src/sort.c

#include "redis.h"
#include "pqsort.h" /* Partial qsort for SORT+LIMIT */

redisSortOperation *createSortOperation(int type, robj *pattern) {
    redisSortOperation *so = zmalloc(sizeof(*so));
    so->type = type;
    so->pattern = pattern;
    return so;
}

/* Return the value associated to the key with a name obtained
 * substituting the first occurence of '*' in 'pattern' with 'subst'.
 * The returned object will always have its refcount increased by 1
 * when it is non-NULL. */
robj *lookupKeyByPattern(redisDb *db, robj *pattern, robj *subst) {
    char *p, *f;
    sds spat, ssub;
    robj keyobj, fieldobj, *o;
    int prefixlen, sublen, postfixlen, fieldlen;
    /* Expoit the internal sds representation to create a sds string allocated on the stack in order to make this function faster */
    struct {
        int len;
        int free;
        char buf[REDIS_SORTKEY_MAX+1];
    } keyname, fieldname;

    /* If the pattern is "#" return the substitution object itself in order
     * to implement the "SORT ... GET #" feature. */
    spat = pattern->ptr;
    if (spat[0] == '#' && spat[1] == '\0') {
        incrRefCount(subst);
        return subst;
    }

    /* The substitution object may be specially encoded. If so we create
     * a decoded object on the fly. Otherwise getDecodedObject will just
     * increment the ref count, that we'll decrement later. */
    subst = getDecodedObject(subst);

    ssub = subst->ptr;
    if (sdslen(spat)+sdslen(ssub)-1 > REDIS_SORTKEY_MAX) return NULL;
    p = strchr(spat,'*');
    if (!p) {
        decrRefCount(subst);
        return NULL;
    }

    /* Find out if we're dealing with a hash dereference. */
    if ((f = strstr(p+1, "->")) != NULL) {
        fieldlen = sdslen(spat)-(f-spat);
        /* this also copies \0 character */
        memcpy(fieldname.buf,f+2,fieldlen-1);
        fieldname.len = fieldlen-2;
    } else {
        fieldlen = 0;
    }

    prefixlen = p-spat;
    sublen = sdslen(ssub);
    postfixlen = sdslen(spat)-(prefixlen+1)-fieldlen;
    memcpy(keyname.buf,spat,prefixlen);
    memcpy(keyname.buf+prefixlen,ssub,sublen);
    memcpy(keyname.buf+prefixlen+sublen,p+1,postfixlen);
    keyname.buf[prefixlen+sublen+postfixlen] = '\0';
    keyname.len = prefixlen+sublen+postfixlen;
    decrRefCount(subst);

    /* Lookup substituted key */
    initStaticStringObject(keyobj,((char*)&keyname)+(sizeof(struct sdshdr)));
    o = lookupKeyRead(db,&keyobj);
    if (o == NULL) return NULL;

    if (fieldlen > 0) {
        if (o->type != REDIS_HASH || fieldname.len < 1) return NULL;

        /* Retrieve value from hash by the field name. This operation
         * already increases the refcount of the returned object. */
        initStaticStringObject(fieldobj,((char*)&fieldname)+(sizeof(struct sdshdr)));
        o = hashTypeGetObject(o, &fieldobj);
    } else {
        if (o->type != REDIS_STRING) return NULL;

        /* Every object that this function returns needs to have its refcount
         * increased. sortCommand decreases it again. */
        incrRefCount(o);
    }

    return o;
}

/* sortCompare() is used by qsort in sortCommand(). Given that qsort_r with
 * the additional parameter is not standard but a BSD-specific we have to
 * pass sorting parameters via the global 'server' structure */
int sortCompare(const void *s1, const void *s2) {
    const redisSortObject *so1 = s1, *so2 = s2;
    int cmp;

