nextcloud/apps/files_external/3rdparty/aws-sdk-php/Aws/S3/StreamWrapper.php

892 lines
28 KiB
PHP

<?php
/**
* Copyright 2010-2013 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.
*/
namespace Aws\S3;
use Aws\Common\Exception\RuntimeException;
use Aws\S3\Exception\S3Exception;
use Aws\S3\Exception\NoSuchKeyException;
use Aws\S3\Iterator\ListObjectsIterator;
use Guzzle\Http\EntityBody;
use Guzzle\Http\CachingEntityBody;
use Guzzle\Http\Mimetypes;
use Guzzle\Iterator\FilterIterator;
use Guzzle\Stream\PhpStreamRequestFactory;
use Guzzle\Service\Command\CommandInterface;
/**
* Amazon S3 stream wrapper to use "s3://<bucket>/<key>" files with PHP streams, supporting "r", "w", "a", "x".
*
* # Supported stream related PHP functions:
* - fopen, fclose, fread, fwrite, fseek, ftell, feof, fflush
* - opendir, closedir, readdir, rewinddir
* - copy, rename, unlink
* - mkdir, rmdir, rmdir (recursive)
* - file_get_contents, file_put_contents
* - file_exists, filesize, is_file, is_dir
*
* # Opening "r" (read only) streams:
*
* Read only streams are truly streaming by default and will not allow you to seek. This is because data
* read from the stream is not kept in memory or on the local filesystem. You can force a "r" stream to be seekable
* by setting the "seekable" stream context option true. This will allow true streaming of data from Amazon S3, but
* will maintain a buffer of previously read bytes in a 'php://temp' stream to allow seeking to previously read bytes
* from the stream.
*
* You may pass any GetObject parameters as 's3' stream context options. These options will affect how the data is
* downloaded from Amazon S3.
*
* # Opening "w" and "x" (write only) streams:
*
* Because Amazon S3 requires a Content-Length header, write only streams will maintain a 'php://temp' stream to buffer
* data written to the stream until the stream is flushed (usually by closing the stream with fclose).
*
* You may pass any PutObject parameters as 's3' stream context options. These options will affect how the data is
* uploaded to Amazon S3.
*
* When opening an "x" stream, the file must exist on Amazon S3 for the stream to open successfully.
*
* # Opening "a" (write only append) streams:
*
* Similar to "w" streams, opening append streams requires that the data be buffered in a "php://temp" stream. Append
* streams will attempt to download the contents of an object in Amazon S3, seek to the end of the object, then allow
* you to append to the contents of the object. The data will then be uploaded using a PutObject operation when the
* stream is flushed (usually with fclose).
*
* You may pass any GetObject and/or PutObject parameters as 's3' stream context options. These options will affect how
* the data is downloaded and uploaded from Amazon S3.
*
* Stream context options:
*
* - "seekable": Set to true to create a seekable "r" (read only) stream by using a php://temp stream buffer
* - For "unlink" only: Any option that can be passed to the DeleteObject operation
*/
class StreamWrapper
{
/**
* @var resource|null Stream context (this is set by PHP when a context is used)
*/
public $context;
/**
* @var S3Client Client used to send requests
*/
protected static $client;
/**
* @var string Mode the stream was opened with
*/
protected $mode;
/**
* @var EntityBody Underlying stream resource
*/
protected $body;
/**
* @var array Current parameters to use with the flush operation
*/
protected $params;
/**
* @var ListObjectsIterator Iterator used with opendir() and subsequent readdir() calls
*/
protected $objectIterator;
/**
* @var string The bucket that was opened when opendir() was called
*/
protected $openedBucket;
/**
* @var string The prefix of the bucket that was opened with opendir()
*/
protected $openedBucketPrefix;
/**
* @var array The next key to retrieve when using a directory iterator. Helps for fast directory traversal.
