The phpredis extension provides an API for communicating with the Redis key-value store. It is released under the PHP License, version 3.01. This code has been developed and maintained by Owlient from November 2009 to March 2011.
You can send comments, patches, questions here on github or to [email protected] (@yowgi).
phpize ./configure make && make install
make install copies redis.so to an appropriate location, but you still need to enable the module in the PHP config file. To do so, either edit your php.ini or add a redis.ini file in /etc/php5/conf.d with the following contents: extension=redis.so.
You can generate a debian package for PHP5, accessible from Apache 2 by running ./mkdeb-apache2.sh or with dpkg-buildpackage or svn-buildpackage.
This extension exports a single class, Redis (and RedisException used in case of errors). Check out https://github.com/ukko/phpredis-phpdoc for a PHP stub that you can use in your IDE for code completion.
If the install fails on OSX, type the following commands in your shell before trying again:
MACOSX_DEPLOYMENT_TARGET=10.6 CFLAGS="-arch i386 -arch x86_64 -g -Os -pipe -no-cpp-precomp" CCFLAGS="-arch i386 -arch x86_64 -g -Os -pipe" CXXFLAGS="-arch i386 -arch x86_64 -g -Os -pipe" LDFLAGS="-arch i386 -arch x86_64 -bind_at_load" export CFLAGS CXXFLAGS LDFLAGS CCFLAGS MACOSX_DEPLOYMENT_TARGET
See also: Install Redis & PHP Extension PHPRedis with Macports.
phpredis can be used to store PHP sessions. To do this, configure session.save_handler and session.save_path in your php.ini to tell phpredis where to store the sessions:
session.save_handler = redis session.save_path = "tcp://host1:6379?weight=1, tcp://host2:6379?weight=2&timeout=2.5, tcp://host3:6379?weight=2"
session.save_path can have a simple host:port format too, but you need to provide the tcp:// scheme if you want to use the parameters. The following parameters are available:
- weight (integer): the weight of a host is used in comparison with the others in order to customize the session distribution on several hosts. If host A has twice the weight of host B, it will get twice the amount of sessions. In the example, host1 stores 20% of all the sessions (1/(1+2+2)) while host2 and host3 each store 40% (2/1+2+2). The target host is determined once and for all at the start of the session, and doesn't change. The default weight is 1.
- timeout (float): the connection timeout to a redis host, expressed in seconds. If the host is unreachable in that amount of time, the session storage will be unavailable for the client. The default timeout is very high (86400 seconds).
- persistent (integer, should be 1 or 0): defines if a persistent connection should be used. (experimental setting)
- prefix (string, defaults to "PHPREDIS_SESSION:"): used as a prefix to the Redis key in which the session is stored. The key is composed of the prefix followed by the session ID.
- auth (string, empty by default): used to authenticate with the Redis server prior to sending commands.
Sessions have a lifetime expressed in seconds and stored in the INI variable "session.gc_maxlifetime". You can change it with ini_set().
The session handler requires a version of Redis with the SETEX command (at least 2.0).
See dedicated page.
phpredis throws a RedisException object if it can't reach the Redis server. That can happen in case of connectivity issues, if the Redis service is down, or if the redis host is overloaded. In any other problematic case that does not involve an unreachable server (such as a key not existing, an invalid command, etc), phpredis will return FALSE.
Creates a Redis client
$redis = new Redis();
Connects to a Redis instance.
host: string. can be a host, or the path to a unix domain socket
port: int, optional
timeout: float, value in seconds (optional, default is 0 meaning unlimited)
BOOL: TRUE on success, FALSE on error.
$redis->connect('127.0.0.1', 6379);
$redis->connect('127.0.0.1'); // port 6379 by default
$redis->connect('127.0.0.1', 6379, 2.5); // 2.5 sec timeout.
$redis->connect('/tmp/redis.sock'); // unix domain socket.
Connects to a Redis instance or reuse a connection already established with pconnect/popen.
The connection will not be closed on close or end of request until the php process ends.
So be patient on to many open FD's (specially on redis server side) when using persistent
connections on many servers connecting to one redis server.
Also more than one persistent connection can be made identified by either host + port + timeout or host + persistent_id or unix socket + timeout.
This feature is not available in threaded versions. pconnect and popen then working like their non
persistent equivalents.
host: string. can be a host, or the path to a unix domain socket
port: int, optional
timeout: float, value in seconds (optional, default is 0 meaning unlimited)
persistent_id: string. identity for the requested persistent connection
BOOL: TRUE on success, FALSE on error.
$redis->pconnect('127.0.0.1', 6379);
$redis->pconnect('127.0.0.1'); // port 6379 by default - same connection like before.
$redis->pconnect('127.0.0.1', 6379, 2.5); // 2.5 sec timeout and would be another connection than the two before.
$redis->pconnect('127.0.0.1', 6379, 2.5, 'x'); // x is sent as persistent_id and would be another connection the the three before.
$redis->pconnect('/tmp/redis.sock'); // unix domain socket - would be another connection than the four before.
Disconnects from the Redis instance, except when pconnect is used.
Set client option.
parameter name
parameter value
BOOL: TRUE on success, FALSE on error.
$redis->setOption(Redis::OPT_SERIALIZER, Redis::SERIALIZER_NONE); // don't serialize data $redis->setOption(Redis::OPT_SERIALIZER, Redis::SERIALIZER_PHP); // use built-in serialize/unserialize $redis->setOption(Redis::OPT_SERIALIZER, Redis::SERIALIZER_IGBINARY); // use igBinary serialize/unserialize $redis->setOption(Redis::OPT_PREFIX, 'myAppName:'); // use custom prefix on all keys
Get client option.
parameter name
Parameter value.
$redis->getOption(Redis::OPT_SERIALIZER); // return Redis::SERIALIZER_NONE, Redis::SERIALIZER_PHP, or Redis::SERIALIZER_IGBINARY.
Check the current connection status
(none)
STRING: +PONG on success. Throws a RedisException object on connectivity error, as described above.
Get the value related to the specified key
key
String or Bool: If key didn't exist, FALSE is returned. Otherwise, the value related to this key is returned.
$redis->get('key');
Set the string value in argument as value of the key.
Key
Value
Timeout (optional). Calling SETEX is preferred if you want a timeout.
Bool TRUE if the command is successful.
$redis->set('key', 'value');
Set the string value in argument as value of the key, with a time to live.
Key TTL Value
Bool TRUE if the command is successful.
