Subversion-Projekte lars-tiefland.php_share

<?php

/*

 * Copyright 2011-2012 Amazon.com, Inc. or its affiliates. All Rights Reserved.

 *

 * Licensed under the Apache License, Version 2.0 (the "License").

 * You may not use this file except in compliance with the License.

 * A copy of the License is located at

 *

 *  http://aws.amazon.com/apache2.0

 *

 * or in the "license" file accompanying this file. This file is distributed

 * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either

 * express or implied. See the License for the specific language governing

 * permissions and limitations under the License.

 */

/**

 * Provides an interface for accessing Amazon S3 using PHP's native file management functions.

 *

 * Amazon S3 file patterns take the following form: <code>s3://bucket/object</code>.

 */

class S3StreamWrapper

{

	/**

	 * @var array An array of AmazonS3 clients registered as stream wrappers.

	 */

	protected static $_clients = array();

	/**

	 * Registers the S3StreamWrapper class as a stream wrapper.

	 *

	 * @param AmazonS3 $s3 (Optional) An instance of the AmazonS3 client.

	 * @param string $protocol (Optional) The name of the protocol to register.

	 * @return boolean Whether or not the registration succeeded.

	 */

	public static function register(AmazonS3 $s3 = null, $protocol = 's3')

	{

		S3StreamWrapper::$_clients[$protocol] = $s3 ? $s3 : new AmazonS3();

		return stream_wrapper_register($protocol, 'S3StreamWrapper');

	}

	/**

	 * Makes the given token PCRE-compatible.

	 *

	 * @param string $token (Required) The token

	 * @return string The PCRE-compatible version of the token

	 */

	public static function regex_token($token)

	{

		$token = str_replace('/', '\/', $token);

		$token = quotemeta($token);

		return str_replace('\\\\', '\\', $token);

	}

	public $position = 0;

	public $path = null;

	public $file_list = null;

	public $open_file = null;

	public $seek_position = 0;

	public $eof = false;

	public $buffer = null;

	public $object_size = 0;

	/**

	 * Fetches the client for the protocol being used.

	 *

	 * @param string $protocol (Optional) The protocol associated with this stream wrapper.

	 * @return AmazonS3 The S3 client associated with this stream wrapper.

	 */

	public function client($protocol = null)

	{

		if ($protocol == null)

		{

			if ($parsed = parse_url($this->path))

			{

				$protocol = $parsed['scheme'];

			}

			else

			{

				trigger_error(__CLASS__ . ' could not determine the protocol of the stream wrapper in use.');

			}

		}

		return self::$_clients[$protocol];

	}

	/**

	 * Parses an S3 URL into the parts needed by the stream wrapper.

	 *

	 * @param string $path The path to parse.

	 * @return array An array of 3 items: protocol, bucket, and object name ready for <code>list()</code>.

	 */

	public function parse_path($path)

	{

		$url = parse_url($path);

		return array(

			$url['scheme'],                                       // Protocol

			$url['host'],                                         // Bucket

			(isset($url['path']) ? substr($url['path'], 1) : ''), // Object

		);

	}

	/**

	 * Close directory handle. This method is called in response to <php:closedir()>.

	 *

	 * Since Amazon S3 doesn't have real directories, always return <code>true</code>.

	 *

	 * @return boolean

	 */

	public function dir_closedir()

	{

		$this->position = 0;

		$this->path = null;

		$this->file_list = null;

		$this->open_file = null;

		$this->seek_position = 0;

		$this->eof = false;

		$this->buffer = null;

		$this->object_size = 0;

		return true;

	}

	/**

	 * Open directory handle. This method is called in response to <php:opendir()>.

	 *

	 * @param string $path (Required) Specifies the URL that was passed to <php:opendir()>.

	 * @param integer $options (Required) Not used. Passed in by <php:opendir()>.

	 * @return boolean Returns <code>true</code> on success or <code>false</code> on failure.

	 */

	public function dir_opendir($path, $options)

	{

		$this->path = $path;

		list($protocol, $bucket, $object_name) = $this->parse_path($path);

		$pattern = '/^' . self::regex_token($object_name) . '(.*)[^\/$]/';

		$this->file_list = $this->client($protocol)->get_object_list($bucket, array(

			'pcre' => $pattern

		));

		return (count($this->file_list)) ? true : false;

	}

	/**

	 * This method is called in response to <php:readdir()>.

	 *

	 * @return string Should return a string representing the next filename, or <code>false</code> if there is no next file.