*/
protected static $nextStat = array();
/**
* Register the 's3://' stream wrapper
*
* @param S3Client $client Client to use with the stream wrapper
*/
public static function register(S3Client $client)
{
if (in_array('s3', stream_get_wrappers())) {
stream_wrapper_unregister('s3');
}
stream_wrapper_register('s3', get_called_class(), STREAM_IS_URL);
static::$client = $client;
}
/**
* Close the stream
*/
public function stream_close()
{
$this->body = null;
}
/**
* @param string $path
* @param string $mode
* @param int $options
* @param string $opened_path
*
* @return bool
*/
public function stream_open($path, $mode, $options, &$opened_path)
{
// We don't care about the binary flag
$this->mode = $mode = rtrim($mode, 'bt');
$this->params = $params = $this->getParams($path);
$errors = array();
if (!$params['Key']) {
$errors[] = 'Cannot open a bucket. You must specify a path in the form of s3://bucket/key';
}
if (strpos($mode, '+')) {
$errors[] = 'The Amazon S3 stream wrapper does not allow simultaneous reading and writing.';
}
if (!in_array($mode, array('r', 'w', 'a', 'x'))) {
$errors[] = "Mode not supported: {$mode}. Use one 'r', 'w', 'a', or 'x'.";
}
// When using mode "x" validate if the file exists before attempting to read
if ($mode == 'x' && static::$client->doesObjectExist($params['Bucket'], $params['Key'], $this->getOptions())) {
$errors[] = "{$path} already exists on Amazon S3";
}
if (!$errors) {
if ($mode == 'r') {
$this->openReadStream($params, $errors);
} elseif ($mode == 'a') {
$this->openAppendStream($params, $errors);
} else {
$this->openWriteStream($params, $errors);
}
}
return $errors ? $this->triggerError($errors) : true;
}
/**
* @return bool
*/
public function stream_eof()
{
return $this->body->feof();
}
/**
* @return bool
*/
public function stream_flush()
{
if ($this->mode == 'r') {
return false;
}
$this->body->rewind();
$params = $this->params;
$params['Body'] = $this->body;
// Attempt to guess the ContentType of the upload based on the
// file extension of the key
if (!isset($params['ContentType']) &&
($type = Mimetypes::getInstance()->fromFilename($params['Key']))
) {
$params['ContentType'] = $type;
}
try {
static::$client->putObject($params);
return true;
} catch (\Exception $e) {
return $this->triggerError($e->getMessage());
}
}
/**
* Read data from the underlying stream
*
* @param int $count Amount of bytes to read
*
* @return string
*/
public function stream_read($count)
{
return $this->body->read($count);
}
/**
* Seek to a specific byte in the stream
*
* @param int $offset Seek offset
* @param int $whence Whence (SEEK_SET, SEEK_CUR, SEEK_END)
*
* @return bool
*/
public function stream_seek($offset, $whence = SEEK_SET)
{
return $this->body->seek($offset, $whence);
}
/**
* Get the current position of the stream
*
* @return int Returns the current position in the stream
*/
public function stream_tell()
{
return $this->body->ftell();
}
/**
* Write data the to the stream
*
* @param string $data
*
* @return int Returns the number of bytes written to the stream
*/
public function stream_write($data)
{
return $this->body->write($data);
}
/**
* Delete a specific object
*
* @param string $path
* @return bool
*/
public function unlink($path)
{
try {
$this->clearStatInfo($path);
static::$client->deleteObject($this->getParams($path));
return true;
} catch (\Exception $e) {
return $this->triggerError($e->getMessage());
}
}
/**
* @return array
*/
public function stream_stat()
{
$stat = fstat($this->body->getStream());
// Add the size of the underlying stream if it is known
if ($this->mode == 'r' && $this->body->getSize()) {
$stat[7] = $stat['size'] = $this->body->getSize();
}
return $stat;
}
/**
* Provides information for is_dir, is_file, filesize, etc. Works on buckets, keys, and prefixes
