Files
predis/lib/Predis/Cluster/PredisClusterHashStrategy.php
T
2013-02-17 15:21:01 +01:00

383 lines
13 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 Predis\Cluster\Hash\HashGeneratorInterface;
use Predis\Command\CommandInterface;
use Predis\Command\ScriptedCommand;
/**
* Default class used by Predis for client-side sharding to calculate
* hashes out of keys of supported commands.
*
* @author Daniele Alessandri <suppakilla@gmail.com>
*/
class PredisClusterHashStrategy implements CommandHashStrategyInterface
{
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
/* 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,
'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'),
/* commands operating on hashes */
'HDEL' => $keyIsFirstArgument,
'HEXISTS' => $keyIsFirstArgument,
'HGET' => $keyIsFirstArgument,
'HGETALL' => $keyIsFirstArgument,
'HMGET' => $keyIsFirstArgument,
'HINCRBY' => $keyIsFirstArgument,
'HINCRBYFLOAT' => $keyIsFirstArgument,
'HKEYS' => $keyIsFirstArgument,
'HLEN' => $keyIsFirstArgument,
'HSET' => $keyIsFirstArgument,
'HSETNX' => $keyIsFirstArgument,
'HVALS' => $keyIsFirstArgument,
/* scripting */
'EVAL' => array($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 The ID of the command to be handled.
* @param mixed $callback A valid callable object or NULL.
*/
public function setCommandHandler($commandId, $callback = null)
{
$commandId = strtoupper($commandId);
if (!isset($callback)) {
unset($this->commands[$commandId]);
return;
}
if (!is_callable($callback)) {
throw new \InvalidArgumentException("Callback must be a valid 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 ScriptedCommand) {
$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 Boolean
*/
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)) {
$key = substr($key, ++$start, $end - $start);
}
}
return $key;
}
}