Flysystem Adapter for Migration.

This adapter's use is for a scenario where you have a long running process of copying content from a source data store to a destination data store. To keep things simple you will copy via rsync mechanism -- which will copy a file from source to destination when the file does not exist in the destination or the last updated time of the destination file is less than the last updated time of the source file.

In order to make use of your new storage mechanism and to prevent migration issues, you want your application to follow these rules:

• Content that has been copied to the destination data store should be served from the destination data store.
• Content that has not yet been copied over should be served from the source data store.
• New content should be written directly to the destination data store.
• Updates should be applied to the destination data store file (if it exists) OR the source data store file.
• Renames should be applied to the destination data store file (if it exists) AND the source data store file.
• Deletes should be applied to the destination data store file (if it exists) AND the source data store file.

Behavior Documentation

The following use case scenario documents actions against the filesystem and the expected results.

Scenario setup

Each of the file system actions listed below will be performed against this example setup:

  # directory structure
  source/
    fileA.txt
    fileB.txt
  dest/
    fileB.txt
  
  # content of fileA.txt
  hello
  # content of fileB.txt
  fizzbuzz

$filesystem = new MigrateAdapter(new Local('source/'), new Local('dest/'));

write

$filesystem->write('fileC.txt', 'hello');

Creates the file dest/fileC.txt with the content hello.

update

$filesystem->update('fileA.txt', 'world');

Appends the file source/fileA.txt with the content world.

$filesystem->update('fileB.txt', 'bar');

Appends the file dest/fileB.txt with the content bar.

read

$filesystem->read('fileB.txt');

Returns dest/fileB.txt content.

$filesystem->read('fileA.txt');

Returns source/fileA.txt content.

copy

$filesystem->copy('fileA.txt', 'fileD.txt');

Copies the file source/fileA.txt to source/fileD.txt.

$filesystem->copy('fileB.txt', 'fileD.txt');

Copies the file dest/fileB.txt to dest/fileD.txt.

rename

$filesystem->rename('fileA.txt', 'fileE.txt');

Renames the file source/fileA.txt to source/fileE.txt.

$filesystem->rename('fileB.txt', 'fileE.txt');

Renames the file dest/fileB.txt to dest/fileE.txt.

delete

$filesystem->delete('fileA.txt');

Deletes the file source/fileA.txt.

$filesystem->delete('fileB.txt');

Deletes the file dest/fileB.txt and source/fileB.txt.

Installation

composer require WebPT/flysystem-migrate-adapter

Usage

$source = new League\Flysystem\Adapter\Local(...);
$replica = new League\Flysystem\Adapter\AwsS3(...);
$adapter = new WebPT\Flysystem\Migrate\MigrateAdapter($source, $replica);