vertilia/filesystem

Filesystem helpers

v1.0.1 2021-11-18 22:54 UTC

Requires (Dev)

• phpunit/phpunit: ^9.5

BSD-2-Clause

README

Filesystem helpers implementing useful functionality.

Usage

• normalizePath()

Converts path to its canonical form, removes leading and trailing slashes(/).

print_r(Vertilia\Filesystem\Filesystem::normalizePath('//b/../a//b/c/./d//'));
// outputs: 'a/b/c/d'

• syncSymlinkDir()

Given the external symlink and local symlink, compares symlink targets and if different, copies external folder to local folder and switches local symlink. Handles local symlink TTL, uses lock file to manage race conditions under heavy load in multi-process environments.

The following example describes a folder on a shared ressource with the latest file structure that needs to be mirrored to local filesystems. Every host is responsible for maintaining the local copy of external ressource locally. Current release is identified by the current symlink inside the release folder.

• on shared ressource

/shared/release
├── v1.0.0
│   ├── file1.txt
│   ├── file2.txt
│   └── file3.txt
├── v1.0.1
│   ├── file1.txt
│   ├── file2.txt
│   └── file3.txt
├── v1.0.2
│   ├── file1.txt
│   ├── file2.txt
│   └── file3.txt
└── current -> v1.0.2

• on every host

/local/release
├── v1.0.0
│   ├── file1.txt
│   ├── file2.txt
│   └── file3.txt
├── v1.0.1
│   ├── file1.txt
│   ├── file2.txt
│   └── file3.txt
└── current -> v1.0.1

The following snippet executed on each host will verify the freshness of current symlink in /local/release folder and if it is older than 600 seconds, will

• try to create a lock file or exit

  • if lockfile exists but is older than 60 seconds, delete the file before exiting

• verify target of current symlink in both /local/release and /shared/release

• if targets point to the same release:

  • touch local current symlink
  • delete lock file
  • exit

• else:

  • copy the contents of /shared/release/v1.0.2 to /local/release/v1.0.2
  • switch /local/release/current symlink to point to v1.0.2
  • delete lock file
  • exit

Snippet:

try {
    Vertilia\Filesystem\Filesystem::syncSymlinkDir(
        '/shared/release/current',
        '/local/release/current',
        600,
        60
    );
} catch (RuntimeException $e) {
    $logger->log($e->getMessage());
}