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).
     * 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) {
        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),"%.17Lg", value);
    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) {
    /* 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;

    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 and if the back end in use is in-memory. For disk store every
     * object in memory used as value should be independent.
     *
     * Note that we also avoid using shared integers when maxmemory is used
     * because every object needs to have a private LRU field for the LRU
     * algorithm to work well. */
    if (server.maxmemory == 0 && value >= 0 && value < REDIS_SHARED_INTEGERS) {
        decrRefCount(o);
        incrRefCount(shared.integers[value]);
        return shared.integers[value];
    } 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_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 ((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	* 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. */
	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;
	33	if (value >= 0 && value < REDIS_SHARED_INTEGERS) {
	34	incrRefCount(shared.integers[value]);
	35	o = shared.integers[value];
	36	} else {
	37	if (value >= LONG_MIN && value <= LONG_MAX) {
	38	o = createObject(REDIS_STRING, NULL);
	39	o->encoding = REDIS_ENCODING_INT;
	40	o->ptr = (void*)((long)value);
	41	} else {
	42	o = createObject(REDIS_STRING,sdsfromlonglong(value));
	43	}
	44	}
	45	return o;
	46	}
	47
	48	/* Note: this function is defined into object.c since here it is where it
	49	* belongs but it is actually designed to be used just for INCRBYFLOAT */
	50	robj *createStringObjectFromLongDouble(long double value) {
	51	char buf[256];
	52	int len;
	53
	54	/* We use 17 digits precision since with 128 bit floats that precision
	55	* after rouding is able to represent most small decimal numbers in a way
	56	* that is "non surprising" for the user (that is, most small decimal
	57	* numbers will be represented in a way that when converted back into
	58	* a string are exactly the same as what the user typed.) */
	59	len = snprintf(buf,sizeof(buf),"%.17Lg", value);
	60	return createStringObject(buf,len);
	61	}
	62
	63	robj dupStringObject(robj o) {
	64	redisAssertWithInfo(NULL,o,o->encoding == REDIS_ENCODING_RAW);
	65	return createStringObject(o->ptr,sdslen(o->ptr));
	66	}
	67
	68	robj *createListObject(void) {
	69	list *l = listCreate();
	70	robj *o = createObject(REDIS_LIST,l);
	71	listSetFreeMethod(l,decrRefCount);
	72	o->encoding = REDIS_ENCODING_LINKEDLIST;
	73	return o;
	74	}
	75
	76	robj *createZiplistObject(void) {
	77	unsigned char *zl = ziplistNew();
	78	robj *o = createObject(REDIS_LIST,zl);
	79	o->encoding = REDIS_ENCODING_ZIPLIST;
	80	return o;
	81	}
	82
	83	robj *createSetObject(void) {
	84	dict *d = dictCreate(&setDictType,NULL);
	85	robj *o = createObject(REDIS_SET,d);
	86	o->encoding = REDIS_ENCODING_HT;
	87	return o;
	88	}
	89
	90	robj *createIntsetObject(void) {
	91	intset *is = intsetNew();
	92	robj *o = createObject(REDIS_SET,is);
	93	o->encoding = REDIS_ENCODING_INTSET;
	94	return o;
	95	}
	96
	97	robj *createHashObject(void) {
	98	/* All the Hashes start as zipmaps. Will be automatically converted
	99	* into hash tables if there are enough elements or big elements
	100	* inside. */
	101	unsigned char *zm = zipmapNew();
	102	robj *o = createObject(REDIS_HASH,zm);
	103	o->encoding = REDIS_ENCODING_ZIPMAP;
	104	return o;
	105	}
	106
	107	robj *createZsetObject(void) {
	108	zset zs = zmalloc(sizeof(zs));
	109	robj *o;
	110
	111	zs->dict = dictCreate(&zsetDictType,NULL);
	112	zs->zsl = zslCreate();
	113	o = createObject(REDIS_ZSET,zs);
	114	o->encoding = REDIS_ENCODING_SKIPLIST;
	115	return o;
	116	}
	117
	118	robj *createZsetZiplistObject(void) {
	119	unsigned char *zl = ziplistNew();
