+#define REDIS_OP_UNION 0
+#define REDIS_OP_DIFF 1
+
+static void sunionDiffGenericCommand(redisClient *c, robj **setskeys, int setsnum, robj *dstkey, int op) {
+ dict **dv = zmalloc(sizeof(dict*)*setsnum);
+ dictIterator *di;
+ dictEntry *de;
+ robj *dstset = NULL;
+ int j, cardinality = 0;
+
+ if (!dv) oom("sunionDiffGenericCommand");
+ for (j = 0; j < setsnum; j++) {
+ robj *setobj;
+
+ setobj = dstkey ?
+ lookupKeyWrite(c->db,setskeys[j]) :
+ lookupKeyRead(c->db,setskeys[j]);
+ if (!setobj) {
+ dv[j] = NULL;
+ continue;
+ }
+ if (setobj->type != REDIS_SET) {
+ zfree(dv);
+ addReply(c,shared.wrongtypeerr);
+ return;
+ }
+ dv[j] = setobj->ptr;
+ }
+
+ /* We need a temp set object to store our union. If the dstkey
+ * is not NULL (that is, we are inside an SUNIONSTORE operation) then
+ * this set object will be the resulting object to set into the target key*/
+ dstset = createSetObject();
+
+ /* Iterate all the elements of all the sets, add every element a single
+ * time to the result set */
+ for (j = 0; j < setsnum; j++) {
+ if (op == REDIS_OP_DIFF && j == 0 && !dv[j]) break; /* result set is empty */
+ if (!dv[j]) continue; /* non existing keys are like empty sets */
+
+ di = dictGetIterator(dv[j]);
+ if (!di) oom("dictGetIterator");
+
+ while((de = dictNext(di)) != NULL) {
+ robj *ele;
+
+ /* dictAdd will not add the same element multiple times */
+ ele = dictGetEntryKey(de);
+ if (op == REDIS_OP_UNION || j == 0) {
+ if (dictAdd(dstset->ptr,ele,NULL) == DICT_OK) {
+ incrRefCount(ele);
+ cardinality++;
+ }
+ } else if (op == REDIS_OP_DIFF) {
+ if (dictDelete(dstset->ptr,ele) == DICT_OK) {
+ cardinality--;
+ }
+ }
+ }
+ dictReleaseIterator(di);
+
+ if (op == REDIS_OP_DIFF && cardinality == 0) break; /* result set is empty */
+ }
+
+ /* Output the content of the resulting set, if not in STORE mode */
+ if (!dstkey) {
+ addReplySds(c,sdscatprintf(sdsempty(),"*%d\r\n",cardinality));
+ di = dictGetIterator(dstset->ptr);
+ if (!di) oom("dictGetIterator");
+ while((de = dictNext(di)) != NULL) {
+ robj *ele;
+
+ ele = dictGetEntryKey(de);
+ addReplySds(c,sdscatprintf(sdsempty(),
+ "$%d\r\n",sdslen(ele->ptr)));
+ addReply(c,ele);
+ addReply(c,shared.crlf);
+ }
+ dictReleaseIterator(di);
+ } else {
+ /* If we have a target key where to store the resulting set
+ * create this key with the result set inside */
+ deleteKey(c->db,dstkey);
+ dictAdd(c->db->dict,dstkey,dstset);
+ incrRefCount(dstkey);
+ server.dirty++;
+ }
+
+ /* Cleanup */
+ if (!dstkey) {
+ decrRefCount(dstset);
+ } else {
+ addReply(c,shared.ok);
+ server.dirty++;
+ }
+ zfree(dv);
+}
+
+static void sunionCommand(redisClient *c) {
+ sunionDiffGenericCommand(c,c->argv+1,c->argc-1,NULL,REDIS_OP_UNION);
+}
+
+static void sunionstoreCommand(redisClient *c) {
+ sunionDiffGenericCommand(c,c->argv+2,c->argc-2,c->argv[1],REDIS_OP_UNION);
+}
+
+static void sdiffCommand(redisClient *c) {
+ sunionDiffGenericCommand(c,c->argv+1,c->argc-1,NULL,REDIS_OP_DIFF);
+}
+
+static void sdiffstoreCommand(redisClient *c) {
+ sunionDiffGenericCommand(c,c->argv+2,c->argc-2,c->argv[1],REDIS_OP_DIFF);
+}
+
projects / redis.git / blobdiff