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lookup rank of a zset entry in a different function

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Pieter Noordhuis 2010-03-04 13:34:50 +01:00
parent 8fe7fad771
commit 27b0ccca71
1 changed files with 43 additions and 32 deletions
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75
redis.c
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@ -5054,6 +5054,33 @@ static zskiplistNode *zslFirstWithScore(zskiplist *zsl, double score) {
return x->forward[0];
}
/* Find the rank for an element by both score and key.
* Returns 0 when the element cannot be found, rank otherwise.
* Note that the rank is 1-based due to the span of zsl->header to the
* first element. */
static unsigned long zslGetRank(zskiplist *zsl, double score, robj *o) {
zskiplistNode *x;
unsigned long rank = 0;
int i;
x = zsl->header;
for (i = zsl->level-1; i >= 0; i--) {
while (x->forward[i] &&
(x->forward[i]->score < score ||
(x->forward[i]->score == score &&
compareStringObjects(x->forward[i]->obj,o) <= 0))) {
rank += x->span[i];
x = x->forward[i];
}
/* x might be equal to zsl->header, so test if obj is non-NULL */
if (x->obj && compareStringObjects(x->obj,o) == 0) {
return rank;
}
}
return 0;
}
/* The actual Z-commands implementations */
/* This generic command implements both ZADD and ZINCRBY.
@ -5467,42 +5494,26 @@ static void zrankCommand(redisClient *c) {
}
if (o->type != REDIS_ZSET) {
addReply(c,shared.wrongtypeerr);
return;
}
} else {
zset *zs = o->ptr;
zskiplist *zsl = zs->zsl;
dictEntry *de;
unsigned long rank;
zset *zs = o->ptr;
zskiplist *zsl = zs->zsl;
dictEntry *de = dictFind(zs->dict,c->argv[2]);
if (!de) {
addReply(c,shared.nullbulk);
return;
}
double *score = dictGetEntryVal(de);
zskiplistNode *x;
unsigned int rank = 0;
int i;
x = zsl->header;
for (i = zsl->level-1; i >= 0; i--) {
while (x->forward[i] &&
(x->forward[i]->score < *score ||
(x->forward[i]->score == *score &&
compareStringObjects(x->forward[i]->obj,c->argv[2]) <= 0))) {
rank += x->span[i];
x = x->forward[i];
}
/* x might be equal to zsl->header, so test if obj is non-NULL */
if (x->obj && compareStringObjects(x->obj,c->argv[2]) == 0) {
/* the pointer from zsl->header to the first element also spans one,
* which makes the rank 1-based */
addReplyLong(c, rank-1);
de = dictFind(zs->dict,c->argv[2]);
if (!de) {
addReply(c,shared.nullbulk);
return;
}
}
addReply(c,shared.nullbulk);
double *score = dictGetEntryVal(de);
rank = zslGetRank(zsl, *score, c->argv[2]);
if (rank) {
addReplyLong(c, rank-1);
} else {
addReply(c,shared.nullbulk);
}
}
}
/* ========================= Non type-specific commands ==================== */