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),"%.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 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_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),"%.17Lf", value);
	60	/* Now remove trailing zeroes after the '.' */
	61	if (strchr(buf,'.') != NULL) {
	62	char *p = buf+len-1;
	63	while(*p == '0') {
	64	p--;
	65	len--;
	66	}
	67	if (*p == '.') len--;
	68	}
	69	return createStringObject(buf,len);
	70	}
	71
	72	robj dupStringObject(robj o) {
	73	redisAssertWithInfo(NULL,o,o->encoding == REDIS_ENCODING_RAW);
	74	return createStringObject(o->ptr,sdslen(o->ptr));
	75	}
	76
	77	robj *createListObject(void) {
	78	list *l = listCreate();
	79	robj *o = createObject(REDIS_LIST,l);
	80	listSetFreeMethod(l,decrRefCount);
	81	o->encoding = REDIS_ENCODING_LINKEDLIST;
	82	return o;
	83	}
	84
	85	robj *createZiplistObject(void) {
	86	unsigned char *zl = ziplistNew();
	87	robj *o = createObject(REDIS_LIST,zl);
	88	o->encoding = REDIS_ENCODING_ZIPLIST;
	89	return o;
	90	}
	91
	92	robj *createSetObject(void) {
	93	dict *d = dictCreate(&setDictType,NULL);
	94	robj *o = createObject(REDIS_SET,d);
	95	o->encoding = REDIS_ENCODING_HT;
	96	return o;
	97	}
	98
	99	robj *createIntsetObject(void) {
	100	intset *is = intsetNew();
	101	robj *o = createObject(REDIS_SET,is);
	102	o->encoding = REDIS_ENCODING_INTSET;
	103	return o;
	104	}
	105
	106	robj *createHashObject(void) {
	107	unsigned char *zl = ziplistNew();
	108	robj *o = createObject(REDIS_HASH, zl);
	109	o->encoding = REDIS_ENCODING_ZIPLIST;
	110	return o;
	111	}
	112
	113	robj *createZsetObject(void) {
	114	zset zs = zmalloc(sizeof(zs));
	115	robj *o;
	116
	117	zs->dict = dictCreate(&zsetDictType,NULL);
	118	zs->zsl = zslCreate();
	119	o = createObject(REDIS_ZSET,zs);
	120	o->encoding = REDIS_ENCODING_SKIPLIST;
	121	return o;
	122	}
	123
	124	robj *createZsetZiplistObject(void) {
	125	unsigned char *zl = ziplistNew();
	126	robj *o = createObject(REDIS_ZSET,zl);
	127	o->encoding = REDIS_ENCODING_ZIPLIST;
	128	return o;
	129	}
	130
	131	void freeStringObject(robj *o) {
	132	if (o->encoding == REDIS_ENCODING_RAW) {
	133	sdsfree(o->ptr);
	134	}
	135	}
	136
	137	void freeListObject(robj *o) {
	138	switch (o->encoding) {
	139	case REDIS_ENCODING_LINKEDLIST:
	140	listRelease((list*) o->ptr);
	141	break;
	142	case REDIS_ENCODING_ZIPLIST:
	143	zfree(o->ptr);
	144	break;
	145	default:
	146	redisPanic("Unknown list encoding type");
	147	}
	148	}
	149
	150	void freeSetObject(robj *o) {
	151	switch (o->encoding) {
	152	case REDIS_ENCODING_HT:
	153	dictRelease((dict*) o->ptr);
	154	break;
	155	case REDIS_ENCODING_INTSET:
	156	zfree(o->ptr);
	157	break;
	158	default:
	159	redisPanic("Unknown set encoding type");
	160	}
	161	}
	162
	163	void freeZsetObject(robj *o) {
	164	zset *zs;
	165	switch (o->encoding) {
	166	case REDIS_ENCODING_SKIPLIST:
	167	zs = o->ptr;
	168	dictRelease(zs->dict);
	169	zslFree(zs->zsl);
	170	zfree(zs);
	171	break;
	172	case REDIS_ENCODING_ZIPLIST:
	173	zfree(o->ptr);
	174	break;
	175	default:
