Files
predis/lib/Predis/Cluster/PredisStrategy.php
T
Daniele Alessandri e23fd9bea8 Use redis-cluster rules for empty key tags for client-side sharding.
This commit represents a breaking change when the first occurrence of
"{}" is found in a key because it will produce a different hash than
previous versions of Predis, thus leading to a different partitioning.

If you really need to stick with the old behavior, you can subclass
Predis\Cluster\PredisStrategy and override extractKeyTag() using the
old implementation of this method and pass the strategy instance when
initializing the cluster connection via client options.
2014-02-11 19:06:47 +01:00

393 lines
14 KiB
PHP

<?php
/*
* This file is part of the Predis package.
*
* (c) Daniele Alessandri <suppakilla@gmail.com>
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/
namespace Predis\Cluster;
use InvalidArgumentException;
use Predis\Cluster\Hash\HashGeneratorInterface;
use Predis\Command\CommandInterface;
use Predis\Command\ScriptCommand;
/**
* Default class used by Predis for client-side sharding to calculate hashes out
* of keys for supported commands.
*
* @author Daniele Alessandri <suppakilla@gmail.com>
*/
class PredisStrategy implements StrategyInterface
{
private $commands;
private $hashGenerator;
/**
* @param HashGeneratorInterface $hashGenerator Hash generator instance.
*/
public function __construct(HashGeneratorInterface $hashGenerator)
{
$this->commands = $this->getDefaultCommands();
$this->hashGenerator = $hashGenerator;
}
/**
* Returns the default map of supported commands with their handlers.
*
* @return array
*/
protected function getDefaultCommands()
{
$keyIsFirstArgument = array($this, 'getKeyFromFirstArgument');
$keysAreAllArguments = array($this, 'getKeyFromAllArguments');
return array(
/* commands operating on the key space */
'EXISTS' => $keyIsFirstArgument,
'DEL' => $keysAreAllArguments,
'TYPE' => $keyIsFirstArgument,
'EXPIRE' => $keyIsFirstArgument,
'EXPIREAT' => $keyIsFirstArgument,
'PERSIST' => $keyIsFirstArgument,
'PEXPIRE' => $keyIsFirstArgument,
'PEXPIREAT' => $keyIsFirstArgument,
'TTL' => $keyIsFirstArgument,
'PTTL' => $keyIsFirstArgument,
'SORT' => $keyIsFirstArgument, // TODO
'DUMP' => $keyIsFirstArgument,
'RESTORE' => $keyIsFirstArgument,
/* commands operating on string values */
'APPEND' => $keyIsFirstArgument,
'DECR' => $keyIsFirstArgument,
'DECRBY' => $keyIsFirstArgument,
'GET' => $keyIsFirstArgument,
'GETBIT' => $keyIsFirstArgument,
'MGET' => $keysAreAllArguments,
'SET' => $keyIsFirstArgument,
'GETRANGE' => $keyIsFirstArgument,
'GETSET' => $keyIsFirstArgument,
'INCR' => $keyIsFirstArgument,
'INCRBY' => $keyIsFirstArgument,
'SETBIT' => $keyIsFirstArgument,
'SETEX' => $keyIsFirstArgument,
'MSET' => array($this, 'getKeyFromInterleavedArguments'),
'MSETNX' => array($this, 'getKeyFromInterleavedArguments'),
'SETNX' => $keyIsFirstArgument,
'SETRANGE' => $keyIsFirstArgument,
'STRLEN' => $keyIsFirstArgument,
'SUBSTR' => $keyIsFirstArgument,
'BITOP' => array($this, 'getKeyFromBitOp'),
'BITCOUNT' => $keyIsFirstArgument,
/* commands operating on lists */
'LINSERT' => $keyIsFirstArgument,
'LINDEX' => $keyIsFirstArgument,
'LLEN' => $keyIsFirstArgument,
'LPOP' => $keyIsFirstArgument,
'RPOP' => $keyIsFirstArgument,
'RPOPLPUSH' => $keysAreAllArguments,