	120	robj *o = createObject(REDIS_ZSET,zl);
	121	o->encoding = REDIS_ENCODING_ZIPLIST;
	122	return o;
	123	}
	124
	125	void freeStringObject(robj *o) {
	126	if (o->encoding == REDIS_ENCODING_RAW) {
	127	sdsfree(o->ptr);
	128	}
	129	}
	130
	131	void freeListObject(robj *o) {
	132	switch (o->encoding) {
	133	case REDIS_ENCODING_LINKEDLIST:
	134	listRelease((list*) o->ptr);
	135	break;
	136	case REDIS_ENCODING_ZIPLIST:
	137	zfree(o->ptr);
	138	break;
	139	default:
	140	redisPanic("Unknown list encoding type");
	141	}
	142	}
	143
	144	void freeSetObject(robj *o) {
	145	switch (o->encoding) {
	146	case REDIS_ENCODING_HT:
	147	dictRelease((dict*) o->ptr);
	148	break;
	149	case REDIS_ENCODING_INTSET:
	150	zfree(o->ptr);
	151	break;
	152	default:
	153	redisPanic("Unknown set encoding type");
	154	}
	155	}
	156
	157	void freeZsetObject(robj *o) {
	158	zset *zs;
	159	switch (o->encoding) {
	160	case REDIS_ENCODING_SKIPLIST:
	161	zs = o->ptr;
	162	dictRelease(zs->dict);
	163	zslFree(zs->zsl);
	164	zfree(zs);
	165	break;
	166	case REDIS_ENCODING_ZIPLIST:
	167	zfree(o->ptr);
	168	break;
	169	default:
	170	redisPanic("Unknown sorted set encoding");
	171	}
	172	}
	173
	174	void freeHashObject(robj *o) {
	175	switch (o->encoding) {
	176	case REDIS_ENCODING_HT:
	177	dictRelease((dict*) o->ptr);
	178	break;
	179	case REDIS_ENCODING_ZIPMAP:
	180	zfree(o->ptr);
	181	break;
	182	default:
	183	redisPanic("Unknown hash encoding type");
	184	break;
	185	}
	186	}
	187
	188	void incrRefCount(robj *o) {
	189	o->refcount++;
	190	}
	191
	192	void decrRefCount(void *obj) {
	193	robj *o = obj;
	194
	195	if (o->refcount <= 0) redisPanic("decrRefCount against refcount <= 0");
	196	if (o->refcount == 1) {
	197	switch(o->type) {
	198	case REDIS_STRING: freeStringObject(o); break;
	199	case REDIS_LIST: freeListObject(o); break;
	200	case REDIS_SET: freeSetObject(o); break;
	201	case REDIS_ZSET: freeZsetObject(o); break;
	202	case REDIS_HASH: freeHashObject(o); break;
	203	default: redisPanic("Unknown object type"); break;
	204	}
	205	zfree(o);
	206	} else {
	207	o->refcount--;
	208	}
	209	}
	210
	211	/* This function set the ref count to zero without freeing the object.
	212	* It is useful in order to pass a new object to functions incrementing
	213	* the ref count of the received object. Example:
	214	*
	215	* functionThatWillIncrementRefCount(resetRefCount(CreateObject(...)));
	216	*
	217	* Otherwise you need to resort to the less elegant pattern:
	218	*
	219	* *obj = createObject(...);
	220	* functionThatWillIncrementRefCount(obj);
	221	* decrRefCount(obj);
	222	*/
	223	robj resetRefCount(robj obj) {
	224	obj->refcount = 0;
	225	return obj;
	226	}
	227
	228	int checkType(redisClient c, robj o, int type) {
	229	if (o->type != type) {
	230	addReply(c,shared.wrongtypeerr);
	231	return 1;
	232	}
	233	return 0;
	234	}
	235
	236	int isObjectRepresentableAsLongLong(robj o, long long llval) {
	237	redisAssertWithInfo(NULL,o,o->type == REDIS_STRING);
	238	if (o->encoding == REDIS_ENCODING_INT) {
	239	if (llval) *llval = (long) o->ptr;
	240	return REDIS_OK;
	241	} else {
	242	return string2ll(o->ptr,sdslen(o->ptr),llval) ? REDIS_OK : REDIS_ERR;
	243	}
	244	}
	245
	246	/* Try to encode a string object in order to save space */
	247	robj tryObjectEncoding(robj o) {
	248	long value;
	249	sds s = o->ptr;
	250
	251	if (o->encoding != REDIS_ENCODING_RAW)
	252	return o; /* Already encoded */
	253
	254	/* It's not safe to encode shared objects: shared objects can be shared
	255	* everywhere in the "object space" of Redis. Encoded objects can only
	256	* appear as "values" (and not, for instance, as keys) */
	257	if (o->refcount > 1) return o;
	258
	259	/* Currently we try to encode only strings */
	260	redisAssertWithInfo(NULL,o,o->type == REDIS_STRING);
	261
	262	/* Check if we can represent this string as a long integer */
	263	if (!string2l(s,sdslen(s),&value)) return o;
	264
	265	/* Ok, this object can be encoded...
