h3-fast-compression/dist/index.mjs

Adds compression to h3 request (brotli, gzip, deflate)

import { promisify } from 'node:util';
import zlib from 'node:zlib';
import { getRequestHeader, getResponseHeader, setResponseHeader, send } from 'h3';

const MINIMUM_COMPRESSION_INPUT_SIZE = 1024;
function getAnyCompression(event) {
  const encoding = getRequestHeader(event, "accept-encoding");
  if (encoding?.includes("br"))
    return "br";
  if (encoding?.includes("gzip"))
    return "gzip";
  if (encoding?.includes("deflate"))
    return "deflate";
  return void 0;
}
async function compress(event, response, method) {
  const acceptEncoding = getRequestHeader(event, "accept-encoding")?.includes(method);
  const contentEncoding = getResponseHeader(event, "content-encoding");
  const responseBody = response.body;
  const shouldCompress = typeof responseBody === "string" && !contentEncoding && responseBody.length >= MINIMUM_COMPRESSION_INPUT_SIZE && acceptEncoding;
  if (shouldCompress) {
    setResponseHeader(event, "Content-Encoding", method);
    const compressed = await (method === "br" ? promisify(zlib.brotliCompress)(responseBody, {
      params: {
        [zlib.constants.BROTLI_PARAM_MODE]: zlib.constants.BROTLI_MODE_TEXT,
        // 4 is generally more appropriate for dynamic content, faster than gzip and better compression ratio
        [zlib.constants.BROTLI_PARAM_QUALITY]: 4
      }
    }) : promisify(zlib[method])(responseBody));
    void send(event, compressed);
  }
}
async function compressStream(event, response, method) {
  const stream = new Response(response.body).body;
  const acceptsEncoding = getRequestHeader(event, "accept-encoding")?.includes(
    method
  );
  if (acceptsEncoding) {
    setResponseHeader(event, "Content-Encoding", method);
    response.body = stream.pipeThrough(new CompressionStream(method));
  } else {
    response.body = stream;
  }
}

async function useGZipCompression(event, response) {
  await compress(event, response, "gzip");
}
async function useDeflateCompression(event, response) {
  await compress(event, response, "deflate");
}
async function useBrotliCompression(event, response) {
  await compress(event, response, "br");
}
async function useCompression(event, response) {
  const compression = getAnyCompression(event);
  if (compression)
    await compress(event, response, compression);
}

async function useGZipCompressionStream(event, response) {
  await compressStream(event, response, "gzip");
}
async function useDeflateCompressionStream(event, response) {
  await compressStream(event, response, "deflate");
}
async function useCompressionStream(event, response) {
  const compression = getAnyCompression(event);
  if (compression && compression !== "br")
    await compressStream(event, response, compression);
}

export { useBrotliCompression, useCompression, useCompressionStream, useDeflateCompression, useDeflateCompressionStream, useGZipCompression, useGZipCompressionStream };