'BLPOP' => array($this, 'getKeyFromBlockingListCommands'),
'BRPOP' => array($this, 'getKeyFromBlockingListCommands'),
'BRPOPLPUSH' => array($this, 'getKeyFromBlockingListCommands'),
'LPUSH' => $keyIsFirstArgument,
'LPUSHX' => $keyIsFirstArgument,
'RPUSH' => $keyIsFirstArgument,
'RPUSHX' => $keyIsFirstArgument,
'LRANGE' => $keyIsFirstArgument,
'LREM' => $keyIsFirstArgument,
'LSET' => $keyIsFirstArgument,
'LTRIM' => $keyIsFirstArgument,
/* commands operating on sets */
'SADD' => $keyIsFirstArgument,
'SCARD' => $keyIsFirstArgument,
'SDIFF' => $keysAreAllArguments,
'SDIFFSTORE' => $keysAreAllArguments,
'SINTER' => $keysAreAllArguments,
'SINTERSTORE' => $keysAreAllArguments,
'SUNION' => $keysAreAllArguments,
'SUNIONSTORE' => $keysAreAllArguments,
'SISMEMBER' => $keyIsFirstArgument,
'SMEMBERS' => $keyIsFirstArgument,
'SSCAN' => $keyIsFirstArgument,
'SPOP' => $keyIsFirstArgument,
'SRANDMEMBER' => $keyIsFirstArgument,
'SREM' => $keyIsFirstArgument,
/* commands operating on sorted sets */
'ZADD' => $keyIsFirstArgument,
'ZCARD' => $keyIsFirstArgument,
'ZCOUNT' => $keyIsFirstArgument,
'ZINCRBY' => $keyIsFirstArgument,
'ZINTERSTORE' => array($this, 'getKeyFromZsetAggregationCommands'),
'ZRANGE' => $keyIsFirstArgument,
'ZRANGEBYSCORE' => $keyIsFirstArgument,
'ZRANK' => $keyIsFirstArgument,
'ZREM' => $keyIsFirstArgument,
'ZREMRANGEBYRANK' => $keyIsFirstArgument,
'ZREMRANGEBYSCORE' => $keyIsFirstArgument,
'ZREVRANGE' => $keyIsFirstArgument,
'ZREVRANGEBYSCORE' => $keyIsFirstArgument,
'ZREVRANK' => $keyIsFirstArgument,
'ZSCORE' => $keyIsFirstArgument,
'ZUNIONSTORE' => array($this, 'getKeyFromZsetAggregationCommands'),
'ZSCAN' => $keyIsFirstArgument,
/* commands operating on hashes */
'HDEL' => $keyIsFirstArgument,
'HEXISTS' => $keyIsFirstArgument,
'HGET' => $keyIsFirstArgument,
'HGETALL' => $keyIsFirstArgument,
'HMGET' => $keyIsFirstArgument,
'HMSET' => $keyIsFirstArgument,
'HINCRBY' => $keyIsFirstArgument,
'HINCRBYFLOAT' => $keyIsFirstArgument,
'HKEYS' => $keyIsFirstArgument,
'HLEN' => $keyIsFirstArgument,
'HSET' => $keyIsFirstArgument,
'HSETNX' => $keyIsFirstArgument,
'HVALS' => $keyIsFirstArgument,
'HSCAN' => $keyIsFirstArgument,
/* scripting */
'EVAL' => array($this, 'getKeyFromScriptingCommands'),
'EVALSHA' => array($this, 'getKeyFromScriptingCommands'),
);
}
/**
* Returns the list of IDs for the supported commands.
*
* @return array
*/
public function getSupportedCommands()
{
return array_keys($this->commands);
}
/**
* Sets an handler for the specified command ID.
*
* The signature of the callback must have a single parameter of type
* Predis\Command\CommandInterface.
*
* When the callback argument is omitted or NULL, the previously associated
* handler for the specified command ID is removed.
*
* @param string $commandID Command ID.
* @param mixed $callback A valid callable object, or NULL to unset the handler.
*/
public function setCommandHandler($commandID, $callback = null)
{
$commandID = strtoupper($commandID);
if (!isset($callback)) {
unset($this->commands[$commandID]);
return;
}
if (!is_callable($callback)) {
throw new InvalidArgumentException(
"The argument must be a callable object or NULL."
);
}
$this->commands[$commandID] = $callback;
}
/**
* Extracts the key from the first argument of a command instance.
