*/
class MemcachedPeclBagOStuff extends MemcachedBagOStuff {
/** @var Memcached */
- protected $client;
+ protected $syncClient;
+ /** @var Memcached|null */
+ protected $asyncClient;
+
+ /** @var bool Whether the non-buffering client is locked from use */
+ protected $syncClientIsBuffering = false;
+ /** @var bool Whether the non-buffering client should be flushed before use */
+ protected $hasUnflushedChanges = false;
+
+ /** @var array Memcached options */
+ private static $OPTS_SYNC_WRITES = [
+ Memcached::OPT_NO_BLOCK => false, // async I/O (using TCP buffers)
+ Memcached::OPT_BUFFER_WRITES => false // libmemcached buffers
+ ];
+ /** @var array Memcached options */
+ private static $OPTS_ASYNC_WRITES = [
+ Memcached::OPT_NO_BLOCK => true, // async I/O (using TCP buffers)
+ Memcached::OPT_BUFFER_WRITES => true // libmemcached buffers
+ ];
/**
* Available parameters are:
- * - servers: The list of IP:port combinations holding the memcached servers.
- * - persistent: Whether to use a persistent connection
- * - compress_threshold: The minimum size an object must be before it is compressed
- * - timeout: The read timeout in microseconds
- * - connect_timeout: The connect timeout in seconds
- * - retry_timeout: Time in seconds to wait before retrying a failed connect attempt
- * - server_failure_limit: Limit for server connect failures before it is removed
- * - serializer: May be either "php" or "igbinary". Igbinary produces more compact
- * values, but serialization is much slower unless the php.ini option
- * igbinary.compact_strings is off.
- * - use_binary_protocol Whether to enable the binary protocol (default is ASCII) (boolean)
+ * - servers: List of IP:port combinations holding the memcached servers.
+ * - persistent: Whether to use a persistent connection
+ * - compress_threshold: The minimum size an object must be before it is compressed
+ * - timeout: The read timeout in microseconds
+ * - connect_timeout: The connect timeout in seconds
+ * - retry_timeout: Time in seconds to wait before retrying a failed connect attempt
+ * - server_failure_limit: Limit for server connect failures before it is removed
+ * - serializer: Either "php" or "igbinary". Igbinary produces more compact
+ * values, but serialization is much slower unless the php.ini
+ * option igbinary.compact_strings is off.
+ * - use_binary_protocol Whether to enable the binary protocol (default is ASCII)
+ * - allow_tcp_nagle_delay Whether to permit Nagle's algorithm for reducing packet count
* @param array $params
- * @throws InvalidArgumentException
*/
function __construct( $params ) {
parent::__construct( $params );
- $params = $this->applyDefaultParams( $params );
+
+ // Default class-specific parameters
+ $params += [
+ 'compress_threshold' => 1500,
+ 'connect_timeout' => 0.5,
+ 'serializer' => 'php',
+ 'use_binary_protocol' => false,
+ 'allow_tcp_nagle_delay' => true
+ ];
if ( $params['persistent'] ) {
// The pool ID must be unique to the server/option combination.
// The Memcached object is essentially shared for each pool ID.
// We can only reuse a pool ID if we keep the config consistent.
- $this->client = new Memcached( md5( serialize( $params ) ) );
- if ( count( $this->client->getServerList() ) ) {
- $this->logger->debug( __METHOD__ . ": persistent Memcached object already loaded." );
- return; // already initialized; don't add duplicate servers
- }
+ $connectionPoolId = md5( serialize( $params ) );
+ $syncClient = new Memcached( "$connectionPoolId-sync" );
+ // Avoid clobbering the main thread-shared Memcached instance
+ $asyncClient = new Memcached( "$connectionPoolId-async" );
} else {
- $this->client = new Memcached;
- }
-
- if ( $params['use_binary_protocol'] ) {
- $this->client->setOption( Memcached::OPT_BINARY_PROTOCOL, true );
- }
-
- if ( isset( $params['retry_timeout'] ) ) {
- $this->client->setOption( Memcached::OPT_RETRY_TIMEOUT, $params['retry_timeout'] );
+ $syncClient = new Memcached();
+ $asyncClient = null;
}
- if ( isset( $params['server_failure_limit'] ) ) {
- $this->client->setOption( Memcached::OPT_SERVER_FAILURE_LIMIT, $params['server_failure_limit'] );
+ $this->initializeClient( $syncClient, $params, self::$OPTS_SYNC_WRITES );
+ if ( $asyncClient ) {
+ $this->initializeClient( $asyncClient, $params, self::$OPTS_ASYNC_WRITES );
}
+ // Set the main client and any dedicated one for buffered writes
+ $this->syncClient = $syncClient;
+ $this->asyncClient = $asyncClient;
// The compression threshold is an undocumented php.ini option for some
// reason. There's probably not much harm in setting it globally, for
// compatibility with the settings for the PHP client.