	266	*
	267	* Can I use a shared object? Only if the object is inside a given
	268	* range and if the back end in use is in-memory. For disk store every
	269	* object in memory used as value should be independent.
	270	*
	271	* Note that we also avoid using shared integers when maxmemory is used
	272	* because every object needs to have a private LRU field for the LRU
	273	* algorithm to work well. */
	274	if (server.maxmemory == 0 && value >= 0 && value < REDIS_SHARED_INTEGERS) {
	275	decrRefCount(o);
	276	incrRefCount(shared.integers[value]);
	277	return shared.integers[value];
	278	} else {
	279	o->encoding = REDIS_ENCODING_INT;
	280	sdsfree(o->ptr);
	281	o->ptr = (void*) value;
	282	return o;
	283	}
	284	}
	285
	286	/* Get a decoded version of an encoded object (returned as a new object).
	287	* If the object is already raw-encoded just increment the ref count. */
	288	robj getDecodedObject(robj o) {
	289	robj *dec;
	290
	291	if (o->encoding == REDIS_ENCODING_RAW) {
	292	incrRefCount(o);
	293	return o;
	294	}
	295	if (o->type == REDIS_STRING && o->encoding == REDIS_ENCODING_INT) {
	296	char buf[32];
	297
	298	ll2string(buf,32,(long)o->ptr);
	299	dec = createStringObject(buf,strlen(buf));
	300	return dec;
	301	} else {
	302	redisPanic("Unknown encoding type");
	303	}
	304	}
	305
	306	/* Compare two string objects via strcmp() or alike.
	307	* Note that the objects may be integer-encoded. In such a case we
	308	* use ll2string() to get a string representation of the numbers on the stack
	309	* and compare the strings, it's much faster than calling getDecodedObject().
	310	*
	311	* Important note: if objects are not integer encoded, but binary-safe strings,
	312	* sdscmp() from sds.c will apply memcmp() so this function ca be considered
	313	* binary safe. */
	314	int compareStringObjects(robj a, robj b) {
	315	redisAssertWithInfo(NULL,a,a->type == REDIS_STRING && b->type == REDIS_STRING);
	316	char bufa[128], bufb[128], astr, bstr;
	317	int bothsds = 1;
	318
	319	if (a == b) return 0;
	320	if (a->encoding != REDIS_ENCODING_RAW) {
	321	ll2string(bufa,sizeof(bufa),(long) a->ptr);
	322	astr = bufa;
	323	bothsds = 0;
	324	} else {
	325	astr = a->ptr;
	326	}
	327	if (b->encoding != REDIS_ENCODING_RAW) {
	328	ll2string(bufb,sizeof(bufb),(long) b->ptr);
	329	bstr = bufb;
	330	bothsds = 0;
	331	} else {
	332	bstr = b->ptr;
	333	}
	334	return bothsds ? sdscmp(astr,bstr) : strcmp(astr,bstr);
	335	}
	336
	337	/* Equal string objects return 1 if the two objects are the same from the
	338	* point of view of a string comparison, otherwise 0 is returned. Note that
	339	* this function is faster then checking for (compareStringObject(a,b) == 0)
	340	* because it can perform some more optimization. */
	341	int equalStringObjects(robj a, robj b) {
	342	if (a->encoding != REDIS_ENCODING_RAW && b->encoding != REDIS_ENCODING_RAW){
	343	return a->ptr == b->ptr;
	344	} else {
	345	return compareStringObjects(a,b) == 0;
	346	}
	347	}
	348
	349	size_t stringObjectLen(robj *o) {
	350	redisAssertWithInfo(NULL,o,o->type == REDIS_STRING);