$redis->setex('key', 3600, 'value'); // sets key → value, with 1h TTL.
Set the string value in argument as value of the key if the key doesn't already exist in the database.
key value
Bool TRUE in case of success, FALSE in case of failure.
$redis->setnx('key', 'value'); /* return TRUE */
$redis->setnx('key', 'value'); /* return FALSE */
Remove specified keys.
An array of keys, or an undefined number of parameters, each a key: key1 key2 key3 ... keyN
Long Number of keys deleted.
$redis->set('key1', 'val1');
$redis->set('key2', 'val2');
$redis->set('key3', 'val3');
$redis->set('key4', 'val4');
$redis->delete('key1', 'key2'); /* return 2 */
$redis->delete(array('key3', 'key4')); /* return 2 */
Enter and exit transactional mode.
(optional) Redis::MULTI or Redis::PIPELINE. Defaults to Redis::MULTI. A Redis::MULTI block of commands runs as a single transaction; a Redis::PIPELINE block is simply transmitted faster to the server, but without any guarantee of atomicity. discard cancels a transaction.
multi() returns the Redis instance and enters multi-mode. Once in multi-mode, all subsequent method calls return the same object until exec() is called.
$ret = $redis->multi()
->set('key1', 'val1')
->get('key1')
->set('key2', 'val2')
->get('key2')
->exec();
/*
$ret == array(
0 => TRUE,
1 => 'val1',
2 => TRUE,
3 => 'val2');
*/
Watches a key for modifications by another client. If the key is modified between WATCH and EXEC, the MULTI/EXEC transaction will fail (return FALSE). unwatch cancels all the watching of all keys by this client.
keys: a list of keys
$redis->watch('x');
/* long code here during the execution of which other clients could well modify `x` */
$ret = $redis->multi()
->incr('x')
->exec();
/*
$ret = FALSE if x has been modified between the call to WATCH and the call to EXEC.
*/
Subscribe to channels. Warning: this function will probably change in the future.
channels: an array of channels to subscribe to
callback: either a string or an array($instance, 'method_name'). The callback function receives 3 parameters: the redis instance, the channel name, and the message.
function f($redis, $chan, $msg) {
switch($chan) {
case 'chan-1':
...
break;
case 'chan-2':
...
break;
case 'chan-2':
...
break;
}
}
$redis->subscribe(array('chan-1', 'chan-2', 'chan-3'), 'f'); // subscribe to 3 chans
Publish messages to channels. Warning: this function will probably change in the future.
channel: a channel to publish to
messsage: string
$redis->publish('chan-1', 'hello, world!'); // send message.
Verify if the specified key exists.
key
BOOL: If the key exists, return TRUE, otherwise return FALSE.
$redis->set('key', 'value');
$redis->exists('key'); /* TRUE */
$redis->exists('NonExistingKey'); /* FALSE */
Increment the number stored at key by one. If the second argument is filled, it will be used as the integer value of the increment.
key
value: value that will be added to key (only for incrBy)
INT the new value
$redis->incr('key1'); /* key1 didn't exists, set to 0 before the increment */
/* and now has the value 1 */
$redis->incr('key1'); /* 2 */
$redis->incr('key1'); /* 3 */
$redis->incr('key1'); /* 4 */
$redis->incrBy('key1', 10); /* 14 */
Decrement the number stored at key by one. If the second argument is filled, it will be used as the integer value of the decrement.
key
value: value that will be substracted to key (only for decrBy)
INT the new value
$redis->decr('key1'); /* key1 didn't exists, set to 0 before the increment */
/* and now has the value -1 */
$redis->decr('key1'); /* -2 */
$redis->decr('key1'); /* -3 */
$redis->decrBy('key1', 10); /* -13 */
Get the values of all the specified keys. If one or more keys dont exist, the array will contain FALSE at the position of the key.
Array: Array containing the list of the keys
Array: Array containing the values related to keys in argument
$redis->set('key1', 'value1');
$redis->set('key2', 'value2');
$redis->set('key3', 'value3');
$redis->getMultiple(array('key1', 'key2', 'key3')); /* array('value1', 'value2', 'value3');
$redis->getMultiple(array('key0', 'key1', 'key5')); /* array(`FALSE`, 'value2', `FALSE`);
Adds the string value to the head (left) of the list. Creates the list if the key didn't exist. If the key exists and is not a list, FALSE is returned.
key
value String, value to push in key
LONG The new length of the list in case of success, FALSE in case of Failure.
$redis->delete('key1');
$redis->lPush('key1', 'C'); // returns 1
$redis->lPush('key1', 'B'); // returns 2
$redis->lPush('key1', 'A'); // returns 3
/* key1 now points to the following list: [ 'A', 'B', 'C' ] */
Adds the string value to the tail (right) of the list. Creates the list if the key didn't exist. If the key exists and is not a list, FALSE is returned.
key
value String, value to push in key
LONG The new length of the list in case of success, FALSE in case of Failure.
$redis->delete('key1');
$redis->rPush('key1', 'A'); // returns 1
$redis->rPush('key1', 'B'); // returns 2
$redis->rPush('key1', 'C'); // returns 3
/* key1 now points to the following list: [ 'A', 'B', 'C' ] */
Adds the string value to the head (left) of the list if the list exists.
key
value String, value to push in key
LONG The new length of the list in case of success, FALSE in case of Failure.
$redis->delete('key1');
$redis->lPushx('key1', 'A'); // returns 0
$redis->lPush('key1', 'A'); // returns 1
$redis->lPushx('key1', 'B'); // returns 2
$redis->lPushx('key1', 'C'); // returns 3
/* key1 now points to the following list: [ 'A', 'B', 'C' ] */
Adds the string value to the tail (right) of the list if the ist exists. FALSE in case of Failure.
key
value String, value to push in key
LONG The new length of the list in case of success, FALSE in case of Failure.
