src/object.c

#include "redis.h"
#include <math.h>
#include <ctype.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). */
    o->lru = server.lruclock;
    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;
}

/* Note: this function is defined into object.c since here it is where it
 * belongs but it is actually designed to be used just for INCRBYFLOAT */
robj *createStringObjectFromLongDouble(long double value) {
    char buf[256];
    int len;

    /* We use 17 digits precision since with 128 bit floats that precision
     * after rouding is able to represent most small decimal numbers in a way
     * that is "non surprising" for the user (that is, most small decimal
     * numbers will be represented in a way that when converted back into
     * a string are exactly the same as what the user typed.) */
    len = snprintf(buf,sizeof(buf),"%.17Lf", value);
    /* Now remove trailing zeroes after the '.' */
    if (strchr(buf,'.') != NULL) {
        char *p = buf+len-1;
        while(*p == '0') {
            p--;
            len--;
        }
        if (*p == '.') len--;
    }
    return createStringObject(buf,len);
}

robj *dupStringObject(robj *o) {
    redisAssertWithInfo(NULL,o,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) {
    unsigned char *zl = ziplistNew();
    robj *o = createObject(REDIS_HASH, zl);
    o->encoding = REDIS_ENCODING_ZIPLIST;
    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_ZIPLIST:
        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 == 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--;
    }
}

/* 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 1;
    }
    return 0;
}

int isObjectRepresentableAsLongLong(robj *o, long long *llval) {
    redisAssertWithInfo(NULL,o,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 */
    redisAssertWithInfo(NULL,o,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
     *
     * 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];
    } 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) {
    redisAssertWithInfo(NULL,a,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) {
    redisAssertWithInfo(NULL,o,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 {
        redisAssertWithInfo(NULL,o,o->type == REDIS_STRING);
        if (o->encoding == REDIS_ENCODING_RAW) {
            errno = 0;
            value = strtod(o->ptr, &eptr);
            if (isspace(((char*)o->ptr)[0]) || eptr[0] != '\0' ||
                errno == ERANGE || 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 valid float");
        }
        return REDIS_ERR;
    }
    *target = value;
    return REDIS_OK;
}

int getLongDoubleFromObject(robj *o, long double *target) {
    long double value;
    char *eptr;

    if (o == NULL) {
        value = 0;
    } else {
        redisAssertWithInfo(NULL,o,o->type == REDIS_STRING);
        if (o->encoding == REDIS_ENCODING_RAW) {
            errno = 0;
            value = strtold(o->ptr, &eptr);
            if (isspace(((char*)o->ptr)[0]) || eptr[0] != '\0' ||
                errno == ERANGE || 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 getLongDoubleFromObjectOrReply(redisClient *c, robj *o, long double *target, const char *msg) {
    long double value;
    if (getLongDoubleFromObject(o, &value) != REDIS_OK) {
        if (msg != NULL) {
            addReplyError(c,(char*)msg);
        } else {
            addReplyError(c,"value is not a valid float");
        }
        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 {
        redisAssertWithInfo(NULL,o,o->type == REDIS_STRING);
        if (o->encoding == REDIS_ENCODING_RAW) {
            errno = 0;
            value = strtoll(o->ptr, &eptr, 10);
            if (isspace(((char*)o->ptr)[0]) || eptr[0] != '\0' ||