    if (!server.sort_alpha) {
        /* Numeric sorting. Here it's trivial as we precomputed scores */
        if (so1->u.score > so2->u.score) {
            cmp = 1;
        } else if (so1->u.score < so2->u.score) {
            cmp = -1;
        } else {
            cmp = 0;
        }
    } else {
        /* Alphanumeric sorting */
        if (server.sort_bypattern) {
            if (!so1->u.cmpobj || !so2->u.cmpobj) {
                /* At least one compare object is NULL */
                if (so1->u.cmpobj == so2->u.cmpobj)
                    cmp = 0;
                else if (so1->u.cmpobj == NULL)
                    cmp = -1;
                else
                    cmp = 1;
            } else {
                /* We have both the objects, use strcoll */
                cmp = strcoll(so1->u.cmpobj->ptr,so2->u.cmpobj->ptr);
            }
        } else {
            /* Compare elements directly. */
            cmp = compareStringObjects(so1->obj,so2->obj);
        }
    }
    return server.sort_desc ? -cmp : cmp;
}

/* The SORT command is the most complex command in Redis. Warning: this code
 * is optimized for speed and a bit less for readability */
void sortCommand(redisClient *c) {
    list *operations;
    unsigned int outputlen = 0;
    int desc = 0, alpha = 0;
    int limit_start = 0, limit_count = -1, start, end;
    int j, dontsort = 0, vectorlen;
    int getop = 0; /* GET operation counter */
    robj *sortval, *sortby = NULL, *storekey = NULL;
    redisSortObject *vector; /* Resulting vector to sort */

    /* Lookup the key to sort. It must be of the right types */
    sortval = lookupKeyRead(c->db,c->argv[1]);
    if (sortval == NULL) {
        addReply(c,shared.emptymultibulk);
        return;
    }
    if (sortval->type != REDIS_SET && sortval->type != REDIS_LIST &&
        sortval->type != REDIS_ZSET)
    {
        addReply(c,shared.wrongtypeerr);
        return;
    }

    /* Create a list of operations to perform for every sorted element.
     * Operations can be GET/DEL/INCR/DECR */
    operations = listCreate();
    listSetFreeMethod(operations,zfree);
    j = 2;

    /* Now we need to protect sortval incrementing its count, in the future
     * SORT may have options able to overwrite/delete keys during the sorting
     * and the sorted key itself may get destroied */
    incrRefCount(sortval);

    /* The SORT command has an SQL-alike syntax, parse it */
    while(j < c->argc) {
        int leftargs = c->argc-j-1;
        if (!strcasecmp(c->argv[j]->ptr,"asc")) {
            desc = 0;
        } else if (!strcasecmp(c->argv[j]->ptr,"desc")) {
            desc = 1;
        } else if (!strcasecmp(c->argv[j]->ptr,"alpha")) {
            alpha = 1;
        } else if (!strcasecmp(c->argv[j]->ptr,"limit") && leftargs >= 2) {
            limit_start = atoi(c->argv[j+1]->ptr);
            limit_count = atoi(c->argv[j+2]->ptr);
            j+=2;
        } else if (!strcasecmp(c->argv[j]->ptr,"store") && leftargs >= 1) {
            storekey = c->argv[j+1];
            j++;
        } else if (!strcasecmp(c->argv[j]->ptr,"by") && leftargs >= 1) {
            sortby = c->argv[j+1];
            /* If the BY pattern does not contain '*', i.e. it is constant,
             * we don't need to sort nor to lookup the weight keys. */
            if (strchr(c->argv[j+1]->ptr,'*') == NULL) dontsort = 1;
            j++;
        } else if (!strcasecmp(c->argv[j]->ptr,"get") && leftargs >= 1) {
            listAddNodeTail(operations,createSortOperation(
                REDIS_SORT_GET,c->argv[j+1]));
            getop++;
            j++;
        } else {
            decrRefCount(sortval);
            listRelease(operations);
            addReply(c,shared.syntaxerr);
            return;
        }
        j++;
    }

