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update LREM to support dual encoding via extra iteration primitives

This commit is contained in:
Pieter Noordhuis 2010-05-30 02:17:36 +02:00
parent 9ae6b0be4a
commit d2ee16abec
1 changed files with 68 additions and 17 deletions
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85
redis.c
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@ -4864,6 +4864,17 @@ static void lReleaseIterator(lIterator *li) {
zfree(li);
}
/* Whether the entry pointed at is a valid entry. */
static int lIsEntry(lIterator *li) {
if (li->encoding == REDIS_ENCODING_ZIPLIST) {
return li->zi != NULL;
} else if (li->encoding == REDIS_ENCODING_LIST) {
return li->ln != NULL;
} else {
redisPanic("Unknown list encoding");
}
}
/* Return entry or NULL at the current position of the iterator. */
static robj *lGet(lIterator *li) {
robj *value = NULL;
@ -4889,6 +4900,36 @@ static robj *lGet(lIterator *li) {
return value;
}
/* Delete the element pointed to. */
static void lDelete(lIterator *li, int direction) {
if (li->encoding == REDIS_ENCODING_ZIPLIST) {
direction = (direction == REDIS_HEAD) ? ZIPLIST_HEAD : ZIPLIST_TAIL;
li->subject->ptr = ziplistDelete(li->subject->ptr,&li->zi,direction);
} else if (li->encoding == REDIS_ENCODING_LIST) {
listNode *next;
if (direction == REDIS_HEAD)
next = li->ln->prev;
else
next = li->ln->next;
listDelNode(li->subject->ptr,li->ln);
li->ln = next;
} else {
redisPanic("Unknown list encoding");
}
}
/* Compare the given object with the entry at the current position. */
static int lEqualTo(lIterator *li, robj *o) {
if (li->encoding == REDIS_ENCODING_ZIPLIST) {
redisAssert(o->encoding == REDIS_ENCODING_RAW);
return ziplistCompare(li->zi,o->ptr,sdslen(o->ptr));
} else if (li->encoding == REDIS_ENCODING_LIST) {
return equalStringObjects(o,listNodeValue(li->ln));
} else {
redisPanic("Unknown list encoding");
}
}
/* Move to the next or previous entry in the list. */
static void lMove(lIterator *li, int where) {
if (li->encoding == REDIS_ENCODING_ZIPLIST) {
@ -5129,35 +5170,45 @@ static void ltrimCommand(redisClient *c) {
}
static void lremCommand(redisClient *c) {
robj *o;
list *list;
listNode *ln, *next;
robj *subject, *obj = c->argv[3];
int toremove = atoi(c->argv[2]->ptr);
int removed = 0;
int fromtail = 0;
int direction;
if ((o = lookupKeyWriteOrReply(c,c->argv[1],shared.czero)) == NULL ||
checkType(c,o,REDIS_LIST)) return;
list = o->ptr;
subject = lookupKeyWriteOrReply(c,c->argv[1],shared.czero);
if (subject == NULL || checkType(c,subject,REDIS_LIST)) return;
/* Make sure obj is raw when we're dealing with a ziplist */
if (subject->encoding == REDIS_ENCODING_ZIPLIST)
obj = getDecodedObject(obj);
lIterator *li;
if (toremove < 0) {
toremove = -toremove;
fromtail = 1;
direction = REDIS_HEAD;
li = lInitIterator(subject,-1);
} else {
direction = REDIS_TAIL;
li = lInitIterator(subject,0);
}
ln = fromtail ? list->tail : list->head;
while (ln) {
robj *ele = listNodeValue(ln);
next = fromtail ? ln->prev : ln->next;
if (equalStringObjects(ele,c->argv[3])) {
listDelNode(list,ln);
while (toremove && lIsEntry(li)) {
if (lEqualTo(li,obj)) {
lDelete(li,direction);
server.dirty++;
toremove--;
removed++;
if (toremove && removed == toremove) break;
} else {
lMove(li,direction);
}
ln = next;
}
if (listLength(list) == 0) deleteKey(c->db,c->argv[1]);
lReleaseIterator(li);
/* Clean up raw encoded object */
if (subject->encoding == REDIS_ENCODING_ZIPLIST)
decrRefCount(obj);
if (lLength(subject) == 0) deleteKey(c->db,c->argv[1]);
addReplySds(c,sdscatprintf(sdsempty(),":%d\r\n",removed));
}