Mojo: Split public/cpp/system/core.h into pieces

mojo/public/cpp/system/data_pipe.h

+// 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.
+
+#ifndef MOJO_PUBLIC_CPP_SYSTEM_DATA_PIPE_H_
+#define MOJO_PUBLIC_CPP_SYSTEM_DATA_PIPE_H_
+
+#include <assert.h>
+
+#include "mojo/public/c/system/data_pipe.h"
+#include "mojo/public/cpp/system/handle.h"
+#include "mojo/public/cpp/system/macros.h"
+
+namespace mojo {
+
+// DataPipeProducerHandle and DataPipeConsumerHandle ---------------------------
+
+class DataPipeProducerHandle : public Handle {
+ public:
+  DataPipeProducerHandle() {}
+  explicit DataPipeProducerHandle(MojoHandle value) : Handle(value) {}
+
+  // Copying and assignment allowed.
+};
+
+MOJO_COMPILE_ASSERT(sizeof(DataPipeProducerHandle) == sizeof(Handle),
+                    bad_size_for_cpp_DataPipeProducerHandle);
+
+typedef ScopedHandleBase<DataPipeProducerHandle> ScopedDataPipeProducerHandle;
+MOJO_COMPILE_ASSERT(sizeof(ScopedDataPipeProducerHandle) ==
+                        sizeof(DataPipeProducerHandle),
+                    bad_size_for_cpp_ScopedDataPipeProducerHandle);
+
+class DataPipeConsumerHandle : public Handle {
+ public:
+  DataPipeConsumerHandle() {}
+  explicit DataPipeConsumerHandle(MojoHandle value) : Handle(value) {}
+
+  // Copying and assignment allowed.
+};
+
+MOJO_COMPILE_ASSERT(sizeof(DataPipeConsumerHandle) == sizeof(Handle),
+                    bad_size_for_cpp_DataPipeConsumerHandle);
+
+typedef ScopedHandleBase<DataPipeConsumerHandle> ScopedDataPipeConsumerHandle;
+MOJO_COMPILE_ASSERT(sizeof(ScopedDataPipeConsumerHandle) ==
+                        sizeof(DataPipeConsumerHandle),
+                    bad_size_for_cpp_ScopedDataPipeConsumerHandle);
+
+inline MojoResult CreateDataPipe(
+    const MojoCreateDataPipeOptions* options,
+    ScopedDataPipeProducerHandle* data_pipe_producer,
+    ScopedDataPipeConsumerHandle* data_pipe_consumer) {
+  assert(data_pipe_producer);
+  assert(data_pipe_consumer);
+  DataPipeProducerHandle producer_handle;
+  DataPipeConsumerHandle consumer_handle;
+  MojoResult rv = MojoCreateDataPipe(options, producer_handle.mutable_value(),
+                                     consumer_handle.mutable_value());
+  // Reset even on failure (reduces the chances that a "stale"/incorrect handle
+  // will be used).
+  data_pipe_producer->reset(producer_handle);
+  data_pipe_consumer->reset(consumer_handle);
+  return rv;
+}
+
+inline MojoResult WriteDataRaw(DataPipeProducerHandle data_pipe_producer,
+                               const void* elements,
+                               uint32_t* num_bytes,
+                               MojoWriteDataFlags flags) {
+  return MojoWriteData(data_pipe_producer.value(), elements, num_bytes, flags);
+}
+
+inline MojoResult BeginWriteDataRaw(DataPipeProducerHandle data_pipe_producer,
+                                    void** buffer,
+                                    uint32_t* buffer_num_bytes,
+                                    MojoWriteDataFlags flags) {
+  return MojoBeginWriteData(data_pipe_producer.value(), buffer,
+                            buffer_num_bytes, flags);
+}
+
+inline MojoResult EndWriteDataRaw(DataPipeProducerHandle data_pipe_producer,
+                                  uint32_t num_bytes_written) {
+  return MojoEndWriteData(data_pipe_producer.value(), num_bytes_written);
+}
+
+inline MojoResult ReadDataRaw(DataPipeConsumerHandle data_pipe_consumer,
+                              void* elements,
+                              uint32_t* num_bytes,
+                              MojoReadDataFlags flags) {
+  return MojoReadData(data_pipe_consumer.value(), elements, num_bytes, flags);
+}
+
+inline MojoResult BeginReadDataRaw(DataPipeConsumerHandle data_pipe_consumer,
+                                   const void** buffer,
+                                   uint32_t* buffer_num_bytes,
+                                   MojoReadDataFlags flags) {
+  return MojoBeginReadData(data_pipe_consumer.value(), buffer, buffer_num_bytes,
+                           flags);
+}
+
+inline MojoResult EndReadDataRaw(DataPipeConsumerHandle data_pipe_consumer,
+                                 uint32_t num_bytes_read) {
+  return MojoEndReadData(data_pipe_consumer.value(), num_bytes_read);
+}
+
+// A wrapper class that automatically creates a data pipe and owns both handles.
+// TODO(vtl): Make an even more friendly version? (Maybe templatized for a
+// particular type instead of some "element"? Maybe functions that take
+// vectors?)
+class DataPipe {
+ public:
+  DataPipe();
+  explicit DataPipe(const MojoCreateDataPipeOptions& options);
+  ~DataPipe();
+
+  ScopedDataPipeProducerHandle producer_handle;
+  ScopedDataPipeConsumerHandle consumer_handle;
+};
+
+inline DataPipe::DataPipe() {
+  MojoResult result MOJO_ALLOW_UNUSED =
+      CreateDataPipe(NULL, &producer_handle, &consumer_handle);
+  assert(result == MOJO_RESULT_OK);
+}
+
+inline DataPipe::DataPipe(const MojoCreateDataPipeOptions& options) {
+  MojoResult result MOJO_ALLOW_UNUSED =
+      CreateDataPipe(&options, &producer_handle, &consumer_handle);
+  assert(result == MOJO_RESULT_OK);
+}
+
+inline DataPipe::~DataPipe() {
+}
+
+}  // namespace mojo
+
+#endif  // MOJO_PUBLIC_CPP_SYSTEM_DATA_PIPE_H_