ini_set( 'memcached.compression_threshold', $params['compress_threshold'] );
+ }
- // Set timeouts
- $this->client->setOption( Memcached::OPT_CONNECT_TIMEOUT, $params['connect_timeout'] * 1000 );
- $this->client->setOption( Memcached::OPT_SEND_TIMEOUT, $params['timeout'] );
- $this->client->setOption( Memcached::OPT_RECV_TIMEOUT, $params['timeout'] );
- $this->client->setOption( Memcached::OPT_POLL_TIMEOUT, $params['timeout'] / 1000 );
-
- // Set libketama mode since it's recommended by the documentation and
- // is as good as any. There's no way to configure libmemcached to use
- // hashes identical to the ones currently in use by the PHP client, and
- // even implementing one of the libmemcached hashes in pure PHP for
- // forwards compatibility would require MemcachedClient::get_sock() to be
- // rewritten.
- $this->client->setOption( Memcached::OPT_LIBKETAMA_COMPATIBLE, true );
-
- // Set the serializer
- $ok = false;
+ /**
+ * Initialize the client only if needed and reuse it otherwise.
+ * This avoids duplicate servers in the list and new connections.
+ *
+ * @param Memcached $client
+ * @param array $params
+ * @param array $options Base options for Memcached::setOptions()
+ * @throws RuntimeException
+ */
+ private function initializeClient( Memcached $client, array $params, array $options ) {
+ if ( $client->getServerList() ) {
+ $this->logger->debug( __METHOD__ . ": pre-initialized client instance." );
+
+ return; // preserve persistent handle
+ }
+
+ $this->logger->debug( __METHOD__ . ": initializing new client instance." );
+
+ $options += [
+ Memcached::OPT_NO_BLOCK => false,
+ Memcached::OPT_BUFFER_WRITES => false,
+ // Network protocol (ASCII or binary)
+ Memcached::OPT_BINARY_PROTOCOL => $params['use_binary_protocol'],
+ // Set various network timeouts
+ Memcached::OPT_CONNECT_TIMEOUT => $params['connect_timeout'] * 1000,
+ Memcached::OPT_SEND_TIMEOUT => $params['timeout'],
+ Memcached::OPT_RECV_TIMEOUT => $params['timeout'],
+ Memcached::OPT_POLL_TIMEOUT => $params['timeout'] / 1000,
+ // Avoid pointless delay when sending/fetching large blobs
+ Memcached::OPT_TCP_NODELAY => !$params['allow_tcp_nagle_delay'],
+ // Set libketama mode since it's recommended by the documentation
+ Memcached::OPT_LIBKETAMA_COMPATIBLE => true
+ ];
+ if ( isset( $params['retry_timeout'] ) ) {
+ $options[Memcached::OPT_RETRY_TIMEOUT] = $params['retry_timeout'];
+ }
+ if ( isset( $params['server_failure_limit'] ) ) {
+ $options[Memcached::OPT_SERVER_FAILURE_LIMIT] = $params['server_failure_limit'];
+ }
if ( $params['serializer'] === 'php' ) {
- $ok = $this->client->setOption( Memcached::OPT_SERIALIZER, Memcached::SERIALIZER_PHP );
+ $options[Memcached::OPT_SERIALIZER] = Memcached::SERIALIZER_PHP;
} elseif ( $params['serializer'] === 'igbinary' ) {
if ( !Memcached::HAVE_IGBINARY ) {
- throw new InvalidArgumentException(
+ throw new RuntimeException(
__CLASS__ . ': the igbinary extension is not available ' .
'but igbinary serialization was requested.'
