README

sacred/flysystem-lazy-migration-adapter provides a small Flysystem adapter wrapper that moves files from an old adapter to a new one the first time they are accessed. Reads, writes, deletes, and metadata calls automatically migrate the underlying file so you can cut over storage backends without a coordinated bulk move.

Installation

composer require sacred/flysystem-lazy-migration-adapter

Supports PHP 7.4+ and both Flysystem v2 and v3 (league/flysystem ^2.0 || ^3.0).

Usage

Wrap your existing adapters and start using the wrapper everywhere you would normally use a FilesystemAdapter. Files encountered on the old adapter will be copied to the new one and removed from the old location on first access.

use Sacred\Flysystem\LazyMigrationAdapter;
use League\Flysystem\Filesystem;
use League\Flysystem\Local\LocalFilesystemAdapter;

$oldAdapter = new LocalFilesystemAdapter('/mnt/old-storage');
$newAdapter = new LocalFilesystemAdapter('/mnt/new-storage');

$migratingAdapter = new LazyMigrationAdapter($oldAdapter, $newAdapter);
$filesystem = new Filesystem($migratingAdapter);

// The first read migrates the file to the new adapter transparently.
$contents = $filesystem->read('path/to/file.txt');

How it works

• Each operation checks the old adapter first. If a file exists there and not on the new adapter, it is streamed over to the new adapter and deleted from the old one.
• If a file exists on both, the copy on the old adapter is removed and the new adapter is used for the operation.
• Directory creation always targets the new adapter; deletes target both when applicable.

Testing

composer install
composer test

The GitHub Actions workflow runs the test suite against Flysystem v2 on PHP 7.4+ and Flysystem v3 on PHP 8.2+.