TenantAtlas/app/Services/Baselines/BaselineSnapshotIdentity.php

60 lines
1.7 KiB
PHP

<?php
declare(strict_types=1);
namespace App\Services\Baselines;
use App\Services\Drift\DriftHasher;
/**
* Computes the snapshot_identity_hash for baseline snapshot content dedupe.
*
* The identity hash is a sha256 over normalized snapshot items, enabling
* detection of "nothing changed" when capturing the same inventory state.
*/
final class BaselineSnapshotIdentity
{
public function __construct(
private readonly DriftHasher $hasher,
) {}
/**
* Compute identity hash over a set of snapshot items.
*
* Each item is represented as an associative array with:
* - subject_type, subject_external_id, policy_type, baseline_hash
*
* @param array<int, array{subject_type: string, subject_external_id: string, policy_type: string, baseline_hash: string}> $items
*/
public function computeIdentity(array $items): string
{
if ($items === []) {
return hash('sha256', '[]');
}
$normalized = array_map(
fn (array $item): string => implode('|', [
trim((string) ($item['subject_type'] ?? '')),
trim((string) ($item['subject_external_id'] ?? '')),
trim((string) ($item['policy_type'] ?? '')),
trim((string) ($item['baseline_hash'] ?? '')),
]),
$items,
);
sort($normalized, SORT_STRING);
return hash('sha256', implode("\n", $normalized));
}
/**
* Compute a stable content hash for a single inventory item's metadata.
*
* Strips volatile OData keys and normalizes for stable comparison.
*/
public function hashItemContent(mixed $metaJsonb): string
{
return $this->hasher->hashNormalized($metaJsonb);
}
}