Initial work on Dart bindings for Mojo.

mojo/public/dart/system/lib/src/message_pipe.dart

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+part of core;
+
+class _MojoMessagePipeNatives {
+  static List MojoCreateMessagePipe(int flags)
+      native "MojoMessagePipe_Create";
+
+  static int MojoWriteMessage(
+      int handle, ByteData data, int num_bytes, List<int> handles, int flags)
+      native "MojoMessagePipe_Write";
+
+  static List MojoReadMessage(
+      int handle, ByteData data, int num_bytes, List<int> handles, int flags)
+      native "MojoMessagePipe_Read";
+}
+
+
+class MojoMessagePipeEndpoint {
+  static final int WRITE_FLAG_NONE = 0;
+  static final int READ_FLAG_NONE = 0;
+  static final int READ_FLAG_MAY_DISCARD = 0;
+
+  RawMojoHandle handle;
+  int status;
+
+  MojoMessagePipeEndpoint(this.handle);
+
+  int write(ByteData data,
+            [int num_bytes = -1,
+             List<RawMojoHandle> handles = null,
+             int flags = 0]) {
+    // If num_bytes has the default value, use the full length of the data.
+    int data_num_bytes = (num_bytes == -1) ? data.lengthInBytes : num_bytes;
+
+    // handles may be null, otherwise convert to ints.
+    List<int> mojo_handles =
+        (handles != null) ? handles.map((h) => h.h).toList() : null;
+
+    // Do the call.
+    int result = _MojoMessagePipeNatives.MojoWriteMessage(
+        handle.h, data, data_num_bytes, mojo_handles, flags);
+
+    status = result;
+    return status;
+  }
+
+  // return[0] = MojoResult
+  // return[1] = bytes read
+  // return[2] = handles read
+  List read(ByteData data,
+            [int num_bytes = -1,
+             List<RawMojoHandle> handles = null,
+             int flags = 0]) {
+    // If num_bytes has the default value, use the full length of the data.
+    int data_num_bytes;
+    if (data == null) {
+      data_num_bytes = 0;
+    } else {
+      data_num_bytes = (num_bytes == -1) ? data.lengthInBytes : num_bytes;
+    }
+
+    // handles may be null, otherwise make an int list for the handles.
+    List<int> mojo_handles;
+    if (handles == null) {
+      mojo_handles = null;
+    } else {
+      mojo_handles = new List<int>(handles.length);
+    }
+
+    // Do the call.
+    List result = _MojoMessagePipeNatives.MojoReadMessage(
+        handle.h, data, data_num_bytes, mojo_handles, flags);
+
+    if (result == null) {
+      status = MojoResult.INVALID_ARGUMENT;
+      return null;
+    }
+    assert((result is List) && (result.length == 3));
+
+    status = result[0];
+    return result;
+  }
+
+  List query() => read(null);
+}
+
+
+class MojoMessagePipe {
+  static final int FLAG_NONE = 0;
+
+  List<MojoMessagePipeEndpoint> endpoints;
+  int status;
+
+  MojoMessagePipe._internal() {
+    endpoints = null;
+    status = MojoResult.OK;
+  }
+
+  factory MojoMessagePipe() {
+    return new MojoMessagePipe.create(FLAG_NONE);
+  }
+
+  factory MojoMessagePipe.create(int flags) {
+    List result = _MojoMessagePipeNatives.MojoCreateMessagePipe(flags);
+    if (result == null) {
+      return null;
+    }
+    assert((result is List) && (result.length == 3));
+
+    RawMojoHandle end1 = new RawMojoHandle(result[1]);
+    RawMojoHandle end2 = new RawMojoHandle(result[2]);
+    MojoMessagePipe pipe = new MojoMessagePipe._internal();
+    pipe.endpoints = new List(2);
+    pipe.endpoints[0] = new MojoMessagePipeEndpoint(end1);
+    pipe.endpoints[1] = new MojoMessagePipeEndpoint(end2);
+    pipe.status = result[0];
+    return pipe;
+  }
+}