    /* Destructively convert encoded sorted sets for SORT. */
    if (sortval->type == REDIS_ZSET) zsetConvert(sortval, REDIS_ENCODING_SKIPLIST);

    /* Load the sorting vector with all the objects to sort */
    switch(sortval->type) {
    case REDIS_LIST: vectorlen = listTypeLength(sortval); break;
    case REDIS_SET: vectorlen =  setTypeSize(sortval); break;
    case REDIS_ZSET: vectorlen = dictSize(((zset*)sortval->ptr)->dict); break;
    default: vectorlen = 0; redisPanic("Bad SORT type"); /* Avoid GCC warning */
    }
    vector = zmalloc(sizeof(redisSortObject)*vectorlen);
    j = 0;

    if (sortval->type == REDIS_LIST) {
        listTypeIterator *li = listTypeInitIterator(sortval,0,REDIS_TAIL);
        listTypeEntry entry;
        while(listTypeNext(li,&entry)) {
            vector[j].obj = listTypeGet(&entry);
            vector[j].u.score = 0;
            vector[j].u.cmpobj = NULL;
            j++;
        }
        listTypeReleaseIterator(li);
    } else if (sortval->type == REDIS_SET) {
        setTypeIterator *si = setTypeInitIterator(sortval);
        robj *ele;
        while((ele = setTypeNextObject(si)) != NULL) {
            vector[j].obj = ele;
            vector[j].u.score = 0;
            vector[j].u.cmpobj = NULL;
            j++;
        }
        setTypeReleaseIterator(si);
    } else if (sortval->type == REDIS_ZSET) {
        dict *set = ((zset*)sortval->ptr)->dict;
        dictIterator *di;
        dictEntry *setele;
        di = dictGetIterator(set);
        while((setele = dictNext(di)) != NULL) {
            vector[j].obj = dictGetEntryKey(setele);
            vector[j].u.score = 0;
            vector[j].u.cmpobj = NULL;
            j++;
        }
        dictReleaseIterator(di);
    } else {
        redisPanic("Unknown type");
    }
    redisAssert(j == vectorlen);

    /* Now it's time to load the right scores in the sorting vector */
    if (dontsort == 0) {
        for (j = 0; j < vectorlen; j++) {
            robj *byval;
            if (sortby) {
                /* lookup value to sort by */
                byval = lookupKeyByPattern(c->db,sortby,vector[j].obj);
                if (!byval) continue;
            } else {
                /* use object itself to sort by */
                byval = vector[j].obj;
            }

            if (alpha) {
                if (sortby) vector[j].u.cmpobj = getDecodedObject(byval);
            } else {
                if (byval->encoding == REDIS_ENCODING_RAW) {
                    vector[j].u.score = strtod(byval->ptr,NULL);
                } else if (byval->encoding == REDIS_ENCODING_INT) {
                    /* Don't need to decode the object if it's
                     * integer-encoded (the only encoding supported) so
                     * far. We can just cast it */
                    vector[j].u.score = (long)byval->ptr;
                } else {
                    redisAssert(1 != 1);
                }
            }

            /* when the object was retrieved using lookupKeyByPattern,
             * its refcount needs to be decreased. */
            if (sortby) {
                decrRefCount(byval);
            }
        }
    }

    /* We are ready to sort the vector... perform a bit of sanity check
     * on the LIMIT option too. We'll use a partial version of quicksort. */
    start = (limit_start < 0) ? 0 : limit_start;
    end = (limit_count < 0) ? vectorlen-1 : start+limit_count-1;
    if (start >= vectorlen) {
        start = vectorlen-1;
        end = vectorlen-2;
    }
    if (end >= vectorlen) end = vectorlen-1;

    if (dontsort == 0) {
        server.sort_desc = desc;
        server.sort_alpha = alpha;
        server.sort_bypattern = sortby ? 1 : 0;
        if (sortby && (start != 0 || end != vectorlen-1))
            pqsort(vector,vectorlen,sizeof(redisSortObject),sortCompare, start,end);
        else
            qsort(vector,vectorlen,sizeof(redisSortObject),sortCompare);
    }

