Class yii\mongodb\file\Download

Inheritanceyii\mongodb\file\Download » yii\base\BaseObject
Available since extension's version2.1
Source Code https://github.com/yiisoft/yii2-mongodb/blob/master/src/file/Download.php

Download represents the GridFS download operation.

A Download object is usually created by calling yii\mongodb\file\Collection::get() or yii\mongodb\file\Collection::createDownload().

Usage example:

Yii::$app->mongodb->getFileCollection()->createDownload($document['_id'])->toFile('/path/to/file.dat');

You can use Download::substr() to read a specific part of the file:

$filePart = Yii::$app->mongodb->getFileCollection()->createDownload($document['_id'])->substr(256, 1024);

Public Properties

Hide inherited properties

Property Type Description Defined By
$bytes string File content. yii\mongodb\file\Download
$chunkCursor \MongoDB\Driver\Cursor Chuck list cursor. yii\mongodb\file\Download
$chunkIterator Iterator Chuck cursor iterator. yii\mongodb\file\Download
$collection yii\mongodb\file\Collection File collection to be used. yii\mongodb\file\Download
$document array Document to be downloaded. yii\mongodb\file\Download
$filename string|null File name. yii\mongodb\file\Download
$resource resource File stream resource. yii\mongodb\file\Download
$size integer File size. yii\mongodb\file\Download

Public Methods

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Method Description Defined By
getBytes() Alias of toString() method. yii\mongodb\file\Download
getChunkCursor() Returns file chunks read cursor. yii\mongodb\file\Download
getChunkIterator() Returns iterator for the file chunks cursor. yii\mongodb\file\Download
getDocument() yii\mongodb\file\Download
getFilename() Returns associated file's filename. yii\mongodb\file\Download
getResource() Returns persistent stream resource, which can be used to read file. yii\mongodb\file\Download
getSize() Returns the size of the associated file. yii\mongodb\file\Download
setDocument() Sets data of the document to be downloaded. yii\mongodb\file\Download
substr() Return part of a file. yii\mongodb\file\Download
toFile() Saves download to the physical file. yii\mongodb\file\Download
toResource() Returns an opened stream resource, which can be used to read file. yii\mongodb\file\Download
toStream() Saves file into the given stream. yii\mongodb\file\Download
toString() Returns a string of the bytes in the associated file. yii\mongodb\file\Download
write() Alias of toFile() method. yii\mongodb\file\Download

Property Details

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$bytes public property

File content.

public string $bytes null
$chunkCursor public property

Chuck list cursor.

public \MongoDB\Driver\Cursor $chunkCursor null
$chunkIterator public property

Chuck cursor iterator.

public Iterator $chunkIterator null
$collection public property

File collection to be used.

$document public property

Document to be downloaded. Note that the type of this property differs in getter and setter. See getDocument() and setDocument() for details.

public array $document null
$filename public property

File name.

public string|null $filename null
$resource public property

File stream resource.

public resource $resource null
$size public property

File size.

public integer $size null

Method Details

Hide inherited methods

getBytes() public method

Alias of toString() method.

public string getBytes ( )
return string

File content.

                public function getBytes()
{
    return $this->toString();
}

            
getChunkCursor() public method

Returns file chunks read cursor.

public \MongoDB\Driver\Cursor getChunkCursor ( $refresh false )
$refresh boolean

Whether to recreate cursor, if it is already exist.

return \MongoDB\Driver\Cursor

Chuck list cursor.

throws \yii\base\InvalidConfigException

                public function getChunkCursor($refresh = false)
{
    if ($refresh || $this->_chunkCursor === null) {
        $file = $this->getDocument();
        $this->_chunkCursor = $this->collection->getChunkCollection()->find(
            ['files_id' => $file['_id']],
            [],
            ['sort' => ['n' => 1]]
        );
    }
    return $this->_chunkCursor;
}

            
getChunkIterator() public method

Returns iterator for the file chunks cursor.

public Iterator getChunkIterator ( $refresh false )
$refresh boolean

Whether to recreate iterator, if it is already exist.

return Iterator

Chuck cursor iterator.

                public function getChunkIterator($refresh = false)
{
    if ($refresh || $this->_chunkIterator === null) {
        $this->_chunkIterator = new \IteratorIterator($this->getChunkCursor($refresh));
        $this->_chunkIterator->rewind();
    }
    return $this->_chunkIterator;
}

            
getDocument() public method

public array getDocument ( )
return array

Document to be downloaded.

throws \yii\base\InvalidConfigException

on invalid document configuration.

                public function getDocument()
{
    if (!is_array($this->_document)) {
        if (is_scalar($this->_document) || $this->_document instanceof ObjectID) {
            $document = $this->collection->findOne(['_id' => $this->_document]);
            if (empty($document)) {
                throw new InvalidConfigException('Document id=' . $this->_document . ' does not exist at collection "' . $this->collection->getFullName() . '"');
            }
            $this->_document = $document;
        } else {
            $this->_document = (array)$this->_document;
        }
    }
    return $this->_document;
}

            
getFilename() public method

Returns associated file's filename.