	176	redisPanic("Unknown sorted set encoding");
	177	}
	178	}
	179
	180	void freeHashObject(robj *o) {
	181	switch (o->encoding) {
	182	case REDIS_ENCODING_HT:
	183	dictRelease((dict*) o->ptr);
	184	break;
	185	case REDIS_ENCODING_ZIPLIST:
	186	zfree(o->ptr);
	187	break;
	188	default:
	189	redisPanic("Unknown hash encoding type");
	190	break;
	191	}
	192	}
	193
	194	void incrRefCount(robj *o) {
	195	o->refcount++;
	196	}
	197
	198	void decrRefCount(void *obj) {
	199	robj *o = obj;
	200
	201	if (o->refcount <= 0) redisPanic("decrRefCount against refcount <= 0");
	202	if (o->refcount == 1) {
	203	switch(o->type) {
	204	case REDIS_STRING: freeStringObject(o); break;
	205	case REDIS_LIST: freeListObject(o); break;
	206	case REDIS_SET: freeSetObject(o); break;
	207	case REDIS_ZSET: freeZsetObject(o); break;
	208	case REDIS_HASH: freeHashObject(o); break;
	209	default: redisPanic("Unknown object type"); break;
	210	}
	211	zfree(o);
	212	} else {
	213	o->refcount--;
	214	}
	215	}
	216
	217	/* This function set the ref count to zero without freeing the object.
	218	* It is useful in order to pass a new object to functions incrementing
	219	* the ref count of the received object. Example:
	220	*
	221	* functionThatWillIncrementRefCount(resetRefCount(CreateObject(...)));
	222	*
	223	* Otherwise you need to resort to the less elegant pattern:
	224	*
	225	* *obj = createObject(...);
	226	* functionThatWillIncrementRefCount(obj);
	227	* decrRefCount(obj);
	228	*/
	229	robj resetRefCount(robj obj) {
	230	obj->refcount = 0;
	231	return obj;
	232	}
	233
	234	int checkType(redisClient c, robj o, int type) {
	235	if (o->type != type) {
	236	addReply(c,shared.wrongtypeerr);
	237	return 1;
	238	}
	239	return 0;
	240	}
	241
	242	int isObjectRepresentableAsLongLong(robj o, long long llval) {
	243	redisAssertWithInfo(NULL,o,o->type == REDIS_STRING);
	244	if (o->encoding == REDIS_ENCODING_INT) {
	245	if (llval) *llval = (long) o->ptr;
	246	return REDIS_OK;
	247	} else {
	248	return string2ll(o->ptr,sdslen(o->ptr),llval) ? REDIS_OK : REDIS_ERR;
	249	}
	250	}
	251
	252	/* Try to encode a string object in order to save space */
	253	robj tryObjectEncoding(robj o) {
	254	long value;
	255	sds s = o->ptr;
	256
	257	if (o->encoding != REDIS_ENCODING_RAW)
	258	return o; /* Already encoded */
	259
	260	/* It's not safe to encode shared objects: shared objects can be shared
	261	* everywhere in the "object space" of Redis. Encoded objects can only
	262	* appear as "values" (and not, for instance, as keys) */
	263	if (o->refcount > 1) return o;
	264
	265	/* Currently we try to encode only strings */
	266	redisAssertWithInfo(NULL,o,o->type == REDIS_STRING);
	267
	268	/* Check if we can represent this string as a long integer */
	269	if (!string2l(s,sdslen(s),&value)) return o;
	270
	271	/* Ok, this object can be encoded...
	272	*
	273	* Can I use a shared object? Only if the object is inside a given
	274	* range and if the back end in use is in-memory. For disk store every
	275	* object in memory used as value should be independent.
