void rpoplpushCommand(redisClient *c) {
robj *sobj, *value;
if ((sobj = lookupKeyWriteOrReply(c,c->argv[1],shared.nullbulk)) == NULL ||
checkType(c,sobj,REDIS_LIST)) return;
if (listTypeLength(sobj) == 0) {
/* This may only happen after loading very old RDB files. Recent
* versions of Redis delete keys of empty lists. */
addReply(c,shared.nullbulk);
} else {
robj *dobj = lookupKeyWrite(c->db,c->argv[2]);
robj *touchedkey = c->argv[1];
if (dobj && checkType(c,dobj,REDIS_LIST)) return;
value = listTypePop(sobj,REDIS_TAIL);
/* We saved touched key, and protect it, since rpoplpushHandlePush
* may change the client command argument vector (it does not
* currently). */
incrRefCount(touchedkey);
rpoplpushHandlePush(c,c->argv[2],dobj,value);
/* listTypePop returns an object with its refcount incremented */
decrRefCount(value);
/* Delete the source list when it is empty */
if (listTypeLength(sobj) == 0) {
dbDelete(c->db,touchedkey);
}
signalModifiedKey(c->db,touchedkey);
decrRefCount(touchedkey);
}
}
/* This is the semantic of this command:
* RPOPLPUSH srclist dstlist:
* IF LLEN(srclist) > 0
* element = RPOP srclist
* LPUSH dstlist element
* RETURN element
* ELSE
* RETURN nil
* END
* END
*
* The idea is to be able to get an element from a list in a reliable way
* since the element is not just returned but pushed against another list
* as well. This command was originally proposed by Ezra Zygmuntowicz.
*/
void rpoplpushcommand(redisClient *c) {
robj *sobj, *value;
if ((sobj = lookupKeyWriteOrReply(c,c->argv[1],shared.nullbulk)) == NULL ||
checkType(c,sobj,REDIS_LIST)) return;
if (listTypeLength(sobj) == 0) {
addReply(c,shared.nullbulk);
} else {
robj *dobj = lookupKeyWrite(c->db,c->argv[2]);
if (dobj && checkType(c,dobj,REDIS_LIST)) return;
value = listTypePop(sobj,REDIS_TAIL);
/* Add the element to the target list (unless it's directly
* passed to some BLPOP-ing client */
if (!handleClientsWaitingListPush(c,c->argv[2],value)) {
/* Create the list if the key does not exist */
if (!dobj) {
dobj = createZiplistObject();
dbAdd(c->db,c->argv[2],dobj);
}
listTypePush(dobj,value,REDIS_HEAD);
}
/* Send the element to the client as reply as well */
addReplyBulk(c,value);
/* listTypePop returns an object with its refcount incremented */
decrRefCount(value);
/* Delete the source list when it is empty */
if (listTypeLength(sobj) == 0) dbDelete(c->db,c->argv[1]);
touchWatchedKey(c->db,c->argv[1]);
server.dirty++;
}
}
void rpoplpushCommand(redisClient *c) {
robj *sobj, *value;
if ((sobj = lookupKeyWriteOrReply(c,c->argv[1],shared.nullbulk)) == NULL ||
checkType(c,sobj,REDIS_LIST)) return;
if (listTypeLength(sobj) == 0) {
addReply(c,shared.nullbulk);
} else {
robj *dobj = lookupKeyWrite(c->db,c->argv[2]);
robj *touchedkey = c->argv[1];
if (dobj && checkType(c,dobj,REDIS_LIST)) return;
value = listTypePop(sobj,REDIS_TAIL);
/* We saved touched key, and protect it, since rpoplpushHandlePush
* may change the client command argument vector. */
incrRefCount(touchedkey);
rpoplpushHandlePush(c,c,c->argv[2],dobj,value);
/* listTypePop returns an object with its refcount incremented */
decrRefCount(value);
/* Delete the source list when it is empty */
if (listTypeLength(sobj) == 0) dbDelete(c->db,touchedkey);
signalModifiedKey(c->db,touchedkey);
decrRefCount(touchedkey);
server.dirty++;
}
}
// LTRIM key start stop
// LTRIM命令实现
void ltrimCommand(client *c) {
robj *o;
long start, end, llen, ltrim, rtrim;
//将字符串类型起始地址start和结束地址end转换为long类型保存在start和end中
//如果任意失败，则直接返回
if ((getLongFromObjectOrReply(c, c->argv[2], &start, NULL) != C_OK) ||
(getLongFromObjectOrReply(c, c->argv[3], &end, NULL) != C_OK)) return;
// 以读操作取出key大小的value值，如果value对象不是列表类型，直接返回
if ((o = lookupKeyWriteOrReply(c,c->argv[1],shared.ok)) == NULL ||
checkType(c,o,OBJ_LIST)) return;
//获取列表元素数量
llen = listTypeLength(o);
/* convert negative indexes */
// 将负数范围转换成合法范围
if (start < 0) start = llen+start;
if (end < 0) end = llen+end;
if (start < 0) start = 0;
/* Invariant: start >= 0, so this test will be true when end < 0.