);
}
- $ok = $this->client->setOption( Memcached::OPT_SERIALIZER, Memcached::SERIALIZER_IGBINARY );
+ $options[Memcached::OPT_SERIALIZER] = Memcached::SERIALIZER_IGBINARY;
}
- if ( !$ok ) {
- throw new InvalidArgumentException( __CLASS__ . ': invalid serializer parameter' );
+
+ if ( !$client->setOptions( $options ) ) {
+ throw new RuntimeException(
+ "Invalid options: " . json_encode( $options, JSON_PRETTY_PRINT )
+ );
}
$servers = [];
$servers[] = [ $host, false ]; // (ip or path, port)
}
}
- $this->client->addServers( $servers );
- }
-
- protected function applyDefaultParams( $params ) {
- $params = parent::applyDefaultParams( $params );
- if ( !isset( $params['use_binary_protocol'] ) ) {
- $params['use_binary_protocol'] = false;
+ if ( !$client->addServers( $servers ) ) {
+ throw new RuntimeException( "Failed to inject server address list" );
}
-
- if ( !isset( $params['serializer'] ) ) {
- $params['serializer'] = 'php';
- }
-
- return $params;
}
protected function doGet( $key, $flags = 0, &$casToken = null ) {
$this->debug( "get($key)" );
+
+ $client = $this->acquireSyncClient();
if ( defined( Memcached::class . '::GET_EXTENDED' ) ) { // v3.0.0
+ /** @noinspection PhpUndefinedClassConstantInspection */
$flags = Memcached::GET_EXTENDED;
- $res = $this->client->get( $this->validateKeyEncoding( $key ), null, $flags );
+ $res = $client->get( $this->validateKeyEncoding( $key ), null, $flags );
if ( is_array( $res ) ) {
$result = $res['value'];
$casToken = $res['cas'];
$casToken = null;
}
} else {
- $result = $this->client->get( $this->validateKeyEncoding( $key ), null, $casToken );
+ $result = $client->get( $this->validateKeyEncoding( $key ), null, $casToken );
}
- $result = $this->checkResult( $key, $result );
- return $result;
+
+ return $this->checkResult( $key, $result );
}
protected function doSet( $key, $value, $exptime = 0, $flags = 0 ) {
$this->debug( "set($key)" );
- $result = $this->client->set(
+
+ $client = $this->acquireSyncClient();
+ $result = $client->set(
$this->validateKeyEncoding( $key ),
$value,
$this->fixExpiry( $exptime )
);
- if ( $result === false && $this->client->getResultCode() === Memcached::RES_NOTSTORED ) {
+
+ return ( $result === false && $client->getResultCode() === Memcached::RES_NOTSTORED )
// "Not stored" is always used as the mcrouter response with AllAsyncRoute
- return true;
- }
- return $this->checkResult( $key, $result );
+ ? true
+ : $this->checkResult( $key, $result );
}
protected function cas( $casToken, $key, $value, $exptime = 0, $flags = 0 ) {
$this->debug( "cas($key)" );
- $result = $this->client->cas( $casToken, $this->validateKeyEncoding( $key ),
- $value, $this->fixExpiry( $exptime ) );
+
+ $result = $this->acquireSyncClient()->cas(
+ $casToken,
+ $this->validateKeyEncoding( $key ),
+ $value, $this->fixExpiry( $exptime )
+ );
+
return $this->checkResult( $key, $result );
}
protected function doDelete( $key, $flags = 0 ) {
$this->debug( "delete($key)" );
- $result = $this->client->delete( $this->validateKeyEncoding( $key ) );
- if ( $result === false && $this->client->getResultCode() === Memcached::RES_NOTFOUND ) {
+
+ $client = $this->acquireSyncClient();
+ $result = $client->delete( $this->validateKeyEncoding( $key ) );
+
+ return ( $result === false && $client->getResultCode() === Memcached::RES_NOTFOUND )
// "Not found" is counted as success in our interface
