Implement WebDataConsumerHandle.

content/child/web_data_consumer_handle_impl.cc

+// 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.
+
+#include "content/child/web_data_consumer_handle_impl.h"
+
+#include <limits>
+#include "base/bind.h"
+#include "base/logging.h"
+#include "mojo/public/c/system/types.h"
+
+namespace content {
+
+typedef blink::WebDataConsumerHandle::Result Result;
+
+WebDataConsumerHandleImpl::WebDataConsumerHandleImpl(Handle handle)
+    : handle_(handle.Pass()), client_(nullptr) {}
+
+WebDataConsumerHandleImpl::~WebDataConsumerHandleImpl() {}
+
+Result WebDataConsumerHandleImpl::read(
+    void* data,
+    size_t size,
+    Flags flags,
+    size_t* read_size) {
+  // We need this variable definition to avoid a link error.
+  const Flags kNone = FlagNone;
+  DCHECK_EQ(flags, kNone);
+  DCHECK_LE(size, std::numeric_limits<uint32_t>::max());
+
+  *read_size = 0;
+
+  uint32_t size_to_pass = size;
+  MojoReadDataFlags flags_to_pass = MOJO_READ_DATA_FLAG_NONE;
+  MojoResult rv =
+      mojo::ReadDataRaw(handle_.get(), data, &size_to_pass, flags_to_pass);
+  if (rv == MOJO_RESULT_OK)
+    *read_size = size_to_pass;
+
+  return HandleReadResult(rv);
+}
+
+Result WebDataConsumerHandleImpl::beginRead(
+    const void** buffer, Flags flags, size_t* available) {
+  // We need this variable definition to avoid a link error.
+  const Flags kNone = FlagNone;
+  DCHECK_EQ(flags, kNone);
+
+  *buffer = nullptr;
+  *available = 0;
+
+  uint32_t size_to_pass = 0;
+  MojoReadDataFlags flags_to_pass = MOJO_READ_DATA_FLAG_NONE;
+
+  MojoResult rv = mojo::BeginReadDataRaw(handle_.get(), buffer,
+                                         &size_to_pass, flags_to_pass);
+  if (rv == MOJO_RESULT_OK)
+    *available = size_to_pass;
+  return HandleReadResult(rv);
+}
+
+Result WebDataConsumerHandleImpl::endRead(size_t read_size) {
+  MojoResult rv = mojo::EndReadDataRaw(handle_.get(), read_size);
+  return
+      rv == MOJO_RESULT_OK ? Ok : UnexpectedError;
+}
+
+void WebDataConsumerHandleImpl::registerClient(Client* client) {
+  DCHECK(!client_);
+  DCHECK(client);
+  client_ = client;
+
+  handle_watcher_.Start(
+      handle_.get(),
+      MOJO_HANDLE_SIGNAL_READABLE,
+      MOJO_DEADLINE_INDEFINITE,
+      base::Bind(&WebDataConsumerHandleImpl::OnHandleGotReadable,
+                 base::Unretained(this)));
+}
+
+void WebDataConsumerHandleImpl::unregisterClient() {
+  client_ = nullptr;
+  handle_watcher_.Stop();
+}
+
+Result WebDataConsumerHandleImpl::HandleReadResult(MojoResult mojo_result) {
+  switch (mojo_result) {
+    case MOJO_RESULT_OK:
+      return Ok;
+    case MOJO_RESULT_FAILED_PRECONDITION:
+      return Done;
+    case MOJO_RESULT_BUSY:
+      return Busy;
+    case MOJO_RESULT_SHOULD_WAIT:
+      if (client_) {
+        handle_watcher_.Start(
+            handle_.get(),
+            MOJO_HANDLE_SIGNAL_READABLE,
+            MOJO_DEADLINE_INDEFINITE,
+            base::Bind(&WebDataConsumerHandleImpl::OnHandleGotReadable,
+                       base::Unretained(this)));
+      }
+      return ShouldWait;
+    case MOJO_RESULT_RESOURCE_EXHAUSTED:
+      return ResourceExhausted;
+    default:
+      return UnexpectedError;
+  }
+}
+
+void WebDataConsumerHandleImpl::OnHandleGotReadable(MojoResult) {
+  DCHECK(client_);
+  client_->didGetReadable();
+}
+
+}  // namespace content