    /* Send command output to the output buffer, performing the specified
     * GET/DEL/INCR/DECR operations if any. */
    outputlen = getop ? getop*(end-start+1) : end-start+1;
    if (storekey == NULL) {
        /* STORE option not specified, sent the sorting result to client */
        addReplyMultiBulkLen(c,outputlen);
        for (j = start; j <= end; j++) {
            listNode *ln;
            listIter li;

            if (!getop) addReplyBulk(c,vector[j].obj);
            listRewind(operations,&li);
            while((ln = listNext(&li))) {
                redisSortOperation *sop = ln->value;
                robj *val = lookupKeyByPattern(c->db,sop->pattern,
                    vector[j].obj);

                if (sop->type == REDIS_SORT_GET) {
                    if (!val) {
                        addReply(c,shared.nullbulk);
                    } else {
                        addReplyBulk(c,val);
                        decrRefCount(val);
                    }
                } else {
                    redisAssert(sop->type == REDIS_SORT_GET); /* always fails */
                }
            }
        }
    } else {
        robj *sobj = createZiplistObject();

        /* STORE option specified, set the sorting result as a List object */
        for (j = start; j <= end; j++) {
            listNode *ln;
            listIter li;

            if (!getop) {
                listTypePush(sobj,vector[j].obj,REDIS_TAIL);
            } else {
                listRewind(operations,&li);
                while((ln = listNext(&li))) {
                    redisSortOperation *sop = ln->value;
                    robj *val = lookupKeyByPattern(c->db,sop->pattern,
                        vector[j].obj);

                    if (sop->type == REDIS_SORT_GET) {
                        if (!val) val = createStringObject("",0);

                        /* listTypePush does an incrRefCount, so we should take care
                         * care of the incremented refcount caused by either
                         * lookupKeyByPattern or createStringObject("",0) */
                        listTypePush(sobj,val,REDIS_TAIL);
                        decrRefCount(val);
                    } else {
                        /* always fails */
                        redisAssert(sop->type == REDIS_SORT_GET);
                    }
                }
            }
        }
        setKey(c->db,storekey,sobj);
        decrRefCount(sobj);
        /* Note: we add 1 because the DB is dirty anyway since even if the
         * SORT result is empty a new key is set and maybe the old content
         * replaced. */
        server.dirty += 1+outputlen;
        addReplyLongLong(c,outputlen);
    }

