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#include "redis.h"
#include <signal.h>
#include <ctype.h>
void SlotToKeyAdd(robj *key);
void SlotToKeyDel(robj *key);
/*-----------------------------------------------------------------------------
* C-level DB API
*----------------------------------------------------------------------------*/
robj *lookupKey(redisDb *db, robj *key) {
dictEntry *de = dictFind(db->dict,key->ptr);
if (de) {
robj *val = dictGetVal(de);
/* Update the access time for the aging algorithm.
* Don't do it if we have a saving child, as this will trigger
* a copy on write madness. */
if (server.rdb_child_pid == -1 && server.aof_child_pid == -1)
val->lru = server.lruclock;
return val;
} else {
return NULL;
}
}
robj *lookupKeyRead(redisDb *db, robj *key) {
robj *val;
expireIfNeeded(db,key);
val = lookupKey(db,key);
if (val == NULL)
server.stat_keyspace_misses++;
else
server.stat_keyspace_hits++;
return val;
}
robj *lookupKeyWrite(redisDb *db, robj *key) {
expireIfNeeded(db,key);
return lookupKey(db,key);
}
robj *lookupKeyReadOrReply(redisClient *c, robj *key, robj *reply) {
robj *o = lookupKeyRead(c->db, key);
if (!o) addReply(c,reply);
return o;
}
robj *lookupKeyWriteOrReply(redisClient *c, robj *key, robj *reply) {
robj *o = lookupKeyWrite(c->db, key);
if (!o) addReply(c,reply);
return o;
}
/* Add the key to the DB. It's up to the caller to increment the reference
* counte of the value if needed.
*
* The program is aborted if the key already exists. */
void dbAdd(redisDb *db, robj *key, robj *val) {
sds copy = sdsdup(key->ptr);
int retval = dictAdd(db->dict, copy, val);
redisAssertWithInfo(NULL,key,retval == REDIS_OK);
if (server.cluster_enabled) SlotToKeyAdd(key);
}
/* Overwrite an existing key with a new value. Incrementing the reference
* count of the new value is up to the caller.
* This function does not modify the expire time of the existing key.
*
* The program is aborted if the key was not already present. */
void dbOverwrite(redisDb *db, robj *key, robj *val) {
struct dictEntry *de = dictFind(db->dict,key->ptr);
redisAssertWithInfo(NULL,key,de != NULL);
dictReplace(db->dict, key->ptr, val);
}
/* High level Set operation. This function can be used in order to set
* a key, whatever it was existing or not, to a new object.
*
* 1) The ref count of the value object is incremented.
* 2) clients WATCHing for the destination key notified.
* 3) The expire time of the key is reset (the key is made persistent). */
void setKey(redisDb *db, robj *key, robj *val) {
if (lookupKeyWrite(db,key) == NULL) {
dbAdd(db,key,val);
} else {
dbOverwrite(db,key,val);
}
incrRefCount(val);
removeExpire(db,key);
signalModifiedKey(db,key);
}
int dbExists(redisDb *db, robj *key) {
return dictFind(db->dict,key->ptr) != NULL;
}
/* Return a random key, in form of a Redis object.
* If there are no keys, NULL is returned.
*
* The function makes sure to return keys not already expired. */
robj *dbRandomKey(redisDb *db) {
struct dictEntry *de;
while(1) {
sds key;
robj *keyobj;
de = dictGetRandomKey(db->dict);
if (de == NULL) return NULL;
key = dictGetKey(de);
keyobj = createStringObject(key,sdslen(key));
if (dictFind(db->expires,key)) {
if (expireIfNeeded(db,keyobj)) {
decrRefCount(keyobj);
continue; /* search for another key. This expired. */
}
}
return keyobj;
}
}
/* Delete a key, value, and associated expiration entry if any, from the DB */
int dbDelete(redisDb *db, robj *key) {
/* Deleting an entry from the expires dict will not free the sds of
* the key, because it is shared with the main dictionary. */
if (dictSize(db->expires) > 0) dictDelete(db->expires,key->ptr);
if (dictDelete(db->dict,key->ptr) == DICT_OK) {
if (server.cluster_enabled) SlotToKeyDel(key);
return 1;
} else {
return 0;
}
}
long long emptyDb() {
int j;
long long removed = 0;
for (j = 0; j < server.dbnum; j++) {
removed += dictSize(server.db[j].dict);
dictEmpty(server.db[j].dict);
dictEmpty(server.db[j].expires);
}
return removed;
}
int selectDb(redisClient *c, int id) {
if (id < 0 || id >= server.dbnum)
return REDIS_ERR;
c->db = &server.db[id];
return REDIS_OK;
}
/*-----------------------------------------------------------------------------
* Hooks for key space changes.
