PHPLIB-154: implement downloadByName

src/GridFS/Bucket.php

@@ -171,4 +171,19 @@ class Bucket
             'projection' => ['_id' => 1],
         ]);
     }
+    public function findFileRevision($filename, $revision)
+    {
+        if ($revision < 0) {
+            $skip = abs($revision) -1;
+            $sortOrder = -1;
+        } else {
+            $skip = $revision;
+            $sortOrder = 1;
+        }
+        $file = $this->filesCollection->findOne(["filename"=> $filename], ["sort" => ["uploadDate"=> $sortOrder], "limit"=>1, "skip" => $skip]);
+        if(is_null($file)) {
+            throw new \MongoDB\Exception\GridFSFileNotFoundException($filename, $this->getBucketName(), $this->getDatabaseName());;
+        }
+        return $file;
+    }
 }

src/GridFS/BucketReadWriter.php

@@ -84,4 +84,33 @@ class BucketReadWriter
 
         $this->bucket->getFilesCollection()->deleteOne(['_id' => $id], $options);
     }
+    /**
+    * Open a stream to download a file from the GridFS bucket. Searches for the file by the specified name then returns a stream to the specified file
+    * @param string    $filename     name of the file to download
+    * @param int       $revision     the revision of the file to download
+    * @throws GridFSFileNotFoundException
+    */
+    public function openDownloadStreamByName($filename, $revision = -1)
+    {
+        $file = $this->bucket->findFileRevision($filename, $revision);
+        $options = ['bucket' => $this->bucket,
+                    'file' => $file
+                ];
+        $context = stream_context_create(['gridfs' => $options]);
+        return fopen(sprintf('gridfs://%s/%s', $this->bucket->getDatabaseName(), $filename), 'r', false, $context);
+    }
+    /**
+    * Download a file from the GridFS bucket by name. Searches for the file by the specified name then loads data into the stream
+    *
+    * @param string    $filename     name of the file to download
+    * @param int       $revision     the revision of the file to download
+    * @throws GridFSFileNotFoundException
+    */
+    public function downloadToStreamByName($filename, $destination, $revision=-1)
+    {
+        $file = $this->bucket->findFileRevision($filename, $revision);
+        $gridFsStream = new GridFsDownload($this->bucket, null, $file);
+        $gridFsStream->downloadToStream($destination);
+    }
+
 }

src/GridFS/GridFsDownload.php

@@ -40,12 +40,17 @@ class GridFsDownload extends GridFsStream
      */
     public function __construct(
         Bucket $bucket,
-        ObjectId $objectId
+        $objectId,
+        $file = null
         )
     {
-        $this->file = $bucket->getFilesCollection()->findOne(['_id' => $objectId]);
-        if (is_null($this->file)) {
-          throw new \MongoDB\Exception\GridFSFileNotFoundException($objectId, $bucket->getBucketName(), $bucket->getDatabaseName());
+        if(!is_null($file)) {
+            $this->file = $file;
+        } else {
+            $this->file = $bucket->getFilesCollection()->findOne(['_id' => $objectId]);
+            if (is_null($this->file)) {
+              throw new \MongoDB\Exception\GridFSFileNotFoundException($objectId, $bucket->getBucketName(), $bucket->getDatabaseName());
+            }
         }
         if ($this->file->length > 0) {
             $cursor = $bucket->getChunksCollection()->find(['files_id' => $this->file->_id], ['sort' => ['n' => 1]]);

src/GridFS/StreamWrapper.php

@@ -72,9 +72,15 @@ class StreamWrapper
         $this->gridFsStream = new GridFsUpload($this->bucket, $this->identifier, $options);
         return true;
     }
+
     public function openReadStream() {
-        $objectId = new \MongoDB\BSON\ObjectId($this->identifier);
-        $this->gridFsStream = new GridFsDownload($this->bucket, $objectId);
+        $context = stream_context_get_options($this->context);
+        if(isset($context['gridfs']['file'])){
+            $this->gridFsStream = new GridFsDownload($this->bucket, null, $context['gridfs']['file']);
+        } else {
+            $objectId = new \MongoDB\BSON\ObjectId($this->identifier);
+            $this->gridFsStream = new GridFsDownload($this->bucket, $objectId);
+        }
         return true;
     }
 }

tests/GridFS/SpecificationTests.php

@@ -91,7 +91,7 @@ class SpecificationTests extends FunctionalTestCase
 
     public function provideSpecificationTests()
     {
-        $testPath=getcwd().'/tests/GridFS/Specification/tests/delete.json';
+        $testPath=getcwd().'/tests/GridFS/Specification/tests/download_by_name.json';
 
         $testArgs = [];
         foreach(glob($testPath) as $filename) {
@@ -237,6 +237,19 @@ class SpecificationTests extends FunctionalTestCase
     }
     function download_by_nameCommand($args)
     {
+        $args = $this->fixTypes($args, false);
+        $streamWrapper = new \MongoDB\GridFS\StreamWrapper();
+        $streamWrapper->register($this->manager);
+        $stream = fopen('php://temp', 'w+');
+        if(isset($args['options']['revision'])) {
+            $this->bucketReadWriter->downloadToStreamByName($args['filename'], $stream, $args['options']['revision']);
+        } else {
+            $this->bucketReadWriter->downloadToStreamByName($args['filename'], $stream);
+        }
+        rewind($stream);
+        $result = stream_get_contents($stream);
+        fclose($stream);
+        return $result;
 
     }
 }