	351	if (o->encoding == REDIS_ENCODING_RAW) {
	352	return sdslen(o->ptr);
	353	} else {
	354	char buf[32];
	355
	356	return ll2string(buf,32,(long)o->ptr);
	357	}
	358	}
	359
	360	int getDoubleFromObject(robj o, double target) {
	361	double value;
	362	char *eptr;
	363
	364	if (o == NULL) {
	365	value = 0;
	366	} else {
	367	redisAssertWithInfo(NULL,o,o->type == REDIS_STRING);
	368	if (o->encoding == REDIS_ENCODING_RAW) {
	369	errno = 0;
	370	value = strtod(o->ptr, &eptr);
	371	if (isspace(((char*)o->ptr)[0]) \|\| eptr[0] != '\0' \|\|
	372	errno == ERANGE \|\| isnan(value))
	373	return REDIS_ERR;
	374	} else if (o->encoding == REDIS_ENCODING_INT) {
	375	value = (long)o->ptr;
	376	} else {
	377	redisPanic("Unknown string encoding");
	378	}
	379	}
	380	*target = value;
	381	return REDIS_OK;
	382	}
	383
	384	int getDoubleFromObjectOrReply(redisClient c, robj o, double target, const char msg) {
	385	double value;
	386	if (getDoubleFromObject(o, &value) != REDIS_OK) {
	387	if (msg != NULL) {
	388	addReplyError(c,(char*)msg);
	389	} else {
	390	addReplyError(c,"value is not a valid float");
	391	}
	392	return REDIS_ERR;
	393	}
	394	*target = value;
	395	return REDIS_OK;
	396	}
	397
	398	int getLongDoubleFromObject(robj o, long double target) {
	399	long double value;
	400	char *eptr;
	401
	402	if (o == NULL) {
	403	value = 0;
	404	} else {
	405	redisAssertWithInfo(NULL,o,o->type == REDIS_STRING);
	406	if (o->encoding == REDIS_ENCODING_RAW) {
	407	errno = 0;
	408	value = strtold(o->ptr, &eptr);
	409	if (isspace(((char*)o->ptr)[0]) \|\| eptr[0] != '\0' \|\|
	410	errno == ERANGE \|\| isnan(value))
	411	return REDIS_ERR;
	412	} else if (o->encoding == REDIS_ENCODING_INT) {
	413	value = (long)o->ptr;
	414	} else {
	415	redisPanic("Unknown string encoding");
	416	}
	417	}
	418	*target = value;
	419	return REDIS_OK;
	420	}
	421
	422	int getLongDoubleFromObjectOrReply(redisClient c, robj o, long double target, const char msg) {
	423	long double value;
	424	if (getLongDoubleFromObject(o, &value) != REDIS_OK) {
	425	if (msg != NULL) {
	426	addReplyError(c,(char*)msg);
	427	} else {
	428	addReplyError(c,"value is not a valid float");
	429	}
	430	return REDIS_ERR;
	431	}
	432	*target = value;
	433	return REDIS_OK;
	434	}
	435
	436	int getLongLongFromObject(robj o, long long target) {
	437	long long value;
	438	char *eptr;
	439
	440	if (o == NULL) {
	441	value = 0;
	442	} else {
	443	redisAssertWithInfo(NULL,o,o->type == REDIS_STRING);
	444	if (o->encoding == REDIS_ENCODING_RAW) {
	445	errno = 0;
	446	value = strtoll(o->ptr, &eptr, 10);
	447	if (isspace(((char*)o->ptr)[0]) \|\| eptr[0] != '\0' \|\|
	448	errno == ERANGE)
	449	return REDIS_ERR;
	450	} else if (o->encoding == REDIS_ENCODING_INT) {
	451	value = (long)o->ptr;
	452	} else {
	453	redisPanic("Unknown string encoding");
	454	}
	455	}
	456	if (target) *target = value;
	457	return REDIS_OK;
	458	}
	459
	460	int getLongLongFromObjectOrReply(redisClient c, robj o, long long target, const char msg) {
	461	long long value;
	462	if (getLongLongFromObject(o, &value) != REDIS_OK) {
	463	if (msg != NULL) {