	276	*
	277	* Note that we also avoid using shared integers when maxmemory is used
	278	* because every object needs to have a private LRU field for the LRU
	279	* algorithm to work well. */
	280	if (server.maxmemory == 0 && value >= 0 && value < REDIS_SHARED_INTEGERS) {
	281	decrRefCount(o);
	282	incrRefCount(shared.integers[value]);
	283	return shared.integers[value];
	284	} else {
	285	o->encoding = REDIS_ENCODING_INT;
	286	sdsfree(o->ptr);
	287	o->ptr = (void*) value;
	288	return o;
	289	}
	290	}
	291
	292	/* Get a decoded version of an encoded object (returned as a new object).
	293	* If the object is already raw-encoded just increment the ref count. */
	294	robj getDecodedObject(robj o) {
	295	robj *dec;
	296
	297	if (o->encoding == REDIS_ENCODING_RAW) {
	298	incrRefCount(o);
	299	return o;
	300	}
	301	if (o->type == REDIS_STRING && o->encoding == REDIS_ENCODING_INT) {
	302	char buf[32];
	303
	304	ll2string(buf,32,(long)o->ptr);
	305	dec = createStringObject(buf,strlen(buf));
	306	return dec;
	307	} else {
	308	redisPanic("Unknown encoding type");
	309	}
	310	}
	311
	312	/* Compare two string objects via strcmp() or alike.
	313	* Note that the objects may be integer-encoded. In such a case we
	314	* use ll2string() to get a string representation of the numbers on the stack
	315	* and compare the strings, it's much faster than calling getDecodedObject().
	316	*
	317	* Important note: if objects are not integer encoded, but binary-safe strings,
	318	* sdscmp() from sds.c will apply memcmp() so this function ca be considered
	319	* binary safe. */
	320	int compareStringObjects(robj a, robj b) {
	321	redisAssertWithInfo(NULL,a,a->type == REDIS_STRING && b->type == REDIS_STRING);
	322	char bufa[128], bufb[128], astr, bstr;
	323	int bothsds = 1;
	324
	325	if (a == b) return 0;
	326	if (a->encoding != REDIS_ENCODING_RAW) {
	327	ll2string(bufa,sizeof(bufa),(long) a->ptr);
	328	astr = bufa;
	329	bothsds = 0;
	330	} else {
	331	astr = a->ptr;
	332	}
	333	if (b->encoding != REDIS_ENCODING_RAW) {
	334	ll2string(bufb,sizeof(bufb),(long) b->ptr);
	335	bstr = bufb;
	336	bothsds = 0;
	337	} else {
	338	bstr = b->ptr;
	339	}
	340	return bothsds ? sdscmp(astr,bstr) : strcmp(astr,bstr);
	341	}
	342
	343	/* Equal string objects return 1 if the two objects are the same from the
	344	* point of view of a string comparison, otherwise 0 is returned. Note that
	345	* this function is faster then checking for (compareStringObject(a,b) == 0)
	346	* because it can perform some more optimization. */
	347	int equalStringObjects(robj a, robj b) {
	348	if (a->encoding != REDIS_ENCODING_RAW && b->encoding != REDIS_ENCODING_RAW){
	349	return a->ptr == b->ptr;
	350	} else {
	351	return compareStringObjects(a,b) == 0;
	352	}
	353	}
	354
	355	size_t stringObjectLen(robj *o) {
	356	redisAssertWithInfo(NULL,o,o->type == REDIS_STRING);
	357	if (o->encoding == REDIS_ENCODING_RAW) {
	358	return sdslen(o->ptr);
	359	} else {
	360	char buf[32];
	361
	362	return ll2string(buf,32,(long)o->ptr);