	 */

	public function dir_readdir()

	{

		if (isset($this->file_list[$this->position]))

		{

			$out = $this->file_list[$this->position];

			$this->position++;

		}

		else

		{

			$out = false;

		}

		return $out;

	}

	/**

	 * This method is called in response to <php:rewinddir()>.

	 *

	 * Should reset the output generated by <php:streamWrapper::dir_readdir()>. i.e.: The next call to

	 * <php:streamWrapper::dir_readdir()> should return the first entry in the location returned by

	 * <php:streamWrapper::dir_opendir()>.

	 *

	 * @return boolean Returns <code>true</code> on success or <code>false</code> on failure.

	 */

	public function dir_rewinddir()

	{

		$this->position = 0;

		return true;

	}

	/**

	 * Create a new bucket. This method is called in response to <php:mkdir()>.

	 *

	 * @param string $path (Required) The bucket name to create.

	 * @param integer $mode (Optional) Permissions. 700-range permissions map to ACL_PUBLIC. 600-range permissions map to ACL_AUTH_READ. All other permissions map to ACL_PRIVATE. Expects octal form.

	 * @param integer $options (Optional) Ignored.

	 * @return boolean Whether the bucket was created successfully or not.

	 */

	public function mkdir($path, $mode, $options)

	{

		// Get the value that was *actually* passed in as mode, and default to 0

		$trace_slice = array_slice(debug_backtrace(), -1);

		$mode = isset($trace_slice[0]['args'][1]) ? decoct($trace_slice[0]['args'][1]) : 0;

		$this->path = $path;

		list($protocol, $bucket, $object_name) = $this->parse_path($path);

		if (in_array($mode, range(700, 799)))

		{

			$acl = AmazonS3::ACL_PUBLIC;

		}

		elseif (in_array($mode, range(600, 699)))

		{

			$acl = AmazonS3::ACL_AUTH_READ;

		}

		else

		{

			$acl = AmazonS3::ACL_PRIVATE;

		}

		$client = $this->client($protocol);

		$region = $client->hostname;

		$response = $client->create_bucket($bucket, $region, $acl);

		return $response->isOK();

	}

	/**

	 * Renames a file or directory. This method is called in response to <php:rename()>.

	 *

	 * @param string $path_from (Required) The URL to the current file.

	 * @param string $path_to (Required) The URL which the <code>$path_from</code> should be renamed to.

	 * @return boolean Returns <code>true</code> on success or <code>false</code> on failure.

	 */

	public function rename($path_from, $path_to)

	{

		list($protocol, $from_bucket_name, $from_object_name) = $this->parse_path($path_from);

		list($protocol, $to_bucket_name, $to_object_name) = $this->parse_path($path_to);

		$copy_response = $this->client($protocol)->copy_object(

			array('bucket' => $from_bucket_name, 'filename' => $from_object_name),

			array('bucket' => $to_bucket_name,   'filename' => $to_object_name  )

		);

		if ($copy_response->isOK())

		{

			$delete_response = $this->client($protocol)->delete_object($from_bucket_name, $from_object_name);

			if ($delete_response->isOK())

			{

				return true;

			}

		}

		return false;

	}

	/**

	 * This method is called in response to <php:rmdir()>.

	 *

	 * @param string $path (Required) The bucket name to create.

	 * @param boolean $context (Optional) Ignored.

	 * @return boolean Whether the bucket was deleted successfully or not.

	 */

	public function rmdir($path, $context)

	{

		$this->path = $path;

		list($protocol, $bucket, $object_name) = $this->parse_path($path);

		$response = $this->client($protocol)->delete_bucket($bucket);

		return $response->isOK();

	}

	/**

	 * NOT IMPLEMENTED!

	 *

	 * @param integer $cast_as

	 * @return resource

	 */

	// public function stream_cast($cast_as) {}

	/**

	 * Close a resource. This method is called in response to <php:fclose()>.

	 *

	 * All resources that were locked, or allocated, by the wrapper should be released.

	 *

	 * @return void

	 */

	public function stream_close()

	{

		$this->position = 0;

		$this->path = null;

		$this->file_list = null;

		$this->open_file = null;

		$this->seek_position = 0;

		$this->eof = false;

		$this->buffer = null;

		$this->object_size = 0;

	}

	/**

	 * Tests for end-of-file on a file pointer. This method is called in response to <php:feof()>.

	 *

	 * @return boolean

	 */

	public function stream_eof()

	{

		return $this->eof;

	}

	/**

	 * Flushes the output. This method is called in response to <php:fflush()>. If you have cached data in

	 * your stream but not yet stored it into the underlying storage, you should do so now.

