Function handleAssemble

packages/aws-lambda/src/handler.ts:392–443

(
  event: AssembleEvent,
  deps?: HandlerDeps,
)

// ── Assemble ────────────────────────────────────────────────────────────────

async function handleAssemble(
  event: AssembleEvent,
  deps?: HandlerDeps,
): Promise<AssembleLambdaResult> {
  const started = Date.now();
  const s3 = deps?.s3 ?? getS3Client();
  const primitive = deps?.primitives?.assemble ?? assemble;

  const work = mkdtempSync(join(deps?.tmpRoot ?? tmpdir(), "hf-lambda-assemble-"));
  const planTar = join(work, "plan.tar.gz");
  const planDir = join(work, "plan");

  try {
    await downloadS3ObjectToFile(s3, event.PlanS3Uri, planTar);
    await untarDirectory(planTar, planDir);

    const chunkPaths = await downloadChunkObjects(s3, event.ChunkS3Uris, work, event.Format);

    let audioPath: string | null = null;
    if (event.AudioS3Uri) {
      audioPath = join(planDir, "audio.aac");
      await downloadS3ObjectToFile(s3, event.AudioS3Uri, audioPath);
    }

    const finalOutput =
      event.Format === "png-sequence"
        ? join(work, "output-frames")
        : join(work, `output${formatExtension(event.Format)}`);

    const result: AssembleResult = await primitive(planDir, chunkPaths, audioPath, finalOutput, {
      cfr: event.Cfr === true,
    });

    if (event.Format === "png-sequence") {
      const tarball = `${finalOutput}.tar.gz`;
      await tarDirectory(finalOutput, tarball);
      await uploadFileToS3(s3, tarball, event.OutputS3Uri, "application/gzip");
    } else {
      await uploadFileToS3(s3, finalOutput, event.OutputS3Uri);
    }

    return {
      Action: "assemble",
      OutputS3Uri: event.OutputS3Uri,
      FramesEncoded: result.framesEncoded,
      FileSize: result.fileSize,
      DurationMs: Date.now() - started,
    };
  } finally {
    cleanupDir(work);
  }
}

async function downloadChunkObjects(
  s3: S3Client,