	464	addReplyError(c,(char*)msg);
	465	} else {
	466	addReplyError(c,"value is not an integer or out of range");
	467	}
	468	return REDIS_ERR;
	469	}
	470	*target = value;
	471	return REDIS_OK;
	472	}
	473
	474	int getLongFromObjectOrReply(redisClient c, robj o, long target, const char msg) {
	475	long long value;
	476
	477	if (getLongLongFromObjectOrReply(c, o, &value, msg) != REDIS_OK) return REDIS_ERR;
	478	if (value < LONG_MIN \|\| value > LONG_MAX) {
	479	if (msg != NULL) {
	480	addReplyError(c,(char*)msg);
	481	} else {
	482	addReplyError(c,"value is out of range");
	483	}
	484	return REDIS_ERR;
	485	}
	486	*target = value;
	487	return REDIS_OK;
	488	}
	489
	490	char *strEncoding(int encoding) {
	491	switch(encoding) {
	492	case REDIS_ENCODING_RAW: return "raw";
	493	case REDIS_ENCODING_INT: return "int";
	494	case REDIS_ENCODING_HT: return "hashtable";
	495	case REDIS_ENCODING_ZIPMAP: return "zipmap";
	496	case REDIS_ENCODING_LINKEDLIST: return "linkedlist";
	497	case REDIS_ENCODING_ZIPLIST: return "ziplist";
	498	case REDIS_ENCODING_INTSET: return "intset";
	499	case REDIS_ENCODING_SKIPLIST: return "skiplist";
	500	default: return "unknown";
	501	}
	502	}
	503
	504	/* Given an object returns the min number of seconds the object was never
	505	* requested, using an approximated LRU algorithm. */
	506	unsigned long estimateObjectIdleTime(robj *o) {
	507	if (server.lruclock >= o->lru) {
	508	return (server.lruclock - o->lru) * REDIS_LRU_CLOCK_RESOLUTION;
	509	} else {
	510	return ((REDIS_LRU_CLOCK_MAX - o->lru) + server.lruclock) *
	511	REDIS_LRU_CLOCK_RESOLUTION;
	512	}
	513	}
	514
	515	/* This is an helper function for the DEBUG command. We need to lookup keys
	516	* without any modification of LRU or other parameters. */
	517	robj objectCommandLookup(redisClient c, robj *key) {
	518	dictEntry *de;
	519
	520	if ((de = dictFind(c->db->dict,key->ptr)) == NULL) return NULL;
	521	return (robj*) dictGetVal(de);
	522	}
	523
	524	robj objectCommandLookupOrReply(redisClient c, robj key, robj reply) {
	525	robj *o = objectCommandLookup(c,key);
	526
	527	if (!o) addReply(c, reply);
	528	return o;
	529	}
	530
	531	/* Object command allows to inspect the internals of an Redis Object.
	532	* Usage: OBJECT <verb> ... arguments ... */
	533	void objectCommand(redisClient *c) {
	534	robj *o;
	535
	536	if (!strcasecmp(c->argv[1]->ptr,"refcount") && c->argc == 3) {
	537	if ((o = objectCommandLookupOrReply(c,c->argv[2],shared.nullbulk))
	538	== NULL) return;
	539	addReplyLongLong(c,o->refcount);
	540	} else if (!strcasecmp(c->argv[1]->ptr,"encoding") && c->argc == 3) {
	541	if ((o = objectCommandLookupOrReply(c,c->argv[2],shared.nullbulk))
	542	== NULL) return;
	543	addReplyBulkCString(c,strEncoding(o->encoding));
	544	} else if (!strcasecmp(c->argv[1]->ptr,"idletime") && c->argc == 3) {
	545	if ((o = objectCommandLookupOrReply(c,c->argv[2],shared.nullbulk))
	546	== NULL) return;
	547	addReplyLongLong(c,estimateObjectIdleTime(o));
	548	} else {
	549	addReplyError(c,"Syntax error. Try OBJECT (refcount\|encoding\|idletime)");
	550	}
	551	}
	552