	 *

	 * Since this implementation doesn't buffer streams, simply return <code>true</code>.

	 *

	 * @return boolean Whether or not flushing succeeded

	 */

	public function stream_flush()

	{

		if ($this->buffer === null)

		{

			return false;

		}

		list($protocol, $bucket, $object_name) = $this->parse_path($this->path);

		$response = $this->client($protocol)->create_object($bucket, $object_name, array(

			'body' => $this->buffer,

		));

		$this->seek_position = 0;

		$this->buffer = null;

		$this->eof = true;

		return $response->isOK();

	}

	/**

	 * This method is called in response to <php:flock()>, when <php:file_put_contents()> (when flags contains

	 * <code>LOCK_EX</code>), <php:stream_set_blocking()> and when closing the stream (<code>LOCK_UN</code>).

	 *

	 * Not implemented in S3, so it's not implemented here.

	 *

	 * @param mode $operation

	 * @return boolean

	 */

	// public function stream_lock($operation) {}

	/**

	 * Opens file or URL. This method is called immediately after the wrapper is initialized

	 * (e.g., by <php:fopen()> and <php:file_get_contents()>).

	 *

	 * @param string $path (Required) Specifies the URL that was passed to the original function.

	 * @param string $mode (Required) Ignored.

	 * @param integer $options (Required) Ignored.

	 * @param string &$opened_path (Required) Returns the same value as was passed into <code>$path</code>.

	 * @return boolean Returns <code>true</code> on success or <code>false</code> on failure.

	 */

	public function stream_open($path, $mode, $options, &$opened_path)

	{

		$opened_path = $path;

		$this->open_file = $path;

		$this->path = $path;

		$this->seek_position = 0;

		$this->object_size = 0;

		return true;

	}

	/**

	 * Read from stream. This method is called in response to <php:fread()> and <php:fgets()>.

	 *

	 *

	 *

	 * It is important to avoid reading files that are near to or larger than the amount of memory

	 * allocated to PHP, otherwise "out of memory" errors will occur.

	 *

	 * @param integer $count (Required) Always equal to 8192. PHP is fun, isn't it?

	 * @return string The contents of the Amazon S3 object.

	 */

	public function stream_read($count)

	{

		if ($this->eof)

		{

			return false;

		}

		list($protocol, $bucket, $object_name) = $this->parse_path($this->path);

		if ($this->seek_position > 0 && $this->object_size)

		{

			if ($count + $this->seek_position > $this->object_size)

			{

				$count = $this->object_size - $this->seek_position;

			}

			$start = $this->seek_position;

			$end = $this->seek_position + $count;

			$response = $this->client($protocol)->get_object($bucket, $object_name, array(

				'range' => $start . '-' . $end

			));

		}

		else

		{

			$response = $this->client($protocol)->get_object($bucket, $object_name);

			$this->object_size = isset($response->header['content-length']) ? $response->header['content-length'] : 0;

		}

		if (!$response->isOK())

		{

			return false;

		}

		$data = substr($response->body, 0, min($count, $this->object_size));

		$this->seek_position += strlen($data);

		if ($this->seek_position >= $this->object_size)

		{

			$this->eof = true;

			$this->seek_position = 0;

			$this->object_size = 0;

		}

		return $data;

	}

	/**

	 * Seeks to specific location in a stream. This method is called in response to <php:fseek()>. The read/write

	 * position of the stream should be updated according to the <code>$offset</code> and <code>$whence</code>

	 * parameters.

	 *

	 * @param integer $offset (Required) The number of bytes to offset from the start of the file.

	 * @param integer $whence (Optional) Ignored. Always uses <code>SEEK_SET</code>.

	 * @return boolean Whether or not the seek was successful.

	 */

	public function stream_seek($offset, $whence)

	{

		$this->seek_position = $offset;

		return true;

	}

	/**

	 * @param integer $option

	 * @param integer $arg1

	 * @param integer $arg2

	 * @return boolean

	 */

	// public function stream_set_option($option, $arg1, $arg2) {}

	/**

	 * Retrieve information about a file resource.

	 *

	 * @return array Returns the same data as a call to <php:stat()>.

	 */

	public function stream_stat()

	{

		return $this->url_stat($this->path, null);

	}

	/**

	 * Retrieve the current position of a stream. This method is called in response to <php:ftell()>.

	 *

	 * @return integer Returns the current position of the stream.

	 */

	public function stream_tell()

	{

		return $this->seek_position;

	}

	/**

	 * Write to stream. This method is called in response to <php:fwrite()>.

