serveio.ts

// Copyright 2019-2020 Yusuke Sakurai. All rights reserved. MIT license.
import {
  BufReader,
  BufWriter,
} from "./vendor/https/deno.land/std/io/bufio.ts";
import {
  TextProtoReader,
} from "./vendor/https/deno.land/std/textproto/mod.ts";
import {
  streamReader,
  timeoutReader,
  closableBodyReader,
} from "./_readers.ts";
import { promiseInterrupter } from "./_util.ts";
import {
  assert,
  AssertionError,
} from "./vendor/https/deno.land/std/testing/asserts.ts";
import {
  BodyReader,
  ClientRequest,
  IncomingRequest,
  IncomingResponse,
  KeepAlive,
  ServeOptions,
  ServerResponse,
  HttpBody,
} from "./server.ts";
import { encode } from "./vendor/https/deno.land/std/encoding/utf8.ts";
import Reader = Deno.Reader;
import Writer = Deno.Writer;
import Buffer = Deno.Buffer;
import { toIMF } from "./vendor/https/deno.land/std/datetime/mod.ts";
import { parseCookie } from "./cookie.ts";
import {
  bodyReader,
  chunkedBodyReader,
  emptyReader,
  writeTrailers,
} from "./vendor/https/deno.land/std/http/_io.ts";
import { createBodyParser } from "./body_parser.ts";
import { UnexpectedEofError } from "./error.ts";
import {
  STATUS_TEXT,
} from "./vendor/https/deno.land/std/http/http_status.ts";

export const kDefaultKeepAliveTimeout = 75000; // ms

export function initServeOptions(opts: ServeOptions = {}): ServeOptions {
  let cancel = opts.cancel;
  let keepAliveTimeout = kDefaultKeepAliveTimeout;
  let readTimeout = kDefaultKeepAliveTimeout;
  if (opts.keepAliveTimeout !== void 0) {
    keepAliveTimeout = opts.keepAliveTimeout;
  }
  if (opts.readTimeout !== void 0) {
    readTimeout = opts.readTimeout;
  }
  assert(keepAliveTimeout >= 0, "keepAliveTimeout must be >= 0");
  assert(readTimeout >= 0, "readTimeout must be >= 0");
  return { cancel, keepAliveTimeout, readTimeout };
}

/**
 * Read http request from reader.
 * 'status-line' and headers are certainly read. body and trailers may not be read.
 * Read will be aborted when opts.cancel is called or any read wait to reader is over opts.readTimeout.
 * */
export async function readRequest(
  r: Reader,
  opts: ServeOptions = {},
): Promise<IncomingRequest> {
  opts = initServeOptions(opts);
  const reader = BufReader.create(r);
  const tpReader = new TextProtoReader(reader);
  // read status line
  // use keepAliveTimeout for reading request line
  const resLine = await promiseInterrupter({
    timeout: opts.keepAliveTimeout,
    cancel: opts.cancel,
  })(tpReader.readLine());
  if (resLine === null) {
    throw new UnexpectedEofError();
  }
  const m = resLine.match(/^([^ ]+)? ([^ ]+?) ([^ ]+?)$/);
  assert(m != null, "invalid start line");
  let [_, method, url, proto] = m;
  const { searchParams: query, pathname: path } = new URL(url, "http://dummy");
  method = method.toUpperCase();
  // read header
  const headers = await promiseInterrupter({
    timeout: opts.readTimeout,
    cancel: opts.cancel,
  })(tpReader.readMIMEHeader());
  if (headers === null) {
    throw new UnexpectedEofError();
  }
  let keepAlive;
  if (headers.has("keep-alive")) {
    keepAlive = parseKeepAlive(headers);
  }
  // cookie
  const cookies = parseCookie(headers.get("Cookie") || "");
  // body
  let body: BodyReader = closableBodyReader(emptyReader());
  if (method === "POST" || method === "PUT") {
    if (headers.get("transfer-encoding") === "chunked") {
      const tr = timeoutReader(chunkedBodyReader(headers, reader), {
        timeout: opts.readTimeout,
        cancel: opts.cancel,
      });
      body = closableBodyReader(tr);
    } else {
      const contentLength = parseInt(headers.get("content-length")!);
      assert(
        contentLength >= 0,
        `content-length is missing or invalid: ${
          headers.get(
            "content-length",
          )
        }`,
      );
      const tr = timeoutReader(bodyReader(contentLength, reader), {
        timeout: opts.readTimeout,
        cancel: opts.cancel,
      });
      body = closableBodyReader(tr);
    }
  }
  const bodyParser = createBodyParser({
    reader: body,
    contentType: headers.get("content-type") ?? "",
  });
  return {
    method,
    url,
    path,
    query,
    proto,
    headers,
    cookies,
    body,
    keepAlive,
    ...bodyParser,
  };
}

