alinea/dist/core/source/FilePatch.js

Headless git-based CMS

import "../../chunks/chunk-NZLE2WMY.js";

// src/core/source/FilePatch.ts
import { assert } from "../util/Assert.js";
import { applyGitDelta, createGitDelta } from "./GitDelta.js";
import { sha1Bytes as computeSha1Bytes } from "./Utils.js";
var encoder = new TextEncoder();
var decoder = new TextDecoder();
var HASH_BYTES = 20;
async function createFilePatch(base, updated) {
  const baseBytes = encoder.encode(base);
  const updatedBytes = encoder.encode(updated);
  const delta = createGitDelta(baseBytes, updatedBytes);
  const [baseHash, updatedHash] = await Promise.all([
    computeSha1Bytes(baseBytes),
    computeSha1Bytes(updatedBytes)
  ]);
  const out = new Uint8Array(HASH_BYTES + delta.length + HASH_BYTES);
  out.set(baseHash, 0);
  out.set(delta, HASH_BYTES);
  out.set(updatedHash, HASH_BYTES + delta.length);
  return out;
}
async function applyFilePatch(base, patch) {
  assert(patch.length >= HASH_BYTES * 2, "Invalid patch: too small");
  const baseBytes = encoder.encode(base);
  const expectedBaseHash = patch.subarray(0, HASH_BYTES);
  const actualBaseHash = await computeSha1Bytes(baseBytes);
  assert(bytesEqual(expectedBaseHash, actualBaseHash), "Patch does not match base");
  const delta = patch.subarray(HASH_BYTES, patch.length - HASH_BYTES);
  const result = applyGitDelta(baseBytes, delta);
  const expectedHash = patch.subarray(patch.length - HASH_BYTES);
  const actualHash = await computeSha1Bytes(result);
  assert(bytesEqual(actualHash, expectedHash), "Patched content hash mismatch");
  return decoder.decode(result);
}
function bytesEqual(a, b) {
  if (a.length !== b.length) return false;
  for (let i = 0; i < a.length; i++) {
    if (a[i] !== b[i]) return false;
  }
  return true;
}
export {
  applyFilePatch,
  createFilePatch
};