	363	}
	364	}
	365
	366	int getDoubleFromObject(robj o, double target) {
	367	double value;
	368	char *eptr;
	369
	370	if (o == NULL) {
	371	value = 0;
	372	} else {
	373	redisAssertWithInfo(NULL,o,o->type == REDIS_STRING);
	374	if (o->encoding == REDIS_ENCODING_RAW) {
	375	errno = 0;
	376	value = strtod(o->ptr, &eptr);
	377	if (isspace(((char*)o->ptr)[0]) \|\| eptr[0] != '\0' \|\|
	378	errno == ERANGE \|\| isnan(value))
	379	return REDIS_ERR;
	380	} else if (o->encoding == REDIS_ENCODING_INT) {
	381	value = (long)o->ptr;
	382	} else {
	383	redisPanic("Unknown string encoding");
	384	}
	385	}
	386	*target = value;
	387	return REDIS_OK;
	388	}
	389
	390	int getDoubleFromObjectOrReply(redisClient c, robj o, double target, const char msg) {
	391	double value;
	392	if (getDoubleFromObject(o, &value) != REDIS_OK) {
	393	if (msg != NULL) {
	394	addReplyError(c,(char*)msg);
	395	} else {
	396	addReplyError(c,"value is not a valid float");
	397	}
	398	return REDIS_ERR;
	399	}
	400	*target = value;
	401	return REDIS_OK;
	402	}
	403
	404	int getLongDoubleFromObject(robj o, long double target) {
	405	long double value;
	406	char *eptr;
	407
	408	if (o == NULL) {
	409	value = 0;
	410	} else {
	411	redisAssertWithInfo(NULL,o,o->type == REDIS_STRING);
	412	if (o->encoding == REDIS_ENCODING_RAW) {
	413	errno = 0;
	414	value = strtold(o->ptr, &eptr);
	415	if (isspace(((char*)o->ptr)[0]) \|\| eptr[0] != '\0' \|\|
	416	errno == ERANGE \|\| isnan(value))
	417	return REDIS_ERR;
	418	} else if (o->encoding == REDIS_ENCODING_INT) {
	419	value = (long)o->ptr;
	420	} else {
	421	redisPanic("Unknown string encoding");
	422	}
	423	}
	424	*target = value;
	425	return REDIS_OK;
	426	}
	427
	428	int getLongDoubleFromObjectOrReply(redisClient c, robj o, long double target, const char msg) {
	429	long double value;
	430	if (getLongDoubleFromObject(o, &value) != REDIS_OK) {
	431	if (msg != NULL) {
	432	addReplyError(c,(char*)msg);
	433	} else {
	434	addReplyError(c,"value is not a valid float");
	435	}
	436	return REDIS_ERR;
	437	}
	438	*target = value;
	439	return REDIS_OK;
	440	}
	441
	442	int getLongLongFromObject(robj o, long long target) {
	443	long long value;
	444	char *eptr;
	445
	446	if (o == NULL) {
	447	value = 0;
	448	} else {
	449	redisAssertWithInfo(NULL,o,o->type == REDIS_STRING);
	450	if (o->encoding == REDIS_ENCODING_RAW) {
	451	errno = 0;
	452	value = strtoll(o->ptr, &eptr, 10);
	453	if (isspace(((char*)o->ptr)[0]) \|\| eptr[0] != '\0' \|\|
	454	errno == ERANGE)
	455	return REDIS_ERR;
	456	} else if (o->encoding == REDIS_ENCODING_INT) {
	457	value = (long)o->ptr;
	458	} else {
	459	redisPanic("Unknown string encoding");
	460	}
	461	}
	462	if (target) *target = value;
	463	return REDIS_OK;
	464	}
	465
	466	int getLongLongFromObjectOrReply(redisClient c, robj o, long long target, const char msg) {
	467	long long value;
	468	if (getLongLongFromObject(o, &value) != REDIS_OK) {
	469	if (msg != NULL) {
	470	addReplyError(c,(char*)msg);
	471	} else {
