DatabaseMysqlBase visibility cleanups

[mediawiki.git] / includes / libs / MultiHttpClient.php

<?php
/**
 * HTTP service client
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 * http://www.gnu.org/copyleft/gpl.html
 *
 * @file
 */

/**
 * Class to handle concurrent HTTP requests
 *
 * HTTP request maps are arrays that use the following format:
 *   - method   : GET/HEAD/PUT/POST/DELETE
 *   - url      : HTTP/HTTPS URL
 *   - query    : <query parameter field/value associative array> (uses RFC 3986)
 *   - headers  : <header name/value associative array>
 *   - body     : source to get the HTTP request body from;
 *                this can simply be a string (always), a resource for
 *                PUT requests, and a field/value array for POST request;
 *                array bodies are encoded as multipart/form-data and strings
 *                use application/x-www-form-urlencoded (headers sent automatically)
 *   - stream   : resource to stream the HTTP response body to
 *   - proxy    : HTTP proxy to use
 *   - flags    : map of boolean flags which supports:
 *                  - relayResponseHeaders : write out header via header()
 * Request maps can use integer index 0 instead of 'method' and 1 instead of 'url'.
 *
 * @author Aaron Schulz
 * @since 1.23
 */
class MultiHttpClient {
        /** @var resource */
        protected $multiHandle = null; // curl_multi handle
        /** @var string|null SSL certificates path  */
        protected $caBundlePath;
        /** @var integer */
        protected $connTimeout = 10;
        /** @var integer */
        protected $reqTimeout = 300;
        /** @var bool */
        protected $usePipelining = false;
        /** @var integer */
        protected $maxConnsPerHost = 50;
        /** @var string|null proxy */
        protected $proxy;
        /** @var string */
        protected $userAgent = 'wikimedia/multi-http-client v1.0';

        /**
         * @param array $options
         *   - connTimeout     : default connection timeout (seconds)
         *   - reqTimeout      : default request timeout (seconds)
         *   - proxy           : HTTP proxy to use
         *   - usePipelining   : whether to use HTTP pipelining if possible (for all hosts)
         *   - maxConnsPerHost : maximum number of concurrent connections (per host)
         *   - userAgent       : The User-Agent header value to send
         * @throws Exception
         */
        public function __construct( array $options ) {
                if ( isset( $options['caBundlePath'] ) ) {
                        $this->caBundlePath = $options['caBundlePath'];
                        if ( !file_exists( $this->caBundlePath ) ) {
                                throw new Exception( "Cannot find CA bundle: " . $this->caBundlePath );
                        }
                }
                static $opts = [
                        'connTimeout', 'reqTimeout', 'usePipelining', 'maxConnsPerHost', 'proxy', 'userAgent'
                ];
                foreach ( $opts as $key ) {
                        if ( isset( $options[$key] ) ) {
                                $this->$key = $options[$key];
                        }
                }
        }

        /**
         * Execute an HTTP(S) request
         *
         * This method returns a response map of:
         *   - code    : HTTP response code or 0 if there was a serious cURL error
         *   - reason  : HTTP response reason (empty if there was a serious cURL error)
         *   - headers : <header name/value associative array>
         *   - body    : HTTP response body or resource (if "stream" was set)
         *   - error     : Any cURL error string
         * The map also stores integer-indexed copies of these values. This lets callers do:
         * @code
         *              list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $http->run( $req );
         * @endcode
         * @param array $req HTTP request array
         * @param array $opts
         *   - connTimeout    : connection timeout per request (seconds)
         *   - reqTimeout     : post-connection timeout per request (seconds)
         * @return array Response array for request
         */
        public function run( array $req, array $opts = [] ) {
                return $this->runMulti( [ $req ], $opts )[0]['response'];
        }

        /**
         * Execute a set of HTTP(S) requests concurrently
         *
         * The maps are returned by this method with the 'response' field set to a map of:
         *   - code    : HTTP response code or 0 if there was a serious cURL error
         *   - reason  : HTTP response reason (empty if there was a serious cURL error)
         *   - headers : <header name/value associative array>
         *   - body    : HTTP response body or resource (if "stream" was set)
         *   - error   : Any cURL error string
         * The map also stores integer-indexed copies of these values. This lets callers do:
         * @code
         *        list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $req['response'];
         * @endcode
         * All headers in the 'headers' field are normalized to use lower case names.
         * This is true for the request headers and the response headers. Integer-indexed
         * method/URL entries will also be changed to use the corresponding string keys.
         *
         * @param array $reqs Map of HTTP request arrays
         * @param array $opts
         *   - connTimeout     : connection timeout per request (seconds)
         *   - reqTimeout      : post-connection timeout per request (seconds)
         *   - usePipelining   : whether to use HTTP pipelining if possible
         *   - maxConnsPerHost : maximum number of concurrent connections (per host)
         * @return array $reqs With response array populated for each
         * @throws Exception
         */
        public function runMulti( array $reqs, array $opts = [] ) {
                $chm = $this->getCurlMulti();