    /* Cleanup */
    if (sortval->type == REDIS_LIST || sortval->type == REDIS_SET)
        for (j = 0; j < vectorlen; j++)
            decrRefCount(vector[j].obj);
    decrRefCount(sortval);
    listRelease(operations);
    for (j = 0; j < vectorlen; j++) {
        if (alpha && vector[j].u.cmpobj)
            decrRefCount(vector[j].u.cmpobj);
    }
    zfree(vector);
}
Commit	Line	Data
	1	#include "redis.h"
	2	#include "pqsort.h" /* Partial qsort for SORT+LIMIT */
	3
	4	redisSortOperation createSortOperation(int type, robj pattern) {
	5	redisSortOperation so = zmalloc(sizeof(so));
	6	so->type = type;
	7	so->pattern = pattern;
	8	return so;
	9	}
	10
	11	/* Return the value associated to the key with a name obtained
	12	* substituting the first occurence of '*' in 'pattern' with 'subst'.
	13	* The returned object will always have its refcount increased by 1
	14	* when it is non-NULL. */
	15	robj lookupKeyByPattern(redisDb db, robj pattern, robj subst) {
	16	char p, f;
	17	sds spat, ssub;
	18	robj keyobj, fieldobj, *o;
	19	int prefixlen, sublen, postfixlen, fieldlen;
	20	/* Expoit the internal sds representation to create a sds string allocated on the stack in order to make this function faster */
	21	struct {
	22	int len;
	23	int free;
	24	char buf[REDIS_SORTKEY_MAX+1];
	25	} keyname, fieldname;
	26
	27	/* If the pattern is "#" return the substitution object itself in order
	28	* to implement the "SORT ... GET #" feature. */
	29	spat = pattern->ptr;
	30	if (spat[0] == '#' && spat[1] == '\0') {
	31	incrRefCount(subst);
	32	return subst;
	33	}
	34
	35	/* The substitution object may be specially encoded. If so we create
	36	* a decoded object on the fly. Otherwise getDecodedObject will just
	37	* increment the ref count, that we'll decrement later. */
	38	subst = getDecodedObject(subst);
	39
	40	ssub = subst->ptr;
	41	if (sdslen(spat)+sdslen(ssub)-1 > REDIS_SORTKEY_MAX) return NULL;
	42	p = strchr(spat,'*');
	43	if (!p) {
	44	decrRefCount(subst);
	45	return NULL;
	46	}
	47
	48	/* Find out if we're dealing with a hash dereference. */
	49	if ((f = strstr(p+1, "->")) != NULL) {
	50	fieldlen = sdslen(spat)-(f-spat);
	51	/* this also copies \0 character */
	52	memcpy(fieldname.buf,f+2,fieldlen-1);
	53	fieldname.len = fieldlen-2;
	54	} else {
	55	fieldlen = 0;
	56	}
	57
	58	prefixlen = p-spat;
	59	sublen = sdslen(ssub);
	60	postfixlen = sdslen(spat)-(prefixlen+1)-fieldlen;
	61	memcpy(keyname.buf,spat,prefixlen);
	62	memcpy(keyname.buf+prefixlen,ssub,sublen);
	63	memcpy(keyname.buf+prefixlen+sublen,p+1,postfixlen);
	64	keyname.buf[prefixlen+sublen+postfixlen] = '\0';
	65	keyname.len = prefixlen+sublen+postfixlen;
	66	decrRefCount(subst);
	67
	68	/* Lookup substituted key */
	69	initStaticStringObject(keyobj,((char*)&keyname)+(sizeof(struct sdshdr)));
	70	o = lookupKeyRead(db,&keyobj);
	71	if (o == NULL) return NULL;
	72
	73	if (fieldlen > 0) {
	74	if (o->type != REDIS_HASH \|\| fieldname.len < 1) return NULL;
	75
	76	/* Retrieve value from hash by the field name. This operation
	77	* already increases the refcount of the returned object. */
	78	initStaticStringObject(fieldobj,((char*)&fieldname)+(sizeof(struct sdshdr)));
	79	o = hashTypeGetObject(o, &fieldobj);
	80	} else {
	81	if (o->type != REDIS_STRING) return NULL;
	82
	83	/* Every object that this function returns needs to have its refcount