*
* @param string $path
* @param int $flags
*
* @return array Returns an array of stat data
* @link http://www.php.net/manual/en/streamwrapper.url-stat.php
*/
public function url_stat($path, $flags)
{
// Check if this path is in the url_stat cache
if (isset(static::$nextStat[$path])) {
return static::$nextStat[$path];
}
$parts = $this->getParams($path);
if (!$parts['Key']) {
// Stat "directories": buckets, or "s3://"
if (!$parts['Bucket'] || static::$client->doesBucketExist($parts['Bucket'])) {
return $this->formatUrlStat($path);
} else {
return $this->triggerError("File or directory not found: {$path}", $flags);
}
}
try {
try {
$result = static::$client->headObject($parts)->toArray();
if (substr($parts['Key'], -1, 1) == '/' && $result['ContentLength'] == 0) {
// Return as if it is a bucket to account for console bucket objects (e.g., zero-byte object "foo/")
return $this->formatUrlStat($path);
} else {
// Attempt to stat and cache regular object
return $this->formatUrlStat($result);
}
} catch (NoSuchKeyException $e) {
// Maybe this isn't an actual key, but a prefix. Do a prefix listing of objects to determine.
$result = static::$client->listObjects(array(
'Bucket' => $parts['Bucket'],
'Prefix' => rtrim($parts['Key'], '/') . '/',
'MaxKeys' => 1
));
if (!$result['Contents'] && !$result['CommonPrefixes']) {
return $this->triggerError("File or directory not found: {$path}", $flags);
}
// This is a directory prefix
return $this->formatUrlStat($path);
}
} catch (\Exception $e) {
return $this->triggerError($e->getMessage(), $flags);
}
}
/**
* Support for mkdir().
*
* @param string $path Directory which should be created.
* @param int $mode 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 int $options A bitwise mask of values, such as STREAM_MKDIR_RECURSIVE.
*
* @return bool
* @link http://www.php.net/manual/en/streamwrapper.mkdir.php
*/
public function mkdir($path, $mode, $options)
{
$params = $this->getParams($path);
if (!$params['Bucket']) {
return false;
}
if (!isset($params['ACL'])) {
$params['ACL'] = $this->determineAcl($mode);
}
return !isset($params['Key']) || $params['Key'] === '/'
? $this->createBucket($path, $params)
: $this->createPseudoDirectory($path, $params);
}
/**
* Remove a bucket from Amazon S3
*
* @param string $path the directory path
*
* @return bool true if directory was successfully removed
* @link http://www.php.net/manual/en/streamwrapper.rmdir.php
*/
public function rmdir($path)
{
$params = $this->getParams($path);
if (!$params['Bucket']) {
return $this->triggerError('You cannot delete s3://. Please specify a bucket.');
}
try {
if (!$params['Key']) {
static::$client->deleteBucket(array('Bucket' => $params['Bucket']));
$this->clearStatInfo($path);
return true;
}
// Use a key that adds a trailing slash if needed.
$prefix = rtrim($params['Key'], '/') . '/';
$result = static::$client->listObjects(array(
'Bucket' => $params['Bucket'],
'Prefix' => $prefix,
'MaxKeys' => 1
));
// Check if the bucket contains keys other than the placeholder
if ($result['Contents']) {
foreach ($result['Contents'] as $key) {
if ($key['Key'] == $prefix) {
continue;
}
return $this->triggerError('Psuedo folder is not empty');
}
return $this->unlink(rtrim($path, '/') . '/');
}
return $result['CommonPrefixes']
? $this->triggerError('Pseudo folder contains nested folders')
: true;
} catch (\Exception $e) {
return $this->triggerError($e->getMessage());
}
}
/**
* Support for opendir().
*
* The opendir() method of the Amazon S3 stream wrapper supports a stream
* context option of "listFilter". listFilter must be a callable that
* accepts an associative array of object data and returns true if the
* object should be yielded when iterating the keys in a bucket.
