1 files changed, 209 insertions, 0 deletions
diff --git a/runtime/rt/30_files.js b/runtime/rt/30_files.js
new file mode 100644
index 000000000..679b184fd
--- /dev/null
+++ b/runtime/rt/30_files.js
@@ -0,0 +1,209 @@
+// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
+
+((window) => {
+  const core = window.Deno.core;
+  const { read, readSync, write, writeSync } = window.__bootstrap.io;
+  const { pathFromURL } = window.__bootstrap.util;
+
+  function seekSync(
+    rid,
+    offset,
+    whence,
+  ) {
+    return core.jsonOpSync("op_seek_sync", { rid, offset, whence });
+  }
+
+  function seek(
+    rid,
+    offset,
+    whence,
+  ) {
+    return core.jsonOpAsync("op_seek_async", { rid, offset, whence });
+  }
+
+  function openSync(
+    path,
+    options = { read: true },
+  ) {
+    checkOpenOptions(options);
+    const mode = options?.mode;
+    const rid = core.jsonOpSync(
+      "op_open_sync",
+      { path: pathFromURL(path), options, mode },
+    );
+
+    return new File(rid);
+  }
+
+  async function open(
+    path,
+    options = { read: true },
+  ) {
+    checkOpenOptions(options);
+    const mode = options?.mode;
+    const rid = await core.jsonOpAsync(
+      "op_open_async",
+      { path: pathFromURL(path), options, mode },
+    );
+
+    return new File(rid);
+  }
+
+  function createSync(path) {
+    return openSync(path, {
+      read: true,
+      write: true,
+      truncate: true,
+      create: true,
+    });
+  }
+
+  function create(path) {
+    return open(path, {
+      read: true,
+      write: true,
+      truncate: true,
+      create: true,
+    });
+  }
+
+  class File {
+    #rid = 0;
+
+    constructor(rid) {
+      this.#rid = rid;
+    }
+
+    get rid() {
+      return this.#rid;
+    }
+
+    write(p) {
+      return write(this.rid, p);
+    }
+
+    writeSync(p) {
+      return writeSync(this.rid, p);
+    }
+
+    read(p) {
+      return read(this.rid, p);
+    }
+
+    readSync(p) {
+      return readSync(this.rid, p);
+    }
+
+    seek(offset, whence) {
+      return seek(this.rid, offset, whence);
+    }
+
+    seekSync(offset, whence) {
+      return seekSync(this.rid, offset, whence);
+    }
+
+    close() {
+      core.close(this.rid);
+    }
+  }
+
+  class Stdin {
+    constructor() {
+    }
+
+    get rid() {
+      return 0;
+    }
+
+    read(p) {
+      return read(this.rid, p);
+    }
+
+    readSync(p) {
+      return readSync(this.rid, p);
+    }
+
+    close() {
+      core.close(this.rid);
+    }
+  }
+
+  class Stdout {
+    constructor() {
+    }
+
+    get rid() {
+      return 1;
+    }
+
+    write(p) {
+      return write(this.rid, p);
+    }
+
+    writeSync(p) {
+      return writeSync(this.rid, p);
+    }
+
+    close() {
+      core.close(this.rid);
+    }
+  }
+
+  class Stderr {
+    constructor() {
+    }
+
+    get rid() {
+      return 2;
+    }
+
+    write(p) {
+      return write(this.rid, p);
+    }
+
+    writeSync(p) {
+      return writeSync(this.rid, p);
+    }
+
+    close() {
+      core.close(this.rid);
+    }
+  }
+
+  const stdin = new Stdin();
+  const stdout = new Stdout();
+  const stderr = new Stderr();
+
+  function checkOpenOptions(options) {
+    if (Object.values(options).filter((val) => val === true).length === 0) {
+      throw new Error("OpenOptions requires at least one option to be true");
+    }
+
+    if (options.truncate && !options.write) {
+      throw new Error("'truncate' option requires 'write' option");
+    }
+
+    const createOrCreateNewWithoutWriteOrAppend =
+      (options.create || options.createNew) &&
+      !(options.write || options.append);
+
+    if (createOrCreateNewWithoutWriteOrAppend) {
+      throw new Error(
+        "'create' or 'createNew' options require 'write' or 'append' option",
+      );
+    }
+  }
+
+  window.__bootstrap.files = {
+    stdin,
+    stdout,
+    stderr,
+    File,
+    create,
+    createSync,
+    open,
+    openSync,
+    seek,
+    seekSync,
+  };
+})(this);