) {
    if (o->type != type) {
        addReply(c,shared.wrongtypeerr);
        return 1;
    }
    return 0;
}

/* 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 (isStringRepresentableAsLong(s,&value) == REDIS_ERR) return o;

    /* Ok, this object can be encoded */
    if (value >= 0 && value < REDIS_SHARED_INTEGERS) {
        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') 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) {
            addReplySds(c, sdscatprintf(sdsempty(), "-ERR %s\r\n", msg));
        } else {
            addReplySds(c, sdsnew("-ERR value is not a double\r\n"));
        }
        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;
        } 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) {
            addReplySds(c, sdscatprintf(sdsempty(), "-ERR %s\r\n", msg));
        } else {
            addReplySds(c, sdsnew("-ERR value is not an integer\r\n"));
        }
        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) {
            addReplySds(c, sdscatprintf(sdsempty(), "-ERR %s\r\n", msg));
        } else {
            addReplySds(c, sdsnew("-ERR value is out of range\r\n"));
        }
        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";
    default: return "unknown";
    }
}
Commit	Line	Data
	1	#include "redis.h"
	2	#include <pthread.h>
	3
	4	robj createObject(int type, void ptr) {
	5	robj *o;
	6
	7	if (server.vm_enabled) pthread_mutex_lock(&server.obj_freelist_mutex);
	8	if (listLength(server.objfreelist)) {
	9	listNode *head = listFirst(server.objfreelist);
	10	o = listNodeValue(head);
	11	listDelNode(server.objfreelist,head);
	12	if (server.vm_enabled) pthread_mutex_unlock(&server.obj_freelist_mutex);
	13	} else {
	14	if (server.vm_enabled)
	15	pthread_mutex_unlock(&server.obj_freelist_mutex);
	16	o = zmalloc(sizeof(*o));
	17	}
	18	o->type = type;
	19	o->encoding = REDIS_ENCODING_RAW;
	20	o->ptr = ptr;
	21	o->refcount = 1;
	22	if (server.vm_enabled) {
	23	/* Note that this code may run in the context of an I/O thread
	24	* and accessing server.lruclock in theory is an error
	25	* (no locks). But in practice this is safe, and even if we read
	26	* garbage Redis will not fail. */
	27	o->lru = server.lruclock;
	28	o->storage = REDIS_VM_MEMORY;
	29	}
	30	return o;
	31	}
	32
	33	robj createStringObject(char ptr, size_t len) {
	34	return createObject(REDIS_STRING,sdsnewlen(ptr,len));
	35	}
	36
	37	robj *createStringObjectFromLongLong(long long value) {
	38	robj *o;
	39	if (value >= 0 && value < REDIS_SHARED_INTEGERS) {
	40	incrRefCount(shared.integers[value]);
	41	o = shared.integers[value];
	42	} else {
	43	if (value >= LONG_MIN && value <= LONG_MAX) {
	44	o = createObject(REDIS_STRING, NULL);
	45	o->encoding = REDIS_ENCODING_INT;
	46	o->ptr = (void*)((long)value);
	47	} else {
	48	o = createObject(REDIS_STRING,sdsfromlonglong(value));
	49	}
	50	}
	51	return o;
	52	}
	53
	54	robj dupStringObject(robj o) {
	55	redisAssert(o->encoding == REDIS_ENCODING_RAW);
	56	return createStringObject(o->ptr,sdslen(o->ptr));
	57	}
	58
	59	robj *createListObject(void) {