$redis->delete('key1');
$redis->rPushx('key1', 'A'); // returns 0
$redis->rPush('key1', 'A'); // returns 1
$redis->rPushx('key1', 'B'); // returns 2
$redis->rPushx('key1', 'C'); // returns 3
/* key1 now points to the following list: [ 'A', 'B', 'C' ] */
Return and remove the first element of the list.
key
STRING if command executed successfully
BOOL FALSE in case of failure (empty list)
$redis->rPush('key1', 'A');
$redis->rPush('key1', 'B');
$redis->rPush('key1', 'C'); /* key1 => [ 'A', 'B', 'C' ] */
$redis->lPop('key1'); /* key1 => [ 'B', 'C' ] */
Returns and removes the first element of the list.
key
STRING if command executed successfully
BOOL FALSE in case of failure (empty list)
$redis->rPush('key1', 'A');
$redis->rPush('key1', 'B');
$redis->rPush('key1', 'C'); /* key1 => [ 'A', 'B', 'C' ] */
$redis->rPop('key1'); /* key1 => [ 'A', 'B' ] */
Is a blocking lPop(rPop) primitive. If at least one of the lists contains at least one element, the element will be popped from the head of the list and returned to the caller. Il all the list identified by the keys passed in arguments are empty, blPop will block during the specified timeout until an element is pushed to one of those lists. This element will be popped.
ARRAY Array containing the keys of the lists INTEGER Timeout Or STRING Key1 STRING Key2 STRING Key3 ... STRING Keyn INTEGER Timeout
ARRAY array('listName', 'element')
/* Non blocking feature */
$redis->lPush('key1', 'A');
$redis->delete('key2');
$redis->blPop('key1', 'key2', 10); /* array('key1', 'A') */
/* OR */
$redis->blPop(array('key1', 'key2'), 10); /* array('key1', 'A') */
$redis->brPop('key1', 'key2', 10); /* array('key1', 'A') */
/* OR */
$redis->brPop(array('key1', 'key2'), 10); /* array('key1', 'A') */
/* Blocking feature */
/* process 1 */
$redis->delete('key1');
$redis->blPop('key1', 10);
/* blocking for 10 seconds */
/* process 2 */
$redis->lPush('key1', 'A');
/* process 1 */
/* array('key1', 'A') is returned*/
Returns the size of a list identified by Key. If the list didn't exist or is empty, the command returns 0. If the data type identified by Key is not a list, the command return FALSE.
Key
LONG The size of the list identified by Key exists.
BOOL FALSE if the data type identified by Key is not list
$redis->rPush('key1', 'A');
$redis->rPush('key1', 'B');
$redis->rPush('key1', 'C'); /* key1 => [ 'A', 'B', 'C' ] */
$redis->lSize('key1');/* 3 */
$redis->rPop('key1');
$redis->lSize('key1');/* 2 */
Return the specified element of the list stored at the specified key.
0 the first element, 1 the second ...
-1 the last element, -2 the penultimate ...
Return FALSE in case of a bad index or a key that doesn't point to a list.
key index
String the element at this index
Bool FALSE if the key identifies a non-string data type, or no value corresponds to this index in the list Key.
$redis->rPush('key1', 'A');
$redis->rPush('key1', 'B');
$redis->rPush('key1', 'C'); /* key1 => [ 'A', 'B', 'C' ] */
$redis->lGet('key1', 0); /* 'A' */
$redis->lGet('key1', -1); /* 'C' */
$redis->lGet('key1', 10); /* `FALSE` */
Set the list at index with the new value.
key index value
BOOL TRUE if the new value is setted. FALSE if the index is out of range, or data type identified by key is not a list.
$redis->rPush('key1', 'A');
$redis->rPush('key1', 'B');
$redis->rPush('key1', 'C'); /* key1 => [ 'A', 'B', 'C' ] */
$redis->lGet('key1', 0); /* 'A' */
$redis->lSet('key1', 0, 'X');
$redis->lGet('key1', 0); /* 'X' */
Returns the specified elements of the list stored at the specified key in the range [start, end]. start and stop are interpretated as indices: 0 the first element, 1 the second ... -1 the last element, -2 the penultimate ...
key start end
Array containing the values in specified range.
$redis->rPush('key1', 'A');
$redis->rPush('key1', 'B');
$redis->rPush('key1', 'C');
$redis->lRange('key1', 0, -1); /* array('A', 'B', 'C') */
Trims an existing list so that it will contain only a specified range of elements.
key start stop
Array
Bool return FALSE if the key identify a non-list value.
$redis->rPush('key1', 'A');
$redis->rPush('key1', 'B');
$redis->rPush('key1', 'C');
$redis->lRange('key1', 0, -1); /* array('A', 'B', 'C') */
$redis->lTrim('key1', 0, 1);
$redis->lRange('key1', 0, -1); /* array('A', 'B') */
Removes the first count occurences of the value element from the list. If count is zero, all the matching elements are removed. If count is negative, elements are removed from tail to head.
Note: The argument order is not the same as in the Redis documentation. This difference is kept for compatibility reasons.
key
value
count
LONG the number of elements to remove
BOOL FALSE if the value identified by key is not a list.
$redis->lPush('key1', 'A');
$redis->lPush('key1', 'B');
$redis->lPush('key1', 'C');
$redis->lPush('key1', 'A');
$redis->lPush('key1', 'A');
$redis->lRange('key1', 0, -1); /* array('A', 'A', 'C', 'B', 'A') */
$redis->lRem('key1', 'A', 2); /* 2 */
$redis->lRange('key1', 0, -1); /* array('C', 'B', 'A') */
Insert value in the list before or after the pivot value. the parameter options specify the position of the insert (before or after). If the list didn't exists, or the pivot didn't exists, the value is not inserted.
key position Redis::BEFORE | Redis::AFTER pivot value
The number of the elements in the list, -1 if the pivot didn't exists.
$redis->delete('key1');
$redis->lInsert('key1', Redis::AFTER, 'A', 'X'); /* 0 */
$redis->lPush('key1', 'A');
$redis->lPush('key1', 'B');
$redis->lPush('key1', 'C');
$redis->lInsert('key1', Redis::BEFORE, 'C', 'X'); /* 4 */
$redis->lRange('key1', 0, -1); /* array('A', 'B', 'X', 'C') */
$redis->lInsert('key1', Redis::AFTER, 'C', 'Y'); /* 5 */
$redis->lRange('key1', 0, -1); /* array('A', 'B', 'X', 'C', 'Y') */
$redis->lInsert('key1', Redis::AFTER, 'W', 'value'); /* -1 */
Adds a value to the set value stored at key. If this value is already in the set, FALSE is returned.
key value
BOOL TRUE if value didn't exist and was added successfully, FALSE if the value is already present.