                errno == ERANGE)
                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_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*) dictGetVal(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)");
    }
}
Commit	Line	Data
	1	#include "redis.h"
	2	#include <math.h>
	3	#include <ctype.h>
	4
	5	robj createObject(int type, void ptr) {
	6	robj o = zmalloc(sizeof(o));
	7	o->type = type;
	8	o->encoding = REDIS_ENCODING_RAW;
	9	o->ptr = ptr;
	10	o->refcount = 1;
	11
	12	/* Set the LRU to the current lruclock (minutes resolution). */
	13	o->lru = server.lruclock;
	14	return o;
	15	}
	16
	17	robj createStringObject(char ptr, size_t len) {
	18	return createObject(REDIS_STRING,sdsnewlen(ptr,len));
	19	}
	20
	21	robj *createStringObjectFromLongLong(long long value) {
	22	robj *o;
	23	if (value >= 0 && value < REDIS_SHARED_INTEGERS) {
	24	incrRefCount(shared.integers[value]);
	25	o = shared.integers[value];
	26	} else {
	27	if (value >= LONG_MIN && value <= LONG_MAX) {
	28	o = createObject(REDIS_STRING, NULL);
	29	o->encoding = REDIS_ENCODING_INT;
	30	o->ptr = (void*)((long)value);
	31	} else {
	32	o = createObject(REDIS_STRING,sdsfromlonglong(value));
	33	}
	34	}
	35	return o;
	36	}
	37
	38	/* Note: this function is defined into object.c since here it is where it
	39	* belongs but it is actually designed to be used just for INCRBYFLOAT */
	40	robj *createStringObjectFromLongDouble(long double value) {
	41	char buf[256];
	42	int len;
	43
	44	/* We use 17 digits precision since with 128 bit floats that precision
	45	* after rouding is able to represent most small decimal numbers in a way
	46	* that is "non surprising" for the user (that is, most small decimal
	47	* numbers will be represented in a way that when converted back into
	48	* a string are exactly the same as what the user typed.) */
	49	len = snprintf(buf,sizeof(buf),"%.17Lf", value);
	50	/* Now remove trailing zeroes after the '.' */
	51	if (strchr(buf,'.') != NULL) {
	52	char *p = buf+len-1;
	53	while(*p == '0') {
	54	p--;
	55	len--;
	56	}
	57	if (*p == '.') len--;
	58	}
	59	return createStringObject(buf,len);
	60	}
	61
	62	robj dupStringObject(robj o) {
	63	redisAssertWithInfo(NULL,o,o->encoding == REDIS_ENCODING_RAW);
	64	return createStringObject(o->ptr,sdslen(o->ptr));
	65	}
	66
	67	robj *createListObject(void) {
	68	list *l = listCreate();
	69	robj *o = createObject(REDIS_LIST,l);
	70	listSetFreeMethod(l,decrRefCount);
	71	o->encoding = REDIS_ENCODING_LINKEDLIST;
	72	return o;
	73	}
	74
	75	robj *createZiplistObject(void) {
	76	unsigned char *zl = ziplistNew();
	77	robj *o = createObject(REDIS_LIST,zl);
	78	o->encoding = REDIS_ENCODING_ZIPLIST;
	79	return o;
	80	}
	81
	82	robj *createSetObject(void) {
	83	dict *d = dictCreate(&setDictType,NULL);
	84	robj *o = createObject(REDIS_SET,d);
	85	o->encoding = REDIS_ENCODING_HT;
	86	return o;
	87	}
	88
	89	robj *createIntsetObject(void) {
	90	intset *is = intsetNew();
	91	robj *o = createObject(REDIS_SET,is);
	92	o->encoding = REDIS_ENCODING_INTSET;
	93	return o;
	94	}
	95
	96	robj *createHashObject(void) {
	97	unsigned char *zl = ziplistNew();
	98	robj *o = createObject(REDIS_HASH, zl);
	99	o->encoding = REDIS_ENCODING_ZIPLIST;
	100	return o;
	101	}
	102
	103	robj *createZsetObject(void) {
	104	zset zs = zmalloc(sizeof(zs));
	105	robj *o;
	106
	107	zs->dict = dictCreate(&zsetDictType,NULL);
	108	zs->zsl = zslCreate();
	109	o = createObject(REDIS_ZSET,zs);
	110	o->encoding = REDIS_ENCODING_SKIPLIST;
	111	return o;
	112	}
	113
	114	robj *createZsetZiplistObject(void) {
	115	unsigned char *zl = ziplistNew();
	116	robj *o = createObject(REDIS_ZSET,zl);
	117	o->encoding = REDIS_ENCODING_ZIPLIST;
	118	return o;
	119	}
	120
	121	void freeStringObject(robj *o) {
