[redis.git] / src / object.c

#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. */
    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 &&
        !server.ds_enabled &&
        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));
    zs->dict = dictCreate(&zsetDictType,NULL);
    zs->zsl = zslCreate();
    return createObject(REDIS_ZSET,zs);
}

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_RAW:
        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;

    if (o->refcount <= 0) redisPanic("decrRefCount against refcount <= 0");
    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;
        }
        o->ptr = NULL; /* defensive programming. We'll see NULL in traces. */
        zfree(o);
    }
}

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...
     *
     * Can I use a shared object? Only if the object is inside a given
     * 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.ds_enabled &&
        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";
    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;
    }
}
Commit	Line	Data
e2641e09	1	#include "redis.h"
e2641e09	2	#include <pthread.h>
673e1fb7	3	#include <math.h>
e2641e09	4
e2641e09	5	robj createObject(int type, void ptr) {
a9b18e54	6	robj o = zmalloc(sizeof(o));
e2641e09	7	o->type = type;
	8	o->encoding = REDIS_ENCODING_RAW;
	9	o->ptr = ptr;
	10	o->refcount = 1;
a9b18e54	11
ef59a8bc	12	/* Set the LRU to the current lruclock (minutes resolution).
	13	* We do this regardless of the fact VM is active as LRU is also
	14	* used for the maxmemory directive when Redis is used as cache.
	15	*
	16	* Note that this code may run in the context of an I/O thread
	17	* and accessing server.lruclock in theory is an error
	18	* (no locks). But in practice this is safe, and even if we read
	19	* garbage Redis will not fail. */
	20	o->lru = server.lruclock;
	21	/* The following is only needed if VM is active, but since the conditional
	22	* is probably more costly than initializing the field it's better to
	23	* have every field properly initialized anyway. */
e2641e09	24	return o;
	25	}
	26
	27	robj createStringObject(char ptr, size_t len) {
	28	return createObject(REDIS_STRING,sdsnewlen(ptr,len));
	29	}
	30
	31	robj *createStringObjectFromLongLong(long long value) {
	32	robj *o;
e002ec68	33	if (value >= 0 && value < REDIS_SHARED_INTEGERS &&
98a9abb6	34	!server.ds_enabled &&
e002ec68	35	pthread_equal(pthread_self(),server.mainthread)) {
e2641e09	36	incrRefCount(shared.integers[value]);
	37	o = shared.integers[value];
	38	} else {
	39	if (value >= LONG_MIN && value <= LONG_MAX) {
	40	o = createObject(REDIS_STRING, NULL);
	41	o->encoding = REDIS_ENCODING_INT;
	42	o->ptr = (void*)((long)value);
	43	} else {
	44	o = createObject(REDIS_STRING,sdsfromlonglong(value));
	45	}
	46	}
	47	return o;
	48	}
	49
	50	robj dupStringObject(robj o) {
	51	redisAssert(o->encoding == REDIS_ENCODING_RAW);
	52	return createStringObject(o->ptr,sdslen(o->ptr));
	53	}
	54
	55	robj *createListObject(void) {
	56	list *l = listCreate();
	57	robj *o = createObject(REDIS_LIST,l);
	58	listSetFreeMethod(l,decrRefCount);
	59	o->encoding = REDIS_ENCODING_LINKEDLIST;
	60	return o;
	61	}
	62
	63	robj *createZiplistObject(void) {
	64	unsigned char *zl = ziplistNew();
	65	robj *o = createObject(REDIS_LIST,zl);
	66	o->encoding = REDIS_ENCODING_ZIPLIST;
	67	return o;
	68	}
	69
	70	robj *createSetObject(void) {
	71	dict *d = dictCreate(&setDictType,NULL);
96ffb2fe PN	72	robj *o = createObject(REDIS_SET,d);
	73	o->encoding = REDIS_ENCODING_HT;
	74	return o;
	75	}
	76
	77	robj *createIntsetObject(void) {
	78	intset *is = intsetNew();
	79	robj *o = createObject(REDIS_SET,is);
	80	o->encoding = REDIS_ENCODING_INTSET;
	81	return o;
e2641e09	82	}
	83
	84	robj *createHashObject(void) {