* The range is empty when start > end or start >= length. */
//不合理的范围，移除所有的元素
if (start > end || start >= llen) {
/* Out of range start or start > end result in empty list */
ltrim = llen;
rtrim = 0;
} else {
if (end >= llen) end = llen-1; //end值不能超过元素个数
ltrim = start; //左边界
rtrim = llen-end-1; //右边界
}
/* Remove list elements to perform the trim */
//只对编码为quicklist类型的value对象操作
if (o->encoding == OBJ_ENCODING_QUICKLIST) {
quicklistDelRange(o->ptr,0,ltrim); //删除左边界以左的所有元素
quicklistDelRange(o->ptr,-rtrim,rtrim); //删除左边界以右的所有元素
} else {
serverPanic("Unknown list encoding");
}
//发送"ltrim"事件通知
notifyKeyspaceEvent(NOTIFY_LIST,"ltrim",c->argv[1],c->db->id);
//如果将所有元素全部删除完了
if (listTypeLength(o) == 0) {
//从数据库中删除该key
dbDelete(c->db,c->argv[1]);
//发送"del"时间通知
notifyKeyspaceEvent(NOTIFY_GENERIC,"del",c->argv[1],c->db->id);
}
//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]);
//更新脏键
server.dirty++;
//发送ok信息给client
addReply(c,shared.ok);
}
void ltrimCommand(redisClient *c) {
robj *o;
long start, end, llen, j, ltrim, rtrim;
list *list;
listNode *ln;
int slotnum = keyHashSlot(c->argv[1]->ptr, sdslen(c->argv[1]->ptr));
if ((getLongFromObjectOrReply(c, c->argv[2], &start, NULL) != REDIS_OK) ||
(getLongFromObjectOrReply(c, c->argv[3], &end, NULL) != REDIS_OK)) return;
if ((o = lookupKeyWriteOrReply(c,c->argv[1],shared.ok,slotnum)) == NULL ||
checkType(c,o,REDIS_LIST)) return;
llen = listTypeLength(o);
/* convert negative indexes */
if (start < 0) start = llen+start;
if (end < 0) end = llen+end;
if (start < 0) start = 0;
/* Invariant: start >= 0, so this test will be true when end < 0.
* The range is empty when start > end or start >= length. */
if (start > end || start >= llen) {
/* Out of range start or start > end result in empty list */
ltrim = llen;
rtrim = 0;
} else {
if (end >= llen) end = llen-1;
ltrim = start;
rtrim = llen-end-1;
}
/* Remove list elements to perform the trim */
if (o->encoding == REDIS_ENCODING_ZIPLIST) {
o->ptr = ziplistDeleteRange(o->ptr,0,ltrim);
o->ptr = ziplistDeleteRange(o->ptr,-rtrim,rtrim);
} else if (o->encoding == REDIS_ENCODING_LINKEDLIST) {
list = o->ptr;
for (j = 0; j < ltrim; j++) {
ln = listFirst(list);
listDelNode(list,ln);
}
for (j = 0; j < rtrim; j++) {
ln = listLast(list);
listDelNode(list,ln);
}
} else {
redisPanic("Unknown list encoding");
}
notifyKeyspaceEvent(REDIS_NOTIFY_LIST,"ltrim",c->argv[1],c->db->id);
if (listTypeLength(o) == 0) {
dbDelete(c->db,c->argv[1],slotnum);
notifyKeyspaceEvent(REDIS_NOTIFY_GENERIC,"del",c->argv[1],c->db->id);
}
signalModifiedKey(c->db,c->argv[1],slotnum);
server.dirty++;
addReply(c,shared.ok);
}
/* Blocking RPOP/LPOP */
void blockingPopGenericCommand(redisClient *c, int where) {
robj *o;
mstime_t timeout;
int j;
int slotnum;
if (getTimeoutFromObjectOrReply(c,c->argv[c->argc-1],&timeout,UNIT_SECONDS)
!= REDIS_OK) return;
for (j = 1; j < c->argc-1; j++) {
slotnum = keyHashSlot(c->argv[j]->ptr, sdslen(c->argv[j]->ptr));
o = lookupKeyWrite(c->db,c->argv[j],slotnum);
if (o != NULL) {
if (o->type != REDIS_LIST) {
addReply(c,shared.wrongtypeerr);
return;
} else {
if (listTypeLength(o) != 0) {
/* Non empty list, this is like a non normal [LR]POP. */
char *event = (where == REDIS_HEAD) ? "lpop" : "rpop";
robj *value = listTypePop(o,where);
redisAssert(value != NULL);
addReplyMultiBulkLen(c,2);
addReplyBulk(c,c->argv[j]);
addReplyBulk(c,value);
decrRefCount(value);
notifyKeyspaceEvent(REDIS_NOTIFY_LIST,event,
c->argv[j],c->db->id);
if (listTypeLength(o) == 0) {
dbDelete(c->db,c->argv[j],slotnum);
notifyKeyspaceEvent(REDIS_NOTIFY_GENERIC,"del",
c->argv[j],c->db->id);
}
signalModifiedKey(c->db,c->argv[j],slotnum);
server.dirty++;
/* Replicate it as an [LR]POP instead of B[LR]POP. */
rewriteClientCommandVector(c,2,
(where == REDIS_HEAD) ? shared.lpop : shared.rpop,
c->argv[j]);
return;
}
}
}
}
/* If we are inside a MULTI/EXEC and the list is empty the only thing
* we can do is treating it as a timeout (even with timeout 0). */
if (c->flags & REDIS_MULTI) {
addReply(c,shared.nullmultibulk);
return;
}
/* If the list is empty or the key does not exists we must block */
blockForKeys(c, c->argv + 1, c->argc - 2, timeout, NULL);
}
void ltrimCommand(redisClient *c) {
robj *o;
int start = atoi(c->argv[2]->ptr);
int end = atoi(c->argv[3]->ptr);
int llen;
int j, ltrim, rtrim;
list *list;
listNode *ln;
if ((o = lookupKeyWriteOrReply(c,c->argv[1],shared.ok)) == NULL ||
checkType(c,o,REDIS_LIST)) return;
llen = listTypeLength(o);
/* convert negative indexes */
if (start < 0) start = llen+start;
if (end < 0) end = llen+end;
if (start < 0) start = 0;
/* Invariant: start >= 0, so this test will be true when end < 0.