*
* Every time a key in the database is modified the function
* signalModifiedKey() is called.
*
* Every time a DB is flushed the function signalFlushDb() is called.
*----------------------------------------------------------------------------*/
void signalModifiedKey(redisDb *db, robj *key) {
touchWatchedKey(db,key);
}
void signalFlushedDb(int dbid) {
touchWatchedKeysOnFlush(dbid);
}
/*-----------------------------------------------------------------------------
* Type agnostic commands operating on the key space
*----------------------------------------------------------------------------*/
void flushdbCommand(redisClient *c) {
server.dirty += dictSize(c->db->dict);
signalFlushedDb(c->db->id);
dictEmpty(c->db->dict);
dictEmpty(c->db->expires);
addReply(c,shared.ok);
}
void flushallCommand(redisClient *c) {
signalFlushedDb(-1);
server.dirty += emptyDb();
addReply(c,shared.ok);
if (server.rdb_child_pid != -1) {
kill(server.rdb_child_pid,SIGKILL);
rdbRemoveTempFile(server.rdb_child_pid);
}
if (server.saveparamslen > 0) {
/* Normally rdbSave() will reset dirty, but we don't want this here
* as otherwise FLUSHALL will not be replicated nor put into the AOF. */
int saved_dirty = server.dirty;
rdbSave(server.rdb_filename);
server.dirty = saved_dirty;
}
server.dirty++;
}
void delCommand(redisClient *c) {
int deleted = 0, j;
for (j = 1; j < c->argc; j++) {
if (dbDelete(c->db,c->argv[j])) {
signalModifiedKey(c->db,c->argv[j]);
server.dirty++;
deleted++;
}
}
addReplyLongLong(c,deleted);
}
void existsCommand(redisClient *c) {
expireIfNeeded(c->db,c->argv[1]);
if (dbExists(c->db,c->argv[1])) {
addReply(c, shared.cone);
} else {
addReply(c, shared.czero);
}
}
void selectCommand(redisClient *c) {
long id;
if (getLongFromObjectOrReply(c, c->argv[1], &id,
"invalid DB index") != REDIS_OK)
return;
if (server.cluster_enabled && id != 0) {
addReplyError(c,"SELECT is not allowed in cluster mode");
return;
}
if (selectDb(c,id) == REDIS_ERR) {
addReplyError(c,"invalid DB index");
} else {
addReply(c,shared.ok);
}
}
void randomkeyCommand(redisClient *c) {
robj *key;
if ((key = dbRandomKey(c->db)) == NULL) {
addReply(c,shared.nullbulk);
return;
}
addReplyBulk(c,key);
decrRefCount(key);
}
void keysCommand(redisClient *c) {
dictIterator *di;
dictEntry *de;
sds pattern = c->argv[1]->ptr;
int plen = sdslen(pattern), allkeys;
unsigned long numkeys = 0;
void *replylen = addDeferredMultiBulkLength(c);
di = dictGetSafeIterator(c->db->dict);
allkeys = (pattern[0] == '*' && pattern[1] == '\0');
while((de = dictNext(di)) != NULL) {
sds key = dictGetKey(de);
robj *keyobj;
if (allkeys || stringmatchlen(pattern,plen,key,sdslen(key),0)) {
keyobj = createStringObject(key,sdslen(key));
if (expireIfNeeded(c->db,keyobj) == 0) {
addReplyBulk(c,keyobj);
numkeys++;
}
decrRefCount(keyobj);
}
}
dictReleaseIterator(di);
setDeferredMultiBulkLength(c,replylen,numkeys);
}
void dbsizeCommand(redisClient *c) {
addReplyLongLong(c,dictSize(c->db->dict));
}
void lastsaveCommand(redisClient *c) {
addReplyLongLong(c,server.lastsave);
}
void typeCommand(redisClient *c) {
robj *o;
char *type;
o = lookupKeyRead(c->db,c->argv[1]);
if (o == NULL) {
type = "none";
} else {
switch(o->type) {
case REDIS_STRING: type = "string"; break;
case REDIS_LIST: type = "list"; break;
case REDIS_SET: type = "set"; break;
case REDIS_ZSET: type = "zset"; break;
case REDIS_HASH: type = "hash"; break;
default: type = "unknown"; break;
}
}
addReplyStatus(c,type);
}
void shutdownCommand(redisClient *c) {
int flags = 0;
if (c->argc > 2) {
addReply(c,shared.syntaxerr);
return;
} else if (c->argc == 2) {
if (!strcasecmp(c->argv[1]->ptr,"nosave")) {