	85	/* All the Hashes start as zipmaps. Will be automatically converted
	86	* into hash tables if there are enough elements or big elements
	87	* inside. */
	88	unsigned char *zm = zipmapNew();
	89	robj *o = createObject(REDIS_HASH,zm);
	90	o->encoding = REDIS_ENCODING_ZIPMAP;
	91	return o;
	92	}
	93
	94	robj *createZsetObject(void) {
	95	zset zs = zmalloc(sizeof(zs));
e2641e09	96	zs->dict = dictCreate(&zsetDictType,NULL);
	97	zs->zsl = zslCreate();
	98	return createObject(REDIS_ZSET,zs);
	99	}
	100
9e7cee0e PN	101	robj *createZsetZiplistObject(void) {
	102	unsigned char *zl = ziplistNew();
	103	robj *o = createObject(REDIS_ZSET,zl);
	104	o->encoding = REDIS_ENCODING_ZIPLIST;
	105	return o;
	106	}
	107
e2641e09	108	void freeStringObject(robj *o) {
	109	if (o->encoding == REDIS_ENCODING_RAW) {
	110	sdsfree(o->ptr);
	111	}
	112	}
	113
	114	void freeListObject(robj *o) {
	115	switch (o->encoding) {
	116	case REDIS_ENCODING_LINKEDLIST:
	117	listRelease((list*) o->ptr);
	118	break;
	119	case REDIS_ENCODING_ZIPLIST:
	120	zfree(o->ptr);
	121	break;
	122	default:
	123	redisPanic("Unknown list encoding type");
	124	}
	125	}
	126
	127	void freeSetObject(robj *o) {
96ffb2fe PN	128	switch (o->encoding) {
	129	case REDIS_ENCODING_HT:
	130	dictRelease((dict*) o->ptr);
	131	break;
	132	case REDIS_ENCODING_INTSET:
	133	zfree(o->ptr);
	134	break;
	135	default:
	136	redisPanic("Unknown set encoding type");
	137	}
e2641e09	138	}
	139
	140	void freeZsetObject(robj *o) {
0f23eb3b PN	141	zset *zs;
	142	switch (o->encoding) {
	143	case REDIS_ENCODING_RAW:
	144	zs = o->ptr;
	145	dictRelease(zs->dict);
	146	zslFree(zs->zsl);
	147	zfree(zs);
	148	break;
	149	case REDIS_ENCODING_ZIPLIST:
	150	zfree(o->ptr);
	151	break;
	152	default:
	153	redisPanic("Unknown sorted set encoding");
	154	}
e2641e09	155	}
	156
	157	void freeHashObject(robj *o) {
	158	switch (o->encoding) {
	159	case REDIS_ENCODING_HT:
	160	dictRelease((dict*) o->ptr);
	161	break;
	162	case REDIS_ENCODING_ZIPMAP:
	163	zfree(o->ptr);
	164	break;
	165	default:
	166	redisPanic("Unknown hash encoding type");
	167	break;
	168	}
	169	}
	170
	171	void incrRefCount(robj *o) {
	172	o->refcount++;
	173	}
	174
	175	void decrRefCount(void *obj) {
	176	robj *o = obj;
	177
e2641e09	178	if (o->refcount <= 0) redisPanic("decrRefCount against refcount <= 0");
e2641e09	179	if (--(o->refcount) == 0) {
	180	switch(o->type) {
	181	case REDIS_STRING: freeStringObject(o); break;
	182	case REDIS_LIST: freeListObject(o); break;
	183	case REDIS_SET: freeSetObject(o); break;
	184	case REDIS_ZSET: freeZsetObject(o); break;
	185	case REDIS_HASH: freeHashObject(o); break;
	186	default: redisPanic("Unknown object type"); break;
	187	}
2f996f02	188	o->ptr = NULL; /* defensive programming. We'll see NULL in traces. */
a9b18e54	189	zfree(o);
e2641e09	190	}
	191	}
	192
	193	int checkType(redisClient c, robj o, int type) {
	194	if (o->type != type) {
	195	addReply(c,shared.wrongtypeerr);
	196	return 1;
	197	}
	198	return 0;
	199	}
	200
	201	/* Try to encode a string object in order to save space */
	202	robj tryObjectEncoding(robj o) {
	203	long value;
	204	sds s = o->ptr;
	205
	206	if (o->encoding != REDIS_ENCODING_RAW)
	207	return o; /* Already encoded */
	208
	209	/* It's not safe to encode shared objects: shared objects can be shared
	210	* everywhere in the "object space" of Redis. Encoded objects can only
	211	* appear as "values" (and not, for instance, as keys) */
	212	if (o->refcount > 1) return o;
	213
	214	/* Currently we try to encode only strings */
	215	redisAssert(o->type == REDIS_STRING);
	216
	217	/* Check if we can represent this string as a long integer */
	218	if (isStringRepresentableAsLong(s,&value) == REDIS_ERR) return o;
	219
0e5441d8	220	/* Ok, this object can be encoded...
