void pushGenericCommand(client *c, int where) {
int j, waiting = 0, pushed = 0;
robj *lobj = lookupKeyWrite(c->db,c->argv[1]);
if (lobj && lobj->type != OBJ_LIST) {
addReply(c,shared.wrongtypeerr);
return;
}
for (j = 2; j < c->argc; j++) {
c->argv[j] = tryObjectEncoding(c->argv[j]);
if (!lobj) {
lobj = createQuicklistObject();
quicklistSetOptions(lobj->ptr, server.list_max_ziplist_size,
server.list_compress_depth);
dbAdd(c->db,c->argv[1],lobj);
}
listTypePush(lobj,c->argv[j],where);
pushed++;
}
addReplyLongLong(c, waiting + (lobj ? listTypeLength(lobj) : 0));
if (pushed) {
char *event = (where == LIST_HEAD) ? "lpush" : "rpush";
signalModifiedKey(c->db,c->argv[1]);
notifyKeyspaceEvent(NOTIFY_LIST,event,c->argv[1],c->db->id);
}
server.dirty += pushed;
}
void rpoplpushHandlePush(client *c, robj *dstkey, robj *dstobj, robj *value) {
/* Create the list if the key does not exist */
if (!dstobj) {
dstobj = createQuicklistObject();
quicklistSetOptions(dstobj->ptr, server.list_max_ziplist_size,
server.list_compress_depth);
dbAdd(c->db,dstkey,dstobj);
}
signalModifiedKey(c->db,dstkey);
listTypePush(dstobj,value,LIST_HEAD);
notifyKeyspaceEvent(NOTIFY_LIST,"lpush",dstkey,c->db->id);
/* Always send the pushed value to the client. */
addReplyBulk(c,value);
}
//PUSH命令的底层实现，where保存push的位置
void pushGenericCommand(client *c, int where) {
int j, waiting = 0, pushed = 0;
robj *lobj = lookupKeyWrite(c->db,c->argv[1]); //以写操作读取key对象的value
//如果value对象不是列表类型则发送错误信息，返回
if (lobj && lobj->type != OBJ_LIST) {
addReply(c,shared.wrongtypeerr);
return;
}
//从第一个value开始遍历
for (j = 2; j < c->argc; j++) {
c->argv[j] = tryObjectEncoding(c->argv[j]); //将value对象优化编码
//如果没有找到key对象
if (!lobj) {
//创建一个quicklist类型的对象
lobj = createQuicklistObject();
//设置ziplist最大的长度和压缩程度，配置文件指定
quicklistSetOptions(lobj->ptr, server.list_max_ziplist_size,
server.list_compress_depth);
//将新的key对象和优化编码过的value对象进行组成键值对
dbAdd(c->db,c->argv[1],lobj);
}
//在where推入一个value对象
listTypePush(lobj,c->argv[j],where);
pushed++; //更新计数器
}
//发送当前列表中元素的个数
addReplyLongLong(c, waiting + (lobj ? listTypeLength(lobj) : 0));
//如果推入元素成功
if (pushed) {
char *event = (where == LIST_HEAD) ? "lpush" : "rpush";
//当数据库的键被改动，则会调用该函数发送信号
signalModifiedKey(c->db,c->argv[1]);
//发送"lpush"或"rpush"事件通知
notifyKeyspaceEvent(NOTIFY_LIST,event,c->argv[1],c->db->id);
}
server.dirty += pushed; //更新脏键
}
//将一个value推入到列表头部，被rpoplpushCommand调用
void rpoplpushHandlePush(client *c, robj *dstkey, robj *dstobj, robj *value) {
/* Create the list if the key does not exist */
//如果目标dstkey不存在
if (!dstobj) {
//创建一个quicklist对象
dstobj = createQuicklistObject();
//设置ziplist的最大长度和压缩程度
quicklistSetOptions(dstobj->ptr, server.list_max_ziplist_size,
server.list_compress_depth);
//将key添加到数据库中
dbAdd(c->db,dstkey,dstobj);
}
//当数据库的键被改动，则会调用该函数发送信号
signalModifiedKey(c->db,dstkey);
//将vlaue推入到列表的头部
listTypePush(dstobj,value,LIST_HEAD);
//发送"lpush"时间通知
notifyKeyspaceEvent(NOTIFY_LIST,"lpush",dstkey,c->db->id);
/* Always send the pushed value to the client. */
//将value值发送给client
addReplyBulk(c,value);
}
/* 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;
long limit_start = 0, limit_count = -1, start, end;
int j, dontsort = 0, vectorlen;
int getop = 0; /* GET operation counter */
int int_convertion_error = 0;
int syntax_error = 0;
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 && 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 */
operations = listCreate();
listSetFreeMethod(operations,zfree);
j = 2; /* options start at argv[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 destroyed */
if (sortval)
incrRefCount(sortval);
else
sortval = createQuicklistObject();
/* 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) {
if ((getLongFromObjectOrReply(c, c->argv[j+1], &limit_start, NULL)
!= REDIS_OK) ||
(getLongFromObjectOrReply(c, c->argv[j+2], &limit_count, NULL)
!= REDIS_OK))
{
syntax_error++;
break;
}
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;
} else {
/* If BY is specified with a real patter, we can't accept
* it in cluster mode. */
if (server.cluster_enabled) {
addReplyError(c,"BY option of SORT denied in Cluster mode.");
syntax_error++;
break;
}
}
j++;
} else if (!strcasecmp(c->argv[j]->ptr,"get") && leftargs >= 1) {
if (server.cluster_enabled) {
addReplyError(c,"GET option of SORT denied in Cluster mode.");
syntax_error++;
break;
}
listAddNodeTail(operations,createSortOperation(
REDIS_SORT_GET,c->argv[j+1]));
getop++;
j++;
} else {
addReply(c,shared.syntaxerr);
syntax_error++;
break;
}
j++;
}
/* Handle syntax errors set during options parsing. */
if (syntax_error) {
decrRefCount(sortval);
listRelease(operations);
return;
}
/* When sorting a set with no sort specified, we must sort the output
* so the result is consistent across scripting and replication.