flags |= REDIS_SHUTDOWN_NOSAVE;
} else if (!strcasecmp(c->argv[1]->ptr,"save")) {
flags |= REDIS_SHUTDOWN_SAVE;
} else {
addReply(c,shared.syntaxerr);
return;
}
}
if (prepareForShutdown(flags) == REDIS_OK) exit(0);
addReplyError(c,"Errors trying to SHUTDOWN. Check logs.");
}
void renameGenericCommand(redisClient *c, int nx) {
robj *o;
long long expire;
/* To use the same key as src and dst is probably an error */
if (sdscmp(c->argv[1]->ptr,c->argv[2]->ptr) == 0) {
addReply(c,shared.sameobjecterr);
return;
}
if ((o = lookupKeyWriteOrReply(c,c->argv[1],shared.nokeyerr)) == NULL)
return;
incrRefCount(o);
expire = getExpire(c->db,c->argv[1]);
if (lookupKeyWrite(c->db,c->argv[2]) != NULL) {
if (nx) {
decrRefCount(o);
addReply(c,shared.czero);
return;
}
/* Overwrite: delete the old key before creating the new one with the same name. */
dbDelete(c->db,c->argv[2]);
}
dbAdd(c->db,c->argv[2],o);
if (expire != -1) setExpire(c->db,c->argv[2],expire);
dbDelete(c->db,c->argv[1]);
signalModifiedKey(c->db,c->argv[1]);
signalModifiedKey(c->db,c->argv[2]);
server.dirty++;
addReply(c,nx ? shared.cone : shared.ok);
}
void renameCommand(redisClient *c) {
renameGenericCommand(c,0);
}
void renamenxCommand(redisClient *c) {
renameGenericCommand(c,1);
}
void moveCommand(redisClient *c) {
robj *o;
redisDb *src, *dst;
int srcid;
if (server.cluster_enabled) {
addReplyError(c,"MOVE is not allowed in cluster mode");
return;
}
/* Obtain source and target DB pointers */
src = c->db;
srcid = c->db->id;
if (selectDb(c,atoi(c->argv[2]->ptr)) == REDIS_ERR) {
addReply(c,shared.outofrangeerr);
return;
}
dst = c->db;
selectDb(c,srcid); /* Back to the source DB */
/* If the user is moving using as target the same
* DB as the source DB it is probably an error. */
if (src == dst) {
addReply(c,shared.sameobjecterr);
return;
}
/* Check if the element exists and get a reference */
o = lookupKeyWrite(c->db,c->argv[1]);
if (!o) {
addReply(c,shared.czero);
return;
}
/* Return zero if the key already exists in the target DB */
if (lookupKeyWrite(dst,c->argv[1]) != NULL) {
addReply(c,shared.czero);
return;
}
dbAdd(dst,c->argv[1],o);
incrRefCount(o);
/* OK! key moved, free the entry in the source DB */
dbDelete(src,c->argv[1]);
server.dirty++;
addReply(c,shared.cone);
}
/*-----------------------------------------------------------------------------
* Expires API
*----------------------------------------------------------------------------*/
int removeExpire(redisDb *db, robj *key) {
/* An expire may only be removed if there is a corresponding entry in the
* main dict. Otherwise, the key will never be freed. */
redisAssertWithInfo(NULL,key,dictFind(db->dict,key->ptr) != NULL);
return dictDelete(db->expires,key->ptr) == DICT_OK;
}
void setExpire(redisDb *db, robj *key, long long when) {
dictEntry *kde, *de;
/* Reuse the sds from the main dict in the expire dict */
kde = dictFind(db->dict,key->ptr);
redisAssertWithInfo(NULL,key,kde != NULL);
de = dictReplaceRaw(db->expires,dictGetKey(kde));
dictSetSignedIntegerVal(de,when);
}
/* Return the expire time of the specified key, or -1 if no expire
* is associated with this key (i.e. the key is non volatile) */
long long getExpire(redisDb *db, robj *key) {
dictEntry *de;
/* No expire? return ASAP */
if (dictSize(db->expires) == 0 ||
(de = dictFind(db->expires,key->ptr)) == NULL) return -1;
/* The entry was found in the expire dict, this means it should also
* be present in the main dict (safety check). */
redisAssertWithInfo(NULL,key,dictFind(db->dict,key->ptr) != NULL);
return dictGetSignedIntegerVal(de);
}
/* Propagate expires into slaves and the AOF file.