$redis->sAdd('key1' , 'set1'); /* TRUE, 'key1' => {'set1'} */
$redis->sAdd('key1' , 'set2'); /* TRUE, 'key1' => {'set1', 'set2'}*/
$redis->sAdd('key1' , 'set2'); /* FALSE, 'key1' => {'set1', 'set2'}*/
Removes the specified member from the set value stored at key.
key member
BOOL TRUE if the member was present in the set, FALSE if it didn't.
$redis->sAdd('key1' , 'set1');
$redis->sAdd('key1' , 'set2');
$redis->sAdd('key1' , 'set3'); /* 'key1' => {'set1', 'set2', 'set3'}*/
$redis->sRem('key1', 'set2'); /* 'key1' => {'set1', 'set3'} */
Moves the specified member from the set at srcKey to the set at dstKey.
srcKey dstKey member
BOOL If the operation is successful, return TRUE. If the srcKey and/or dstKey didn't exist, and/or the member didn't exist in srcKey, FALSE is returned.
$redis->sAdd('key1' , 'set11');
$redis->sAdd('key1' , 'set12');
$redis->sAdd('key1' , 'set13'); /* 'key1' => {'set11', 'set12', 'set13'}*/
$redis->sAdd('key2' , 'set21');
$redis->sAdd('key2' , 'set22'); /* 'key2' => {'set21', 'set22'}*/
$redis->sMove('key1', 'key2', 'set13'); /* 'key1' => {'set11', 'set12'} */
/* 'key2' => {'set21', 'set22', 'set13'} */
Checks if value is a member of the set stored at the key key.
key value
BOOL TRUE if value is a member of the set at key key, FALSE otherwise.
$redis->sAdd('key1' , 'set1');
$redis->sAdd('key1' , 'set2');
$redis->sAdd('key1' , 'set3'); /* 'key1' => {'set1', 'set2', 'set3'}*/
$redis->sIsMember('key1', 'set1'); /* TRUE */
$redis->sIsMember('key1', 'setX'); /* FALSE */
Returns the cardinality of the set identified by key.
key
LONG the cardinality of the set identified by key, 0 if the set doesn't exist.
$redis->sAdd('key1' , 'set1');
$redis->sAdd('key1' , 'set2');
$redis->sAdd('key1' , 'set3'); /* 'key1' => {'set1', 'set2', 'set3'}*/
$redis->sCard('key1'); /* 3 */
$redis->sCard('keyX'); /* 0 */
Removes and returns a random element from the set value at Key.
key
String "popped" value
Bool FALSE if set identified by key is empty or doesn't exist.
$redis->sAdd('key1' , 'set1');
$redis->sAdd('key1' , 'set2');
$redis->sAdd('key1' , 'set3'); /* 'key1' => {'set3', 'set1', 'set2'}*/
$redis->sPop('key1'); /* 'set1', 'key1' => {'set3', 'set2'} */
$redis->sPop('key1'); /* 'set3', 'key1' => {'set2'} */
Returns a random element from the set value at Key, without removing it.
key
String value from the set
Bool FALSE if set identified by key is empty or doesn't exist.
$redis->sAdd('key1' , 'set1');
$redis->sAdd('key1' , 'set2');
$redis->sAdd('key1' , 'set3'); /* 'key1' => {'set3', 'set1', 'set2'}*/
$redis->sRandMember('key1'); /* 'set1', 'key1' => {'set3', 'set1', 'set2'} */
$redis->sRandMember('key1'); /* 'set3', 'key1' => {'set3', 'set1', 'set2'} */
Returns the members of a set resulting from the intersection of all the sets held at the specified keys.
If just a single key is specified, then this command produces the members of this set. If one of the keys
is missing, FALSE is returned.
key1, key2, keyN: keys identifying the different sets on which we will apply the intersection.
Array, contain the result of the intersection between those keys. If the intersection beteen the different sets is empty, the return value will be empty array.
$redis->sAdd('key1', 'val1');
$redis->sAdd('key1', 'val2');
$redis->sAdd('key1', 'val3');
$redis->sAdd('key1', 'val4');
$redis->sAdd('key2', 'val3');
$redis->sAdd('key2', 'val4');
$redis->sAdd('key3', 'val3');
$redis->sAdd('key3', 'val4');
var_dump($redis->sInter('key1', 'key2', 'key3'));
Output:
array(2) {
[0]=>
string(4) "val4"
[1]=>
string(4) "val3"
}
Performs a sInter command and stores the result in a new set.
Key: dstkey, the key to store the diff into.
Keys: key1, key2... keyN. key1..keyN are intersected as in sInter.
INTEGER: The cardinality of the resulting set, or FALSE in case of a missing key.
$redis->sAdd('key1', 'val1');
$redis->sAdd('key1', 'val2');
$redis->sAdd('key1', 'val3');
$redis->sAdd('key1', 'val4');
$redis->sAdd('key2', 'val3');
$redis->sAdd('key2', 'val4');
$redis->sAdd('key3', 'val3');
$redis->sAdd('key3', 'val4');
var_dump($redis->sInterStore('output', 'key1', 'key2', 'key3'));
var_dump($redis->sMembers('output'));
Output:
int(2)
array(2) {
[0]=>
string(4) "val4"
[1]=>
string(4) "val3"
}
Performs the union between N sets and returns it.
Keys: key1, key2, ... , keyN: Any number of keys corresponding to sets in redis.
Array of strings: The union of all these sets.
$redis->delete('s0', 's1', 's2');
$redis->sAdd('s0', '1');
$redis->sAdd('s0', '2');
$redis->sAdd('s1', '3');
$redis->sAdd('s1', '1');
$redis->sAdd('s2', '3');
$redis->sAdd('s2', '4');
var_dump($redis->sUnion('s0', 's1', 's2'));
Return value: all elements that are either in s0 or in s1 or in s2.
array(4) {
[0]=>
string(1) "3"
[1]=>
string(1) "4"
[2]=>
string(1) "1"
[3]=>
string(1) "2"
}
Performs the same action as sUnion, but stores the result in the first key
Key: dstkey, the key to store the diff into.
Keys: key1, key2, ... , keyN: Any number of keys corresponding to sets in redis.
INTEGER: The cardinality of the resulting set, or FALSE in case of a missing key.