	221	*
	222	* Can I use a shared object? Only if the object is inside a given
cea8c5cd	223	* range and if the back end in use is in-memory. For disk store every
cea8c5cd	224	* object in memory used as value should be independent.
13a49af4	225	*
13a49af4	226	* Note that we also avoid using shared integers when maxmemory is used
cea8c5cd	227	* because every object needs to have a private LRU field for the LRU
13a49af4	228	* algorithm to work well. */
98a9abb6	229	if (!server.ds_enabled &&
cea8c5cd	230	server.maxmemory == 0 && value >= 0 && value < REDIS_SHARED_INTEGERS &&
	231	pthread_equal(pthread_self(),server.mainthread))
	232	{
e2641e09	233	decrRefCount(o);
	234	incrRefCount(shared.integers[value]);
	235	return shared.integers[value];
	236	} else {
	237	o->encoding = REDIS_ENCODING_INT;
	238	sdsfree(o->ptr);
	239	o->ptr = (void*) value;
	240	return o;
	241	}
	242	}
	243
	244	/* Get a decoded version of an encoded object (returned as a new object).
	245	* If the object is already raw-encoded just increment the ref count. */
	246	robj getDecodedObject(robj o) {
	247	robj *dec;
	248
	249	if (o->encoding == REDIS_ENCODING_RAW) {
	250	incrRefCount(o);
	251	return o;
	252	}
	253	if (o->type == REDIS_STRING && o->encoding == REDIS_ENCODING_INT) {
	254	char buf[32];
	255
	256	ll2string(buf,32,(long)o->ptr);
	257	dec = createStringObject(buf,strlen(buf));
	258	return dec;
	259	} else {
	260	redisPanic("Unknown encoding type");
	261	}
	262	}
	263
	264	/* Compare two string objects via strcmp() or alike.
	265	* Note that the objects may be integer-encoded. In such a case we
	266	* use ll2string() to get a string representation of the numbers on the stack
	267	* and compare the strings, it's much faster than calling getDecodedObject().
	268	*
	269	* Important note: if objects are not integer encoded, but binary-safe strings,
	270	* sdscmp() from sds.c will apply memcmp() so this function ca be considered
	271	* binary safe. */
	272	int compareStringObjects(robj a, robj b) {
	273	redisAssert(a->type == REDIS_STRING && b->type == REDIS_STRING);
	274	char bufa[128], bufb[128], astr, bstr;
	275	int bothsds = 1;
	276
	277	if (a == b) return 0;
	278	if (a->encoding != REDIS_ENCODING_RAW) {
	279	ll2string(bufa,sizeof(bufa),(long) a->ptr);
	280	astr = bufa;
	281	bothsds = 0;
	282	} else {
	283	astr = a->ptr;
	284	}
	285	if (b->encoding != REDIS_ENCODING_RAW) {
	286	ll2string(bufb,sizeof(bufb),(long) b->ptr);
	287	bstr = bufb;
	288	bothsds = 0;
	289	} else {
	290	bstr = b->ptr;
	291	}
	292	return bothsds ? sdscmp(astr,bstr) : strcmp(astr,bstr);
	293	}
	294
	295	/* Equal string objects return 1 if the two objects are the same from the
	296	* point of view of a string comparison, otherwise 0 is returned. Note that
297	* this function is faster then checking for (compareStringObject(a,b) == 0)
298	* because it can perform some more optimization. */
299	int equalStringObjects(robj a, robj b) {
300	if (a->encoding != REDIS_ENCODING_RAW && b->encoding != REDIS_ENCODING_RAW){
301	return a->ptr == b->ptr;
302	} else {
303	return compareStringObjects(a,b) == 0;
304	}
305	}
306
307	size_t stringObjectLen(robj *o) {
308	redisAssert(o->type == REDIS_STRING);
309	if (o->encoding == REDIS_ENCODING_RAW) {
310	return sdslen(o->ptr);
311	} else {
312	char buf[32];
313
314	return ll2string(buf,32,(long)o->ptr);
315	}
316	}
317
318	int getDoubleFromObject(robj o, double target) {
319	double value;
320	char *eptr;
321
322	if (o == NULL) {