* The range is empty when start > end or start >= length. */
if (start > end || start >= llen) {
/* Out of range start or start > end result in empty list */
ltrim = llen;
rtrim = 0;
} else {
if (end >= llen) end = llen-1;
ltrim = start;
rtrim = llen-end-1;
}
/* Remove list elements to perform the trim */
if (o->encoding == REDIS_ENCODING_ZIPLIST) {
o->ptr = ziplistDeleteRange(o->ptr,0,ltrim);
o->ptr = ziplistDeleteRange(o->ptr,-rtrim,rtrim);
} else if (o->encoding == REDIS_ENCODING_LINKEDLIST) {
list = o->ptr;
for (j = 0; j < ltrim; j++) {
ln = listFirst(list);
listDelNode(list,ln);
}
for (j = 0; j < rtrim; j++) {
ln = listLast(list);
listDelNode(list,ln);
}
} else {
redisPanic("Unknown list encoding");
}
if (listTypeLength(o) == 0) dbDelete(c->db,c->argv[1]);
signalModifiedKey(c->db,c->argv[1]);
server.dirty++;
addReply(c,shared.ok);
}
// RPOPLPUSH source destination
// RPOPLPUSH命令的实现
void rpoplpushCommand(client *c) {
robj *sobj, *value;
//以写操作读取source对象的值，并且检查数据类型是否为OBJ_LIST
if ((sobj = lookupKeyWriteOrReply(c,c->argv[1],shared.nullbulk)) == NULL ||
checkType(c,sobj,OBJ_LIST)) return;
//如果列表长度为0，没有元素，直接发送空信息
if (listTypeLength(sobj) == 0) {
/* This may only happen after loading very old RDB files. Recent
* versions of Redis delete keys of empty lists. */
addReply(c,shared.nullbulk);
} else {
//以写操作读取destination对象的值
robj *dobj = lookupKeyWrite(c->db,c->argv[2]);
robj *touchedkey = c->argv[1]; //将source键备份
//如果目标对象类型是否是列表类型
if (dobj && checkType(c,dobj,OBJ_LIST)) return;
//从source尾部弹出一个元素
value = listTypePop(sobj,LIST_TAIL);
/* We saved touched key, and protect it, since rpoplpushHandlePush
* may change the client command argument vector (it does not
* currently). */
//备份一份source键，因为rpoplpushHandlePush可能会更改client命令行参数
incrRefCount(touchedkey);
//将一个value推入到destination列表头部，如果destination列表不存在，则新创建一个
rpoplpushHandlePush(c,c->argv[2],dobj,value);
/* listTypePop returns an object with its refcount incremented */
decrRefCount(value); //将弹出的value释放
/* Delete the source list when it is empty */
//发送"rpop"时间通知
notifyKeyspaceEvent(NOTIFY_LIST,"rpop",touchedkey,c->db->id);
//如果source列表为空了，则删除key
if (listTypeLength(sobj) == 0) {
//删除之前备份的key键
dbDelete(c->db,touchedkey);
//发送"rpop"时间通知
notifyKeyspaceEvent(NOTIFY_GENERIC,"del",
touchedkey,c->db->id);
}
//当数据库的键被改动，则会调用该函数发送信号
signalModifiedKey(c->db,touchedkey);
//释放备份的source键
decrRefCount(touchedkey);
//脏键加1
server.dirty++;
}
}
/*
LINSERTAT command: insert an item at specified index
LINSERTAT KEY INDEX VALUE
1. If INDEX <0, move cursor backwards from end
2. If INDEX >= LENGTH_OF_LIST, append the value at the end of list
3. ELSE, insert val before item at INDEX
return the new length of list
*/
void linsertat(client* c){
robj *subject;
listTypeIterator *iter;
listTypeEntry entry;
int inserted = 0;
int index;
if ((subject = lookupKeyWriteOrReply(c,c->argv[1],shared.czero)) == NULL ||
checkType(c,subject,OBJ_LIST)) return;
if ((getLongFromObjectOrReply(c, c->argv[2], &index, NULL) != C_OK))
return;
robj *val = c->argv[3];
int insertWhere = LIST_HEAD;
if(index >= listTypeLength(subject)){
// insert at the end of list, after the last element
iter = listTypeInitIterator(subject,-1,LIST_HEAD);
index = 0;
insertWhere = LIST_TAIL;
} else if(index < 0) {
iter = listTypeInitIterator(subject,-1,LIST_HEAD);
index = (-index)-1;
} else {
iter = listTypeInitIterator(subject,0,LIST_TAIL);
}
while (listTypeNext(iter,&entry)) {
if (index==0) {
listTypeInsert(&entry,val,insertWhere);
inserted = 1;
break;
}
index--;
}
listTypeReleaseIterator(iter);
if (inserted) {
signalModifiedKey(c->db,c->argv[1]);
notifyKeyspaceEvent(NOTIFY_LIST,"linsertat", c->argv[1],c->db->id);
server.dirty++;
} else {
addReply(c,shared.cnegone);
return;
}
// Return the new length of list
addReplyLongLong(c,listTypeLength(subject));
}
//POP命令的底层实现，where保存pop的位置
void popGenericCommand(client *c, int where) {
//以写操作取出key对象的value值
robj *o = lookupKeyWriteOrReply(c,c->argv[1],shared.nullbulk);
// 如果key没找到或value对象不是列表类型则直接返回
