Using PHP getimagesize and imagecreate with Google App Engine and Google Cloud Storage

Question

I want to use PHP in GAE to upload file image files.

Before storing, I want to convert each file to JPEG and reduce it to thumbnail quality.

Using the following code (which fully works in a normal PHP environment, less the bucket-specific adjustments), I am able to receive the uploads and determine the temporary file name and location, but getimagesize produces an error when attempting to access the CloudStorage.

$bucket = CloudStorageTools::getDefaultGoogleStorageBucketName();
$bucketPath = "gs://" . $bucket . "/" . $_SERVER["REQUEST_ID_HASH"] . "/";
$counter = 0;

foreach($_FILES["file"]["name"] as $idx => $tempFile) {
    $counter++;
    $sourceFile = $bucketPath . $tempFile;

    syslog(LOG_DEBUG, $sourceFile);

    $photoInfo = getimagesize($sourceFile);
    if ($photoInfo["mime"] == "image/jpeg") {
        $photoImage = imagecreatefromjpeg($sourceFile);
        $valid = true;
    }
    elseif ($photoInfo["mime"] == "image/gif") {
        $photoImage = imagecreatefromgif($sourceFile);
        $valid = true;
    }
    elseif ($photoInfo["mime"] == "image/png") {
        $photoImage = imagecreatefrompng($sourceFile);
        $valid = true;
    }

    if (isset($valid)) {
        $date = date("Y-m-d H:i:s");

        $photoFolder = rtrim($photoFolder, "/") . "/";
        $photoFile = "Test {$counter} {$date}.jpg";

        $imageSaved = imagejpeg($photoImage, $photoFolder.$photoFile, 50);

        syslog(LOG_DEBUG, "File saved is " . $imageSaved);
    }
}

The first syslog entry confirms the file path and name...

gs://[myappid].appspot.com/AC3E3530/IMG_20160701_120144.jpg

The error log shows an error in attempting to open the stream, but I don't know how to address it.

PHP Warning:  getimagesize(gs://[myappid].appspot.com/AC3E3530/IMG_20160701_120144.jpg): failed to open stream: "\google\appengine\ext\cloud_storage_streams\CloudStorageStreamWrapper::stream_open" call failed in /base/data/home/apps/s~[myappid]/v1.394746390020376247/code/server.php on line 169

---

I already have a variation of this functionality working on GAE with photos that my server receives through Twilio (where processPhoto() is a function identical to the code I excerpted above). In this case, I'm using getimagesize and imagecreate with a URL. I just don't know how to do the same with CloudStorage.

if ($fetch && $numMedia > 0) {
    for ($x = 0; $x < $numMedia; $x++) {
        $sourceFile = $_REQUEST["MediaUrl" . $x];
        $sid = $_REQUEST["MessageSid"];
        processPhoto("sms", $projectID, $sourceFile, $caption, $sid, $mobile, $message);
    }
}

Answer 1

I think the problem was that the temporary file was removed before I could process it. So, I...

1. Removed the functionality of processing multiple files (which I didn't need anyhow).
2. Immediately move the file to another bucket.
3. Examine the file for its type.
4. Save it as desired.
5. Remove the temporary file.

---

This is the form that I generate in PHP. There's no Submit button because I watch for a file change with jQuery.

<form id='form_uploadPhotos' method='post' enctype='multipart/form-data' action='{$websiteURL}?action=uploadPhotos'>
    <input type='file' id='input_uploadPhoto' name='file'>
    <input type='hidden' name='projectID' value='{$projectID}'>
</form>

---

This is the uploadPhotos function that's called when the form is submitted:

if ($action == "uploadPhotos") {
    $projectID = preg_replace("/\D/", "", $_REQUEST["projectID"]);

    $bucket = CloudStorageTools::getDefaultGoogleStorageBucketName();
    $bucketPath = "gs://" . $bucket . "/" . $_SERVER["REQUEST_ID_HASH"] . "/";

    $date = date("Y-m-d H:i:s");
    $time = time();

    $photoFile = sprintf("%08d", $projectID) . "." . $date . "." . $time . ".TEMP";
    $sourceFile = $photoFolder.$photoFile; // The default photo folder is defined elsewhere.

    move_uploaded_file($_FILES["file"]["tmp_name"], $sourceFile);
    processPhoto("upload", $projectID, $sourceFile, null, null, null, null);
}

---

This is the function that processes the photo. It's called by other processes that also receive photos (eg, SMS attachments via Twilio).

function processPhoto($via, $projectID, $sourceFile, $caption, $twilioMessageID, $smsMobile, $smsMessage) {
    global $photoFolder;

    $photoInfo = getimagesize($sourceFile);
    if ($photoInfo["mime"] == "image/jpeg") {
        $photoImage = imagecreatefromjpeg($sourceFile);
        $valid = true;
    }
    elseif ($photoInfo["mime"] == "image/gif") {
        $photoImage = imagecreatefromgif($sourceFile);
        $valid = true;
    }
    elseif ($photoInfo["mime"] == "image/png") {
        $photoImage = imagecreatefrompng($sourceFile);
        $valid = true;
    }

    if (isset($valid)) {
        $date = date("Y-m-d H:i:s");
        $time = time();
        $photoFile = sprintf("%08d", $projectID) . "." . $date . "." . $time . ".JPEG";

        $photoImage = imagecreatefromjpeg($sourceFile);
        list($width, $height) = getimagesize($sourceFile);
        if (max($width, $height) > 800) {
            $scale = 800/max($width, $height);
            $newWidth = floor($width * $scale);
            $newHeight = floor($height * $scale);
            $saveImage = imagecreatetruecolor($newWidth, $newHeight);
            imagecopyresampled($saveImage, $photoImage, 0, 0, 0, 0, $newWidth, $newHeight, $width, $height);
        }

        $imageSaved = imagejpeg($photoImage, $photoFolder.$photoFile);
        imagedestroy($photoImage);

        if ($imageSaved) {
            if (isset($twilioMessageID)) {
                $twilioMediaID = substr($sourceFile, strrpos($sourceFile, "/") + 1);
                purgeTwilioMedia($twilioMessageID, $twilioMediaID);
            }
            elseif (substr($sourceFile, strrpos($sourceFile, ".")) == ".TEMP") {
                unlink($sourceFile);
            }

            <Additional processing (e.g., adding entry to database.)
            .
            .
            .
        }
    }
}

Note: The image scaling code between "list($width, $height..." and "imagecopyresampled..." is based on Dano's answer to another question.

Answer 2

我猜想您遇到了标准环境的限制，即标准运行时中的getimagesize本机函数不适用于文件扩展名，例如gs:// URL。