- return true;
- }
- return $this->checkResult( $key, $result );
+ ? true
+ : $this->checkResult( $key, $result );
}
public function add( $key, $value, $exptime = 0, $flags = 0 ) {
$this->debug( "add($key)" );
- $result = $this->client->add(
+
+ $result = $this->acquireSyncClient()->add(
$this->validateKeyEncoding( $key ),
$value,
$this->fixExpiry( $exptime )
);
+
return $this->checkResult( $key, $result );
}
public function incr( $key, $value = 1 ) {
$this->debug( "incr($key)" );
- $result = $this->client->increment( $key, $value );
+
+ $result = $this->acquireSyncClient()->increment( $key, $value );
+
return $this->checkResult( $key, $result );
}
public function decr( $key, $value = 1 ) {
$this->debug( "decr($key)" );
- $result = $this->client->decrement( $key, $value );
+
+ $result = $this->acquireSyncClient()->decrement( $key, $value );
+
return $this->checkResult( $key, $result );
}
if ( $result !== false ) {
return $result;
}
- switch ( $this->client->getResultCode() ) {
+
+ $client = $this->syncClient;
+ switch ( $client->getResultCode() ) {
case Memcached::RES_SUCCESS:
break;
case Memcached::RES_DATA_EXISTS:
case Memcached::RES_NOTSTORED:
case Memcached::RES_NOTFOUND:
- $this->debug( "result: " . $this->client->getResultMessage() );
+ $this->debug( "result: " . $client->getResultMessage() );
break;
default:
- $msg = $this->client->getResultMessage();
+ $msg = $client->getResultMessage();
$logCtx = [];
if ( $key !== false ) {
- $server = $this->client->getServerByKey( $key );
+ $server = $client->getServerByKey( $key );
$logCtx['memcached-server'] = "{$server['host']}:{$server['port']}";
$logCtx['memcached-key'] = $key;
- $msg = "Memcached error for key \"{memcached-key}\" on server \"{memcached-server}\": $msg";
+ $msg = "Memcached error for key \"{memcached-key}\" " .
+ "on server \"{memcached-server}\": $msg";
} else {
$msg = "Memcached error: $msg";
}
return $result;
}
- public function doGetMulti( array $keys, $flags = 0 ) {
+ protected function doGetMulti( array $keys, $flags = 0 ) {
$this->debug( 'getMulti(' . implode( ', ', $keys ) . ')' );
+
foreach ( $keys as $key ) {
$this->validateKeyEncoding( $key );
}
- $result = $this->client->getMulti( $keys ) ?: [];
+
+ // The PECL implementation uses "gets" which works as well as a pipeline
+ $result = $this->acquireSyncClient()->getMulti( $keys ) ?: [];
+
return $this->checkResult( false, $result );
}
- public function setMulti( array $data, $exptime = 0, $flags = 0 ) {
+ protected function doSetMulti( array $data, $exptime = 0, $flags = 0 ) {
$this->debug( 'setMulti(' . implode( ', ', array_keys( $data ) ) . ')' );
+
+ $exptime = $this->fixExpiry( $exptime );
foreach ( array_keys( $data ) as $key ) {
$this->validateKeyEncoding( $key );
}
- $result = $this->client->setMulti( $data, $this->fixExpiry( $exptime ) );
+
+ // The PECL implementation is a naïve for-loop so use async I/O to pipeline;
+ // https://github.com/php-memcached-dev/php-memcached/blob/master/php_memcached.c#L1852
+ if ( ( $flags & self::WRITE_BACKGROUND ) == self::WRITE_BACKGROUND ) {
+ $client = $this->acquireAsyncClient();
+ $result = $client->setMulti( $data, $exptime );
+ $this->releaseAsyncClient( $client );
+ } else {
+ $result = $this->acquireSyncClient()->setMulti( $data, $exptime );
+ }
+
return $this->checkResult( false, $result );
}
- public function deleteMulti( array $keys, $flags = 0 ) {