	122	if (o->encoding == REDIS_ENCODING_RAW) {
	123	sdsfree(o->ptr);
	124	}
	125	}
	126
	127	void freeListObject(robj *o) {
	128	switch (o->encoding) {
	129	case REDIS_ENCODING_LINKEDLIST:
	130	listRelease((list*) o->ptr);
	131	break;
	132	case REDIS_ENCODING_ZIPLIST:
	133	zfree(o->ptr);
	134	break;
	135	default:
	136	redisPanic("Unknown list encoding type");
	137	}
	138	}
	139
	140	void freeSetObject(robj *o) {
	141	switch (o->encoding) {
	142	case REDIS_ENCODING_HT:
	143	dictRelease((dict*) o->ptr);
	144	break;
	145	case REDIS_ENCODING_INTSET:
	146	zfree(o->ptr);
	147	break;
	148	default:
	149	redisPanic("Unknown set encoding type");
	150	}
	151	}
	152
	153	void freeZsetObject(robj *o) {
	154	zset *zs;
	155	switch (o->encoding) {
	156	case REDIS_ENCODING_SKIPLIST:
	157	zs = o->ptr;
	158	dictRelease(zs->dict);
	159	zslFree(zs->zsl);
	160	zfree(zs);
	161	break;
	162	case REDIS_ENCODING_ZIPLIST:
	163	zfree(o->ptr);
	164	break;
	165	default:
	166	redisPanic("Unknown sorted set encoding");
	167	}
	168	}
	169
	170	void freeHashObject(robj *o) {
	171	switch (o->encoding) {
	172	case REDIS_ENCODING_HT:
	173	dictRelease((dict*) o->ptr);
	174	break;
	175	case REDIS_ENCODING_ZIPLIST:
	176	zfree(o->ptr);
	177	break;
	178	default:
	179	redisPanic("Unknown hash encoding type");
	180	break;
	181	}
	182	}
	183
	184	void incrRefCount(robj *o) {
	185	o->refcount++;
	186	}
	187
	188	void decrRefCount(void *obj) {
	189	robj *o = obj;
	190
	191	if (o->refcount <= 0) redisPanic("decrRefCount against refcount <= 0");
	192	if (o->refcount == 1) {
	193	switch(o->type) {
	194	case REDIS_STRING: freeStringObject(o); break;
	195	case REDIS_LIST: freeListObject(o); break;
	196	case REDIS_SET: freeSetObject(o); break;
	197	case REDIS_ZSET: freeZsetObject(o); break;
	198	case REDIS_HASH: freeHashObject(o); break;
	199	default: redisPanic("Unknown object type"); break;
	200	}
	201	zfree(o);
	202	} else {
	203	o->refcount--;
	204	}
	205	}
	206
	207	/* This function set the ref count to zero without freeing the object.
	208	* It is useful in order to pass a new object to functions incrementing
	209	* the ref count of the received object. Example:
	210	*
	211	* functionThatWillIncrementRefCount(resetRefCount(CreateObject(...)));
	212	*
	213	* Otherwise you need to resort to the less elegant pattern:
	214	*
	215	* *obj = createObject(...);
	216	* functionThatWillIncrementRefCount(obj);
	217	* decrRefCount(obj);
	218	*/
	219	robj resetRefCount(robj obj) {
	220	obj->refcount = 0;
	221	return obj;
	222	}
	223
	224	int checkType(redisClient c, robj o, int type) {
	225	if (o->type != type) {
	226	addReply(c,shared.wrongtypeerr);
	227	return 1;
	228	}
	229	return 0;
	230	}
	231
	232	int isObjectRepresentableAsLongLong(robj o, long long llval) {
	233	redisAssertWithInfo(NULL,o,o->type == REDIS_STRING);
	234	if (o->encoding == REDIS_ENCODING_INT) {
	235	if (llval) *llval = (long) o->ptr;
	236	return REDIS_OK;
	237	} else {
	238	return string2ll(o->ptr,sdslen(o->ptr),llval) ? REDIS_OK : REDIS_ERR;
	239	}
	240	}
	241
	242	/* Try to encode a string object in order to save space */
	243	robj tryObjectEncoding(robj o) {
	244	long value;
	245	sds s = o->ptr;
	246
	247	if (o->encoding != REDIS_ENCODING_RAW)
	248	return o; /* Already encoded */
	249
	250	/* It's not safe to encode shared objects: shared objects can be shared
	251	* everywhere in the "object space" of Redis. Encoded objects can only
	252	* appear as "values" (and not, for instance, as keys) */
	253	if (o->refcount > 1) return o;
	254
	255	/* Currently we try to encode only strings */
	256	redisAssertWithInfo(NULL,o,o->type == REDIS_STRING);
	257
	258	/* Check if we can represent this string as a long integer */
	259	if (!string2l(s,sdslen(s),&value)) return o;
	260
	261	/* Ok, this object can be encoded...