*
* @param CommandInterface $command Command instance.
* @return string
*/
protected function getKeyFromFirstArgument(CommandInterface $command)
{
return $command->getArgument(0);
}
/**
* Extracts the key from a command with multiple keys only when all keys in
* the arguments array produce the same hash.
*
* @param CommandInterface $command Command instance.
* @return string
*/
protected function getKeyFromAllArguments(CommandInterface $command)
{
$arguments = $command->getArguments();
if ($this->checkSameHashForKeys($arguments)) {
return $arguments[0];
}
}
/**
* Extracts the key from a command with multiple keys only when all keys in
* the arguments array produce the same hash.
*
* @param CommandInterface $command Command instance.
* @return string
*/
protected function getKeyFromInterleavedArguments(CommandInterface $command)
{
$arguments = $command->getArguments();
$keys = array();
for ($i = 0; $i < count($arguments); $i += 2) {
$keys[] = $arguments[$i];
}
if ($this->checkSameHashForKeys($keys)) {
return $arguments[0];
}
}
/**
* Extracts the key from BLPOP and BRPOP commands.
*
* @param CommandInterface $command Command instance.
* @return string
*/
protected function getKeyFromBlockingListCommands(CommandInterface $command)
{
$arguments = $command->getArguments();
if ($this->checkSameHashForKeys(array_slice($arguments, 0, count($arguments) - 1))) {
return $arguments[0];
}
}
/**
* Extracts the key from BITOP command.
*
* @param CommandInterface $command Command instance.
* @return string
*/
protected function getKeyFromBitOp(CommandInterface $command)
{
$arguments = $command->getArguments();
if ($this->checkSameHashForKeys(array_slice($arguments, 1, count($arguments)))) {
return $arguments[1];
}
}
/**
* Extracts the key from ZINTERSTORE and ZUNIONSTORE commands.
*
* @param CommandInterface $command Command instance.
* @return string
*/
protected function getKeyFromZsetAggregationCommands(CommandInterface $command)
{
$arguments = $command->getArguments();
$keys = array_merge(array($arguments[0]), array_slice($arguments, 2, $arguments[1]));
if ($this->checkSameHashForKeys($keys)) {
return $arguments[0];
}
}
/**
* Extracts the key from EVAL and EVALSHA commands.
*
* @param CommandInterface $command Command instance.
* @return string
*/
protected function getKeyFromScriptingCommands(CommandInterface $command)
{
if ($command instanceof ScriptCommand) {
$keys = $command->getKeys();
} else {
$keys = array_slice($args = $command->getArguments(), 2, $args[1]);
}
if ($keys && $this->checkSameHashForKeys($keys)) {
return $keys[0];
}
}
/**
* {@inheritdoc}
*/
public function getHash(CommandInterface $command)
{
$hash = $command->getHash();
if (!isset($hash) && isset($this->commands[$cmdID = $command->getId()])) {
$key = call_user_func($this->commands[$cmdID], $command);
if (isset($key)) {
$hash = $this->getKeyHash($key);
$command->setHash($hash);
}
}
return $hash;
}
/**
* {@inheritdoc}
*/
public function getKeyHash($key)
{
$key = $this->extractKeyTag($key);
$hash = $this->hashGenerator->hash($key);
return $hash;
}
/**
* Checks if the specified array of keys will generate the same hash.
*
* @param array $keys Array of keys.
* @return bool
*/
protected function checkSameHashForKeys(array $keys)
{
if (!$count = count($keys)) {
return false;
}
$currentKey = $this->extractKeyTag($keys[0]);
for ($i = 1; $i < $count; $i++) {
$nextKey = $this->extractKeyTag($keys[$i]);
if ($currentKey !== $nextKey) {
return false;
}
$currentKey = $nextKey;
}
return true;
}
/**
* Returns only the hashable part of a key (delimited by "{...}"), or the
* whole key if a key tag is not found in the string.
*
* @param string $key A key.
* @return string
*/
protected function extractKeyTag($key)
{
if (false !== $start = strpos($key, '{')) {
if (false !== ($end = strpos($key, '}', $start)) && $end !== ++$start) {
$key = substr($key, $start, $end - $start);
}
}
return $key;
}
}