markguinn / silverstripe-cloudassets

code/CloudFileExtension.php

<?php
/**
 * This is added to all File objects for shared functionality.
 *
 * @author Mark Guinn <mark@adaircreative.com>
 * @date 01.10.2014
 * @package cloudassets
 */
class CloudFileExtension extends DataExtension
{
    private static $db = array(
        'CloudStatus'   => "Enum('Local,Live,Error','Local')",
        'CloudSize'     => 'Int',
        'CloudMetaJson' => 'Text',      // saves any bucket or file-type specific information
    );

    /** @var File|CloudFileExtension */
    protected $owner;

    private $inUpdate = false;


    /**
     * Handle renames
     */
    public function onBeforeWrite()
    {
        $bucket = CloudAssets::inst()->map($this->owner->getFilename());
        if ($bucket) {
            if (!$this->owner->isChanged('Filename')) {
                return;
            }

            $changedFields = $this->owner->getChangedFields();
            $pathBefore = $changedFields['Filename']['before'];
            $pathAfter = $changedFields['Filename']['after'];

            // If the file or folder didn't exist before, don't rename - its created
            if (!$pathBefore) {
                return;
            }

            // Tell the remote to rename the file (or delete and recreate or whatever)
            if ($this->owner->hasMethod('onBeforeCloudRename')) {
                $this->owner->onBeforeCloudRename($pathBefore, $pathAfter);
            }
            CloudAssets::inst()->getLogger()->info("CloudAssets: Renaming $pathBefore to $pathAfter");
            $bucket->rename($this->owner, $pathBefore, $pathAfter);
            if ($this->owner->hasMethod('onAfterCloudRename')) {
                $this->owner->onAfterCloudRename($pathBefore, $pathAfter);
            }
        }
    }


    /**
     * Update cloud status any time the file is written
     */
    public function onAfterWrite()
    {
        $this->updateCloudStatus();
    }


    /**
     * Delete the file from the cloud (if it was ever there)
     */
    public function onAfterDelete()
    {
        $bucket = CloudAssets::inst()->map($this->owner->getFilename());
        if ($bucket && !Config::inst()->get('CloudAssets', 'uploads_disabled')) {
            if ($this->owner->hasMethod('onBeforeCloudDelete')) {
                $this->owner->onBeforeCloudDelete();
            }

            try {
                CloudAssets::inst()->getLogger()->info("CloudAssets: deleting {$this->owner->getFilename()}");
                $bucket->delete($this->owner);
            } catch (Exception $e) {
                CloudAssets::inst()->getLogger()->error("CloudAssets: Failed bucket delete: " . $e->getMessage() . " for " . $this->owner->getFullPath());
            }

            if ($this->owner->hasMethod('onAfterCloudDelete')) {
                $this->owner->onAfterCloudDelete();
            }
        }
    }


    /**
     * Performs two functions:
     * 1. Wraps this object in CloudFile (etc) by changing the classname if it should be and is not
     * 2. Uploads the file to the cloud storage if it doesn't contain the placeholder
     *
     * @return File
     */
    public function updateCloudStatus()
    {
        if ($this->inUpdate) {
            return;
        }
        $this->inUpdate = true;
        $cloud  = CloudAssets::inst();

        // does this file fall under a cloud bucket?
        $bucket = $cloud->map($this->owner->getFilename());
        if ($bucket) {
            // does this file need to be wrapped?
            $wrapClass = $cloud->getWrapperClass($this->owner->ClassName);
            if (!empty($wrapClass)) {
                if ($wrapClass != $this->owner->ClassName) {
                    $cloud->getLogger()->debug("CloudAssets: wrapping {$this->owner->ClassName} to $wrapClass. ID={$this->owner->ID}");
                    $this->owner->ClassName = $wrapClass;
                    $this->owner->write();
                    $wrapped = DataObject::get($wrapClass)->byID($this->owner->ID);
                    if ($wrapped->hasMethod('onAfterCloudWrap')) {
                        $wrapped->onAfterCloudWrap();
                    }
                } else {
                    $wrapped = $this->owner;
                }