/** write http request. Host, Content-Length, Transfer-Encoding headers are set if needed */
export async function writeRequest(
  w: Writer,
  req: ClientRequest,
): Promise<void> {
  const writer = BufWriter.create(w);
  let { method, body, headers } = req;
  method = method.toUpperCase();
  const url = new URL(req.url);
  if (!headers) {
    headers = new Headers();
  }
  // start line
  await writer.write(
    encode(`${method} ${url.pathname}${url.search || ""} HTTP/1.1\r\n`),
  );
  // header
  if (!headers.has("host")) {
    headers.set("host", url.host);
  }
  let contentLength: number | undefined;
  let bodyReader: Reader | undefined;
  if (body) {
    [bodyReader, contentLength] = setupBody(body, headers);
  }
  await writeHeaders(writer, headers);
  await writer.flush();
  if (bodyReader) {
    await writeBody(writer, bodyReader, contentLength);
  }
  if (req.trailers) {
    const trailers = await req.trailers();
    await writeTrailers(writer, headers, trailers);
  }
}

/** read http response from reader */
export async function readResponse(
  r: Reader,
  { timeout, cancel }: { timeout?: number; cancel?: Promise<void> } = {},
): Promise<IncomingResponse> {
  const reader = BufReader.create(r);
  const tp = new TextProtoReader(reader);
  const timeoutOrCancel = promiseInterrupter({ timeout, cancel });
  // First line: HTTP/1,1 200 OK
  const line = await timeoutOrCancel(tp.readLine());
  if (line === null) {
    throw new UnexpectedEofError();
  }
  const [proto, status, statusText] = line.split(" ", 3);
  const headers = await timeoutOrCancel(tp.readMIMEHeader());
  if (headers === null) {
    throw new UnexpectedEofError();
  }
  const contentLength = headers.get("content-length");
  const isChunked = headers.get("transfer-encoding")?.match(/^chunked/);
  let body: BodyReader;
  if (isChunked) {
    const tr = timeoutReader(chunkedBodyReader(headers, reader), {
      timeout,
      cancel,
    });
    body = closableBodyReader(tr);
  } else if (contentLength != null) {
    const tr = timeoutReader(bodyReader(parseInt(contentLength), reader), {
      timeout,
      cancel,
    });
    body = closableBodyReader(tr);
  } else {
    throw new Error("unkown conetnt-lengh or chunked");
  }
  const bodyParser = createBodyParser({
    reader: body,
    contentType: headers.get("content-type") ?? "",
  });
  return {
    proto,
    status: parseInt(status),
    statusText,
    headers,
    body,
    ...bodyParser,
  };
}

function bodyToReader(
  body: HttpBody,
  headers: Headers,
): [Reader, number | undefined] {
  if (typeof body === "string") {
    const bin = encode(body);
    return [new Buffer(bin), bin.byteLength];
  } else if (body instanceof Uint8Array) {
    return [new Buffer(body), body.byteLength];
  } else if (body instanceof ReadableStream) {
    const cl = headers.get("content-length");
    return [streamReader(body), cl ? parseInt(cl) : undefined];
  } else {
    const cl = headers.get("content-length");
    return [body, cl ? parseInt(cl) : undefined];
  }
}