if (o == NULL || checkType(c,o,OBJ_LIST)) return;
//从where 弹出一个value
robj *value = listTypePop(o,where);
//如果value为空，则发送空信息
if (value == NULL) {
addReply(c,shared.nullbulk);
} else {
//保存时间名称
char *event = (where == LIST_HEAD) ? "lpop" : "rpop";
//发送value给client
addReplyBulk(c,value);
//释放value对象
decrRefCount(value);
//发送事件通知
notifyKeyspaceEvent(NOTIFY_LIST,event,c->argv[1],c->db->id);
//如果弹出一个元素后，列表为空
if (listTypeLength(o) == 0) {
//发送"del"时间通知
notifyKeyspaceEvent(NOTIFY_GENERIC,"del",
c->argv[1],c->db->id);
//从数据库中删除当前的key
dbDelete(c->db,c->argv[1]);
}
//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]);
//更新脏键
server.dirty++;
}
}
void pushGenericCommand(redisClient *c, int where) {
int j, waiting = 0, pushed = 0;
robj *lobj = lookupKeyWrite(c->db,c->argv[1]);
int may_have_waiting_clients = (lobj == NULL);
if (lobj && lobj->type != REDIS_LIST) {//检查类型是否是list类型
addReply(c,shared.wrongtypeerr);
return;
}
if (may_have_waiting_clients) signalListAsReady(c,c->argv[1]);
for (j = 2; j < c->argc; j++) {
c->argv[j] = tryObjectEncoding(c->argv[j]);
if (!lobj) {//该键不存在 创建压缩列表
lobj = createZiplistObject();
dbAdd(c->db,c->argv[1],lobj);//该键添加到db中
}
listTypePush(lobj,c->argv[j],where);//把value添加列表中
pushed++;
}
addReplyLongLong(c, waiting + (lobj ? listTypeLength(lobj) : 0));
if (pushed) {
char *event = (where == REDIS_HEAD) ? "lpush" : "rpush";
signalModifiedKey(c->db,c->argv[1]);
notifyKeyspaceEvent(REDIS_NOTIFY_LIST,event,c->argv[1],c->db->id);//使用键空间通知
}
//改变最后一次保存的节点
server.dirty += pushed;
}
void pushGenericCommand(redisClient *c, int where) {
robj *lobj = lookupKeyWrite(c->db,c->argv[1]);
c->argv[2] = tryObjectEncoding(c->argv[2]);
if (lobj == NULL) {
if (handleClientsWaitingListPush(c,c->argv[1],c->argv[2])) {
addReply(c,shared.cone);
return;
}
lobj = createZiplistObject();
dbAdd(c->db,c->argv[1],lobj);
} else {
if (lobj->type != REDIS_LIST) {
addReply(c,shared.wrongtypeerr);
return;
}
if (handleClientsWaitingListPush(c,c->argv[1],c->argv[2])) {
touchWatchedKey(c->db,c->argv[1]);
addReply(c,shared.cone);
return;
}
}
listTypePush(lobj,c->argv[2],where);
addReplyLongLong(c,listTypeLength(lobj));
touchWatchedKey(c->db,c->argv[1]);
server.dirty++;
}
void brpoplpushCommand(redisClient *c) {
time_t timeout;
if (getTimeoutFromObjectOrReply(c,c->argv[3],&timeout) != REDIS_OK)
return;
robj *key = lookupKeyWrite(c->db, c->argv[1]);
if (key == NULL) {
if (c->flags & REDIS_MULTI) {
/* Blocking against an empty list in a multi state
* returns immediately. */
addReply(c, shared.nullbulk);
} else {
/* The list is empty and the client blocks. */
blockForKeys(c, c->argv + 1, 1, timeout, c->argv[2]);
}
} else {
if (key->type != REDIS_LIST) {
addReply(c, shared.wrongtypeerr);
} else {
/* The list exists and has elements, so
* the regular rpoplpushCommand is executed. */
redisAssertWithInfo(c,key,listTypeLength(key) > 0);
rpoplpushCommand(c);
}
}
}
void pushGenericCommand(redisClient *c, int where) {
int j, addlen = 0, pushed = 0;
robj *lobj = lookupKeyWrite(c->db,c->argv[1]);
int may_have_waiting_clients = (lobj == NULL);
if (lobj && lobj->type != REDIS_LIST) {
addReply(c,shared.wrongtypeerr);
return;
}
for (j = 2; j < c->argc; j++) {
c->argv[j] = tryObjectEncoding(c->argv[j]);
if (may_have_waiting_clients) {
if (handleClientsWaitingListPush(c,c->argv[1],c->argv[j])) {
addlen++;
continue;
} else {
may_have_waiting_clients = 0;
}
}
if (!lobj) {
lobj = createZiplistObject();
dbAdd(c->db,c->argv[1],lobj);
}
listTypePush(lobj,c->argv[j],where);
pushed++;
}
addReplyLongLong(c,addlen + (lobj ? listTypeLength(lobj) : 0));
if (pushed) signalModifiedKey(c->db,c->argv[1]);
server.dirty += pushed;
}
void pushGenericCommand(redisClient *c, int where) {
int j, waiting = 0, pushed = 0;
robj *lobj = lookupKeyWrite(c->db,c->argv[1]);
if (lobj && lobj->type != REDIS_LIST) {
addReply(c,shared.wrongtypeerr);
return;
}
for (j = 2; j < c->argc; j++) {
c->argv[j] = tryObjectEncoding(c->argv[j]);
if (!lobj) {
lobj = createZiplistObject();