                // does this file need to be uploaded to storage?
                if ($wrapped->canBeInCloud() && $wrapped->isCloudPutNeeded() && !Config::inst()->get('CloudAssets', 'uploads_disabled')) {
                    try {
                        if ($wrapped->hasMethod('onBeforeCloudPut')) {
                            $wrapped->onBeforeCloudPut();
                        }
                        $cloud->getLogger()->debug("CloudAssets: uploading file ".$wrapped->getFilename());
                        $bucket->put($wrapped);

                        $wrapped->setCloudMeta('LastPut', time());
                        $wrapped->CloudStatus = 'Live';
                        $wrapped->CloudSize   = filesize($this->owner->getFullPath());
                        $wrapped->write();

                        $wrapped->convertToPlaceholder();
                        if ($wrapped->hasMethod('onAfterCloudPut')) {
                            $wrapped->onAfterCloudPut();
                        }
                    } catch (Exception $e) {
                        $wrapped->CloudStatus = 'Error';
                        $wrapped->write();
                        $cloud->getLogger()->error("CloudAssets: Failed bucket upload: " . $e->getMessage() . " for " . $wrapped->getFullPath());
                        // Fail silently for now. This will cause the local copy to be served.
                    }
                } elseif ($wrapped->CloudStatus !== 'Live' && $wrapped->containsPlaceholder()) {
                    // If this is a duplicate file, update the status
                    // This shouldn't happen ever and won't happen often but when it does this will be helpful
                    $dup = File::get()->filter(array(
                        'Filename'      => $wrapped->Filename,
                        'CloudStatus'   => 'Live',
                    ))->first();

                    if ($dup && $dup->exists()) {
                        $cloud->getLogger()->warn("CloudAssets: fixing status for duplicate file: {$wrapped->ID} and {$dup->ID}");
                        $wrapped->CloudStatus   = $dup->CloudStatus;
                        $wrapped->CloudSize     = $dup->CloudSize;
                        $wrapped->CloudMetaJson = $dup->CloudMetaJson;
                        $wrapped->write();
                    }
                }

                $this->inUpdate = false;
                return $wrapped;
            }
        }

        $this->inUpdate = false;
        return $this->owner;
    }


    /**
     * @return bool
     */
    public function canBeInCloud()
    {
        if ($this->owner instanceof Folder) {
            return false;
        }
        if (!file_exists($this->owner->getFullPath())) {
            return false;
        }
        return true;
    }


    /**
     * @return bool
     */
    public function containsPlaceholder()
    {
        $placeholder = Config::inst()->get('CloudAssets', 'file_placeholder');
        $path = $this->owner->getFullPath();

        // check the size first to avoid reading crazy huge files into memory
        return (file_exists($path) && filesize($path) == strlen($placeholder) && file_get_contents($path) == $placeholder);
    }


    /**
     * Wipes out the contents of this file and replaces with placeholder text
     */
    public function convertToPlaceholder()
    {
        $bucket = $this->getCloudBucket();
        if ($bucket && !$bucket->isLocalCopyEnabled()) {
            $path = $this->owner->getFullPath();
            CloudAssets::inst()->getLogger()->debug("CloudAssets: converting $path to placeholder");
            Filesystem::makeFolder(dirname($path));
            file_put_contents($path, Config::inst()->get('CloudAssets', 'file_placeholder'));
            clearstatcache();
        }

        return $this->owner;
    }


    /**
     * @return CloudBucket
     */
    public function getCloudBucket()
    {
        return CloudAssets::inst()->map($this->owner);
    }