export function setupBody(
  body: HttpBody,
  headers: Headers,
): [Reader, number | undefined] {
  let [r, len] = bodyToReader(body, headers);
  const transferEncoding = headers.get("transfer-encoding");
  let chunked = transferEncoding?.match(/^chunked/) != null;
  if (!chunked && typeof len === "number") {
    headers.set("content-length", `${len}`);
  }
  if (typeof body === "string") {
    if (!headers.has("content-type")) {
      headers.set("content-type", "text/plain; charset=UTF-8");
    }
  } else if (body instanceof Uint8Array) {
    // noop
  } else {
    if (!headers.has("content-length") && !headers.has("transfer-encoding")) {
      headers.set("transfer-encoding", "chunked");
      chunked = true;
    }
  }
  if (!headers.has("content-type")) {
    headers.set("content-type", "application/octet-stream");
  }
  return [r, chunked ? undefined : len];
}
/** write http response to writer. Content-Length, Transfer-Encoding headers are set if needed */
export async function writeResponse(
  w: Writer,
  res: ServerResponse,
): Promise<void> {
  const writer = BufWriter.create(w);
  if (!res.headers) {
    res.headers = new Headers();
  }
  // status line
  const statusText = STATUS_TEXT.get(res.status);
  assert(!!statusText, `unsupported status code: ${statusText}`);
  await writer.write(encode(`HTTP/1.1 ${res.status} ${statusText}\r\n`));
  let bodyReader: Reader | undefined;
  let contentLength: number | undefined;
  if (res.body) {
    [bodyReader, contentLength] = setupBody(res.body, res.headers);
  } else if (!res.headers.has("content-length")) {
    res.headers.set("content-length", "0");
  }
  await writeHeaders(writer, res.headers);
  if (bodyReader) {
    await writeBody(writer, bodyReader, contentLength);
  }
  if (res.trailers) {
    const trailer = await res.trailers();
    await writeTrailers(writer, res.headers, trailer);
  }
}

/** write headers to writer */
export async function writeHeaders(w: Writer, headers: Headers): Promise<
  void
> {
  const lines: string[] = [];
  const writer = BufWriter.create(w);
  if (!headers.has("date")) {
    headers.set("date", toIMF(new Date()));
  }
  if (headers) {
    for (const [key, value] of headers) {
      lines.push(`${key}: ${value}`);
    }
  }
  lines.push("\r\n");
  const headerText = lines.join("\r\n");
  await writer.write(encode(headerText));
  await writer.flush();
}

/** write http body to writer. Reader without contentLength will be written by chunked encoding */
export async function writeBody(
  w: Writer,
  body: Reader,
  contentLength?: number,
): Promise<void> {
  let writer = BufWriter.create(w);
  const hasContentLength = typeof contentLength === "number" &&
    Number.isInteger(contentLength);
  if (hasContentLength) {
    await Deno.copy(body, writer);
    await writer.flush();
  } else {
    while (true) {
      // TODO: add opts for buffer size
      const buf = new Uint8Array(2048);
      const result = await body.read(buf);
      if (result === null) {
        await writer.write(encode("0\r\n\r\n"));
        await writer.flush();
        break;
      } else if (result > 0) {
        const chunk = buf.slice(0, result);
        const size = result.toString(16);
        await writer.write(encode(`${size}\r\n`));
        await writer.write(chunk);
        await writer.write(encode("\r\n"));
        await writer.flush();
      }
    }
  }
}

export function parseKeepAlive(h: Headers): KeepAlive {
  let timeout: number = -1;
  let max: number = -1;
  const keepAlive = h.get("keep-alive");
  if (keepAlive === null) {
    throw new AssertionError("keep-alive must be set");
  }
  const kv = keepAlive.split(",").map((s) => s.trim().split("="));
  for (const [key, value] of kv) {
    if (key === "timeout") {
      timeout = parseInt(value);
    } else if (key === "max") {
      max = parseInt(value);
    }
  }
  assert(Number.isInteger(timeout), `"timeout" must be integer: ${timeout}`);
  assert(Number.isInteger(max), `"max" max be integer: ${max}`);
  return { timeout, max };
}