README

This library makes it easy to write files to S3 with high availability. It includes the following features:

• Upload an S3 file to the first successful file location.
• Download an S3 file that is available in multiple file locations.

Usage

The APIs require you to pass in an \Aws\Sdk object. In the examples below, $awsSdk is used for this object.

Uploading a File

1. Create a list of available upload locations.
   • This is an S3AvailableUploadFileBucketAndKeyLocations object.
   • You can add anything that implements S3FileBucketAndKeyProviderInterface to the list of locations.
   • The simplest option is to use S3FileBucketAndKey, which implements this interface.
2. Set up S3UploadFileMetadata with metadata for the file to be uploaded.
3. Create an AwsHighAvailabilityS3Uploader object and call uploadFileToS3.
   • You can configure the uploader with an AwsHighAvailabilityS3UploaderErrorHandlerInterface to customize handling of failures. For example, you might want to use it to log the exception or you can throw an exception if you want to stop attempted alternative locations.

// Set up possible locations
$primaryLocation = new S3FileBucketAndKey('us-east-1', 'phpunit-test-us-east-1', 'us-east-1/path/to/file.txt');
$backupLocation = new S3FileBucketAndKey('us-west-1', 'phpunit-test-us-west-1', 'us-west-1/path/to/file.txt');
$locations = new S3AvailableUploadFileBucketAndKeyLocations($primaryLocation);
$locations->addAlternativeLocation($backupLocation);

// Set up meta data
$metadata = new S3UploadFileMetadata();

// Upload
$s3Uploader = new AwsHighAvailabilityS3Uploader($awsSdk);
$finalLocation = $s3Uploader->uploadFileToS3($locations, 'File contents.', 'text/plain', $metadata);

Downloading a File

1. Create a list of available download locations.
   • This is an S3AvailableDownloadFileBucketAndKeyLocations object.
   • You can add anything that implements S3FileBucketAndKeyProviderInterface to the list of locations.
   • The simplest option is to use S3FileBucketAndKey, which implements this interface.
2. Create an AwsHighAvailabilityS3Downloader object and call downloadFileFromS3.
   • You can configure the downloader with an AwsHighAvailabilityS3DownloaderErrorHandlerInterface to customize handling of failures. For example, you might want to use it to log the exception or you can throw an exception if you want to stop attempted alternative locations.

// Set up possible locations
$primaryLocation = new S3FileBucketAndKey('us-east-1', 'phpunit-test-us-east-1', 'us-east-1/path/to/file.txt');
$backupLocation = new S3FileBucketAndKey('us-west-1', 'phpunit-test-us-west-1', 'us-west-1/path/to/file.txt');
$locations = new S3AvailableDownloadFileBucketAndKeyLocations($primaryLocation);
$locations->addAlternativeLocation($backupLocation);

// Download
$s3Downloader = new AwsHighAvailabilityS3Downloader($awsSdk);
$contents = $s3Downloader->downloadFileFromS3($locations);

S3UploadFileMetadata Options

The S3UploadFileMetadata class allows you to customize the following:

• S3 storage class.
• S3 ACL (public vs private).
• Cache TTL for public objects.