                // Normalize $reqs and add all of the required cURL handles...
                $handles = [];
                foreach ( $reqs as $index => &$req ) {
                        $req['response'] = [
                                'code'     => 0,
                                'reason'   => '',
                                'headers'  => [],
                                'body'     => '',
                                'error'    => ''
                        ];
                        if ( isset( $req[0] ) ) {
                                $req['method'] = $req[0]; // short-form
                                unset( $req[0] );
                        }
                        if ( isset( $req[1] ) ) {
                                $req['url'] = $req[1]; // short-form
                                unset( $req[1] );
                        }
                        if ( !isset( $req['method'] ) ) {
                                throw new Exception( "Request has no 'method' field set." );
                        } elseif ( !isset( $req['url'] ) ) {
                                throw new Exception( "Request has no 'url' field set." );
                        }
                        $req['query'] = isset( $req['query'] ) ? $req['query'] : [];
                        $headers = []; // normalized headers
                        if ( isset( $req['headers'] ) ) {
                                foreach ( $req['headers'] as $name => $value ) {
                                        $headers[strtolower( $name )] = $value;
                                }
                        }
                        $req['headers'] = $headers;
                        if ( !isset( $req['body'] ) ) {
                                $req['body'] = '';
                                $req['headers']['content-length'] = 0;
                        }
                        $req['flags'] = isset( $req['flags'] ) ? $req['flags'] : [];
                        $handles[$index] = $this->getCurlHandle( $req, $opts );
                        if ( count( $reqs ) > 1 ) {
                                // https://github.com/guzzle/guzzle/issues/349
                                curl_setopt( $handles[$index], CURLOPT_FORBID_REUSE, true );
                        }
                }
                unset( $req ); // don't assign over this by accident

                $indexes = array_keys( $reqs );
                if ( isset( $opts['usePipelining'] ) ) {
                        curl_multi_setopt( $chm, CURLMOPT_PIPELINING, (int)$opts['usePipelining'] );
                }
                if ( isset( $opts['maxConnsPerHost'] ) ) {
                        // Keep these sockets around as they may be needed later in the request
                        curl_multi_setopt( $chm, CURLMOPT_MAXCONNECTS, (int)$opts['maxConnsPerHost'] );
                }

                // @TODO: use a per-host rolling handle window (e.g. CURLMOPT_MAX_HOST_CONNECTIONS)
                $batches = array_chunk( $indexes, $this->maxConnsPerHost );
                $infos = [];

                foreach ( $batches as $batch ) {
                        // Attach all cURL handles for this batch
                        foreach ( $batch as $index ) {
                                curl_multi_add_handle( $chm, $handles[$index] );
                        }
                        // Execute the cURL handles concurrently...
                        $active = null; // handles still being processed
                        do {
                                // Do any available work...
                                do {
                                        $mrc = curl_multi_exec( $chm, $active );
                                        $info = curl_multi_info_read( $chm );
                                        if ( $info !== false ) {
                                                $infos[(int)$info['handle']] = $info;
                                        }
                                } while ( $mrc == CURLM_CALL_MULTI_PERFORM );
                                // Wait (if possible) for available work...
                                if ( $active > 0 && $mrc == CURLM_OK ) {
                                        if ( curl_multi_select( $chm, 10 ) == -1 ) {
                                                // PHP bug 63411; http://curl.haxx.se/libcurl/c/curl_multi_fdset.html
                                                usleep( 5000 ); // 5ms
                                        }
                                }
                        } while ( $active > 0 && $mrc == CURLM_OK );
                }

                // Remove all of the added cURL handles and check for errors...
                foreach ( $reqs as $index => &$req ) {
                        $ch = $handles[$index];
                        curl_multi_remove_handle( $chm, $ch );