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 == REDIS_HEAD) ? "lpush" : "rpush";
signalModifiedKey(c->db,c->argv[1]);
notifyKeyspaceEvent(REDIS_NOTIFY_LIST,event,c->argv[1],c->db->id);
}
server.dirty += pushed;
}
/* Blocking RPOP/LPOP */
void blockingPopGenericCommand(redisClient *c, int where) {
robj *o;
time_t timeout;
int j;
if (getTimeoutFromObjectOrReply(c,c->argv[c->argc-1],&timeout) != REDIS_OK)
return;
for (j = 1; j < c->argc-1; j++) {
o = lookupKeyWrite(c->db,c->argv[j]);
if (o != NULL) {
if (o->type != REDIS_LIST) {
addReply(c,shared.wrongtypeerr);
return;
} else {
if (listTypeLength(o) != 0) {
/* If the list contains elements fall back to the usual
* non-blocking POP operation */
robj *argv[2], **orig_argv;
int orig_argc;
/* We need to alter the command arguments before to call
* popGenericCommand() as the command takes a single key. */
orig_argv = c->argv;
orig_argc = c->argc;
argv[1] = c->argv[j];
c->argv = argv;
c->argc = 2;
/* Also the return value is different, we need to output
* the multi bulk reply header and the key name. The
* "real" command will add the last element (the value)
* for us. If this souds like an hack to you it's just
* because it is... */
addReplyMultiBulkLen(c,2);
addReplyBulk(c,argv[1]);
popGenericCommand(c,where);
/* Fix the client structure with the original stuff */
c->argv = orig_argv;
c->argc = orig_argc;
return;
}
}
}
}
/* If we are inside a MULTI/EXEC and the list is empty the only thing
* we can do is treating it as a timeout (even with timeout 0). */
if (c->flags & REDIS_MULTI) {
addReply(c,shared.nullmultibulk);
return;
}
/* If the list is empty or the key does not exists we must block */
blockForKeys(c, c->argv + 1, c->argc - 2, timeout, NULL);
}
//当key存在时则push，PUSHX，INSERT命令的底层实现
void pushxGenericCommand(client *c, robj *refval, robj *val, int where) {
robj *subject;
listTypeIterator *iter;
listTypeEntry entry;
int inserted = 0;
//以写操作读取key对象的value
//如果读取失败或读取的value对象不是列表类型则返回
if ((subject = lookupKeyWriteOrReply(c,c->argv[1],shared.czero)) == NULL ||
checkType(c,subject,OBJ_LIST)) return;
//寻找基准值refval
if (refval != NULL) {
/* Seek refval from head to tail */
//创建一个列表的迭代器
iter = listTypeInitIterator(subject,0,LIST_TAIL);
//将指向当前的entry节点保存到列表类型的entry中，然后指向下一个entry节点
while (listTypeNext(iter,&entry)) {
//当前的entry节点的值与基准值refval是否相等
if (listTypeEqual(&entry,refval)) {
//如果相等，根据where插入val对象
listTypeInsert(&entry,val,where);
inserted = 1; //设置插入的标识，跳出循环
break;
}
}
//事项迭代器
listTypeReleaseIterator(iter);
//如果插入成功，键值被修改，则发送信号并且发送"linsert"时间通知
if (inserted) {
signalModifiedKey(c->db,c->argv[1]);
notifyKeyspaceEvent(NOTIFY_LIST,"linsert",
c->argv[1],c->db->id);
server.dirty++; //更新脏键
} else {
/* Notify client of a failed insert */
//如果没有插入，则发送插入失败的信息
addReply(c,shared.cnegone);
return;
}
//如果基准值为空
} else {
//根据where判断出事件名称
char *event = (where == LIST_HEAD) ? "lpush" : "rpush";
//将val对象推入到列表的头部或尾部
listTypePush(subject,val,where);
//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]);
//发送事件通知
notifyKeyspaceEvent(NOTIFY_LIST,event,c->argv[1],c->db->id);
server.dirty++; //更新脏键
}
//将插入val后的列表的元素个数发送给client
addReplyLongLong(c,listTypeLength(subject));
}
// LLEN key
//LLEN命令实现
void llenCommand(client *c) {
//以读操作取出key大小的value值
robj *o = lookupKeyReadOrReply(c,c->argv[1],shared.czero);
//如果key没找到或value大小不是列表类型则直接返回
if (o == NULL || checkType(c,o,OBJ_LIST)) return;
//发送列表中的元素数量给client
addReplyLongLong(c,listTypeLength(o));
}
void lrangeCommand(redisClient *c) {
robj *o;
long start, end, llen, rangelen;
if ((getLongFromObjectOrReply(c, c->argv[2], &start, NULL) != REDIS_OK) ||
(getLongFromObjectOrReply(c, c->argv[3], &end, NULL) != REDIS_OK)) return;
if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.emptymultibulk)) == NULL
|| checkType(c,o,REDIS_LIST)) return;
llen = listTypeLength(o);
/* convert negative indexes */
if (start < 0) start = llen+start;
if (end < 0) end = llen+end;
if (start < 0) start = 0;
/* Invariant: start >= 0, so this test will be true when end < 0.
