Registry

A tiny, dependency-injection-friendly in-memory registry with per-key locks and a global freeze switch.

Designed as a safer alternative to ad-hoc globals for configuration, runtime state, and bootstrapping data in PHP applications.

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Features

• Simple in-memory key/value storage
• Per-key lock flags to prevent specific mutations
• Global freeze to make the registry fully read-only after boot
• Clean interface for DI containers and frameworks
• Zero dependencies, tiny footprint

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Installation

composer require tlmcclatchey/registry

Requires PHP 8.4+.

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Quick Start

use TLMcClatchey\Registry\MemoryRegistry;

$registry = new MemoryRegistry();

// define keys
$registry->define('config', array: true);
$registry->assign('config', 'env', 'prod');

// set scalar value
$registry->set('debug', false);

// freeze registry after boot
$registry->freeze();

// reads still work
$env = $registry->get('config')['env'];

After calling freeze(), all mutation operations throw.

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Core Concepts

1. Keys

A key may contain:

• scalar value (int|string|bool|float|null)
• array value (for map/list-style storage)

$registry->set('version', '1.0.0');
$registry->define('services', array: true);

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2. Assigning Array Values

$registry->assign('services', 'cache', 'redis');
$registry->assign('services', 'queue', 'sqs');

Check existence:

$registry->isAssigned('services', 'cache'); // true

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3. Lock Flags

Each key can prevent specific mutations.

Flag	Prevents
NO_SET	overwriting the whole value
NO_APPEND	appending to arrays
NO_PREPEND	prepending to arrays
NO_ASSIGN	assigning subkeys
NO_UNASSIGN	removing subkeys
NO_CLEAR	removing the key entirely

Convenience presets:

RegistryLocks::READONLY
RegistryLocks::READ_MODIFY

Example:

use TLMcClatchey\Registry\RegistryLocks;

$registry->define('config', lock: RegistryLocks::READONLY, array: true);

// any mutation now throws RegistryException

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4. Global Freeze

Freeze the entire registry once bootstrapping is complete:

$registry->freeze();

After freezing:

• All mutation methods throw RegistryException
• Read operations continue working

Perfect for:

• application boot phases
• compiled container configs
• immutable runtime state

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API Overview

Read

$registry->get(string $key, mixed $default = null);
$registry->has(string $key);
$registry->all();
$registry->keys();

Write

$registry->define(string $key, int $lock = 0, bool $array = false);
$registry->set(string $key, mixed $value, int $lock = 0);
$registry->clear(string $key);

Array Operations

$registry->assign(string $key, string $subkey, scalar|null $value);
$registry->unassign(string $key, string $subkey);
$registry->prepend(string $key, scalar|null $value);
$registry->append(string $key, scalar|null $value);

Lifecycle

$registry->freeze();
$registry->isFrozen();

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When to Use This

Good fit:

• boot configuration storage
• DI container build phase
• runtime feature flags
• small framework kernels
• CLI app state

Not intended for:

• persistence
• cross-request storage
• caching layers
• large datasets

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Philosophy

This library exists for one reason:

Sometimes you do need global state. You just don’t need chaos.

So instead of banning globals, this gives you:

• rules
• immutability after boot
• predictable failure

Like a registry… but with adult supervision.

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License

See the LICENSE.md file for full details.