Proyectos de Subversion Moodle

<?php

// This file is part of Moodle - http://moodle.org/

//

// Moodle 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 3 of the License, or

// (at your option) any later version.

//

// Moodle 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 Moodle.  If not, see <http://www.gnu.org/licenses/>.

/**

 * @package    moodlecore

 * @subpackage backup-xml

 * @copyright  2010 onwards Eloy Lafuente (stronk7) {@link http://stronk7.com}

 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

/**

 * This abstract class outputs XML contents provided by @xml_writer

 *

 * Contains the common functionalities for all the xml_output_xxx classes

 * and the interface for them. Mainly it's in charge of:

 *   - Initialize the corresponding stream/handler (file, DB connection...)

 *   - Finalize the stream/handler

 *   - Provide one common buffer for all output implementations

 *   - Receive XML contents from the @xml_writer and output them

 *   - Some basic throughtput stats

 *

 * TODO: Finish phpdocs

 */

abstract class xml_output {

    const DEFAULT_BUFFER_SIZE = 4096; // Use a default buffer size of 4K

    protected $inittime;  // Initial microtime

    protected $sentbytes; // Bytes sent to output

    protected $usebuffer; // Boolean to specify if output supports buffer (true) or no (false)

    protected $buffersize;// Size, in bytes, of the buffer.

    protected $currentbuffer;    // Buffer contents

    protected $currentbuffersize;// Current buffer size

    protected $running; // To know if output is running

    /** @var string|float finish microtime. */

    protected $finishtime;

    public function __construct($usebuffer = true) {

        $this->inittime   = microtime(true);

        $this->finishtime = $this->inittime;

        $this->sentbytes  = 0;

        $this->usebuffer         = $usebuffer;

        $this->buffersize        = $this->usebuffer ? self::DEFAULT_BUFFER_SIZE : 0;

        $this->running = null;

    }

    public function set_buffersize($buffersize) {

        if ($this->running) {

            throw new xml_output_exception('xml_output_already_started');

        }

        if (!$this->usebuffer) {

            throw new xml_output_exception('xml_output_buffer_nosupport');

        }

        // TODO: check it is integer > 0

        $this->buffersize = $buffersize;

    }

    public function start() {

        if ($this->running === true) {

            throw new xml_output_exception('xml_output_already_started');

        }

        if ($this->running === false) {

            throw new xml_output_exception('xml_output_already_stopped');

        }

        $this->inittime  = microtime(true);

        $this->sentbytes = 0;

        $this->running = true;

        $this->currentbuffer     = '';

        $this->currentbuffersize = 0;

        $this->init();

    }

    public function stop() {

        if (!$this->running) {

            throw new xml_output_exception('xml_output_not_started');

        }

        $this->finishtime = microtime(true);

        if ($this->usebuffer && $this->currentbuffersize > 0) { // Have pending contents in buffer

            $this->send($this->currentbuffer); // Send them

            $this->currentbuffer = '';

            $this->currentbuffersize = 0;

        }

        $this->running = false;

        $this->finish();

    }

    /**

     * Get contents from @xml_writer and buffer/output them

     */

    public function write($content) {

        if (!$this->running) {

            throw new xml_output_exception('xml_output_not_started');

        }

        $lenc = strlen($content ?? ''); // Get length in bytes.

        if ($lenc == 0) { // 0 length contents, nothing to do

            return;

        }

        // Buffer handling if available

        $tooutput = true; // By default, perform output

        if ($this->usebuffer) { // Buffer

            $this->currentbuffer .= $content;

            $this->currentbuffersize += $lenc;

            if ($this->currentbuffersize < $this->buffersize) {

                $tooutput = false; // Still within the buffer, don't output

            } else {

                $content = $this->currentbuffer; // Prepare for output

                $lenc = $this->currentbuffersize;

                $this->currentbuffer = '';

                $this->currentbuffersize = 0;

            }

        }

        // Output

        if ($tooutput) {

            $this->send($content); // Efectively send the contents

            $this->sentbytes += $lenc;

        }

    }

    public function debug_info() {

        if ($this->running !== false) {

            throw new xml_output_exception('xml_output_not_stopped');

        }

        return array('memory' => memory_get_peak_usage(true),

                     'time'   => $this->finishtime - $this->inittime,

                     'sent'   => $this->sentbytes);

    }

// Implementable API starts here

    abstract protected function init();

    abstract protected function finish();

    abstract protected function send($content);

}

/*

 * Exception class used by all the @xml_output stuff

 */

class xml_output_exception extends moodle_exception {

    public function __construct($errorcode, $a=NULL, $debuginfo=null) {

        parent::__construct($errorcode, 'error', '', $a, null, $debuginfo);

    }

}