	84	* increased. sortCommand decreases it again. */
	85	incrRefCount(o);
	86	}
	87
	88	return o;
	89	}
	90
	91	/* sortCompare() is used by qsort in sortCommand(). Given that qsort_r with
	92	* the additional parameter is not standard but a BSD-specific we have to
	93	* pass sorting parameters via the global 'server' structure */
	94	int sortCompare(const void s1, const void s2) {
	95	const redisSortObject so1 = s1, so2 = s2;
	96	int cmp;
	97
	98	if (!server.sort_alpha) {
	99	/* Numeric sorting. Here it's trivial as we precomputed scores */
	100	if (so1->u.score > so2->u.score) {
	101	cmp = 1;
	102	} else if (so1->u.score < so2->u.score) {
	103	cmp = -1;
	104	} else {
	105	cmp = 0;
	106	}
	107	} else {
	108	/* Alphanumeric sorting */
	109	if (server.sort_bypattern) {
	110	if (!so1->u.cmpobj \|\| !so2->u.cmpobj) {
	111	/* At least one compare object is NULL */
	112	if (so1->u.cmpobj == so2->u.cmpobj)
	113	cmp = 0;
	114	else if (so1->u.cmpobj == NULL)
	115	cmp = -1;
	116	else
	117	cmp = 1;
	118	} else {
	119	/* We have both the objects, use strcoll */
	120	cmp = strcoll(so1->u.cmpobj->ptr,so2->u.cmpobj->ptr);
	121	}
	122	} else {
	123	/* Compare elements directly. */
	124	cmp = compareStringObjects(so1->obj,so2->obj);
	125	}
	126	}
	127	return server.sort_desc ? -cmp : cmp;
	128	}
	129
	130	/* The SORT command is the most complex command in Redis. Warning: this code
	131	* is optimized for speed and a bit less for readability */
	132	void sortCommand(redisClient *c) {
	133	list *operations;
	134	unsigned int outputlen = 0;
	135	int desc = 0, alpha = 0;
	136	int limit_start = 0, limit_count = -1, start, end;
	137	int j, dontsort = 0, vectorlen;
	138	int getop = 0; /* GET operation counter */
	139	robj sortval, sortby = NULL, *storekey = NULL;
	140	redisSortObject vector; / Resulting vector to sort */
	141
	142	/* Lookup the key to sort. It must be of the right types */
	143	sortval = lookupKeyRead(c->db,c->argv[1]);
	144	if (sortval == NULL) {
	145	addReply(c,shared.emptymultibulk);
	146	return;
	147	}
	148	if (sortval->type != REDIS_SET && sortval->type != REDIS_LIST &&
	149	sortval->type != REDIS_ZSET)
	150	{
	151	addReply(c,shared.wrongtypeerr);
	152	return;
	153	}
	154
	155	/* Create a list of operations to perform for every sorted element.
	156	* Operations can be GET/DEL/INCR/DECR */
	157	operations = listCreate();
	158	listSetFreeMethod(operations,zfree);
	159	j = 2;
	160
	161	/* Now we need to protect sortval incrementing its count, in the future
	162	* SORT may have options able to overwrite/delete keys during the sorting
	163	* and the sorted key itself may get destroied */
	164	incrRefCount(sortval);
	165
	166	/* The SORT command has an SQL-alike syntax, parse it */
	167	while(j < c->argc) {
	168	int leftargs = c->argc-j-1;
	169	if (!strcasecmp(c->argv[j]->ptr,"asc")) {
	170	desc = 0;
	171	} else if (!strcasecmp(c->argv[j]->ptr,"desc")) {
	172	desc = 1;
	173	} else if (!strcasecmp(c->argv[j]->ptr,"alpha")) {
	174	alpha = 1;
	175	} else if (!strcasecmp(c->argv[j]->ptr,"limit") && leftargs >= 2) {
	176	limit_start = atoi(c->argv[j+1]->ptr);
	177	limit_count = atoi(c->argv[j+2]->ptr);
	178	j+=2;
	179	} else if (!strcasecmp(c->argv[j]->ptr,"store") && leftargs >= 1) {
	180	storekey = c->argv[j+1];
	181	j++;
	182	} else if (!strcasecmp(c->argv[j]->ptr,"by") && leftargs >= 1) {