$redis->delete('s0', 's1', 's2');
$redis->sAdd('s0', '1');
$redis->sAdd('s0', '2');
$redis->sAdd('s1', '3');
$redis->sAdd('s1', '1');
$redis->sAdd('s2', '3');
$redis->sAdd('s2', '4');
var_dump($redis->sUnionStore('dst', 's0', 's1', 's2'));
var_dump($redis->sMembers('dst'));
Return value: the number of elements that are either in s0 or in s1 or in s2.
int(4)
array(4) {
[0]=>
string(1) "3"
[1]=>
string(1) "4"
[2]=>
string(1) "1"
[3]=>
string(1) "2"
}
Performs the difference between N sets and returns it.
Keys: key1, key2, ... , keyN: Any number of keys corresponding to sets in redis.
Array of strings: The difference of the first set will all the others.
$redis->delete('s0', 's1', 's2');
$redis->sAdd('s0', '1');
$redis->sAdd('s0', '2');
$redis->sAdd('s0', '3');
$redis->sAdd('s0', '4');
$redis->sAdd('s1', '1');
$redis->sAdd('s2', '3');
var_dump($redis->sDiff('s0', 's1', 's2'));
Return value: all elements of s0 that are neither in s1 nor in s2.
array(2) {
[0]=>
string(1) "4"
[1]=>
string(1) "2"
}
Performs the same action as sDiff, but stores the result in the first key
Key: dstkey, the key to store the diff into.
Keys: key1, key2, ... , keyN: Any number of keys corresponding to sets in redis
INTEGER: The cardinality of the resulting set, or FALSE in case of a missing key.
$redis->delete('s0', 's1', 's2');
$redis->sAdd('s0', '1');
$redis->sAdd('s0', '2');
$redis->sAdd('s0', '3');
$redis->sAdd('s0', '4');
$redis->sAdd('s1', '1');
$redis->sAdd('s2', '3');
var_dump($redis->sDiffStore('dst', 's0', 's1', 's2'));
var_dump($redis->sMembers('dst'));
Return value: the number of elements of s0 that are neither in s1 nor in s2.
int(2)
array(2) {
[0]=>
string(1) "4"
[1]=>
string(1) "2"
}
Returns the contents of a set.
Key: key
An array of elements, the contents of the set.
$redis->delete('s');
$redis->sAdd('s', 'a');
$redis->sAdd('s', 'b');
$redis->sAdd('s', 'a');
$redis->sAdd('s', 'c');
var_dump($redis->sMembers('s'));
Output:
array(3) {
[0]=>
string(1) "c"
[1]=>
string(1) "a"
[2]=>
string(1) "b"
}
The order is random and corresponds to redis' own internal representation of the set structure.
Sets a value and returns the previous entry at that key.
Key: key
STRING: value
A string, the previous value located at this key.
$redis->set('x', '42');
$exValue = $redis->getSet('x', 'lol'); // return '42', replaces x by 'lol'
$newValue = $redis->get('x')' // return 'lol'
Returns a random key.
None.
STRING: an existing key in redis.
$key = $redis->randomKey(); $surprise = $redis->get($key); // who knows what's in there.
Switches to a given database.
INTEGER: dbindex, the database number to switch to.
TRUE in case of success, FALSE in case of failure.
(See following function)
Moves a key to a different database.
Key: key, the key to move.
INTEGER: dbindex, the database number to move the key to.
BOOL: TRUE in case of success, FALSE in case of failure.
$redis->select(0); // switch to DB 0
$redis->set('x', '42'); // write 42 to x
$redis->move('x', 1); // move to DB 1
$redis->select(1); // switch to DB 1
$redis->get('x'); // will return 42
Renames a key.
STRING: srckey, the key to rename.
STRING: dstkey, the new name for the key.
BOOL: TRUE in case of success, FALSE in case of failure.
$redis->set('x', '42');
$redis->rename('x', 'y');
$redis->get('y'); // → 42
$redis->get('x'); // → `FALSE`
Same as rename, but will not replace a key if the destination already exists. This is the same behaviour as setNx.
Sets an expiration date (a timeout) on an item.
Key: key. The key that will disappear.
Integer: ttl. The key's remaining Time To Live, in seconds.
BOOL: TRUE in case of success, FALSE in case of failure.
$redis->set('x', '42');
$redis->setTimeout('x', 3); // x will disappear in 3 seconds.
sleep(5); // wait 5 seconds
$redis->get('x'); // will return `FALSE`, as 'x' has expired.
Sets an expiration date (a timestamp) on an item.
Key: key. The key that will disappear.
Integer: Unix timestamp. The key's date of death, in seconds from Epoch time.
BOOL: TRUE in case of success, FALSE in case of failure.
$redis->set('x', '42');
$now = time(NULL); // current timestamp
$redis->expireAt('x', $now + 3); // x will disappear in 3 seconds.
sleep(5); // wait 5 seconds
$redis->get('x'); // will return `FALSE`, as 'x' has expired.
Returns the keys that match a certain pattern.
STRING: pattern, using '*' as a wildcard.
Array of STRING: The keys that match a certain pattern.
$allKeys = $redis->keys('*'); // all keys will match this.
$keyWithUserPrefix = $redis->keys('user*');
Returns the current database's size.
None.
INTEGER: DB size, in number of keys.
$count = $redis->dbSize(); echo "Redis has $count keys\n";
Authenticate the connection using a password. Warning: The password is sent in plain-text over the network.
STRING: password
BOOL: TRUE if the connection is authenticated, FALSE otherwise.
$redis->auth('foobared');
Starts the background rewrite of AOF (Append-Only File)
None.
BOOL: TRUE in case of success, FALSE in case of failure.
$redis->bgrewriteaof();
Changes the slave status
Either host (string) and port (int), or no parameter to stop being a slave.
BOOL: TRUE in case of success, FALSE in case of failure.
$redis->slaveof('10.0.1.7', 6379);
/* ... */
$redis->slaveof();
Describes the object pointed to by a key.
The information to retrieve (string) and the key (string). Info can be one of the following:
- "encoding"
- "refcount"
- "idletime"
STRING for "encoding", LONG for "refcount" and "idletime", FALSE if the key doesn't exist.
$redis->object("encoding", "l"); // → ziplist
$redis->object("refcount", "l"); // → 1
$redis->object("idletime", "l"); // → 400 (in seconds, with a precision of 10 seconds).
Performs a synchronous save.
None.
BOOL: TRUE in case of success, FALSE in case of failure. If a save is already running, this command will fail and return FALSE.
$redis->save();
Performs a background save.
None.
BOOL: TRUE in case of success, FALSE in case of failure. If a save is already running, this command will fail and return FALSE.
$redis->bgSave();
Returns the timestamp of the last disk save.