	262	*
	263	* Can I use a shared object? Only if the object is inside a given range
	264	*
	265	* Note that we also avoid using shared integers when maxmemory is used
	266	* because every object needs to have a private LRU field for the LRU
	267	* algorithm to work well. */
	268	if (server.maxmemory == 0 && value >= 0 && value < REDIS_SHARED_INTEGERS) {
	269	decrRefCount(o);
	270	incrRefCount(shared.integers[value]);
	271	return shared.integers[value];
	272	} else {
	273	o->encoding = REDIS_ENCODING_INT;
	274	sdsfree(o->ptr);
	275	o->ptr = (void*) value;
	276	return o;
	277	}
	278	}
	279
	280	/* Get a decoded version of an encoded object (returned as a new object).
	281	* If the object is already raw-encoded just increment the ref count. */
	282	robj getDecodedObject(robj o) {
	283	robj *dec;
	284
	285	if (o->encoding == REDIS_ENCODING_RAW) {
	286	incrRefCount(o);
	287	return o;
	288	}
	289	if (o->type == REDIS_STRING && o->encoding == REDIS_ENCODING_INT) {
	290	char buf[32];
	291
	292	ll2string(buf,32,(long)o->ptr);
	293	dec = createStringObject(buf,strlen(buf));
	294	return dec;
	295	} else {
	296	redisPanic("Unknown encoding type");
	297	}
	298	}
	299
	300	/* Compare two string objects via strcmp() or alike.
	301	* Note that the objects may be integer-encoded. In such a case we
	302	* use ll2string() to get a string representation of the numbers on the stack
	303	* and compare the strings, it's much faster than calling getDecodedObject().
	304	*
	305	* Important note: if objects are not integer encoded, but binary-safe strings,
	306	* sdscmp() from sds.c will apply memcmp() so this function ca be considered
	307	* binary safe. */
	308	int compareStringObjects(robj a, robj b) {
	309	redisAssertWithInfo(NULL,a,a->type == REDIS_STRING && b->type == REDIS_STRING);
	310	char bufa[128], bufb[128], astr, bstr;
	311	int bothsds = 1;
	312
	313	if (a == b) return 0;
	314	if (a->encoding != REDIS_ENCODING_RAW) {
	315	ll2string(bufa,sizeof(bufa),(long) a->ptr);
	316	astr = bufa;
	317	bothsds = 0;
	318	} else {
	319	astr = a->ptr;
	320	}
	321	if (b->encoding != REDIS_ENCODING_RAW) {
	322	ll2string(bufb,sizeof(bufb),(long) b->ptr);
	323	bstr = bufb;
	324	bothsds = 0;
	325	} else {
	326	bstr = b->ptr;
	327	}
	328	return bothsds ? sdscmp(astr,bstr) : strcmp(astr,bstr);
	329	}
	330
	331	/* Equal string objects return 1 if the two objects are the same from the
	332	* point of view of a string comparison, otherwise 0 is returned. Note that
	333	* this function is faster then checking for (compareStringObject(a,b) == 0)
	334	* because it can perform some more optimization. */
	335	int equalStringObjects(robj a, robj b) {
	336	if (a->encoding != REDIS_ENCODING_RAW && b->encoding != REDIS_ENCODING_RAW){
	337	return a->ptr == b->ptr;
	338	} else {
	339	return compareStringObjects(a,b) == 0;
	340	}
	341	}
	342
	343	size_t stringObjectLen(robj *o) {
	344	redisAssertWithInfo(NULL,o,o->type == REDIS_STRING);
	345	if (o->encoding == REDIS_ENCODING_RAW) {
	346	return sdslen(o->ptr);
	347	} else {