                        if ( isset( $infos[(int)$ch] ) ) {
                                $info = $infos[(int)$ch];
                                $errno = $info['result'];
                                if ( $errno !== 0 ) {
                                        $req['response']['error'] = "(curl error: $errno)";
                                        if ( function_exists( 'curl_strerror' ) ) {
                                                $req['response']['error'] .= " " . curl_strerror( $errno );
                                        }
                                }
                        } else {
                                $req['response']['error'] = "(curl error: no status set)";
                        }

                        // For convenience with the list() operator
                        $req['response'][0] = $req['response']['code'];
                        $req['response'][1] = $req['response']['reason'];
                        $req['response'][2] = $req['response']['headers'];
                        $req['response'][3] = $req['response']['body'];
                        $req['response'][4] = $req['response']['error'];
                        curl_close( $ch );
                        // Close any string wrapper file handles
                        if ( isset( $req['_closeHandle'] ) ) {
                                fclose( $req['_closeHandle'] );
                                unset( $req['_closeHandle'] );
                        }
                }
                unset( $req ); // don't assign over this by accident

                // Restore the default settings
                curl_multi_setopt( $chm, CURLMOPT_PIPELINING, (int)$this->usePipelining );
                curl_multi_setopt( $chm, CURLMOPT_MAXCONNECTS, (int)$this->maxConnsPerHost );

                return $reqs;
        }

        /**
         * @param array $req HTTP request map
         * @param array $opts
         *   - connTimeout    : default connection timeout
         *   - reqTimeout     : default request timeout
         * @return resource
         * @throws Exception
         */
        protected function getCurlHandle( array &$req, array $opts = [] ) {
                $ch = curl_init();

                curl_setopt( $ch, CURLOPT_CONNECTTIMEOUT,
                        isset( $opts['connTimeout'] ) ? $opts['connTimeout'] : $this->connTimeout );
                curl_setopt( $ch, CURLOPT_PROXY, isset( $req['proxy'] ) ? $req['proxy'] : $this->proxy );
                curl_setopt( $ch, CURLOPT_TIMEOUT,
                        isset( $opts['reqTimeout'] ) ? $opts['reqTimeout'] : $this->reqTimeout );
                curl_setopt( $ch, CURLOPT_FOLLOWLOCATION, 1 );
                curl_setopt( $ch, CURLOPT_MAXREDIRS, 4 );
                curl_setopt( $ch, CURLOPT_HEADER, 0 );
                if ( !is_null( $this->caBundlePath ) ) {
                        curl_setopt( $ch, CURLOPT_SSL_VERIFYPEER, true );
                        curl_setopt( $ch, CURLOPT_CAINFO, $this->caBundlePath );
                }
                curl_setopt( $ch, CURLOPT_RETURNTRANSFER, 1 );

                $url = $req['url'];
                $query = http_build_query( $req['query'], '', '&', PHP_QUERY_RFC3986 );
                if ( $query != '' ) {
                        $url .= strpos( $req['url'], '?' ) === false ? "?$query" : "&$query";
                }
                curl_setopt( $ch, CURLOPT_URL, $url );

                curl_setopt( $ch, CURLOPT_CUSTOMREQUEST, $req['method'] );
                if ( $req['method'] === 'HEAD' ) {
                        curl_setopt( $ch, CURLOPT_NOBODY, 1 );
                }