*
* @param string $path The path to the directory (e.g. "s3://dir[</prefix>]")
* @param string $options Whether or not to enforce safe_mode (0x04). Unused.
*
* @return bool true on success
* @see http://www.php.net/manual/en/function.opendir.php
*/
public function dir_opendir($path, $options)
{
// Reset the cache
$this->clearStatInfo();
$params = $this->getParams($path);
$delimiter = $this->getOption('delimiter');
$filterFn = $this->getOption('listFilter');
if ($delimiter === null) {
$delimiter = '/';
}
if ($params['Key']) {
$params['Key'] = rtrim($params['Key'], $delimiter) . $delimiter;
}
$this->openedBucket = $params['Bucket'];
$this->openedBucketPrefix = $params['Key'];
$operationParams = array('Bucket' => $params['Bucket'], 'Prefix' => $params['Key']);
if ($delimiter) {
$operationParams['Delimiter'] = $delimiter;
}
$objectIterator = static::$client->getIterator('ListObjects', $operationParams, array(
'return_prefixes' => true,
'sort_results' => true
));
// Filter our "/" keys added by the console as directories, and ensure
// that if a filter function is provided that it passes the filter.
$this->objectIterator = new FilterIterator(
$objectIterator,
function ($key) use ($filterFn) {
// Each yielded results can contain a "Key" or "Prefix"
return (!$filterFn || call_user_func($filterFn, $key)) &&
(!isset($key['Key']) || substr($key['Key'], -1, 1) !== '/');
}
);
$this->objectIterator->next();
return true;
}
/**
* Close the directory listing handles
*
* @return bool true on success
*/
public function dir_closedir()
{
$this->objectIterator = null;
return true;
}
/**
* This method is called in response to rewinddir()
*
* @return boolean true on success
*/
public function dir_rewinddir()
{
$this->clearStatInfo();
$this->objectIterator->rewind();
return true;
}
/**
* This method is called in response to readdir()
*
* @return string Should return a string representing the next filename, or false if there is no next file.
*
* @link http://www.php.net/manual/en/function.readdir.php
*/
public function dir_readdir()
{
// Skip empty result keys
if (!$this->objectIterator->valid()) {
return false;
}
$current = $this->objectIterator->current();
if (isset($current['Prefix'])) {
// Include "directories". Be sure to strip a trailing "/"
// on prefixes.
$prefix = rtrim($current['Prefix'], '/');
$result = str_replace($this->openedBucketPrefix, '', $prefix);
$key = "s3://{$this->openedBucket}/{$prefix}";
$stat = $this->formatUrlStat($prefix);
} else {
// Remove the prefix from the result to emulate other
// stream wrappers.
$result = str_replace($this->openedBucketPrefix, '', $current['Key']);
$key = "s3://{$this->openedBucket}/{$current['Key']}";
$stat = $this->formatUrlStat($current);
}
// Cache the object data for quick url_stat lookups used with
// RecursiveDirectoryIterator.
static::$nextStat = array($key => $stat);
$this->objectIterator->next();
return $result;
}
/**
* Called in response to rename() to rename a file or directory. Currently only supports renaming objects.