	183	sortby = c->argv[j+1];
	184	/* If the BY pattern does not contain '*', i.e. it is constant,
	185	* we don't need to sort nor to lookup the weight keys. */
	186	if (strchr(c->argv[j+1]->ptr,'*') == NULL) dontsort = 1;
	187	j++;
	188	} else if (!strcasecmp(c->argv[j]->ptr,"get") && leftargs >= 1) {
	189	listAddNodeTail(operations,createSortOperation(
	190	REDIS_SORT_GET,c->argv[j+1]));
	191	getop++;
	192	j++;
	193	} else {
	194	decrRefCount(sortval);
	195	listRelease(operations);
	196	addReply(c,shared.syntaxerr);
	197	return;
	198	}
	199	j++;
	200	}
	201
	202	/* Destructively convert encoded sorted sets for SORT. */
	203	if (sortval->type == REDIS_ZSET) zsetConvert(sortval, REDIS_ENCODING_SKIPLIST);
	204
	205	/* Load the sorting vector with all the objects to sort */
	206	switch(sortval->type) {
	207	case REDIS_LIST: vectorlen = listTypeLength(sortval); break;
	208	case REDIS_SET: vectorlen = setTypeSize(sortval); break;
	209	case REDIS_ZSET: vectorlen = dictSize(((zset*)sortval->ptr)->dict); break;
	210	default: vectorlen = 0; redisPanic("Bad SORT type"); /* Avoid GCC warning */
	211	}
	212	vector = zmalloc(sizeof(redisSortObject)*vectorlen);
	213	j = 0;
	214
	215	if (sortval->type == REDIS_LIST) {
	216	listTypeIterator *li = listTypeInitIterator(sortval,0,REDIS_TAIL);
	217	listTypeEntry entry;
	218	while(listTypeNext(li,&entry)) {
	219	vector[j].obj = listTypeGet(&entry);
	220	vector[j].u.score = 0;
	221	vector[j].u.cmpobj = NULL;
	222	j++;
	223	}
	224	listTypeReleaseIterator(li);
	225	} else if (sortval->type == REDIS_SET) {
	226	setTypeIterator *si = setTypeInitIterator(sortval);
	227	robj *ele;
	228	while((ele = setTypeNextObject(si)) != NULL) {
	229	vector[j].obj = ele;
	230	vector[j].u.score = 0;
	231	vector[j].u.cmpobj = NULL;
	232	j++;
	233	}
	234	setTypeReleaseIterator(si);
	235	} else if (sortval->type == REDIS_ZSET) {
	236	dict set = ((zset)sortval->ptr)->dict;
	237	dictIterator *di;
	238	dictEntry *setele;
	239	di = dictGetIterator(set);
	240	while((setele = dictNext(di)) != NULL) {
	241	vector[j].obj = dictGetEntryKey(setele);
	242	vector[j].u.score = 0;
	243	vector[j].u.cmpobj = NULL;
	244	j++;
	245	}
	246	dictReleaseIterator(di);
	247	} else {
	248	redisPanic("Unknown type");
	249	}
	250	redisAssert(j == vectorlen);
	251
	252	/* Now it's time to load the right scores in the sorting vector */
	253	if (dontsort == 0) {
	254	for (j = 0; j < vectorlen; j++) {
	255	robj *byval;
	256	if (sortby) {
	257	/* lookup value to sort by */
	258	byval = lookupKeyByPattern(c->db,sortby,vector[j].obj);
	259	if (!byval) continue;
	260	} else {
	261	/* use object itself to sort by */
	262	byval = vector[j].obj;
	263	}
	264
	265	if (alpha) {
	266	if (sortby) vector[j].u.cmpobj = getDecodedObject(byval);
	267	} else {
	268	if (byval->encoding == REDIS_ENCODING_RAW) {
	269	vector[j].u.score = strtod(byval->ptr,NULL);
	270	} else if (byval->encoding == REDIS_ENCODING_INT) {
	271	/* Don't need to decode the object if it's
	272	* integer-encoded (the only encoding supported) so
	273	* far. We can just cast it */
	274	vector[j].u.score = (long)byval->ptr;
	275	} else {
	276	redisAssert(1 != 1);
	277	}
	278	}
	279
	280	/* when the object was retrieved using lookupKeyByPattern,
	281	* its refcount needs to be decreased. */
	282	if (sortby) {