None.
INT: timestamp.
$redis->lastSave();
Returns the type of data pointed by a given key.
Key: key
Depending on the type of the data pointed by the key, this method will return the following value:
string: Redis::REDIS_STRING
set: Redis::REDIS_SET
list: Redis::REDIS_LIST
zset: Redis::REDIS_ZSET
hash: Redis::REDIS_HASH
other: Redis::REDIS_NOT_FOUND
$redis->type('key');
Append specified string to the string stored in specified key.
Key Value
INTEGER: Size of the value after the append
$redis->set('key', 'value1');
$redis->append('key', 'value2'); /* 12 */
$redis->get('key'); /* 'value1value2' */
Return a substring of a larger string
key start end
STRING: the substring
$redis->set('key', 'string value');
$redis->getRange('key', 0, 5); /* 'string' */
$redis->getRange('key', -5, -1); /* 'value' */
Changes a substring of a larger string.
key
offset
value
STRING: the length of the string after it was modified.
$redis->set('key', 'Hello world');
$redis->setRange('key', 6, "redis"); /* returns 11 */
$redis->get('key'); /* "Hello redis" */
Get the length of a string value.
key
INTEGER
$redis->set('key', 'value');
$redis->strlen('key'); /* 5 */
Return a single bit out of a larger string
key
offset
LONG: the bit value (0 or 1)
$redis->set('key', "\x7f"); // this is 0111 1111
$redis->getBit('key', 0); /* 0 */
$redis->getBit('key', 1); /* 1 */
Changes a single bit of a string.
key
offset
value: bool or int (1 or 0)
LONG: 0 or 1, the value of the bit before it was set.
$redis->set('key', "*"); // ord("*") = 42 = 0x2f = "0010 1010"
$redis->setBit('key', 5, 1); /* returns 0 */
$redis->setBit('key', 7, 1); /* returns 0 */
$redis->get('key'); /* chr(0x2f) = "/" = b("0010 1111") */
Removes all entries from the current database.
None.
BOOL: Always TRUE.
$redis->flushDB();
Removes all entries from all databases.
None.
BOOL: Always TRUE.
$redis->flushAll();
Key: key Options: array(key => value, ...) - optional, with the following keys and values:
'by' => 'some_pattern_*',
'limit' => array(0, 1),
'get' => 'some_other_pattern_*' or an array of patterns,
'sort' => 'asc' or 'desc',
'alpha' => TRUE,
'store' => 'external-key'
An array of values, or a number corresponding to the number of elements stored if that was used.
$redis->delete('s');
$redis->sadd('s', 5);
$redis->sadd('s', 4);
$redis->sadd('s', 2);
$redis->sadd('s', 1);
$redis->sadd('s', 3);
var_dump($redis->sort('s')); // 1,2,3,4,5
var_dump($redis->sort('s', array('sort' => 'desc'))); // 5,4,3,2,1
var_dump($redis->sort('s', array('sort' => 'desc', 'store' => 'out'))); // (int)5
Returns an associative array of strings and integers, with the following keys:
- redis_version
- arch_bits
- uptime_in_seconds
- uptime_in_days
- connected_clients
- connected_slaves
- used_memory
- changes_since_last_save
- bgsave_in_progress
- last_save_time
- total_connections_received
- total_commands_processed
- role
None.
$redis->info();
Resets the statistics reported by Redis using the INFO command (info() function).
These are the counters that are reset:
- Keyspace hits
- Keyspace misses
- Number of commands processed
- Number of connections received
- Number of expired keys
None.
BOOL: TRUE in case of success, FALSE in case of failure.
$redis->resetStat();
Returns the time to live left for a given key, in seconds. If the key doesn't exist, FALSE is returned.
Key: key
Long, the time left to live in seconds.
$redis->ttl('key');
Remove the expiration timer from a key.
Key: key
BOOL: TRUE if a timeout was removed, FALSE if the key didn’t exist or didn’t have an expiration timer.
$redis->persist('key');
Sets multiple key-value pairs in one atomic command. MSETNX only returns TRUE if all the keys were set (see SETNX).
Pairs: array(key => value, ...)
Bool TRUE in case of success, FALSE in case of failure.
$redis->mset(array('key0' => 'value0', 'key1' => 'value1'));
var_dump($redis->get('key0'));
var_dump($redis->get('key1'));
Output:
string(6) "value0" string(6) "value1"
Pops a value from the tail of a list, and pushes it to the front of another list. Also return this value.
Key: srckey
Key: dstkey
STRING The element that was moved in case of success, FALSE in case of failure.
$redis->delete('x', 'y');
$redis->lPush('x', 'abc');
$redis->lPush('x', 'def');
$redis->lPush('y', '123');
$redis->lPush('y', '456');
// move the last of x to the front of y.
var_dump($redis->rpoplpush('x', 'y'));
var_dump($redis->lRange('x', 0, -1));
var_dump($redis->lRange('y', 0, -1));
Output:
string(3) "abc"
array(1) {
[0]=>
string(3) "def"
}
array(3) {
[0]=>
string(3) "abc"
[1]=>
string(3) "456"
[2]=>
string(3) "123"
}
A blocking version of rpoplpush, with an integral timeout in the third parameter.
Key: srckey
Key: dstkey
Long: timeout
STRING The element that was moved in case of success, FALSE in case of timeout.
Adds the specified member with a given score to the sorted set stored at key.
key
score : double
value: string
Long 1 if the element is added. 0 otherwise.
$redis->zAdd('key', 1, 'val1');
$redis->zAdd('key', 0, 'val0');
$redis->zAdd('key', 5, 'val5');
$redis->zRange('key', 0, -1); // array(val0, val1, val5)
Returns a range of elements from the ordered set stored at the specified key, with values in the range [start, end]. start and stop are interpreted as zero-based indices: 0 the first element, 1 the second ... -1 the last element, -2 the penultimate ...
key
start: long
end: long
withscores: bool = false
Array containing the values in specified range.
$redis->zAdd('key1', 0, 'val0');
$redis->zAdd('key1', 2, 'val2');
$redis->zAdd('key1', 10, 'val10');
$redis->zRange('key1', 0, -1); /* array('val0', 'val2', 'val10') */
// with scores
$redis->zRange('key1', 0, -1, true); /* array('val0' => 0, 'val2' => 2, 'val10' => 10) */
Deletes a specified member from the ordered set.
key
member
LONG 1 on success, 0 on failure.