+ protected function doDeleteMulti( array $keys, $flags = 0 ) {
$this->debug( 'deleteMulti(' . implode( ', ', $keys ) . ')' );
+
foreach ( $keys as $key ) {
$this->validateKeyEncoding( $key );
}
- $result = $this->client->deleteMulti( $keys ) ?: [];
- $ok = true;
- foreach ( $result as $code ) {
+
+ // The PECL implementation is a naïve for-loop so use async I/O to pipeline;
+ // https://github.com/php-memcached-dev/php-memcached/blob/7443d16d02fb73cdba2e90ae282446f80969229c/php_memcached.c#L1852
+ if ( ( $flags & self::WRITE_BACKGROUND ) == self::WRITE_BACKGROUND ) {
+ $client = $this->acquireAsyncClient();
+ $resultArray = $client->deleteMulti( $keys ) ?: [];
+ $this->releaseAsyncClient( $client );
+ } else {
+ $resultArray = $this->acquireSyncClient()->deleteMulti( $keys ) ?: [];
+ }
+
+ $result = true;
+ foreach ( $resultArray as $code ) {
if ( !in_array( $code, [ true, Memcached::RES_NOTFOUND ], true ) ) {
// "Not found" is counted as success in our interface
- $ok = false;
+ $result = false;
}
}
- return $this->checkResult( false, $ok );
+
+ return $this->checkResult( false, $result );
}
- public function changeTTL( $key, $exptime = 0, $flags = 0 ) {
+ protected function doChangeTTL( $key, $exptime, $flags ) {
$this->debug( "touch($key)" );
- $result = $this->client->touch( $key, $exptime );
+
+ $result = $this->acquireSyncClient()->touch( $key, $this->fixExpiry( $exptime ) );
+
return $this->checkResult( $key, $result );
}
return $value;
}
- $serializer = $this->client->getOption( Memcached::OPT_SERIALIZER );
+ $serializer = $this->syncClient->getOption( Memcached::OPT_SERIALIZER );
if ( $serializer === Memcached::SERIALIZER_PHP ) {
return serialize( $value );
} elseif ( $serializer === Memcached::SERIALIZER_IGBINARY ) {
return (int)$value;
}
- $serializer = $this->client->getOption( Memcached::OPT_SERIALIZER );
+ $serializer = $this->syncClient->getOption( Memcached::OPT_SERIALIZER );
if ( $serializer === Memcached::SERIALIZER_PHP ) {
return unserialize( $value );
} elseif ( $serializer === Memcached::SERIALIZER_IGBINARY ) {
throw new UnexpectedValueException( __METHOD__ . ": got serializer '$serializer'." );
}
+
+ /**
+ * @return Memcached
+ */
+ private function acquireSyncClient() {
+ if ( $this->syncClientIsBuffering ) {
+ throw new RuntimeException( "The main (unbuffered I/O) client is locked" );
+ }
+
+ if ( $this->hasUnflushedChanges ) {
+ // Force a synchronous flush of async writes so that their changes are visible
+ $this->syncClient->fetch();
+ if ( $this->asyncClient ) {
+ $this->asyncClient->fetch();
+ }
+ $this->hasUnflushedChanges = false;
+ }
+
+ return $this->syncClient;
+ }
+
+ /**
+ * @return Memcached
+ */
+ private function acquireAsyncClient() {
+ if ( $this->asyncClient ) {
+ return $this->asyncClient; // dedicated buffering instance
+ }
+
+ // Modify the main instance to temporarily buffer writes
+ $this->syncClientIsBuffering = true;
+ $this->syncClient->setOptions( self::$OPTS_ASYNC_WRITES );
+
+ return $this->syncClient;
+ }
+
+ /**
+ * @param Memcached $client
+ */
+ private function releaseAsyncClient( $client ) {
+ $this->hasUnflushedChanges = true;
+
+ if ( !$this->asyncClient ) {
+ // This is the main instance; make it stop buffering writes again
+ $client->setOptions( self::$OPTS_SYNC_WRITES );
+ $this->syncClientIsBuffering = false;
+ }
+ }
}