*
* @param string $path_from the path to the file to rename
* @param string $path_to the new path to the file
*
* @return bool true if file was successfully renamed
* @link http://www.php.net/manual/en/function.rename.php
*/
public function rename($path_from, $path_to)
{
$partsFrom = $this->getParams($path_from);
$partsTo = $this->getParams($path_to);
$this->clearStatInfo($path_from);
$this->clearStatInfo($path_to);
if (!$partsFrom['Key'] || !$partsTo['Key']) {
return $this->triggerError('The Amazon S3 stream wrapper only supports copying objects');
}
try {
// Copy the object and allow overriding default parameters if desired, but by default copy metadata
static::$client->copyObject($this->getOptions() + array(
'Bucket' => $partsTo['Bucket'],
'Key' => $partsTo['Key'],
'CopySource' => '/' . $partsFrom['Bucket'] . '/' . rawurlencode($partsFrom['Key']),
'MetadataDirective' => 'COPY'
));
// Delete the original object
static::$client->deleteObject(array(
'Bucket' => $partsFrom['Bucket'],
'Key' => $partsFrom['Key']
) + $this->getOptions());
} catch (\Exception $e) {
return $this->triggerError($e->getMessage());
}
return true;
}
/**
* Cast the stream to return the underlying file resource
*
* @param int $cast_as STREAM_CAST_FOR_SELECT or STREAM_CAST_AS_STREAM
*
* @return resource
*/
public function stream_cast($cast_as)
{
return $this->body->getStream();
}
/**
* Get the stream context options available to the current stream
*
* @return array
*/
protected function getOptions()
{
$context = $this->context ?: stream_context_get_default();
$options = stream_context_get_options($context);
return isset($options['s3']) ? $options['s3'] : array();
}
/**
* Get a specific stream context option
*
* @param string $name Name of the option to retrieve
*
* @return mixed|null
*/
protected function getOption($name)
{
$options = $this->getOptions();
return isset($options[$name]) ? $options[$name] : null;
}
/**
* Get the bucket and key from the passed path (e.g. s3://bucket/key)
*
* @param string $path Path passed to the stream wrapper
*
* @return array Hash of 'Bucket', 'Key', and custom params
*/
protected function getParams($path)
{
$parts = explode('/', substr($path, 5), 2);
$params = $this->getOptions();
unset($params['seekable']);
return array(
'Bucket' => $parts[0],
'Key' => isset($parts[1]) ? $parts[1] : null
) + $params;
}
/**
* Serialize and sign a command, returning a request object
*
* @param CommandInterface $command Command to sign
*
* @return RequestInterface
*/
protected function getSignedRequest($command)
{
$request = $command->prepare();
$request->dispatch('request.before_send', array('request' => $request));
return $request;
}
/**
* Initialize the stream wrapper for a read only stream
*
* @param array $params Operation parameters
* @param array $errors Any encountered errors to append to
*
* @return bool
*/
protected function openReadStream(array $params, array &$errors)
{
// Create the command and serialize the request
$request = $this->getSignedRequest(static::$client->getCommand('GetObject', $params));
// Create a stream that uses the EntityBody object
$factory = $this->getOption('stream_factory') ?: new PhpStreamRequestFactory();
$this->body = $factory->fromRequest($request, array(), array('stream_class' => 'Guzzle\Http\EntityBody'));
// Wrap the body in a caching entity body if seeking is allowed
if ($this->getOption('seekable')) {
$this->body = new CachingEntityBody($this->body);
}
return true;
}
/**
* Initialize the stream wrapper for a write only stream
*
* @param array $params Operation parameters
* @param array $errors Any encountered errors to append to
*
* @return bool
*/
protected function openWriteStream(array $params, array &$errors)
{
$this->body = new EntityBody(fopen('php://temp', 'r+'));
}
/**
* Initialize the stream wrapper for an append stream
*
* @param array $params Operation parameters
* @param array $errors Any encountered errors to append to
*
* @return bool
*/
protected function openAppendStream(array $params, array &$errors)
