Stale Cache File Purge Plan

Code

<?php

/*
 * Copyright (c) 2026 Jeffery L. Paris <jparis@phpog.com>.
 * Free for personal and internal use. Paid project use requires visible credit
 * to Jeffery L. Paris. Corporate use requires a paid license fee unless a
 * separate written license states otherwise.
 */

/**
 * Stale Cache File Purge Plan.
 *
 * Purpose:
 * Plans stale cache-file deletions by age, extension, size, and protected filename rules without deleting files.
 *
 * @param array $cache_files File rows with path, modified_at, bytes, and extension.
 * @param int $max_age_seconds Maximum allowed age in seconds.
 * @return array Purge plan without deleting files.
 */
function ogSnippetStaleCacheFilePurgePlan(array $cache_files, int $max_age_seconds): array {
	$now = time();
	$plan = array('purge' => array(), 'keep' => array());
	foreach ($cache_files as $file_row) {
		$path = (string) $file_row['path'];
		$modified_at = (int) $file_row['modified_at'];
		$extension = strtolower((string) $file_row['extension']);
		$age = $now - $modified_at;
		$protected = false;
		if (strpos($path, '.htaccess') !== false || strpos($path, 'index.html') !== false) {
			$protected = true;
		}
		if ($age > $max_age_seconds && $extension === 'cache' && $protected === false) {
			$plan['purge'][] = array('path' => $path, 'age_seconds' => $age);
		} else {
			$plan['keep'][] = array('path' => $path, 'reason' => 'not_stale_or_protected');
		}
	}
	return $plan;
}

$cache_rows = array(array('path' => '/tmp/ring-gate.cache', 'modified_at' => time() - 90000, 'extension' => 'cache'));
$purge_plan = ogSnippetStaleCacheFilePurgePlan($cache_rows, 86400);
echo count($purge_plan['purge']);