*
* The other types (list, sorted set) will retain their native order
* even if no sort order is requested, so they remain stable across
* scripting and replication. */
if (dontsort &&
sortval->type == REDIS_SET &&
(storekey || c->flags & REDIS_LUA_CLIENT))
{
/* Force ALPHA sorting */
dontsort = 0;
alpha = 1;
sortby = NULL;
}
/* Destructively convert encoded sorted sets for SORT. */
if (sortval->type == REDIS_ZSET)
zsetConvert(sortval, REDIS_ENCODING_SKIPLIST);
/* Objtain the length of the object 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 */
}
/* Perform LIMIT start,count sanity checking. */
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;
/* Whenever possible, we load elements into the output array in a more
* direct way. This is possible if:
*
* 1) The object to sort is a sorted set or a list (internally sorted).
* 2) There is nothing to sort as dontsort is true (BY <constant string>).
*
* In this special case, if we have a LIMIT option that actually reduces
* the number of elements to fetch, we also optimize to just load the
* range we are interested in and allocating a vector that is big enough
* for the selected range length. */
if ((sortval->type == REDIS_ZSET || sortval->type == REDIS_LIST) &&
dontsort &&
(start != 0 || end != vectorlen-1))
{
vectorlen = end-start+1;
}
/* Load the sorting vector with all the objects to sort */
vector = zmalloc(sizeof(redisSortObject)*vectorlen);
j = 0;
if (sortval->type == REDIS_LIST && dontsort) {
/* Special handling for a list, if 'dontsort' is true.
* This makes sure we return elements in the list original
* ordering, accordingly to DESC / ASC options.
*
* Note that in this case we also handle LIMIT here in a direct
* way, just getting the required range, as an optimization. */
if (end >= start) {
listTypeIterator *li;
listTypeEntry entry;
li = listTypeInitIterator(sortval,
desc ? (long)(listTypeLength(sortval) - start - 1) : start,
desc ? REDIS_HEAD : REDIS_TAIL);
while(j < vectorlen && listTypeNext(li,&entry)) {
vector[j].obj = listTypeGet(&entry);
vector[j].u.score = 0;
vector[j].u.cmpobj = NULL;
j++;
}
listTypeReleaseIterator(li);
/* Fix start/end: output code is not aware of this optimization. */
end -= start;
start = 0;
}
} else 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 && dontsort) {
/* Special handling for a sorted set, if 'dontsort' is true.
* This makes sure we return elements in the sorted set original
* ordering, accordingly to DESC / ASC options.
*
* Note that in this case we also handle LIMIT here in a direct
* way, just getting the required range, as an optimization. */
zset *zs = sortval->ptr;
zskiplist *zsl = zs->zsl;
zskiplistNode *ln;
robj *ele;
int rangelen = vectorlen;
/* Check if starting point is trivial, before doing log(N) lookup. */
if (desc) {
long zsetlen = dictSize(((zset*)sortval->ptr)->dict);
ln = zsl->tail;
if (start > 0)
ln = zslGetElementByRank(zsl,zsetlen-start);
} else {
ln = zsl->header->level[0].forward;
if (start > 0)
ln = zslGetElementByRank(zsl,start+1);
}
while(rangelen--) {
redisAssertWithInfo(c,sortval,ln != NULL);
ele = ln->obj;
vector[j].obj = ele;
vector[j].u.score = 0;
vector[j].u.cmpobj = NULL;
j++;
ln = desc ? ln->backward : ln->level[0].forward;
}
/* Fix start/end: output code is not aware of this optimization. */
end -= start;
start = 0;
} 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 = dictGetKey(setele);
vector[j].u.score = 0;
vector[j].u.cmpobj = NULL;
j++;
}
dictReleaseIterator(di);
} else {
redisPanic("Unknown type");
}
redisAssertWithInfo(c,sortval,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 (sdsEncodedObject(byval)) {
char *eptr;
vector[j].u.score = strtod(byval->ptr,&eptr);
if (eptr[0] != '\0' || errno == ERANGE ||
isnan(vector[j].u.score))
{
int_convertion_error = 1;
}
} 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 {
redisAssertWithInfo(c,sortval,1 != 1);
}
}
/* when the object was retrieved using lookupKeyByPattern,
* its refcount needs to be decreased. */
if (sortby) {
decrRefCount(byval);
}
}
}
if (dontsort == 0) {
server.sort_desc = desc;
server.sort_alpha = alpha;
server.sort_bypattern = sortby ? 1 : 0;
server.sort_store = storekey ? 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 (int_convertion_error) {
addReplyError(c,"One or more scores can't be converted into double");
} else 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 {
/* Always fails */
redisAssertWithInfo(c,sortval,sop->type == REDIS_SORT_GET);
}
}
}
} else {
robj *sobj = createQuicklistObject();
/* 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 */
redisAssertWithInfo(c,sortval,sop->type == REDIS_SORT_GET);
}
}
}
}
if (outputlen) {
setKey(c->db,storekey,sobj);
notifyKeyspaceEvent(REDIS_NOTIFY_LIST,"sortstore",storekey,
c->db->id);
server.dirty += outputlen;
} else if (dbDelete(c->db,storekey)) {
signalModifiedKey(c->db,storekey);
notifyKeyspaceEvent(REDIS_NOTIFY_GENERIC,"del",storekey,c->db->id);
server.dirty++;
}
decrRefCount(sobj);
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);
}