    /**
     * @param int $linkType [optional] - see CloudBucket::LINK_XXX constants
     * @return string
     */
    public function getCloudURL($linkType = CloudBucket::LINK_SMART)
    {
        $bucket = $this->getCloudBucket();
        return $bucket ? $bucket->getLinkFor($this->owner, $linkType) : '';
    }


    /**
     * @param string $key [optional] - if not present returns the whole array
     * @return array
     */
    public function getCloudMeta($key = null)
    {
        $data = json_decode($this->owner->CloudMetaJson, true);
        if (empty($data) || !is_array($data)) {
            $data = array();
        }

        if (!empty($key)) {
            return isset($data[$key]) ? $data[$key] : null;
        } else {
            return $data;
        }
    }


    /**
     * @param string|array $key - passing an array as the first argument replaces the meta data entirely
     * @param mixed        $val
     * @return File - chainable
     */
    public function setCloudMeta($key, $val = null)
    {
        if (is_array($key)) {
            $data = $key;
        } else {
            $data = $this->getCloudMeta();
            $data[$key] = $val;
        }

        $this->owner->CloudMetaJson = json_encode($data);
        return $this->owner;
    }


    /**
     * If this file is stored in the cloud, downloads the cloud
     * copy and replaces whatever is local.
     */
    public function downloadFromCloud()
    {
        if ($this->owner->CloudStatus === 'Live') {
            $bucket   = $this->owner->getCloudBucket();
            if ($bucket) {
                $contents = $bucket->getContents($this->owner);
                $path     = $this->owner->getFullPath();
                Filesystem::makeFolder(dirname($path));
                CloudAssets::inst()->getLogger()->debug("CloudAssets: downloading $path from cloud (size=".strlen($contents).")");
                // if there was an error and we overwrote the local file with empty or null, it could delete the remote
                // file as well. Better to err on the side of not writing locally when we should than that.
                if (!empty($contents)) {
                    file_put_contents($path, $contents);
                }
            }
        }
    }


    /**
     * If the file is present in the database and the cloud but not
     * locally, create a placeholder for it. This can happen in a lot
     * of cases such as load balanced servers and local development.
     */
    public function createLocalIfNeeded()
    {
        if ($this->owner->CloudStatus === 'Live') {
            $bucket = $this->getCloudBucket();
            if ($bucket && $bucket->isLocalCopyEnabled()) {
                if (!file_exists($this->owner->getFullPath()) || $this->containsPlaceholder()) {
                    try {
                        $this->downloadFromCloud();
                    } catch (Exception $e) {
                        // I'm not sure what the correct behaviour is here
                        // Pretty sure it'd be better to have a broken image
                        // link than a 500 error though.
                        CloudAssets::inst()->getLogger()->error("CloudAssets: Failed bucket download: " . $e->getMessage() . " for " . $this->owner->getFullPath());
                    }
                }
            } else {
                if (!file_exists($this->owner->getFullPath())) {
                    $this->convertToPlaceholder();
                }
            }
        }
    }


    /**
     * @return bool
     */
    public function isCloudPutNeeded()
    {
        // we never want to upload the placeholder
        if ($this->containsPlaceholder()) {
            return false;
        }

        // we never want to upload an empty file
        $path = $this->owner->getFullPath();
        if (!file_exists($path)) {
            return false;
        }

        // we always want to upload if it's the first time
        $lastPut = $this->getCloudMeta('LastPut');
        if (!$lastPut) {

The expression $lastPut of type array is implicitly converted to a boolean; are you sure this is intended? If so, consider using empty($expr) instead to make it clear that you intend to check for an array without elements.

            return true;
        }

        // additionally, we want to upload if the file has been changed or replaced
        $mtime = filemtime($path);
        if ($mtime > $lastPut) {
            return true;
        }

        return false;
    }


    /**
     * Returns true if the local file is not available
     * @return bool
     */
    public function isLocalMissing()
    {
        return !file_exists($this->owner->getFullPath()) || $this->containsPlaceholder();
    }
}