PHP (FFI)

The PHP binding goplasmatic/datalogic uses PHP’s native FFI extension (ext-ffi) to interact with the shared C ABI. It requires PHP 8.4 or newer.

Installation

Add the Composer dependency to your project:

composer require goplasmatic/datalogic

Ensure that PHP’s FFI extension is enabled in your php.ini configuration:

extension=ffi
# For command line tools and web servers, allow FFI
ffi.enable=true

The Composer package ships with precompiled shared libraries under lib/<os>-<arch>/. The loader automatically detects and loads the library for the current platform.

Quick Start

One-Shot Evaluation

<?php

use Goplasmatic\Datalogic\Engine;

$engine = new Engine();
$result = $engine->apply('{"+": [1, 2, 3]}', '{}');
echo $result; // "6"

Reusable Compiled Rules

Always compile rules when executing them repeatedly. This parses the rule into optimized bytecode on the Rust side:

<?php

use Goplasmatic\Datalogic\Engine;

$engine = new Engine();
$rule = $engine->compile('{"if": [{ ">": [{"var": "score"}, 50] }, "pass", "fail"]}');

echo $rule->evaluate(json_encode(['score' => 75])), "\n"; // "pass"
echo $rule->evaluate(json_encode(['score' => 30])), "\n"; // "fail"

// Explicitly close resources to free native handles early
$rule->close();
$engine->close();

Arena Recycling with `Session`

To recycle memory allocations in hot loops, open a Session:

<?php

use Goplasmatic\Datalogic\Engine;

$engine = new Engine();
$rule = $engine->compile('{"var": "user.name"}');

$session = $engine->openSession();
foreach ($dataset as $input) {
    // Reuses the session's internal memory arena
    $name = $session->evaluate($rule, $input);
    echo $name, "\n";
}

$session->close();
$rule->close();
$engine->close();

In PHP, FFI-allocated memory is released when wrapper objects go out of scope and are collected by the PHP engine. However, in long-running environments (such as PHP-FPM, Swoole, RoadRunner, or CLI daemons), garbage collection delays can accumulate heap usage.

To guarantee immediate cleanup, call $object->close() explicitly on the Engine, Rule, or Session wrappers.

Going deeper

C ABI internals: memory management & thread safety — the native-heap ownership rules every FFI binding shares
Engine configuration semantics
Package README on Packagist — full API surface, error types, and platform table

datalogic-rs Documentation