	60	list *l = listCreate();
	61	robj *o = createObject(REDIS_LIST,l);
	62	listSetFreeMethod(l,decrRefCount);
	63	o->encoding = REDIS_ENCODING_LINKEDLIST;
	64	return o;
	65	}
	66
	67	robj *createZiplistObject(void) {
	68	unsigned char *zl = ziplistNew();
	69	robj *o = createObject(REDIS_LIST,zl);
	70	o->encoding = REDIS_ENCODING_ZIPLIST;
	71	return o;
	72	}
	73
	74	robj *createSetObject(void) {
	75	dict *d = dictCreate(&setDictType,NULL);
	76	robj *o = createObject(REDIS_SET,d);
	77	o->encoding = REDIS_ENCODING_HT;
	78	return o;
	79	}
	80
	81	robj *createIntsetObject(void) {
	82	intset *is = intsetNew();
	83	robj *o = createObject(REDIS_SET,is);
	84	o->encoding = REDIS_ENCODING_INTSET;
	85	return o;
	86	}
	87
	88	robj *createHashObject(void) {
	89	/* All the Hashes start as zipmaps. Will be automatically converted
	90	* into hash tables if there are enough elements or big elements
	91	* inside. */
	92	unsigned char *zm = zipmapNew();
	93	robj *o = createObject(REDIS_HASH,zm);
	94	o->encoding = REDIS_ENCODING_ZIPMAP;
	95	return o;
	96	}
	97
	98	robj *createZsetObject(void) {
	99	zset zs = zmalloc(sizeof(zs));
	100
	101	zs->dict = dictCreate(&zsetDictType,NULL);
	102	zs->zsl = zslCreate();
	103	return createObject(REDIS_ZSET,zs);
	104	}
	105
	106	void freeStringObject(robj *o) {
	107	if (o->encoding == REDIS_ENCODING_RAW) {
	108	sdsfree(o->ptr);
	109	}
	110	}
	111
	112	void freeListObject(robj *o) {
	113	switch (o->encoding) {
	114	case REDIS_ENCODING_LINKEDLIST:
	115	listRelease((list*) o->ptr);
	116	break;
	117	case REDIS_ENCODING_ZIPLIST:
	118	zfree(o->ptr);
	119	break;
	120	default:
	121	redisPanic("Unknown list encoding type");
	122	}
	123	}
	124
	125	void freeSetObject(robj *o) {
	126	switch (o->encoding) {
	127	case REDIS_ENCODING_HT:
	128	dictRelease((dict*) o->ptr);
	129	break;
	130	case REDIS_ENCODING_INTSET:
	131	zfree(o->ptr);
	132	break;
	133	default:
	134	redisPanic("Unknown set encoding type");
	135	}
	136	}
	137
	138	void freeZsetObject(robj *o) {
	139	zset *zs = o->ptr;
	140
	141	dictRelease(zs->dict);
	142	zslFree(zs->zsl);
	143	zfree(zs);
	144	}
	145
	146	void freeHashObject(robj *o) {
	147	switch (o->encoding) {
	148	case REDIS_ENCODING_HT:
	149	dictRelease((dict*) o->ptr);
	150	break;
	151	case REDIS_ENCODING_ZIPMAP:
	152	zfree(o->ptr);
	153	break;
	154	default:
	155	redisPanic("Unknown hash encoding type");
	156	break;
	157	}
	158	}
	159
	160	void incrRefCount(robj *o) {
	161	o->refcount++;
	162	}
	163
	164	void decrRefCount(void *obj) {
	165	robj *o = obj;
	166
	167	/* Object is a swapped out value, or in the process of being loaded. */
	168	if (server.vm_enabled &&
	169	(o->storage == REDIS_VM_SWAPPED \|\| o->storage == REDIS_VM_LOADING))
	170	{
	171	vmpointer *vp = obj;
	172	if (o->storage == REDIS_VM_LOADING) vmCancelThreadedIOJob(o);
	173	vmMarkPagesFree(vp->page,vp->usedpages);
	174	server.vm_stats_swapped_objects--;
	175	zfree(vp);
	176	return;
	177	}
	178
	179	if (o->refcount <= 0) redisPanic("decrRefCount against refcount <= 0");
	180	/* Object is in memory, or in the process of being swapped out.