	 *

	 * It is important to avoid reading files that are larger than the amount of memory allocated to PHP,

	 * otherwise "out of memory" errors will occur.

	 *

	 * @param string $data (Required) The data to write to the stream.

	 * @return integer The number of bytes that were written to the stream.

	 */

	public function stream_write($data)

	{

		$size = strlen($data);

		$this->seek_position = $size;

		$this->buffer .= $data;

		return $this->seek_position;

	}

	/**

	 * Delete a file. This method is called in response to <php:unlink()>.

	 *

	 * @param string $path (Required) The file URL which should be deleted.

	 * @return boolean Returns <code>true</code> on success or <code>false</code> on failure.

	 */

	public function unlink($path)

	{

		$this->path = $path;

		list($protocol, $bucket, $object_name) = $this->parse_path($path);

		$response = $this->client($protocol)->delete_object($bucket, $object_name);

		return $response->isOK();

	}

	/**

	 * This method is called in response to all <php:stat()> related functions.

	 *

	 * @param string $path (Required) The file path or URL to stat. Note that in the case of a URL, it must be a <code>://</code> delimited URL. Other URL forms are not supported.

	 * @param integer $flags (Required) Holds additional flags set by the streams API. This implementation ignores all defined flags.

	 * @return array Should return as many elements as <php:stat()> does. Unknown or unavailable values should be set to a rational value (usually <code>0</code>).

	 */

	public function url_stat($path, $flags)

	{

		// Defaults

		$out = array();

		$out[0] = $out['dev'] = 0;

		$out[1] = $out['ino'] = 0;

		$out[2] = $out['mode'] = 0;

		$out[3] = $out['nlink'] = 0;

		$out[4] = $out['uid'] = 0;

		$out[5] = $out['gid'] = 0;

		$out[6] = $out['rdev'] = 0;

		$out[7] = $out['size'] = 0;

		$out[8] = $out['atime'] = 0;

		$out[9] = $out['mtime'] = 0;

		$out[10] = $out['ctime'] = 0;

		$out[11] = $out['blksize'] = 0;

		$out[12] = $out['blocks'] = 0;

		$this->path = $path;

		list($protocol, $bucket, $object_name) = $this->parse_path($this->path);

		$file = null;

		$mode = 0;

		if ($object_name)

		{

			$response = $this->client($protocol)->list_objects($bucket, array(

				'prefix' => $object_name

			));

			if (!$response->isOK())

			{

				return $out;

			}

			// Ummm... yeah...

			if (is_object($response->body))

			{

				$file = $response->body->Contents[0];

			}

			else

			{

				$body = simplexml_load_string($response->body);

				$file = $body->Contents[0];

			}

		}

		else

		{

			$response = $this->client($protocol)->list_objects($bucket);

			if (!$response->isOK())

			{

				return $out;

			}

		}

		/*

		Type & Permission bitwise values (only those that pertain to S3).

		Simulate the concept of a "directory". Nothing has an executable bit because there's no executing on S3.

		Reference: http://docstore.mik.ua/orelly/webprog/pcook/ch19_13.htm

		0100000 => type:   regular file

		0040000 => type:   directory

		0000400 => owner:  read permission

		0000200 => owner:  write permission

		0000040 => group:  read permission

		0000020 => group:  write permission

		0000004 => others: read permission

		0000002 => others: write permission

		*/

		// File or directory?

		// @todo: Add more detailed support for permissions. Currently only takes OWNER into account.

		if (!$object_name) // Root of the bucket

		{

			$mode = octdec('0040777');

		}

		elseif ($file)

		{

			$mode = (str_replace('//', '/', $object_name . '/') === (string) $file->Key) ? octdec('0040777') : octdec('0100777'); // Directory, Owner R/W : Regular File, Owner R/W

		}

		else

		{

			$mode = octdec('0100777');

		}

		// Update stat output

		$out[2] = $out['mode'] = $mode;

		$out[4] = $out['uid'] = (isset($file) ? (string) $file->Owner->ID : 0);

		$out[7] = $out['size'] = (isset($file) ? (string) $file->Size : 0);

		$out[8] = $out['atime'] = (isset($file) ? date('U', strtotime((string) $file->LastModified)) : 0);

		$out[9] = $out['mtime'] = (isset($file) ? date('U', strtotime((string) $file->LastModified)) : 0);

		$out[10] = $out['ctime'] = (isset($file) ? date('U', strtotime((string) $file->LastModified)) : 0);

		return $out;

	}

}