rhubarb-lip-sync/rhubarb/lib/webrtc-8d2248ff/webrtc/base/dbus.h

169 lines
5.5 KiB
C++

/*
* Copyright 2004 The WebRTC Project Authors. All rights reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#ifndef WEBRTC_BASE_DBUS_H_
#define WEBRTC_BASE_DBUS_H_
#ifdef HAVE_DBUS_GLIB
#include <dbus/dbus.h>
#include <string>
#include <vector>
#include "webrtc/base/libdbusglibsymboltable.h"
#include "webrtc/base/messagehandler.h"
#include "webrtc/base/thread.h"
namespace rtc {
#define DBUS_TYPE "type"
#define DBUS_SIGNAL "signal"
#define DBUS_PATH "path"
#define DBUS_INTERFACE "interface"
#define DBUS_MEMBER "member"
#ifdef CHROMEOS
#define CROS_PM_PATH "/"
#define CROS_PM_INTERFACE "org.chromium.PowerManager"
#define CROS_SIG_POWERCHANGED "PowerStateChanged"
#define CROS_VALUE_SLEEP "mem"
#define CROS_VALUE_RESUME "on"
#else
#define UP_PATH "/org/freedesktop/UPower"
#define UP_INTERFACE "org.freedesktop.UPower"
#define UP_SIG_SLEEPING "Sleeping"
#define UP_SIG_RESUMING "Resuming"
#endif // CHROMEOS
// Wraps a DBus messages.
class DBusSigMessageData : public TypedMessageData<DBusMessage *> {
public:
explicit DBusSigMessageData(DBusMessage *message);
~DBusSigMessageData();
};
// DBusSigFilter is an abstract class that defines the interface of DBus
// signal handling.
// The subclasses implement ProcessSignal() for various purposes.
// When a DBus signal comes, a DSM_SIGNAL message is posted to the caller thread
// which will then invokes ProcessSignal().
class DBusSigFilter : protected MessageHandler {
public:
enum DBusSigMessage { DSM_SIGNAL };
// This filter string should ususally come from BuildFilterString()
explicit DBusSigFilter(const std::string &filter)
: caller_thread_(Thread::Current()), filter_(filter) {
}
// Builds a DBus monitor filter string from given DBus path, interface, and
// member.
// See http://dbus.freedesktop.org/doc/api/html/group__DBusConnection.html
static std::string BuildFilterString(const std::string &path,
const std::string &interface,
const std::string &member);
// Handles callback on DBus messages by DBus system.
static DBusHandlerResult DBusCallback(DBusConnection *dbus_conn,
DBusMessage *message,
void *instance);
// Handles callback on DBus messages to each DBusSigFilter instance.
DBusHandlerResult Callback(DBusMessage *message);
// From MessageHandler.
virtual void OnMessage(Message *message);
// Returns the DBus monitor filter string.
const std::string &filter() const { return filter_; }
private:
// On caller thread.
virtual void ProcessSignal(DBusMessage *message) = 0;
Thread *caller_thread_;
const std::string filter_;
};
// DBusMonitor is a class for DBus signal monitoring.
//
// The caller-thread calls AddFilter() first to add the signals that it wants to
// monitor and then calls StartMonitoring() to start the monitoring.
// This will create a worker-thread which listens on DBus connection and sends
// DBus signals back through the callback.
// The worker-thread will be running forever until either StopMonitoring() is
// called from the caller-thread or the worker-thread hit some error.
//
// Programming model:
// 1. Caller-thread: Creates an object of DBusMonitor.
// 2. Caller-thread: Calls DBusMonitor::AddFilter() one or several times.
// 3. Caller-thread: StartMonitoring().
// ...
// 4. Worker-thread: DBus signal recieved. Post a message to caller-thread.
// 5. Caller-thread: DBusFilterBase::ProcessSignal() is invoked.
// ...
// 6. Caller-thread: StopMonitoring().
//
// Assumption:
// AddFilter(), StartMonitoring(), and StopMonitoring() methods are called by
// a single thread. Hence, there is no need to make them thread safe.
class DBusMonitor {
public:
// Status of DBus monitoring.
enum DBusMonitorStatus {
DMS_NOT_INITIALIZED, // Not initialized.
DMS_INITIALIZING, // Initializing the monitoring thread.
DMS_RUNNING, // Monitoring.
DMS_STOPPED, // Not monitoring. Stopped normally.
DMS_FAILED, // Not monitoring. Failed.
};
// Returns the DBus-Glib symbol table.
// We should only use this function to access DBus-Glib symbols.
static LibDBusGlibSymbolTable *GetDBusGlibSymbolTable();
// Creates an instance of DBusMonitor.
static DBusMonitor *Create(DBusBusType type);
~DBusMonitor();
// Adds a filter to DBusMonitor.
bool AddFilter(DBusSigFilter *filter);
// Starts DBus message monitoring.
bool StartMonitoring();
// Stops DBus message monitoring.
bool StopMonitoring();
// Gets the status of DBus monitoring.
DBusMonitorStatus GetStatus();
private:
// Forward declaration. Defined in the .cc file.
class DBusMonitoringThread;
explicit DBusMonitor(DBusBusType type);
// Updates status_ when monitoring status has changed.
void OnMonitoringStatusChanged(DBusMonitorStatus status);
DBusBusType type_;
DBusMonitorStatus status_;
DBusMonitoringThread *monitoring_thread_;
std::vector<DBusSigFilter *> filter_list_;
};
} // namespace rtc
#endif // HAVE_DBUS_GLIB
#endif // WEBRTC_BASE_DBUS_H_