                if ( $req['method'] === 'PUT' ) {
                        curl_setopt( $ch, CURLOPT_PUT, 1 );
                        if ( is_resource( $req['body'] ) ) {
                                curl_setopt( $ch, CURLOPT_INFILE, $req['body'] );
                                if ( isset( $req['headers']['content-length'] ) ) {
                                        curl_setopt( $ch, CURLOPT_INFILESIZE, $req['headers']['content-length'] );
                                } elseif ( isset( $req['headers']['transfer-encoding'] ) &&
                                        $req['headers']['transfer-encoding'] === 'chunks'
                                ) {
                                        curl_setopt( $ch, CURLOPT_UPLOAD, true );
                                } else {
                                        throw new Exception( "Missing 'Content-Length' or 'Transfer-Encoding' header." );
                                }
                        } elseif ( $req['body'] !== '' ) {
                                $fp = fopen( "php://temp", "wb+" );
                                fwrite( $fp, $req['body'], strlen( $req['body'] ) );
                                rewind( $fp );
                                curl_setopt( $ch, CURLOPT_INFILE, $fp );
                                curl_setopt( $ch, CURLOPT_INFILESIZE, strlen( $req['body'] ) );
                                $req['_closeHandle'] = $fp; // remember to close this later
                        } else {
                                curl_setopt( $ch, CURLOPT_INFILESIZE, 0 );
                        }
                        curl_setopt( $ch, CURLOPT_READFUNCTION,
                                function ( $ch, $fd, $length ) {
                                        $data = fread( $fd, $length );
                                        $len = strlen( $data );
                                        return $data;
                                }
                        );
                } elseif ( $req['method'] === 'POST' ) {
                        curl_setopt( $ch, CURLOPT_POST, 1 );
                        // Don't interpret POST parameters starting with '@' as file uploads, because this
                        // makes it impossible to POST plain values starting with '@' (and causes security
                        // issues potentially exposing the contents of local files).
                        // The PHP manual says this option was introduced in PHP 5.5 defaults to true in PHP 5.6,
                        // but we support lower versions, and the option doesn't exist in HHVM 5.6.99.
                        if ( defined( 'CURLOPT_SAFE_UPLOAD' ) ) {
                                curl_setopt( $ch, CURLOPT_SAFE_UPLOAD, true );
                        } elseif ( is_array( $req['body'] ) ) {
                                // In PHP 5.2 and later, '@' is interpreted as a file upload if POSTFIELDS
                                // is an array, but not if it's a string. So convert $req['body'] to a string
                                // for safety.
                                $req['body'] = http_build_query( $req['body'] );
                        }
                        curl_setopt( $ch, CURLOPT_POSTFIELDS, $req['body'] );
                } else {
                        if ( is_resource( $req['body'] ) || $req['body'] !== '' ) {
                                throw new Exception( "HTTP body specified for a non PUT/POST request." );
                        }
                        $req['headers']['content-length'] = 0;
                }

                if ( !isset( $req['headers']['user-agent'] ) ) {
                        $req['headers']['user-agent'] = $this->userAgent;
                }

                $headers = [];
                foreach ( $req['headers'] as $name => $value ) {
                        if ( strpos( $name, ': ' ) ) {
                                throw new Exception( "Headers cannot have ':' in the name." );
                        }
                        $headers[] = $name . ': ' . trim( $value );
                }
                curl_setopt( $ch, CURLOPT_HTTPHEADER, $headers );

                curl_setopt( $ch, CURLOPT_HEADERFUNCTION,
                        function ( $ch, $header ) use ( &$req ) {
                                if ( !empty( $req['flags']['relayResponseHeaders'] ) ) {
                                        header( $header );
                                }
                                $length = strlen( $header );
                                $matches = [];
                                if ( preg_match( "/^(HTTP\/1\.[01]) (\d{3}) (.*)/", $header, $matches ) ) {
                                        $req['response']['code'] = (int)$matches[2];
                                        $req['response']['reason'] = trim( $matches[3] );
                                        return $length;
                                }
                                if ( strpos( $header, ":" ) === false ) {
                                        return $length;
                                }
                                list( $name, $value ) = explode( ":", $header, 2 );
                                $req['response']['headers'][strtolower( $name )] = trim( $value );
                                return $length;
                        }
                );

                if ( isset( $req['stream'] ) ) {
                        // Don't just use CURLOPT_FILE as that might give:
                        // curl_setopt(): cannot represent a stream of type Output as a STDIO FILE*
                        // The callback here handles both normal files and php://temp handles.
                        curl_setopt( $ch, CURLOPT_WRITEFUNCTION,
                                function ( $ch, $data ) use ( &$req ) {
                                        return fwrite( $req['stream'], $data );
                                }
                        );
                } else {
                        curl_setopt( $ch, CURLOPT_WRITEFUNCTION,
                                function ( $ch, $data ) use ( &$req ) {
                                        $req['response']['body'] .= $data;
                                        return strlen( $data );
                                }
                        );
                }

                return $ch;
        }

        /**
         * @return resource
         */
        protected function getCurlMulti() {
                if ( !$this->multiHandle ) {
                        $cmh = curl_multi_init();
                        curl_multi_setopt( $cmh, CURLMOPT_PIPELINING, (int)$this->usePipelining );
                        curl_multi_setopt( $cmh, CURLMOPT_MAXCONNECTS, (int)$this->maxConnsPerHost );
                        $this->multiHandle = $cmh;
                }
                return $this->multiHandle;
        }

        function __destruct() {
                if ( $this->multiHandle ) {
                        curl_multi_close( $this->multiHandle );
                }
        }
}