public string|null getFilename ( )
return string|null

File name.

                public function getFilename()
{
    $document = $this->getDocument();
    return isset($document['filename']) ? $document['filename'] : null;
}

            
getResource() public method

Returns persistent stream resource, which can be used to read file.

public resource getResource ( )
return resource

File stream resource.

                public function getResource()
{
    if ($this->_resource === null) {
        $this->_resource = $this->toResource();
    }
    return $this->_resource;
}

            
getSize() public method

Returns the size of the associated file.

public integer getSize ( )
return integer

File size.

                public function getSize()
{
    $document = $this->getDocument();
    return isset($document['length']) ? $document['length'] : 0;
}

            
setDocument() public method

Sets data of the document to be downloaded.

Document can be specified by its ID, in this case its data will be fetched automatically via extra query.

public void setDocument ( $document )
$document array|\MongoDB\BSON\ObjectID

Document raw data or document ID.

                public function setDocument($document)
{
    $this->_document = $document;
}

            
substr() public method

Return part of a file.

public string|false substr ( $start, $length )
$start integer

Reading start position. If non-negative, the returned string will start at the start'th position in file, counting from zero. If negative, the returned string will start at the start'th character from the end of file.

$length integer

Number of bytes to read. If given and is positive, the string returned will contain at most length characters beginning from start (depending on the length of file). If given and is negative, then that many characters will be omitted from the end of file (after the start position has been calculated when a start is negative).

return string|false

The extracted part of file or false on failure

                public function substr($start, $length)
{
    $document = $this->getDocument();
    if ($start < 0) {
        $start = max($document['length'] + $start, 0);
    }
    if ($start > $document['length']) {
        return false;
    }
    if ($length < 0) {
        $length = $document['length'] - $start + $length;
        if ($length < 0) {
            return false;
        }
    }
    $chunkSize = $document['chunkSize'];
    $startChunkNumber = floor($start / $chunkSize);
    $chunkIterator = $this->getChunkIterator();
    if (!$chunkIterator->valid()) {
        // invalid iterator state - recreate iterator
        // unable to use `rewind` due to error "Cursors cannot rewind after starting iteration"
        $chunkIterator = $this->getChunkIterator(true);
    }
    if ($chunkIterator->key() > $startChunkNumber) {
        // unable to go back by iterator
        // unable to use `rewind` due to error "Cursors cannot rewind after starting iteration"
        $chunkIterator = $this->getChunkIterator(true);
    }
    $result = '';
    $chunkDataOffset = $start - $startChunkNumber * $chunkSize;
    while ($chunkIterator->valid()) {
        if ($chunkIterator->key() >= $startChunkNumber) {
            $chunk = $chunkIterator->current();
            $data = $chunk['data']->getData();
            $readLength = min($chunkSize - $chunkDataOffset, $length);
            $result .= StringHelper::byteSubstr($data, $chunkDataOffset, $readLength);
            $length -= $readLength;
            if ($length <= 0) {
                break;
            }
            $chunkDataOffset = 0;
        }
        $chunkIterator->next();
    }
    return $result;
}

            
toFile() public method

Saves download to the physical file.

public integer toFile ( $filename )
$filename string

Name of the physical file.

return integer

Number of written bytes.

                public function toFile($filename)
{
    $filename = Yii::getAlias($filename);
    FileHelper::createDirectory(dirname($filename));
    return $this->toStream(fopen($filename, 'w+'));
}

            
toResource() public method

Returns an opened stream resource, which can be used to read file.

Note: each invocation of this method will create new file resource.

public resource toResource ( )
return resource

Stream resource.

                public function toResource()
{
    $protocol = $this->collection->database->connection->registerFileStreamWrapper();
    $context = stream_context_create([
        $protocol => [
            'download' => $this,
        ]
    ]);
    $document = $this->getDocument();
    $url = "{$protocol}://{$this->collection->database->name}.{$this->collection->prefix}?_id={$document['_id']}";
    return fopen($url, 'r', false, $context);
}

            
toStream() public method

Saves file into the given stream.

public integer toStream ( $stream )
$stream resource

Stream, which file should be saved to.

return integer

Number of written bytes.

                public function toStream($stream)
{
    $bytesWritten = 0;
    foreach ($this->getChunkCursor() as $chunk) {
        $bytesWritten += fwrite($stream, $chunk['data']->getData());
    }
    return $bytesWritten;
}

            
toString() public method

Returns a string of the bytes in the associated file.

public string toString ( )
return string

File content.

                public function toString()
{
    $result = '';
    foreach ($this->getChunkCursor() as $chunk) {
        $result .= $chunk['data']->getData();
    }
    return $result;
}

            
write() public method

Alias of toFile() method.

public integer write ( $filename )
$filename string

Name of the physical file.

return integer

Number of written bytes.

                public function write($filename)
{
    return $this->toFile($filename);
}