{
try {
// Get the body of the object
$this->body = static::$client->getObject($params)->get('Body');
$this->body->seek(0, SEEK_END);
} catch (S3Exception $e) {
// The object does not exist, so use a simple write stream
$this->openWriteStream($params, $errors);
}
return true;
}
/**
* Trigger one or more errors
*
* @param string|array $errors Errors to trigger
* @param mixed $flags If set to STREAM_URL_STAT_QUIET, then no error or exception occurs
*
* @return bool Returns false
* @throws RuntimeException if throw_errors is true
*/
protected function triggerError($errors, $flags = null)
{
if ($flags & STREAM_URL_STAT_QUIET) {
// This is triggered with things like file_exists()
if ($flags & STREAM_URL_STAT_LINK) {
// This is triggered for things like is_link()
return $this->formatUrlStat(false);
}
return false;
}
// This is triggered when doing things like lstat() or stat()
trigger_error(implode("\n", (array) $errors), E_USER_WARNING);
return false;
}
/**
* Prepare a url_stat result array
*
* @param string|array $result Data to add
*
* @return array Returns the modified url_stat result
*/
protected function formatUrlStat($result = null)
{
static $statTemplate = array(
0 => 0, 'dev' => 0,
1 => 0, 'ino' => 0,
2 => 0, 'mode' => 0,
3 => 0, 'nlink' => 0,
4 => 0, 'uid' => 0,
5 => 0, 'gid' => 0,
6 => -1, 'rdev' => -1,
7 => 0, 'size' => 0,
8 => 0, 'atime' => 0,
9 => 0, 'mtime' => 0,
10 => 0, 'ctime' => 0,
11 => -1, 'blksize' => -1,
12 => -1, 'blocks' => -1,
);
$stat = $statTemplate;
$type = gettype($result);
// Determine what type of data is being cached
if ($type == 'NULL' || $type == 'string') {
// Directory with 0777 access - see "man 2 stat".
$stat['mode'] = $stat[2] = 0040777;
} elseif ($type == 'array' && isset($result['LastModified'])) {
// ListObjects or HeadObject result
$stat['mtime'] = $stat[9] = $stat['ctime'] = $stat[10] = strtotime($result['LastModified']);
$stat['size'] = $stat[7] = (isset($result['ContentLength']) ? $result['ContentLength'] : $result['Size']);
// Regular file with 0777 access - see "man 2 stat".
$stat['mode'] = $stat[2] = 0100777;
}
return $stat;
}
/**
* Clear the next stat result from the cache
*
* @param string $path If a path is specific, clearstatcache() will be called
*/
protected function clearStatInfo($path = null)
{
static::$nextStat = array();
if ($path) {
clearstatcache(true, $path);
}
}
/**
* Creates a bucket for the given parameters.
*
* @param string $path Stream wrapper path
* @param array $params A result of StreamWrapper::getParams()
*
* @return bool Returns true on success or false on failure
*/
private function createBucket($path, array $params)
{
if (static::$client->doesBucketExist($params['Bucket'])) {
return $this->triggerError("Directory already exists: {$path}");
}
try {
static::$client->createBucket($params);
$this->clearStatInfo($path);
return true;
} catch (\Exception $e) {
return $this->triggerError($e->getMessage());
}
}
/**
* Creates a pseudo-folder by creating an empty "/" suffixed key
*
* @param string $path Stream wrapper path
* @param array $params A result of StreamWrapper::getParams()
*
* @return bool
*/
private function createPseudoDirectory($path, array $params)
{
// Ensure the path ends in "/" and the body is empty.
$params['Key'] = rtrim($params['Key'], '/') . '/';
$params['Body'] = '';
// Fail if this pseudo directory key already exists
if (static::$client->doesObjectExist($params['Bucket'], $params['Key'])) {
return $this->triggerError("Directory already exists: {$path}");
}
try {
static::$client->putObject($params);
$this->clearStatInfo($path);
return true;
} catch (\Exception $e) {
return $this->triggerError($e->getMessage());
}
}
/**
* Determine the most appropriate ACL based on a file mode.
*
* @param int $mode File mode
*
* @return string
*/
private function determineAcl($mode)
{
$mode = decoct($mode);
if ($mode >= 700 && $mode <= 799) {
return 'public-read';
}
if ($mode >= 600 && $mode <= 699) {
return 'authenticated-read';
}
return 'private';
}
}