* When a key expires in the master, a DEL operation for this key is sent
* to all the slaves and the AOF file if enabled.
*
* This way the key expiry is centralized in one place, and since both
* AOF and the master->slave link guarantee operation ordering, everything
* will be consistent even if we allow write operations against expiring
* keys. */
void propagateExpire(redisDb *db, robj *key) {
robj *argv[2];
argv[0] = shared.del;
argv[1] = key;
incrRefCount(argv[0]);
incrRefCount(argv[1]);
if (server.aof_state != REDIS_AOF_OFF)
feedAppendOnlyFile(server.delCommand,db->id,argv,2);
if (listLength(server.slaves))
replicationFeedSlaves(server.slaves,db->id,argv,2);
decrRefCount(argv[0]);
decrRefCount(argv[1]);
}
int expireIfNeeded(redisDb *db, robj *key) {
long long when = getExpire(db,key);
if (when < 0) return 0; /* No expire for this key */
/* Don't expire anything while loading. It will be done later. */
if (server.loading) return 0;
/* If we are running in the context of a slave, return ASAP:
* the slave key expiration is controlled by the master that will
* send us synthesized DEL operations for expired keys.
*
* Still we try to return the right information to the caller,
* that is, 0 if we think the key should be still valid, 1 if
* we think the key is expired at this time. */
if (server.masterhost != NULL) {
return mstime() > when;
}
/* Return when this key has not expired */
if (mstime() <= when) return 0;
/* Delete the key */
server.stat_expiredkeys++;
propagateExpire(db,key);
return dbDelete(db,key);
}
/*-----------------------------------------------------------------------------
* Expires Commands
*----------------------------------------------------------------------------*/
/* This is the generic command implementation for EXPIRE, PEXPIRE, EXPIREAT
* and PEXPIREAT. Because the commad second argument may be relative or absolute
* the "basetime" argument is used to signal what the base time is (either 0
* for *AT variants of the command, or the current time for relative expires).
*
* unit is either UNIT_SECONDS or UNIT_MILLISECONDS, and is only used for
* the argv[2] parameter. The basetime is always specified in milliesconds. */
void expireGenericCommand(redisClient *c, long long basetime, int unit) {
dictEntry *de;
robj *key = c->argv[1], *param = c->argv[2];
long long when; /* unix time in milliseconds when the key will expire. */
if (getLongLongFromObjectOrReply(c, param, &when, NULL) != REDIS_OK)
return;
if (unit == UNIT_SECONDS) when *= 1000;
when += basetime;
de = dictFind(c->db->dict,key->ptr);
if (de == NULL) {
addReply(c,shared.czero);
return;
}
/* EXPIRE with negative TTL, or EXPIREAT with a timestamp into the past
* should never be executed as a DEL when load the AOF or in the context
* of a slave instance.
