Initial work on Dart bindings for Mojo.

mojo/public/dart/system/lib/src/data_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 _MojoDataPipeNatives {
+  static List MojoCreateDataPipe(
+      int element_bytes, int capacity_bytes, int flags)
+      native "MojoDataPipe_Create";
+
+  static List MojoWriteData(int handle, ByteData data, int num_bytes, int flags)
+      native "MojoDataPipe_WriteData";
+
+  static List MojoBeginWriteData(int handle, int buffer_bytes, int flags)
+      native "MojoDataPipe_BeginWriteData";
+
+  static int MojoEndWriteData(int handle, int bytes_written)
+      native "MojoDataPipe_EndWriteData";
+
+  static List MojoReadData(int handle, ByteData data, int num_bytes, int flags)
+      native "MojoDataPipe_ReadData";
+
+  static List MojoBeginReadData(int handle, int buffer_bytes, int flags)
+      native "MojoDataPipe_BeginReadData";
+
+  static int MojoEndReadData(int handle, int bytes_read)
+      native "MojoDataPipe_EndReadData";
+}
+
+
+class MojoDataPipeProducer {
+  static final int FLAG_NONE = 0;
+  static final int FLAG_ALL_OR_NONE = 1 << 0;
+
+  RawMojoHandle handle;
+  int status;
+  final int element_bytes;
+
+  MojoDataPipeProducer(this.handle,
+                       this.status,
+                       this.element_bytes);
+
+  int write(ByteData data, [int num_bytes = -1, int flags = 0]) {
+    int data_num_bytes = (num_bytes == -1) ? data.lengthInBytes : num_bytes;
+    List result = _MojoDataPipeNatives.MojoWriteData(
+        handle.h, data, data_num_bytes, flags);
+    if (result == null) {
+      status = MojoResult.INVALID_ARGUMENT;
+      return status;
+    }
+    assert((result is List) && (result.length == 2));
+
+    status = result[0];
+    return result[1];
+  }
+
+  ByteData beginWrite(int buffer_bytes, [int flags = 0]) {
+    List result = _MojoDataPipeNatives.MojoBeginWriteData(
+        handle.h, buffer_bytes, flags);
+    if (result == null) {
+      status = MojoResult.INVALID_ARGUMENT;
+      return null;
+    }
+    assert((result is List) && (result.length == 2));
+    status = result[0];
+    return result[1];
+  }
+
+  void endWrite(int bytes_written) {
+    status = _MojoDataPipeNatives.MojoEndWriteData(handle.h, bytes_written);
+  }
+}
+
+
+class MojoDataPipeConsumer {
+  static final int FLAG_NONE = 0;
+  static final int FLAG_ALL_OR_NONE = 1 << 0;
+  static final int FLAG_MAY_DISCARD = 1 << 1;
+  static final int FLAG_QUERY = 1 << 2;
+
+  RawMojoHandle handle;
+  int status;
+  final int element_bytes;
+
+  MojoDataPipeConsumer(this.handle,
+                       this.status,
+                       this.element_bytes);
+
+  int read(ByteData data, [int num_bytes = -1, int flags = 0]) {
+    int data_num_bytes = (num_bytes == -1) ? data.lengthInBytes : num_bytes;
+    List result = _MojoDataPipeNatives.MojoReadData(
+        handle.h, data, data_num_bytes, flags);
+    if (result == null) {
+      status = MojoResult.INVALID_ARGUMENT;
+      return status;
+    }
+    assert((result is List) && (result.length == 2));
+    status = result[0];
+    return result[1];
+  }
+
+  ByteData beginRead(int buffer_bytes, [int flags = 0]) {
+    List result = _MojoDataPipeNatives.MojoBeginReadData(
+        handle.h, buffer_bytes, flags);
+    if (result == null) {
+      status = MojoResult.INVALID_ARGUMENT;
+      return null;
+    }
+    assert((result is List) && (result.length == 2));
+    status = result[0];
+    return result[1];
+  }
+
+  void endRead(int bytes_read) {
+    status = _MojoDataPipeNatives.MojoEndReadData(handle.h, bytes_read);
+  }
+}
+
+
+class MojoDataPipe {
+  static final int FLAG_NONE = 0;
+  static final int FLAG_MAY_DISCARD = 1 << 0;
+  static final int DEFAULT_ELEMENT_SIZE = 1;
+  static final int DEFAULT_CAPACITY = 0;
+
+  MojoDataPipeProducer producer;
+  MojoDataPipeConsumer consumer;
+  int status;
+
+  MojoDataPipe._internal() {
+    producer = null;
+    consumer = null;
+    status = MojoResult.OK;
+  }
+
+  factory MojoDataPipe() {
+    return new MojoDataPipe.create(
+        DEFAULT_ELEMENT_SIZE, DEFAULT_CAPACITY, FLAG_NONE);
+  }
+
+  factory MojoDataPipe.create(int element_bytes,
+                              int capacity_bytes,
+                              int flags) {
+    List result = _MojoDataPipeNatives.MojoCreateDataPipe(
+        element_bytes, capacity_bytes, flags);
+    if (result == null) {
+      return null;
+    }
+    assert((result is List) && (result.length == 3));
+    RawMojoHandle producer_handle = new RawMojoHandle(result[1]);
+    RawMojoHandle consumer_handle = new RawMojoHandle(result[2]);
+    MojoDataPipe pipe = new MojoDataPipe._internal();
+    pipe.producer = new MojoDataPipeProducer(
+        producer_handle, result[0], element_bytes);
+    pipe.consumer = new MojoDataPipeConsumer(
+        consumer_handle, result[0], element_bytes);
+    pipe.status = result[0];
+    return pipe;
+  }
+}