README

Tiny versioned key-value manager for PHP.

Concepts

Scope + ID + Key ⇒ versioned value.

Think of:

• scope – logical bucket, e.g. "user", "feature", "tenant".
• id – identifier inside scope, e.g. "123", "acme".
• key – name inside that document, e.g. "theme", "feature_x_enabled".

Example:

use rafalmasiarek\KV;
use rafalmasiarek\KV\Storage\FileStorage;

$storage = new FileStorage(__DIR__ . '/storage');
$kv = new KV($storage);

// create versions
$kv->set('user', '123', 'theme', 'dark');
$kv->set('user', '123', 'theme', 'light');

// read latest
$current = $kv->get('user', '123', 'theme'); // "light"

// list all latest values for given (scope,id)
$all = $kv->all('user', '123');

// detailed info (with history)
$info = $kv->info('user', '123', 'theme');
// [
//   'schema'          => 'v1',
//   'current_version' => 2,
//   'created_at'      => '2025-01-01T12:00:00+00:00',
//   'updated_at'      => '2025-01-02T09:00:00+00:00',
//   'history'         => [
//       '1' => ['value' => 'dark',  'created_at' => '...'],
//       '2' => ['value' => 'light', 'created_at' => '...'],
//   ],
// ]

// delete a key (all its versions)
$kv->delete('user', '123', 'theme');

// delete whole document (scope+id)
$kv->deleteDocument('user', '123');

Schema format

Internally each (scope, id) document is stored as JSON:

{
  "schema": "v1",
  "keys": {
    "theme": {
      "schema": "v1",
      "current_version": 2,
      "created_at": "2025-01-01T12:00:00+00:00",
      "updated_at": "2025-01-02T09:00:00+00:00",
      "history": {
        "1": { "value": "dark",  "created_at": "2025-01-01T12:00:00+00:00" },
        "2": { "value": "light", "created_at": "2025-01-02T09:00:00+00:00" }
      }
    }
  }
}

Schemas are managed in one place: Schema\SchemaRegistry.

• SchemaRegistry::CURRENT – currently used schema id (e.g. "v1").
• SchemaRegistry::DEFINITIONS – associative array of all supported schema versions.
• SchemaRegistry contains helpers used by KV for reading/updating documents and guarantees backwards compatibility: when you introduce "v2", old "v1" docs continue to work and can be upgraded or appended to.

To change schema:

1. Add new entry in SchemaRegistry::DEFINITIONS.
2. Update SchemaRegistry::CURRENT.
3. Implement upgrade logic inside SchemaRegistry if shape changes.

Storage backends

All backends implement Storage\StorageInterface:

interface StorageInterface
{
    public function load(string $scope, string $id): ?array;
    public function save(string $scope, string $id, array $document): void;
    public function delete(string $scope, string $id): void;
}

Included:

• FileStorage – JSON files on disk.
• RedisStorage – single key per document (kv:{scope}:{id}).
• MongoStorage – one document per (scope,id).

You can implement your own storage (e.g. SQL) by implementing this interface.

Installation

composer require rafalmasiarek/php-kv

Minimal usage

use rafalmasiarek\KV;
use rafalmasiarek\KV\Storage\FileStorage;

$kv = new KV(new FileStorage(__DIR__ . '/var/kv'));

// Set
$kv->set('app', 'flags', 'new_ui', true);

// Get
if ($kv->get('app', 'flags', 'new_ui')) {
    // ...
}