	181	*
	182	* If the object is being swapped out, abort the operation on
	183	* decrRefCount even if the refcount does not drop to 0: the object
	184	* is referenced at least two times, as value of the key AND as
	185	* job->val in the iojob. So if we don't invalidate the iojob, when it is
	186	* done but the relevant key was removed in the meantime, the
	187	* complete jobs handler will not find the key about the job and the
	188	* assert will fail. */
	189	if (server.vm_enabled && o->storage == REDIS_VM_SWAPPING)
	190	vmCancelThreadedIOJob(o);
	191	if (--(o->refcount) == 0) {
	192	switch(o->type) {
	193	case REDIS_STRING: freeStringObject(o); break;
	194	case REDIS_LIST: freeListObject(o); break;
	195	case REDIS_SET: freeSetObject(o); break;
	196	case REDIS_ZSET: freeZsetObject(o); break;
	197	case REDIS_HASH: freeHashObject(o); break;
	198	default: redisPanic("Unknown object type"); break;
	199	}
	200	if (server.vm_enabled) pthread_mutex_lock(&server.obj_freelist_mutex);
	201	if (listLength(server.objfreelist) > REDIS_OBJFREELIST_MAX \|\|
	202	!listAddNodeHead(server.objfreelist,o))
	203	zfree(o);
	204	if (server.vm_enabled) pthread_mutex_unlock(&server.obj_freelist_mutex);
	205	}
	206	}
	207
	208	int checkType(redisClient c, robj o, int type) {
	209	if (o->type != type) {
	210	addReply(c,shared.wrongtypeerr);
	211	return 1;
	212	}
	213	return 0;
	214	}
	215
	216	/* Try to encode a string object in order to save space */
	217	robj tryObjectEncoding(robj o) {
	218	long value;
	219	sds s = o->ptr;
	220
	221	if (o->encoding != REDIS_ENCODING_RAW)
	222	return o; /* Already encoded */
	223
	224	/* It's not safe to encode shared objects: shared objects can be shared
	225	* everywhere in the "object space" of Redis. Encoded objects can only
	226	* appear as "values" (and not, for instance, as keys) */
	227	if (o->refcount > 1) return o;
	228
	229	/* Currently we try to encode only strings */
	230	redisAssert(o->type == REDIS_STRING);
	231
	232	/* Check if we can represent this string as a long integer */
	233	if (isStringRepresentableAsLong(s,&value) == REDIS_ERR) return o;
	234
	235	/* Ok, this object can be encoded */
	236	if (value >= 0 && value < REDIS_SHARED_INTEGERS) {
	237	decrRefCount(o);
	238	incrRefCount(shared.integers[value]);
	239	return shared.integers[value];
	240	} else {
	241	o->encoding = REDIS_ENCODING_INT;
	242	sdsfree(o->ptr);
	243	o->ptr = (void*) value;
	244	return o;
	245	}
	246	}
	247
	248	/* Get a decoded version of an encoded object (returned as a new object).
	249	* If the object is already raw-encoded just increment the ref count. */
	250	robj getDecodedObject(robj o) {
	251	robj *dec;
	252
	253	if (o->encoding == REDIS_ENCODING_RAW) {
	254	incrRefCount(o);
	255	return o;
	256	}
	257	if (o->type == REDIS_STRING && o->encoding == REDIS_ENCODING_INT) {
	258	char buf[32];
	259
	260	ll2string(buf,32,(long)o->ptr);
	261	dec = createStringObject(buf,strlen(buf));
	262	return dec;
	263	} else {
	264	redisPanic("Unknown encoding type");
	265	}
	266	}
	267
	268	/* Compare two string objects via strcmp() or alike.
	269	* Note that the objects may be integer-encoded. In such a case we
	270	* use ll2string() to get a string representation of the numbers on the stack
	271	* and compare the strings, it's much faster than calling getDecodedObject().
	272	*
	273	* Important note: if objects are not integer encoded, but binary-safe strings,
	274	* sdscmp() from sds.c will apply memcmp() so this function ca be considered
	275	* binary safe. */
	276	int compareStringObjects(robj a, robj b) {
	277	redisAssert(a->type == REDIS_STRING && b->type == REDIS_STRING);
	278	char bufa[128], bufb[128], astr, bstr;
	279	int bothsds = 1;
	280
	281	if (a == b) return 0;
	282	if (a->encoding != REDIS_ENCODING_RAW) {
	283	ll2string(bufa,sizeof(bufa),(long) a->ptr);
	284	astr = bufa;
	285	bothsds = 0;
	286	} else {
	287	astr = a->ptr;
	288	}
	289	if (b->encoding != REDIS_ENCODING_RAW) {
