93 lines
2.2 KiB
PHP
93 lines
2.2 KiB
PHP
<?php
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/**
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* Copyright (c) 2014 Robin Appelman <icewind@owncloud.com>
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* This file is licensed under the Licensed under the MIT license:
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* http://opensource.org/licenses/MIT
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*/
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namespace Icewind\Streams;
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/**
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* Wrapper that provides callbacks for write, read and close
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*
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* The following options should be passed in the context when opening the stream
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* [
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* 'callback' => [
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* 'source' => resource
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* ]
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* ]
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*
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* All callbacks are called after the operation is executed on the source stream
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*/
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class SeekableWrapper extends Wrapper {
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/**
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* @var resource
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*/
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protected $cache;
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/**
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* Wraps a stream to make it seekable
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*
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* @param resource $source
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* @return resource
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*
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* @throws \BadMethodCallException
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*/
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public static function wrap($source) {
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$context = stream_context_create(array(
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'callback' => array(
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'source' => $source
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)
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));
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return Wrapper::wrapSource($source, $context, 'callback', '\Icewind\Streams\SeekableWrapper');
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}
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public function dir_opendir($path, $options) {
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return false;
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}
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public function stream_open($path, $mode, $options, &$opened_path) {
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$this->loadContext('callback');
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$this->cache = fopen('php://temp', 'w+');
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return true;
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}
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protected function readTill($position) {
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$current = ftell($this->source);
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if ($position > $current) {
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$data = parent::stream_read($position - $current);
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$cachePosition = ftell($this->cache);
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fseek($this->cache, $current);
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fwrite($this->cache, $data);
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fseek($this->cache, $cachePosition);
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}
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}
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public function stream_read($count) {
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$current = ftell($this->cache);
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$this->readTill($current + $count);
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return fread($this->cache, $count);
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}
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public function stream_seek($offset, $whence = SEEK_SET) {
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if ($whence === SEEK_SET) {
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$target = $offset;
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} else if ($whence === SEEK_CUR) {
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$current = ftell($this->cache);
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$target = $current + $offset;
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} else {
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return false;
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}
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$this->readTill($target);
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return fseek($this->cache, $target) === 0;
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}
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public function stream_tell() {
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return ftell($this->cache);
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}
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public function stream_eof() {
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return parent::stream_eof() and (ftell($this->source) === ftell($this->cache));
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}
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}
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