* The range is empty when start > end or start >= length. */
if (start > end || start >= llen) {
addReply(c,shared.emptymultibulk);
return;
}
if (end >= llen) end = llen-1;
rangelen = (end-start)+1;
/* Return the result in form of a multi-bulk reply */
addReplyMultiBulkLen(c,rangelen);
if (o->encoding == REDIS_ENCODING_ZIPLIST) {
unsigned char *p = ziplistIndex(o->ptr,start);
unsigned char *vstr;
unsigned int vlen;
long long vlong;
while(rangelen--) {
ziplistGet(p,&vstr,&vlen,&vlong);
if (vstr) {
addReplyBulkCBuffer(c,vstr,vlen);
} else {
addReplyBulkLongLong(c,vlong);
}
p = ziplistNext(o->ptr,p);
}
} else if (o->encoding == REDIS_ENCODING_LINKEDLIST) {
listNode *ln;
/* If we are nearest to the end of the list, reach the element
* starting from tail and going backward, as it is faster. */
if (start > llen/2) start -= llen;
ln = listIndex(o->ptr,start);
while(rangelen--) {
addReplyBulk(c,ln->value);
ln = ln->next;
}
} else {
redisPanic("List encoding is not LINKEDLIST nor ZIPLIST!");
}
}
void ltrimCommand(client *c) {
robj *o;
long start, end, llen, ltrim, rtrim;
if ((getLongFromObjectOrReply(c, c->argv[2], &start, NULL) != C_OK) ||
(getLongFromObjectOrReply(c, c->argv[3], &end, NULL) != C_OK)) return;
if ((o = lookupKeyWriteOrReply(c,c->argv[1],shared.ok)) == NULL ||
checkType(c,o,OBJ_LIST)) return;
llen = listTypeLength(o);
/* convert negative indexes */
if (start < 0) start = llen+start;
if (end < 0) end = llen+end;
if (start < 0) start = 0;
/* Invariant: start >= 0, so this test will be true when end < 0.
* The range is empty when start > end or start >= length. */
if (start > end || start >= llen) {
/* Out of range start or start > end result in empty list */
ltrim = llen;
rtrim = 0;
} else {
if (end >= llen) end = llen-1;
ltrim = start;
rtrim = llen-end-1;
}
/* Remove list elements to perform the trim */
if (o->encoding == OBJ_ENCODING_QUICKLIST) {
quicklistDelRange(o->ptr,0,ltrim);
quicklistDelRange(o->ptr,-rtrim,rtrim);
} else {
serverPanic("Unknown list encoding");
}
notifyKeyspaceEvent(NOTIFY_LIST,"ltrim",c->argv[1],c->db->id);
if (listTypeLength(o) == 0) {
dbDelete(c->db,c->argv[1]);
notifyKeyspaceEvent(NOTIFY_GENERIC,"del",c->argv[1],c->db->id);
}
signalModifiedKey(c->db,c->argv[1]);
server.dirty++;
addReply(c,shared.ok);
}
void pushnGenericCommand(redisClient *c, int where) {
/* return_value must be null,otherwise it have memory leak */
c->returncode = REDIS_ERR;
robj *lobj = lookupKeyWriteWithVersion(c->db, c->argv[1], &c->version);
robj* key = c->argv[1];
if(lobj != NULL) {
if(checkType(c, lobj, REDIS_LIST)) {
c->returncode = REDIS_ERR_WRONG_TYPE_ERROR;
return;
}
uint16_t version = sdsversion(key->ptr);
if(c->version_care && version != 0 && version != c->version) {
c->returncode = REDIS_ERR_VERSION_ERROR;
return;
} else {
sdsversion_change(key->ptr, c->version);
}
} else {
sdsversion_change(key->ptr, 0);
}
if(c->version_care) {
sdsversion_add(key->ptr, 1);
}
c->return_value = (void*)zmalloc(sizeof(push_return_value));
if(c->return_value == NULL) {
c->returncode = REDIS_ERR_MEMORY_ALLOCATE_ERROR;
return;
}
int i = 2;
for(; i < c->argc; i++) {
if(lobj == NULL) {
c->argv[i] = tryObjectEncoding(c->argv[i]);
lobj = createZiplistObject();
dbAdd(c->db,c->argv[1],lobj);
}
unsigned long list_len = listTypeLength(lobj);
if (list_len >= (unsigned long)(c->server->list_max_size)) {
break;
}
listTypePush(c,lobj,c->argv[i],where);
c->server->dirty++;
}
if (i != 2) {
dbUpdateKey(c->db, key);
EXPIRE_OR_NOT
}
/* Emit the commands needed to rebuild a list object.
* The function returns 0 on error, 1 on success. */
int rewriteListObject(rio *r, robj *key, robj *o) {
long long count = 0, items = listTypeLength(o);
if (o->encoding == REDIS_ENCODING_ZIPLIST) {
unsigned char *zl = o->ptr;
unsigned char *p = ziplistIndex(zl,0);
unsigned char *vstr;
unsigned int vlen;
long long vlong;
while(ziplistGet(p,&vstr,&vlen,&vlong)) {
if (count == 0) {
int cmd_items = (items > REDIS_AOF_REWRITE_ITEMS_PER_CMD) ?
REDIS_AOF_REWRITE_ITEMS_PER_CMD : items;
if (rioWriteBulkCount(r,'*',2+cmd_items) == 0) return 0;
if (rioWriteBulkString(r,"RPUSH",5) == 0) return 0;
if (rioWriteBulkObject(r,key) == 0) return 0;
}
if (vstr) {
if (rioWriteBulkString(r,(char*)vstr,vlen) == 0) return 0;
} else {
if (rioWriteBulkLongLong(r,vlong) == 0) return 0;
}
p = ziplistNext(zl,p);
if (++count == REDIS_AOF_REWRITE_ITEMS_PER_CMD) count = 0;
items--;
}
} else if (o->encoding == REDIS_ENCODING_LINKEDLIST) {
list *list = o->ptr;
listNode *ln;
listIter li;
listRewind(list,&li);
while((ln = listNext(&li))) {
robj *eleobj = listNodeValue(ln);
if (count == 0) {
int cmd_items = (items > REDIS_AOF_REWRITE_ITEMS_PER_CMD) ?