	283	decrRefCount(byval);
	284	}
	285	}
	286	}
	287
	288	/* We are ready to sort the vector... perform a bit of sanity check
	289	* on the LIMIT option too. We'll use a partial version of quicksort. */
	290	start = (limit_start < 0) ? 0 : limit_start;
	291	end = (limit_count < 0) ? vectorlen-1 : start+limit_count-1;
	292	if (start >= vectorlen) {
	293	start = vectorlen-1;
	294	end = vectorlen-2;
	295	}
	296	if (end >= vectorlen) end = vectorlen-1;
	297
	298	if (dontsort == 0) {
	299	server.sort_desc = desc;
	300	server.sort_alpha = alpha;
	301	server.sort_bypattern = sortby ? 1 : 0;
	302	if (sortby && (start != 0 \|\| end != vectorlen-1))
	303	pqsort(vector,vectorlen,sizeof(redisSortObject),sortCompare, start,end);
	304	else
	305	qsort(vector,vectorlen,sizeof(redisSortObject),sortCompare);
	306	}
	307
	308	/* Send command output to the output buffer, performing the specified
	309	* GET/DEL/INCR/DECR operations if any. */
	310	outputlen = getop ? getop*(end-start+1) : end-start+1;
	311	if (storekey == NULL) {
	312	/* STORE option not specified, sent the sorting result to client */
	313	addReplyMultiBulkLen(c,outputlen);
	314	for (j = start; j <= end; j++) {
	315	listNode *ln;
	316	listIter li;
	317
	318	if (!getop) addReplyBulk(c,vector[j].obj);
	319	listRewind(operations,&li);
	320	while((ln = listNext(&li))) {
	321	redisSortOperation *sop = ln->value;
	322	robj *val = lookupKeyByPattern(c->db,sop->pattern,
	323	vector[j].obj);
	324
	325	if (sop->type == REDIS_SORT_GET) {
	326	if (!val) {
	327	addReply(c,shared.nullbulk);
	328	} else {
	329	addReplyBulk(c,val);
	330	decrRefCount(val);
	331	}
	332	} else {
	333	redisAssert(sop->type == REDIS_SORT_GET); /* always fails */
	334	}
	335	}
	336	}
	337	} else {
	338	robj *sobj = createZiplistObject();
	339
	340	/* STORE option specified, set the sorting result as a List object */
	341	for (j = start; j <= end; j++) {
	342	listNode *ln;
	343	listIter li;
	344
	345	if (!getop) {
	346	listTypePush(sobj,vector[j].obj,REDIS_TAIL);
	347	} else {
	348	listRewind(operations,&li);
	349	while((ln = listNext(&li))) {
	350	redisSortOperation *sop = ln->value;
	351	robj *val = lookupKeyByPattern(c->db,sop->pattern,
	352	vector[j].obj);
	353
	354	if (sop->type == REDIS_SORT_GET) {
	355	if (!val) val = createStringObject("",0);
	356
	357	/* listTypePush does an incrRefCount, so we should take care
	358	* care of the incremented refcount caused by either
	359	* lookupKeyByPattern or createStringObject("",0) */
	360	listTypePush(sobj,val,REDIS_TAIL);
	361	decrRefCount(val);
	362	} else {
	363	/* always fails */
	364	redisAssert(sop->type == REDIS_SORT_GET);
	365	}
	366	}
	367	}
	368	}
	369	setKey(c->db,storekey,sobj);
	370	decrRefCount(sobj);
	371	/* Note: we add 1 because the DB is dirty anyway since even if the
	372	* SORT result is empty a new key is set and maybe the old content
	373	* replaced. */
	374	server.dirty += 1+outputlen;
	375	addReplyLongLong(c,outputlen);
	376	}
	377
	378	/* Cleanup */
	379	if (sortval->type == REDIS_LIST \|\| sortval->type == REDIS_SET)
	380	for (j = 0; j < vectorlen; j++)
	381	decrRefCount(vector[j].obj);
	382	decrRefCount(sortval);
	383	listRelease(operations);
	384	for (j = 0; j < vectorlen; j++) {
	385	if (alpha && vector[j].u.cmpobj)
	386	decrRefCount(vector[j].u.cmpobj);
	387	}
	388	zfree(vector);
	389	}
	390
	391