*
* Instead we take the other branch of the IF statement setting an expire
* (possibly in the past) and wait for an explicit DEL from the master. */
if (when <= mstime() && !server.loading && !server.masterhost) {
robj *aux;
redisAssertWithInfo(c,key,dbDelete(c->db,key));
server.dirty++;
/* Replicate/AOF this as an explicit DEL. */
aux = createStringObject("DEL",3);
rewriteClientCommandVector(c,2,aux,key);
decrRefCount(aux);
signalModifiedKey(c->db,key);
addReply(c, shared.cone);
return;
} else {
setExpire(c->db,key,when);
addReply(c,shared.cone);
signalModifiedKey(c->db,key);
server.dirty++;
return;
}
}
void expireCommand(redisClient *c) {
expireGenericCommand(c,mstime(),UNIT_SECONDS);
}
void expireatCommand(redisClient *c) {
expireGenericCommand(c,0,UNIT_SECONDS);
}
void pexpireCommand(redisClient *c) {
expireGenericCommand(c,mstime(),UNIT_MILLISECONDS);
}
void pexpireatCommand(redisClient *c) {
expireGenericCommand(c,0,UNIT_MILLISECONDS);
}
void ttlGenericCommand(redisClient *c, int output_ms) {
long long expire, ttl = -1;
expire = getExpire(c->db,c->argv[1]);
if (expire != -1) {
ttl = expire-mstime();
if (ttl < 0) ttl = -1;
}
if (ttl == -1) {
addReplyLongLong(c,-1);
} else {
addReplyLongLong(c,output_ms ? ttl : ((ttl+500)/1000));
}
}
void ttlCommand(redisClient *c) {
ttlGenericCommand(c, 0);
}
void pttlCommand(redisClient *c) {
ttlGenericCommand(c, 1);
}
void persistCommand(redisClient *c) {
dictEntry *de;
de = dictFind(c->db->dict,c->argv[1]->ptr);
if (de == NULL) {
addReply(c,shared.czero);
} else {
if (removeExpire(c->db,c->argv[1])) {
addReply(c,shared.cone);
server.dirty++;
} else {
addReply(c,shared.czero);
}
}
}
/* -----------------------------------------------------------------------------
* API to get key arguments from commands
* ---------------------------------------------------------------------------*/
int *getKeysUsingCommandTable(struct redisCommand *cmd,robj **argv, int argc, int *numkeys) {
int j, i = 0, last, *keys;
REDIS_NOTUSED(argv);
if (cmd->firstkey == 0) {
*numkeys = 0;
return NULL;
}
last = cmd->lastkey;
if (last < 0) last = argc+last;
keys = zmalloc(sizeof(int)*((last - cmd->firstkey)+1));
for (j = cmd->firstkey; j <= last; j += cmd->keystep) {
redisAssert(j < argc);
keys[i++] = j;
}
*numkeys = i;
return keys;
}
int *getKeysFromCommand(struct redisCommand *cmd,robj **argv, int argc, int *numkeys, int flags) {
if (cmd->getkeys_proc) {
return cmd->getkeys_proc(cmd,argv,argc,numkeys,flags);
} else {
return getKeysUsingCommandTable(cmd,argv,argc,numkeys);
}
}
void getKeysFreeResult(int *result) {
zfree(result);
}
int *noPreloadGetKeys(struct redisCommand *cmd,robj **argv, int argc, int *numkeys, int flags) {
if (flags & REDIS_GETKEYS_PRELOAD) {
*numkeys = 0;
return NULL;
} else {
return getKeysUsingCommandTable(cmd,argv,argc,numkeys);
}
}
int *renameGetKeys(struct redisCommand *cmd,robj **argv, int argc, int *numkeys, int flags) {
if (flags & REDIS_GETKEYS_PRELOAD) {
int *keys = zmalloc(sizeof(int));
*numkeys = 1;
keys[0] = 1;
return keys;
} else {
return getKeysUsingCommandTable(cmd,argv,argc,numkeys);
}
}
int *zunionInterGetKeys(struct redisCommand *cmd,robj **argv, int argc, int *numkeys, int flags) {
int i, num, *keys;
REDIS_NOTUSED(cmd);
REDIS_NOTUSED(flags);
num = atoi(argv[2]->ptr);
/* Sanity check. Don't return any key if the command is going to
* reply with syntax error. */
if (num > (argc-3)) {
*numkeys = 0;
return NULL;
}
keys = zmalloc(sizeof(int)*num);
for (i = 0; i < num; i++) keys[i] = 3+i;
*numkeys = num;
return keys;
}
/* Slot to Key API. This is used by Redis Cluster in order to obtain in
* a fast way a key that belongs to a specified hash slot. This is useful
* while rehashing the cluster. */
void SlotToKeyAdd(robj *key) {
unsigned int hashslot = keyHashSlot(key->ptr,sdslen(key->ptr));
zslInsert(server.cluster.slots_to_keys,hashslot,key);
incrRefCount(key);
}
void SlotToKeyDel(robj *key) {
unsigned int hashslot = keyHashSlot(key->ptr,sdslen(key->ptr));
zslDelete(server.cluster.slots_to_keys,hashslot,key);
}
unsigned int GetKeysInSlot(unsigned int hashslot, robj **keys, unsigned int count) {
zskiplistNode *n;
zrangespec range;
int j = 0;
range.min = range.max = hashslot;
range.minex = range.maxex = 0;
n = zslFirstInRange(server.cluster.slots_to_keys, range);
while(n && n->score == hashslot && count--) {
keys[j++] = n->obj;
n = n->level[0].forward;
}
return j;
}
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