REDIS_AOF_REWRITE_ITEMS_PER_CMD : items;
if (rioWriteBulkCount(r,'*',2+cmd_items) == 0) return 0;
if (rioWriteBulkString(r,"RPUSH",5) == 0) return 0;
if (rioWriteBulkObject(r,key) == 0) return 0;
}
if (rioWriteBulkObject(r,eleobj) == 0) return 0;
if (++count == REDIS_AOF_REWRITE_ITEMS_PER_CMD) count = 0;
items--;
}
} else {
redisPanic("Unknown list encoding");
}
return 1;
}
void pushxGenericCommand(redisClient *c, robj *refval, robj *val, int where) {
robj *subject;
listTypeIterator *iter;
listTypeEntry entry;
int inserted = 0;
int slotnum = keyHashSlot(c->argv[1]->ptr, sdslen(c->argv[1]->ptr));
if ((subject = lookupKeyReadOrReply(c,c->argv[1],shared.czero)) == NULL ||
checkType(c,subject,REDIS_LIST)) return;
if (refval != NULL) {
/* We're not sure if this value can be inserted yet, but we cannot
* convert the list inside the iterator. We don't want to loop over
* the list twice (once to see if the value can be inserted and once
* to do the actual insert), so we assume this value can be inserted
* and convert the ziplist to a regular list if necessary. */
listTypeTryConversion(subject,val);
/* Seek refval from head to tail */
iter = listTypeInitIterator(subject,0,REDIS_TAIL);
while (listTypeNext(iter,&entry)) {
if (listTypeEqual(&entry,refval)) {
listTypeInsert(&entry,val,where);
inserted = 1;
break;
}
}
listTypeReleaseIterator(iter);
if (inserted) {
/* Check if the length exceeds the ziplist length threshold. */
if (subject->encoding == REDIS_ENCODING_ZIPLIST &&
ziplistLen(subject->ptr) > server.list_max_ziplist_entries)
listTypeConvert(subject,REDIS_ENCODING_LINKEDLIST);
signalModifiedKey(c->db,c->argv[1],slotnum);
notifyKeyspaceEvent(REDIS_NOTIFY_LIST,"linsert",
c->argv[1],c->db->id);
server.dirty++;
} else {
/* Notify client of a failed insert */
addReply(c,shared.cnegone);
return;
}
} else {
char *event = (where == REDIS_HEAD) ? "lpush" : "rpush";
listTypePush(subject,val,where);
signalModifiedKey(c->db,c->argv[1],slotnum);
notifyKeyspaceEvent(REDIS_NOTIFY_LIST,event,c->argv[1],c->db->id);
server.dirty++;
}
addReplyLongLong(c,listTypeLength(subject));
}
void pushxGenericCommand(redisClient *c, robj *refval, robj *val, int where) {
robj *subject;
listTypeIterator *iter;
listTypeEntry entry;
int inserted = 0;
if ((subject = lookupKeyReadOrReply(c,c->argv[1],shared.czero)) == NULL ||
checkType(c,subject,REDIS_LIST)) return;
if (refval != NULL) {
/* Note: we expect refval to be string-encoded because it is *not* the
* last argument of the multi-bulk LINSERT. */
redisAssertWithInfo(c,refval,refval->encoding == REDIS_ENCODING_RAW);
/* We're not sure if this value can be inserted yet, but we cannot
* convert the list inside the iterator. We don't want to loop over
* the list twice (once to see if the value can be inserted and once
* to do the actual insert), so we assume this value can be inserted
* and convert the ziplist to a regular list if necessary. */
listTypeTryConversion(subject,val);
/* Seek refval from head to tail */
iter = listTypeInitIterator(subject,0,REDIS_TAIL);
while (listTypeNext(iter,&entry)) {
if (listTypeEqual(&entry,refval)) {
listTypeInsert(&entry,val,where);
inserted = 1;
break;
}
}
listTypeReleaseIterator(iter);
if (inserted) {
/* Check if the length exceeds the ziplist length threshold. */
if (subject->encoding == REDIS_ENCODING_ZIPLIST &&
ziplistLen(subject->ptr) > server.list_max_ziplist_entries)
listTypeConvert(subject,REDIS_ENCODING_LINKEDLIST);
signalModifiedKey(c->db,c->argv[1]);
server.dirty++;
} else {
/* Notify client of a failed insert */
addReply(c,shared.cnegone);
return;
}
} else {
listTypePush(subject,val,where);
signalModifiedKey(c->db,c->argv[1]);
server.dirty++;
}
addReplyLongLong(c,listTypeLength(subject));
}
void rpoplpushCommand(redisClient *c) {
robj *sobj, *value;
if ((sobj = lookupKeyWriteOrReply(c,c->argv[1],shared.nullbulk)) == NULL ||
checkType(c,sobj,REDIS_LIST)) return;
if (listTypeLength(sobj) == 0) {
addReply(c,shared.nullbulk);
} else {
robj *dobj = lookupKeyWrite(c->db,c->argv[2]);
if (dobj && checkType(c,dobj,REDIS_LIST)) return;
value = listTypePop(sobj,REDIS_TAIL);
rpoplpushHandlePush(c,c->argv[2],dobj,value);
/* listTypePop returns an object with its refcount incremented */
decrRefCount(value);
/* Delete the source list when it is empty */
if (listTypeLength(sobj) == 0) dbDelete(c->db,c->argv[1]);
touchWatchedKey(c->db,c->argv[1]);
server.dirty++;
}
}
void rpoplpushCommand(redisClient *c) {
robj *sobj, *value;
if ((sobj = lookupKeyWriteOrReply(c,c->argv[1],shared.nullbulk)) == NULL ||