	348	char buf[32];
	349
	350	return ll2string(buf,32,(long)o->ptr);
	351	}
	352	}
	353
	354	int getDoubleFromObject(robj o, double target) {
	355	double value;
	356	char *eptr;
	357
	358	if (o == NULL) {
	359	value = 0;
	360	} else {
	361	redisAssertWithInfo(NULL,o,o->type == REDIS_STRING);
	362	if (o->encoding == REDIS_ENCODING_RAW) {
	363	errno = 0;
	364	value = strtod(o->ptr, &eptr);
	365	if (isspace(((char*)o->ptr)[0]) \|\| eptr[0] != '\0' \|\|
	366	errno == ERANGE \|\| isnan(value))
	367	return REDIS_ERR;
	368	} else if (o->encoding == REDIS_ENCODING_INT) {
	369	value = (long)o->ptr;
	370	} else {
	371	redisPanic("Unknown string encoding");
	372	}
	373	}
	374	*target = value;
	375	return REDIS_OK;
	376	}
	377
	378	int getDoubleFromObjectOrReply(redisClient c, robj o, double target, const char msg) {
	379	double value;
	380	if (getDoubleFromObject(o, &value) != REDIS_OK) {
	381	if (msg != NULL) {
	382	addReplyError(c,(char*)msg);
	383	} else {
	384	addReplyError(c,"value is not a valid float");
	385	}
	386	return REDIS_ERR;
	387	}
	388	*target = value;
	389	return REDIS_OK;
	390	}
	391
	392	int getLongDoubleFromObject(robj o, long double target) {
	393	long double value;
	394	char *eptr;
	395
	396	if (o == NULL) {
	397	value = 0;
	398	} else {
	399	redisAssertWithInfo(NULL,o,o->type == REDIS_STRING);
	400	if (o->encoding == REDIS_ENCODING_RAW) {
	401	errno = 0;
	402	value = strtold(o->ptr, &eptr);
	403	if (isspace(((char*)o->ptr)[0]) \|\| eptr[0] != '\0' \|\|
	404	errno == ERANGE \|\| isnan(value))
	405	return REDIS_ERR;
	406	} else if (o->encoding == REDIS_ENCODING_INT) {
	407	value = (long)o->ptr;
	408	} else {
	409	redisPanic("Unknown string encoding");
	410	}
	411	}
	412	*target = value;
	413	return REDIS_OK;
	414	}
	415
	416	int getLongDoubleFromObjectOrReply(redisClient c, robj o, long double target, const char msg) {
	417	long double value;
	418	if (getLongDoubleFromObject(o, &value) != REDIS_OK) {
	419	if (msg != NULL) {
	420	addReplyError(c,(char*)msg);
	421	} else {
	422	addReplyError(c,"value is not a valid float");
	423	}
	424	return REDIS_ERR;
	425	}
	426	*target = value;
	427	return REDIS_OK;
	428	}
	429
	430	int getLongLongFromObject(robj o, long long target) {
	431	long long value;
	432	char *eptr;
	433
	434	if (o == NULL) {
	435	value = 0;
	436	} else {
	437	redisAssertWithInfo(NULL,o,o->type == REDIS_STRING);
	438	if (o->encoding == REDIS_ENCODING_RAW) {
	439	errno = 0;
	440	value = strtoll(o->ptr, &eptr, 10);
	441	if (isspace(((char*)o->ptr)[0]) \|\| eptr[0] != '\0' \|\|
	442	errno == ERANGE)
	443	return REDIS_ERR;
	444	} else if (o->encoding == REDIS_ENCODING_INT) {
	445	value = (long)o->ptr;
	446	} else {
	447	redisPanic("Unknown string encoding");
	448	}
	449	}
	450	if (target) *target = value;
	451	return REDIS_OK;
	452	}
	453
	454	int getLongLongFromObjectOrReply(redisClient c, robj o, long long target, const char msg) {
	455	long long value;
	456	if (getLongLongFromObject(o, &value) != REDIS_OK) {
	457	if (msg != NULL) {
