Cleanup: More random cleanup for gamepad code.

content/browser/gamepad/platform_data_fetcher_linux.cc

 // Copyright (c) 2012 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/browser/gamepad/platform_data_fetcher_linux.h"
 
 #include <fcntl.h>
 #include <libudev.h>
 #include <linux/joystick.h>
 #include <string.h>
@@ skipping 12 matching lines @@
 namespace {
 
 const char kInputSubsystem[] = "input";
 const float kMaxLinuxAxisValue = 32767.0;
 
 void CloseFileDescriptorIfValid(int fd) {
   if (fd >= 0)
     close(fd);
 }
 
+bool IsGamepad(udev_device* dev, int* index, std::string* path) {
+  if (!udev_device_get_property_value(dev, "ID_INPUT_JOYSTICK"))
+    return false;
+
+  const char* node_path = udev_device_get_devnode(dev);
+  if (!node_path)
+    return false;
+
+  static const char kJoystickRoot[] = "/dev/input/js";
+  bool is_gamepad = StartsWithASCII(node_path, kJoystickRoot, true);
+  if (!is_gamepad)
+    return false;
+
+  int tmp_idx = -1;
+  const int base_len = sizeof(kJoystickRoot) - 1;
+  base::StringPiece str(&node_path[base_len], strlen(node_path) - base_len);
+  if (!base::StringToInt(str, &tmp_idx))
+    return false;
+  if (tmp_idx < 0 ||
+      tmp_idx >= static_cast<int>(WebKit::WebGamepads::itemsLengthCap)) {
+    return false;
+  }
+  *index = tmp_idx;
+  *path = node_path;
+  return true;
+}
+
 }  // namespace
 
 namespace content {
 
 using WebKit::WebGamepad;
 using WebKit::WebGamepads;
 
 GamepadPlatformDataFetcherLinux::GamepadPlatformDataFetcherLinux() {
   for (size_t i = 0; i < arraysize(device_fds_); ++i)
     device_fds_[i] = -1;
@@ skipping 58 matching lines @@
   udev_device* dev = udev_monitor_receive_device(monitor_);
   if (!dev)
     return;
   RefreshDevice(dev);
   udev_device_unref(dev);
 }
 
 void GamepadPlatformDataFetcherLinux::OnFileCanWriteWithoutBlocking(int fd) {
 }
 
-bool GamepadPlatformDataFetcherLinux::IsGamepad(udev_device* dev,
-                                                int* index,
-                                                std::string* path) {
-  if (!udev_device_get_property_value(dev, "ID_INPUT_JOYSTICK"))
-    return false;
-
-  const char* node_path = udev_device_get_devnode(dev);
-  if (!node_path)
-    return false;
-
-  static const char kJoystickRoot[] = "/dev/input/js";
-  bool is_gamepad = StartsWithASCII(node_path, kJoystickRoot, true);
-  if (!is_gamepad)
-    return false;
-
-  int tmp_idx = -1;
-  const int base_len = sizeof(kJoystickRoot) - 1;
-  base::StringPiece str(&node_path[base_len], strlen(node_path) - base_len);
-  if (!base::StringToInt(str, &tmp_idx))
-    return false;
-  if (tmp_idx < 0 || tmp_idx >= static_cast<int>(WebGamepads::itemsLengthCap))
-    return false;
-  *index = tmp_idx;
-  *path = node_path;
-  return true;
-}
-
 // Used during enumeration, and monitor notifications.
 void GamepadPlatformDataFetcherLinux::RefreshDevice(udev_device* dev) {
   int index;
   std::string node_path;
   if (IsGamepad(dev, &index, &node_path)) {
     int& device_fd = device_fds_[index];
     WebGamepad& pad = data_.items[index];
     GamepadStandardMappingFunction& mapper = mappers_[index];
 
     CloseFileDescriptorIfValid(device_fd);
@@ skipping 73 matching lines @@
   udev_enumerate_unref(enumerate);
 }
 
 void GamepadPlatformDataFetcherLinux::ReadDeviceData(size_t index) {
   // Linker does not like CHECK_LT(index, WebGamepads::itemsLengthCap). =/
   if (index >= WebGamepads::itemsLengthCap) {
     CHECK(false);
     return;
   }
 
-  int& fd = device_fds_[index];
+  const int& fd = device_fds_[index];
   WebGamepad& pad = data_.items[index];
   DCHECK_GE(fd, 0);
 
   js_event event;
   while (HANDLE_EINTR(read(fd, &event, sizeof(struct js_event)) > 0)) {
     size_t item = event.number;
     if (event.type & JS_EVENT_AXIS) {
       if (item >= WebGamepad::axesLengthCap)
         continue;
       pad.axes[item] = event.value / kMaxLinuxAxisValue;
       if (item >= pad.axesLength)
         pad.axesLength = item + 1;
     } else if (event.type & JS_EVENT_BUTTON) {
       if (item >= WebGamepad::buttonsLengthCap)
         continue;
       pad.buttons[item] = event.value ? 1.0 : 0.0;
       if (item >= pad.buttonsLength)
         pad.buttonsLength = item + 1;
     }
     pad.timestamp = event.time;
   }
 }
 
 }  // namespace content