	290	ll2string(bufb,sizeof(bufb),(long) b->ptr);
	291	bstr = bufb;
	292	bothsds = 0;
	293	} else {
	294	bstr = b->ptr;
	295	}
	296	return bothsds ? sdscmp(astr,bstr) : strcmp(astr,bstr);
	297	}
	298
	299	/* Equal string objects return 1 if the two objects are the same from the
	300	* point of view of a string comparison, otherwise 0 is returned. Note that
	301	* this function is faster then checking for (compareStringObject(a,b) == 0)
	302	* because it can perform some more optimization. */
	303	int equalStringObjects(robj a, robj b) {
	304	if (a->encoding != REDIS_ENCODING_RAW && b->encoding != REDIS_ENCODING_RAW){
	305	return a->ptr == b->ptr;
	306	} else {
	307	return compareStringObjects(a,b) == 0;
	308	}
	309	}
	310
	311	size_t stringObjectLen(robj *o) {
	312	redisAssert(o->type == REDIS_STRING);
	313	if (o->encoding == REDIS_ENCODING_RAW) {
	314	return sdslen(o->ptr);
	315	} else {
	316	char buf[32];
	317
	318	return ll2string(buf,32,(long)o->ptr);
	319	}
	320	}
	321
	322	int getDoubleFromObject(robj o, double target) {
	323	double value;
	324	char *eptr;
	325
	326	if (o == NULL) {
	327	value = 0;
	328	} else {
	329	redisAssert(o->type == REDIS_STRING);
	330	if (o->encoding == REDIS_ENCODING_RAW) {
	331	value = strtod(o->ptr, &eptr);
	332	if (eptr[0] != '\0') return REDIS_ERR;
	333	} else if (o->encoding == REDIS_ENCODING_INT) {
	334	value = (long)o->ptr;
	335	} else {
	336	redisPanic("Unknown string encoding");
	337	}
	338	}
	339
	340	*target = value;
	341	return REDIS_OK;
	342	}
	343
	344	int getDoubleFromObjectOrReply(redisClient c, robj o, double target, const char msg) {
	345	double value;
	346	if (getDoubleFromObject(o, &value) != REDIS_OK) {
	347	if (msg != NULL) {
	348	addReplySds(c, sdscatprintf(sdsempty(), "-ERR %s\r\n", msg));
	349	} else {
	350	addReplySds(c, sdsnew("-ERR value is not a double\r\n"));
	351	}
	352	return REDIS_ERR;
	353	}
	354
	355	*target = value;
	356	return REDIS_OK;
	357	}
	358
	359	int getLongLongFromObject(robj o, long long target) {
	360	long long value;
	361	char *eptr;
	362
	363	if (o == NULL) {
	364	value = 0;
	365	} else {
	366	redisAssert(o->type == REDIS_STRING);
	367	if (o->encoding == REDIS_ENCODING_RAW) {
	368	value = strtoll(o->ptr, &eptr, 10);
	369	if (eptr[0] != '\0') return REDIS_ERR;
	370	} else if (o->encoding == REDIS_ENCODING_INT) {
	371	value = (long)o->ptr;
	372	} else {
	373	redisPanic("Unknown string encoding");
	374	}
	375	}
	376
	377	if (target) *target = value;
	378	return REDIS_OK;
	379	}
	380
	381	int getLongLongFromObjectOrReply(redisClient c, robj o, long long target, const char msg) {
	382	long long value;
	383	if (getLongLongFromObject(o, &value) != REDIS_OK) {
	384	if (msg != NULL) {
	385	addReplySds(c, sdscatprintf(sdsempty(), "-ERR %s\r\n", msg));
	386	} else {
	387	addReplySds(c, sdsnew("-ERR value is not an integer\r\n"));
	388	}
	389	return REDIS_ERR;
	390	}
	391
	392	*target = value;
	393	return REDIS_OK;
	394	}
	395
	396	int getLongFromObjectOrReply(redisClient c, robj o, long target, const char msg) {
	397	long long value;
	398
	399	if (getLongLongFromObjectOrReply(c, o, &value, msg) != REDIS_OK) return REDIS_ERR;
	400	if (value < LONG_MIN \|\| value > LONG_MAX) {
	401	if (msg != NULL) {
	402	addReplySds(c, sdscatprintf(sdsempty(), "-ERR %s\r\n", msg));
	403	} else {
	404	addReplySds(c, sdsnew("-ERR value is out of range\r\n"));
	405	}
	406	return REDIS_ERR;
	407	}
	408
	409	*target = value;
	410	return REDIS_OK;
	411	}
	412
	413	char *strEncoding(int encoding) {
	414	switch(encoding) {
	415	case REDIS_ENCODING_RAW: return "raw";
	416	case REDIS_ENCODING_INT: return "int";
	417	case REDIS_ENCODING_HT: return "hashtable";
	418	case REDIS_ENCODING_ZIPMAP: return "zipmap";
	419	case REDIS_ENCODING_LINKEDLIST: return "linkedlist";
	420	case REDIS_ENCODING_ZIPLIST: return "ziplist";
	421	case REDIS_ENCODING_INTSET: return "intset";
	422	default: return "unknown";
	423	}
	424	}