checkType(c,sobj,REDIS_LIST)) return;
if (listTypeLength(sobj) == 0) {
/* This may only happen after loading very old RDB files. Recent
* versions of Redis delete keys of empty lists. */
addReply(c,shared.nullbulk);
} else {
robj *dobj = lookupKeyWrite(c->db,c->argv[2]);
robj *touchedkey = c->argv[1];
if (dobj && checkType(c,dobj,REDIS_LIST)) return;
value = listTypePop(sobj,REDIS_TAIL);
/* We saved touched key, and protect it, since rpoplpushHandlePush
* may change the client command argument vector. */
incrRefCount(touchedkey);
rpoplpushHandlePush(c,c,c->argv[2],dobj,value);
/* listTypePop returns an object with its refcount incremented */
decrRefCount(value);
/* Delete the source list when it is empty */
if (listTypeLength(sobj) == 0) dbDelete(c->db,touchedkey);
signalModifiedKey(c->db,touchedkey);
decrRefCount(touchedkey);
server.dirty++;
/* Replicate this as a simple RPOP since the LPUSH side is replicated
* by rpoplpushHandlePush() call if needed (it may not be needed
* if a client is blocking wait a push against the list). */
rewriteClientCommandVector(c,2,
resetRefCount(createStringObject("RPOP",4)),
c->argv[1]);
}
}
void popGenericCommand(redisClient *c, int where) {
robj *o = lookupKeyWriteOrReply(c,c->argv[1],shared.nullbulk);
if (o == NULL || checkType(c,o,REDIS_LIST)) return;
robj *value = listTypePop(o,where);
if (value == NULL) {
addReply(c,shared.nullbulk);
} else {
addReplyBulk(c,value);
decrRefCount(value);
if (listTypeLength(o) == 0) dbDelete(c->db,c->argv[1]);
signalModifiedKey(c->db,c->argv[1]);
server.dirty++;
}
}
/* Blocking RPOP/LPOP */
void blockingPopGenericCommand(redisClient *c, int where) {
robj *o;
time_t timeout;
int j;
for (j = 1; j < c->argc-1; j++) {
o = lookupKeyWrite(c->db,c->argv[j]);
if (o != NULL) {
if (o->type != REDIS_LIST) {
addReply(c,shared.wrongtypeerr);
return;
} else {
if (listTypeLength(o) != 0) {
/* If the list contains elements fall back to the usual
* non-blocking POP operation */
robj *argv[2], **orig_argv;
int orig_argc;
/* We need to alter the command arguments before to call
* popGenericCommand() as the command takes a single key. */
orig_argv = c->argv;
orig_argc = c->argc;
argv[1] = c->argv[j];
c->argv = argv;
c->argc = 2;
/* Also the return value is different, we need to output
* the multi bulk reply header and the key name. The
* "real" command will add the last element (the value)
* for us. If this souds like an hack to you it's just
* because it is... */
addReplySds(c,sdsnew("*2\r\n"));
addReplyBulk(c,argv[1]);
popGenericCommand(c,where);
/* Fix the client structure with the original stuff */
c->argv = orig_argv;
c->argc = orig_argc;
return;
}
}
}
}
/* If the list is empty or the key does not exists we must block */
timeout = strtol(c->argv[c->argc-1]->ptr,NULL,10);
if (timeout > 0) timeout += time(NULL);
blockForKeys(c,c->argv+1,c->argc-2,timeout);
}
void lrangeCommand(client *c) {
robj *o;
long start, end, llen, rangelen;
if ((getLongFromObjectOrReply(c, c->argv[2], &start, NULL) != C_OK) ||
(getLongFromObjectOrReply(c, c->argv[3], &end, NULL) != C_OK)) return;
if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.emptymultibulk)) == NULL
|| checkType(c,o,OBJ_LIST)) return;
llen = listTypeLength(o);
/* convert negative indexes */
if (start < 0) start = llen+start;
if (end < 0) end = llen+end;
if (start < 0) start = 0;
/* Invariant: start >= 0, so this test will be true when end < 0.
* The range is empty when start > end or start >= length. */
if (start > end || start >= llen) {
addReply(c,shared.emptymultibulk);
return;
}
if (end >= llen) end = llen-1;
rangelen = (end-start)+1;
/* Return the result in form of a multi-bulk reply */
addReplyMultiBulkLen(c,rangelen);
if (o->encoding == OBJ_ENCODING_QUICKLIST) {
listTypeIterator *iter = listTypeInitIterator(o, start, LIST_TAIL);
while(rangelen--) {
listTypeEntry entry;
listTypeNext(iter, &entry);
quicklistEntry *qe = &entry.entry;
if (qe->value) {
addReplyBulkCBuffer(c,qe->value,qe->sz);
} else {
addReplyBulkLongLong(c,qe->longval);
}
}
listTypeReleaseIterator(iter);
} else {
serverPanic("List encoding is not QUICKLIST!");
}
}
/*
LREVERSE command: reverse the items in list
LREV KEY
Time: O(N)
*/
void lreverseCommand(client* c){
robj *o = lookupKeyWriteOrReply(c,c->argv[1],shared.nokeyerr);
if (checkType(c,o,OBJ_LIST)) {
addReply(c,shared.wrongtypeerr);
return;
}
if(listTypeLength(o)<=1){
addReply(c,shared.ok);
return;
}
if (o->encoding == OBJ_ENCODING_QUICKLIST) {
quicklistReverse(o->ptr);
addReply(c,shared.ok);
return;
} else {
serverPanic("Unknown list encoding");
}
}