$redis->zAdd('key', 0, 'val0');
$redis->zAdd('key', 2, 'val2');
$redis->zAdd('key', 10, 'val10');
$redis->zDelete('key', 'val2');
$redis->zRange('key', 0, -1); /* array('val0', 'val10') */
Returns the elements of the sorted set stored at the specified key in the range [start, end] in reverse order. start and stop are interpretated as zero-based indices: 0 the first element, 1 the second ... -1 the last element, -2 the penultimate ...
key
start: long
end: long
withscores: bool = false
Array containing the values in specified range.
$redis->zAdd('key', 0, 'val0');
$redis->zAdd('key', 2, 'val2');
$redis->zAdd('key', 10, 'val10');
$redis->zRevRange('key', 0, -1); /* array('val10', 'val2', 'val0') */
// with scores
$redis->zRevRange('key', 0, -1, true); /* array('val10' => 10, 'val2' => 2, 'val0' => 0) */
Returns the elements of the sorted set stored at the specified key which have scores in the range [start,end]. Adding a parenthesis before start or end excludes it from the range. +inf and -inf are also valid limits. zRevRangeByScore returns the same items in reverse order, when the start and end parameters are swapped.
key
start: string
end: string
options: array
Two options are available: withscores => TRUE, and limit => array($offset, $count)
Array containing the values in specified range.
$redis->zAdd('key', 0, 'val0');
$redis->zAdd('key', 2, 'val2');
$redis->zAdd('key', 10, 'val10');
$redis->zRangeByScore('key', 0, 3); /* array('val0', 'val2') */
$redis->zRangeByScore('key', 0, 3, array('withscores' => TRUE); /* array('val0' => 0, 'val2' => 2) */
$redis->zRangeByScore('key', 0, 3, array('limit' => array(1, 1)); /* array('val2' => 2) */
$redis->zRangeByScore('key', 0, 3, array('limit' => array(1, 1)); /* array('val2') */
$redis->zRangeByScore('key', 0, 3, array('withscores' => TRUE, 'limit' => array(1, 1)); /* array('val2' => 2) */
Returns the number of elements of the sorted set stored at the specified key which have scores in the range [start,end]. Adding a parenthesis before start or end excludes it from the range. +inf and -inf are also valid limits.
key
start: string
end: string
LONG the size of a corresponding zRangeByScore.
$redis->zAdd('key', 0, 'val0');
$redis->zAdd('key', 2, 'val2');
$redis->zAdd('key', 10, 'val10');
$redis->zCount('key', 0, 3); /* 2, corresponding to array('val0', 'val2') */
Deletes the elements of the sorted set stored at the specified key which have scores in the range [start,end].
key
start: double or "+inf" or "-inf" string
end: double or "+inf" or "-inf" string
LONG The number of values deleted from the sorted set
$redis->zAdd('key', 0, 'val0');
$redis->zAdd('key', 2, 'val2');
$redis->zAdd('key', 10, 'val10');
$redis->zRemRangeByScore('key', 0, 3); /* 2 */
Deletes the elements of the sorted set stored at the specified key which have rank in the range [start,end].
key
start: LONG
end: LONG
LONG The number of values deleted from the sorted set
$redis->zAdd('key', 1, 'one');
$redis->zAdd('key', 2, 'two');
$redis->zAdd('key', 3, 'three');
$redis->zRemRangeByRank('key', 0, 1); /* 2 */
$redis->zRange('key', 0, -1, array('withscores' => TRUE)); /* array('three' => 3) */
Returns the cardinality of an ordered set.
key
Long, the set's cardinality
$redis->zAdd('key', 0, 'val0');
$redis->zAdd('key', 2, 'val2');
$redis->zAdd('key', 10, 'val10');
$redis->zSize('key'); /* 3 */
Returns the score of a given member in the specified sorted set.
key
member
Double
$redis->zAdd('key', 2.5, 'val2');
$redis->zScore('key', 'val2'); /* 2.5 */
Returns the rank of a given member in the specified sorted set, starting at 0 for the item with the smallest score. zRevRank starts at 0 for the item with the largest score.
key
member
Long, the item's score.
$redis->delete('z');
$redis->zAdd('key', 1, 'one');
$redis->zAdd('key', 2, 'two');
$redis->zRank('key', 'one'); /* 0 */
$redis->zRank('key', 'two'); /* 1 */
$redis->zRevRank('key', 'one'); /* 1 */
$redis->zRevRank('key', 'two'); /* 0 */
Increments the score of a member from a sorted set by a given amount.
key
value: (double) value that will be added to the member's score
member
DOUBLE the new value
$redis->delete('key');
$redis->zIncrBy('key', 2.5, 'member1'); /* key or member1 didn't exist, so member1's score is to 0 before the increment */
/* and now has the value 2.5 */
$redis->zIncrBy('key', 1, 'member1'); /* 3.5 */
Creates an union of sorted sets given in second argument. The result of the union will be stored in the sorted set defined by the first argument.
The third optionnel argument defines weights to apply to the sorted sets in input. In this case, the weights will be multiplied by the score of each element in the sorted set before applying the aggregation.
The forth argument defines the AGGREGATE option which specify how the results of the union are aggregated.
keyOutput
arrayZSetKeys
arrayWeights
aggregateFunction Either "SUM", "MIN", or "MAX": defines the behaviour to use on duplicate entries during the zUnion.
LONG The number of values in the new sorted set.
$redis->delete('k1');
$redis->delete('k2');
$redis->delete('k3');
$redis->delete('ko1');
$redis->delete('ko2');
$redis->delete('ko3');
$redis->zAdd('k1', 0, 'val0');
$redis->zAdd('k1', 1, 'val1');
$redis->zAdd('k2', 2, 'val2');
$redis->zAdd('k2', 3, 'val3');
$redis->zUnion('ko1', array('k1', 'k2')); /* 4, 'ko1' => array('val0', 'val1', 'val2', 'val3') */
/* Weighted zUnion */
$redis->zUnion('ko2', array('k1', 'k2'), array(1, 1)); /* 4, 'ko1' => array('val0', 'val1', 'val2', 'val3') */
$redis->zUnion('ko3', array('k1', 'k2'), array(5, 1)); /* 4, 'ko1' => array('val0', 'val2', 'val3', 'val1') */
Creates an intersection of sorted sets given in second argument. The result of the union will be stored in the sorted set defined by the first argument.