323	value = 0;
324	} else {
325	redisAssert(o->type == REDIS_STRING);
326	if (o->encoding == REDIS_ENCODING_RAW) {
327	value = strtod(o->ptr, &eptr);
673e1fb7	328	if (eptr[0] != '\0' \|\| isnan(value)) return REDIS_ERR;
e2641e09	329	} else if (o->encoding == REDIS_ENCODING_INT) {
	330	value = (long)o->ptr;
	331	} else {
	332	redisPanic("Unknown string encoding");
	333	}
	334	}
	335
	336	*target = value;
	337	return REDIS_OK;
	338	}
	339
	340	int getDoubleFromObjectOrReply(redisClient c, robj o, double target, const char msg) {
	341	double value;
	342	if (getDoubleFromObject(o, &value) != REDIS_OK) {
	343	if (msg != NULL) {
3ab20376	344	addReplyError(c,(char*)msg);
e2641e09	345	} else {
3ab20376	346	addReplyError(c,"value is not a double");
e2641e09	347	}
	348	return REDIS_ERR;
	349	}
	350
	351	*target = value;
	352	return REDIS_OK;
	353	}
	354
	355	int getLongLongFromObject(robj o, long long target) {
	356	long long value;
	357	char *eptr;
	358
	359	if (o == NULL) {
	360	value = 0;
	361	} else {
	362	redisAssert(o->type == REDIS_STRING);
	363	if (o->encoding == REDIS_ENCODING_RAW) {
	364	value = strtoll(o->ptr, &eptr, 10);
	365	if (eptr[0] != '\0') return REDIS_ERR;
c91abdcd	366	if (errno == ERANGE && (value == LLONG_MIN \|\| value == LLONG_MAX))
c91abdcd	367	return REDIS_ERR;
e2641e09	368	} else if (o->encoding == REDIS_ENCODING_INT) {
	369	value = (long)o->ptr;
	370	} else {
	371	redisPanic("Unknown string encoding");
	372	}
	373	}
	374
96ffb2fe	375	if (target) *target = value;
e2641e09	376	return REDIS_OK;
	377	}
	378
	379	int getLongLongFromObjectOrReply(redisClient c, robj o, long long target, const char msg) {
	380	long long value;
	381	if (getLongLongFromObject(o, &value) != REDIS_OK) {
	382	if (msg != NULL) {
3ab20376	383	addReplyError(c,(char*)msg);
e2641e09	384	} else {
3ab20376	385	addReplyError(c,"value is not an integer or out of range");
e2641e09	386	}
	387	return REDIS_ERR;
	388	}
	389
	390	*target = value;
	391	return REDIS_OK;
	392	}
	393
	394	int getLongFromObjectOrReply(redisClient c, robj o, long target, const char msg) {
	395	long long value;
	396
	397	if (getLongLongFromObjectOrReply(c, o, &value, msg) != REDIS_OK) return REDIS_ERR;
	398	if (value < LONG_MIN \|\| value > LONG_MAX) {
	399	if (msg != NULL) {
3ab20376	400	addReplyError(c,(char*)msg);
e2641e09	401	} else {
3ab20376	402	addReplyError(c,"value is out of range");
e2641e09	403	}
	404	return REDIS_ERR;
	405	}
	406
	407	*target = value;
	408	return REDIS_OK;
	409	}
	410
	411	char *strEncoding(int encoding) {
	412	switch(encoding) {
	413	case REDIS_ENCODING_RAW: return "raw";
	414	case REDIS_ENCODING_INT: return "int";
	415	case REDIS_ENCODING_HT: return "hashtable";
	416	case REDIS_ENCODING_ZIPMAP: return "zipmap";
	417	case REDIS_ENCODING_LINKEDLIST: return "linkedlist";
	418	case REDIS_ENCODING_ZIPLIST: return "ziplist";
96ffb2fe	419	case REDIS_ENCODING_INTSET: return "intset";
e2641e09	420	default: return "unknown";
	421	}
	422	}
ef59a8bc	423
	424	/* Given an object returns the min number of seconds the object was never
	425	* requested, using an approximated LRU algorithm. */
	426	unsigned long estimateObjectIdleTime(robj *o) {
	427	if (server.lruclock >= o->lru) {
165346ca	428	return (server.lruclock - o->lru) * REDIS_LRU_CLOCK_RESOLUTION;
ef59a8bc	429	} else {
165346ca	430	return ((REDIS_LRU_CLOCK_MAX - o->lru) + server.lruclock) *
165346ca	431	REDIS_LRU_CLOCK_RESOLUTION;
ef59a8bc	432	}
ef59a8bc	433	}