	472	addReplyError(c,"value is not an integer or out of range");
	473	}
	474	return REDIS_ERR;
	475	}
	476	*target = value;
	477	return REDIS_OK;
	478	}
	479
	480	int getLongFromObjectOrReply(redisClient c, robj o, long target, const char msg) {
	481	long long value;
	482
	483	if (getLongLongFromObjectOrReply(c, o, &value, msg) != REDIS_OK) return REDIS_ERR;
	484	if (value < LONG_MIN \|\| value > LONG_MAX) {
	485	if (msg != NULL) {
	486	addReplyError(c,(char*)msg);
	487	} else {
	488	addReplyError(c,"value is out of range");
	489	}
	490	return REDIS_ERR;
	491	}
	492	*target = value;
	493	return REDIS_OK;
	494	}
	495
	496	char *strEncoding(int encoding) {
	497	switch(encoding) {
	498	case REDIS_ENCODING_RAW: return "raw";
	499	case REDIS_ENCODING_INT: return "int";
	500	case REDIS_ENCODING_HT: return "hashtable";
	501	case REDIS_ENCODING_LINKEDLIST: return "linkedlist";
	502	case REDIS_ENCODING_ZIPLIST: return "ziplist";
	503	case REDIS_ENCODING_INTSET: return "intset";
	504	case REDIS_ENCODING_SKIPLIST: return "skiplist";
	505	default: return "unknown";
	506	}
	507	}
	508
	509	/* Given an object returns the min number of seconds the object was never
	510	* requested, using an approximated LRU algorithm. */
	511	unsigned long estimateObjectIdleTime(robj *o) {
	512	if (server.lruclock >= o->lru) {
	513	return (server.lruclock - o->lru) * REDIS_LRU_CLOCK_RESOLUTION;
	514	} else {
	515	return ((REDIS_LRU_CLOCK_MAX - o->lru) + server.lruclock) *
	516	REDIS_LRU_CLOCK_RESOLUTION;
	517	}
	518	}
	519
	520	/* This is an helper function for the DEBUG command. We need to lookup keys
	521	* without any modification of LRU or other parameters. */
	522	robj objectCommandLookup(redisClient c, robj *key) {
	523	dictEntry *de;
	524
	525	if ((de = dictFind(c->db->dict,key->ptr)) == NULL) return NULL;
	526	return (robj*) dictGetVal(de);
	527	}
	528
	529	robj objectCommandLookupOrReply(redisClient c, robj key, robj reply) {
	530	robj *o = objectCommandLookup(c,key);
	531
	532	if (!o) addReply(c, reply);
	533	return o;
	534	}
	535
	536	/* Object command allows to inspect the internals of an Redis Object.
	537	* Usage: OBJECT <verb> ... arguments ... */
	538	void objectCommand(redisClient *c) {
	539	robj *o;
	540
	541	if (!strcasecmp(c->argv[1]->ptr,"refcount") && c->argc == 3) {
	542	if ((o = objectCommandLookupOrReply(c,c->argv[2],shared.nullbulk))
	543	== NULL) return;
	544	addReplyLongLong(c,o->refcount);
	545	} else if (!strcasecmp(c->argv[1]->ptr,"encoding") && c->argc == 3) {
	546	if ((o = objectCommandLookupOrReply(c,c->argv[2],shared.nullbulk))
	547	== NULL) return;
	548	addReplyBulkCString(c,strEncoding(o->encoding));
	549	} else if (!strcasecmp(c->argv[1]->ptr,"idletime") && c->argc == 3) {
	550	if ((o = objectCommandLookupOrReply(c,c->argv[2],shared.nullbulk))
	551	== NULL) return;
	552	addReplyLongLong(c,estimateObjectIdleTime(o));
	553	} else {
	554	addReplyError(c,"Syntax error. Try OBJECT (refcount\|encoding\|idletime)");
	555	}
	556	}
	557