HID backend

device/hid/hid_service.cc

+// Copyright (c) 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 "device/hid/hid_service.h"
+
+#include <vector>
+
+#include "base/lazy_instance.h"
+#include "base/logging.h"
+#include "base/memory/scoped_vector.h"
+#include "base/message_loop/message_loop.h"
+#include "base/threading/thread_restrictions.h"
+#include "build/build_config.h"
+#include "device/hid/hid_device_info.h"
+
+#if defined(OS_LINUX)
+#include "device/hid/hid_service_linux.h"
+#elif defined(OS_MACOSX)
+#include "device/hid/hid_service_mac.h"
+#else
+#include "device/hid/hid_service_win.h"
+#endif
+
+namespace device {
+
+namespace {
+
+// The instance will be reset when message loop destroys.
+base::LazyInstance<scoped_ptr<HidService> >::Leaky g_hid_service_ptr =
+    LAZY_INSTANCE_INITIALIZER;
+
+}  // namespace
+
+HidService::HidService() : initialized_(false) {
+  base::ThreadRestrictions::AssertIOAllowed();
+  DCHECK(thread_checker_.CalledOnValidThread());
+  base::MessageLoop::current()->AddDestructionObserver(this);
+}
+
+HidService::~HidService() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  base::MessageLoop::current()->RemoveDestructionObserver(this);
+}
+
+void HidService::WillDestroyCurrentMessageLoop() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  g_hid_service_ptr.Get().reset(NULL);
+}
+
+void HidService::GetDevices(std::vector<HidDeviceInfo>* devices) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  STLClearObject(devices);
+  for (DeviceMap::iterator it = devices_.begin();
+      it != devices_.end();
+      ++it) {
+    devices->push_back(it->second);
+  }
+}
+
+void HidService::DeviceAdd(HidDeviceInfo info) {
+  if (!ContainsKey(devices_, info.device_id)) {
+    DCHECK(thread_checker_.CalledOnValidThread());
+    devices_[info.device_id] = info;
+  }
+}
+
+void HidService::DeviceRemove(std::string device_id) {
+  if (ContainsKey(devices_, device_id)) {
+    DCHECK(thread_checker_.CalledOnValidThread());
+    devices_.erase(device_id);
+  }
+}
+
+HidService* HidService::CreateInstance() {
+#if defined(OS_LINUX)
+    return new HidServiceLinux();
+#elif defined(OS_MACOSX)
+    return new HidServiceMac();
+#elif defined(OS_WIN)
+    return new HidServiceWin();
+#else
+    return NULL;
+#endif
+}
+
+HidService* HidService::GetInstance() {
+  if (!g_hid_service_ptr.Get().get()){
+    if (base::MessageLoop::current()->type() != base::MessageLoop::TYPE_IO) {
+      LOG(ERROR) << "HidService must be obtained on IO message loop";
+      return NULL;
+    }
+
+    scoped_ptr<HidService> service(CreateInstance());
+
+    if (service && service->initialized())
+      g_hid_service_ptr.Get().reset(service.release());
+  }
+  return g_hid_service_ptr.Get().get();
+}
+
+}  // namespace device