The third optionnel argument defines weights to apply to the sorted sets in input. In this case, the weights will be multiplied by the score of each element in the sorted set before applying the aggregation.
The forth argument defines the AGGREGATE option which specify how the results of the union are aggregated.
keyOutput
arrayZSetKeys
arrayWeights
aggregateFunction Either "SUM", "MIN", or "MAX": defines the behaviour to use on duplicate entries during the zInter.
LONG The number of values in the new sorted set.
$redis->delete('k1');
$redis->delete('k2');
$redis->delete('k3');
$redis->delete('ko1');
$redis->delete('ko2');
$redis->delete('ko3');
$redis->delete('ko4');
$redis->zAdd('k1', 0, 'val0');
$redis->zAdd('k1', 1, 'val1');
$redis->zAdd('k1', 3, 'val3');
$redis->zAdd('k2', 2, 'val1');
$redis->zAdd('k2', 3, 'val3');
$redis->zInter('ko1', array('k1', 'k2')); /* 2, 'ko1' => array('val1', 'val3') */
$redis->zInter('ko2', array('k1', 'k2'), array(1, 1)); /* 2, 'ko2' => array('val1', 'val3') */
/* Weighted zInter */
$redis->zInter('ko3', array('k1', 'k2'), array(1, 5), 'min'); /* 2, 'ko3' => array('val1', 'val3') */
$redis->zInter('ko4', array('k1', 'k2'), array(1, 5), 'max'); /* 2, 'ko4' => array('val3', 'val1') */
Adds a value to the hash stored at key. If this value is already in the hash, FALSE is returned.
key hashKey value
LONG 1 if value didn't exist and was added successfully, 0 if the value was already present and was replaced, FALSE if there was an error.
$redis->delete('h')
$redis->hSet('h', 'key1', 'hello'); /* 1, 'key1' => 'hello' in the hash at "h" */
$redis->hGet('h', 'key1'); /* returns "hello" */
$redis->hSet('h', 'key1', 'plop'); /* 0, value was replaced. */
$redis->hGet('h', 'key1'); /* returns "plop" */
Adds a value to the hash stored at key only if this field isn't already in the hash.
BOOL TRUE if the field was set, FALSE if it was already present.
$redis->delete('h')
$redis->hSetNx('h', 'key1', 'hello'); /* TRUE, 'key1' => 'hello' in the hash at "h" */
$redis->hSetNx('h', 'key1', 'world'); /* FALSE, 'key1' => 'hello' in the hash at "h". No change since the field wasn't replaced. */
Gets a value from the hash stored at key. If the hash table doesn't exist, or the key doesn't exist, FALSE is returned.
key hashKey
STRING The value, if the command executed successfully
BOOL FALSE in case of failure
Returns the length of a hash, in number of items
key
LONG the number of items in a hash, FALSE if the key doesn't exist or isn't a hash.
$redis->delete('h')
$redis->hSet('h', 'key1', 'hello');
$redis->hSet('h', 'key2', 'plop');
$redis->hLen('h'); /* returns 2 */
Removes a value from the hash stored at key. If the hash table doesn't exist, or the key doesn't exist, FALSE is returned.
key hashKey
BOOL TRUE in case of success, FALSE in case of failure
Returns the keys in a hash, as an array of strings.
Key: key
An array of elements, the keys of the hash. This works like PHP's array_keys().
$redis->delete('h');
$redis->hSet('h', 'a', 'x');
$redis->hSet('h', 'b', 'y');
$redis->hSet('h', 'c', 'z');
$redis->hSet('h', 'd', 't');
var_dump($redis->hKeys('h'));
Output:
array(4) {
[0]=>
string(1) "a"
[1]=>
string(1) "b"
[2]=>
string(1) "c"
[3]=>
string(1) "d"
}
The order is random and corresponds to redis' own internal representation of the set structure.
Returns the values in a hash, as an array of strings.
Key: key
An array of elements, the values of the hash. This works like PHP's array_values().
$redis->delete('h');
$redis->hSet('h', 'a', 'x');
$redis->hSet('h', 'b', 'y');
$redis->hSet('h', 'c', 'z');
$redis->hSet('h', 'd', 't');
var_dump($redis->hVals('h'));
Output:
array(4) {
[0]=>
string(1) "x"
[1]=>
string(1) "y"
[2]=>
string(1) "z"
[3]=>
string(1) "t"
}
The order is random and corresponds to redis' own internal representation of the set structure.
Returns the whole hash, as an array of strings indexed by strings.
Key: key
An array of elements, the contents of the hash.
$redis->delete('h');
$redis->hSet('h', 'a', 'x');
$redis->hSet('h', 'b', 'y');
$redis->hSet('h', 'c', 'z');
$redis->hSet('h', 'd', 't');
var_dump($redis->hGetAll('h'));
Output:
array(4) {
["a"]=>
string(1) "x"
["b"]=>
string(1) "y"
["c"]=>
string(1) "z"
["d"]=>
string(1) "t"
}
The order is random and corresponds to redis' own internal representation of the set structure.
Verify if the specified member exists in a key.
key
memberKey
BOOL: If the member exists in the hash table, return TRUE, otherwise return FALSE.
$redis->hSet('h', 'a', 'x');
$redis->hExists('h', 'a'); /* TRUE */
$redis->hExists('h', 'NonExistingKey'); /* FALSE */
Increments the value of a member from a hash by a given amount.
key
member
value: (integer) value that will be added to the member's value
LONG the new value
$redis->delete('h');
$redis->hIncrBy('h', 'x', 2); /* returns 2: h[x] = 2 now. */
$redis->hIncrBy('h', 'x', 1); /* h[x] ← 2 + 1. Returns 3 */
Fills in a whole hash. Non-string values are converted to string, using the standard (string) cast. NULL values are stored as empty strings.
key
members: key → value array
BOOL
$redis->delete('user:1');
$redis->hMset('user:1', array('name' => 'Joe', 'salary' => 2000));
$redis->hIncrBy('user:1', 'salary', 100); // Joe earns 100 more now.
Retirieve the values associated to the specified fields in the hash.
key
memberKeys Array
Array An array of elements, the values of the specified fields in the hash, with the hash keys as array keys.
$redis->delete('h');
$redis->hSet('h', 'field1', 'value1');
$redis->hSet('h', 'field2', 'value2');
$redis->hmGet('h', array('field1', 'field2')); /* returns array('field1' => 'value1', 'field2' => 'value2') */