	458	addReplyError(c,(char*)msg);
	459	} else {
	460	addReplyError(c,"value is not an integer or out of range");
	461	}
	462	return REDIS_ERR;
	463	}
	464	*target = value;
	465	return REDIS_OK;
	466	}
	467
	468	int getLongFromObjectOrReply(redisClient c, robj o, long target, const char msg) {
	469	long long value;
	470
	471	if (getLongLongFromObjectOrReply(c, o, &value, msg) != REDIS_OK) return REDIS_ERR;
	472	if (value < LONG_MIN \|\| value > LONG_MAX) {
	473	if (msg != NULL) {
	474	addReplyError(c,(char*)msg);
	475	} else {
	476	addReplyError(c,"value is out of range");
	477	}
	478	return REDIS_ERR;
	479	}
	480	*target = value;
	481	return REDIS_OK;
	482	}
	483
	484	char *strEncoding(int encoding) {
	485	switch(encoding) {
	486	case REDIS_ENCODING_RAW: return "raw";
	487	case REDIS_ENCODING_INT: return "int";
	488	case REDIS_ENCODING_HT: return "hashtable";
	489	case REDIS_ENCODING_LINKEDLIST: return "linkedlist";
	490	case REDIS_ENCODING_ZIPLIST: return "ziplist";
	491	case REDIS_ENCODING_INTSET: return "intset";
	492	case REDIS_ENCODING_SKIPLIST: return "skiplist";
	493	default: return "unknown";
	494	}
	495	}
	496
	497	/* Given an object returns the min number of seconds the object was never
	498	* requested, using an approximated LRU algorithm. */
	499	unsigned long estimateObjectIdleTime(robj *o) {
	500	if (server.lruclock >= o->lru) {
	501	return (server.lruclock - o->lru) * REDIS_LRU_CLOCK_RESOLUTION;
	502	} else {
	503	return ((REDIS_LRU_CLOCK_MAX - o->lru) + server.lruclock) *
	504	REDIS_LRU_CLOCK_RESOLUTION;
	505	}
	506	}
	507
	508	/* This is an helper function for the DEBUG command. We need to lookup keys
	509	* without any modification of LRU or other parameters. */
	510	robj objectCommandLookup(redisClient c, robj *key) {
	511	dictEntry *de;
	512
	513	if ((de = dictFind(c->db->dict,key->ptr)) == NULL) return NULL;
	514	return (robj*) dictGetVal(de);
	515	}
	516
	517	robj objectCommandLookupOrReply(redisClient c, robj key, robj reply) {
	518	robj *o = objectCommandLookup(c,key);
	519
	520	if (!o) addReply(c, reply);
	521	return o;
	522	}
	523
	524	/* Object command allows to inspect the internals of an Redis Object.
	525	* Usage: OBJECT <verb> ... arguments ... */
	526	void objectCommand(redisClient *c) {
	527	robj *o;
	528
	529	if (!strcasecmp(c->argv[1]->ptr,"refcount") && c->argc == 3) {
	530	if ((o = objectCommandLookupOrReply(c,c->argv[2],shared.nullbulk))
	531	== NULL) return;
	532	addReplyLongLong(c,o->refcount);
	533	} else if (!strcasecmp(c->argv[1]->ptr,"encoding") && c->argc == 3) {
	534	if ((o = objectCommandLookupOrReply(c,c->argv[2],shared.nullbulk))
	535	== NULL) return;
	536	addReplyBulkCString(c,strEncoding(o->encoding));
	537	} else if (!strcasecmp(c->argv[1]->ptr,"idletime") && c->argc == 3) {
	538	if ((o = objectCommandLookupOrReply(c,c->argv[2],shared.nullbulk))
	539	== NULL) return;
	540	addReplyLongLong(c,estimateObjectIdleTime(o));
	541	} else {
	542	addReplyError(c,"Syntax error. Try OBJECT (refcount\|encoding\|idletime)");
	543	}
	544	}
	545