src/ipc/ipc_path_manager.h

// Copyright 2010, Google Inc.
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#ifndef MOZC_IPC_IPC_PATH_MANAGER_H_
#define MOZC_IPC_IPC_PATH_MANAGER_H_

#include <string>
#include "base/base.h"
#include "base/mutex.h"

namespace mozc {

namespace ipc {
class IPCPathInfo;
}

class ProcessMutex;

class IPCPathManager {
 public:
  // Create new path name and save it inside internal memory.
  // if the path is already created, return true and do nothing.
  bool CreateNewPathName();

  // Save ipc path to ~/.mozc/.ipc.<name>
  // if server_ipc_key_ is empty, CreateNewPathName()
  // is called automatically
  // If the file is already locked, return false
  bool SavePathName();

  // Get the current path from memory.
  // return false if LoadPathName() failed.
  bool GetPathName(string *path_name);

  // Get the old path name from memory.
  // return false if LoadPathName() failed.
  bool GetOldPathName(string *path_name);

  // return protocol version.
  // return 0 if protocol version is not defined.
  uint32 GetServerProtocolVersion() const;

  // return product version.
  // return "0.0.0.0" if product version is not defined
  const string &GetServerProductVersion() const;

  // return process id of the server
  uint32 GetServerProcessId() const;

  // Check the server pid is the valid server specified with server_path.
  // server pid can be obtained by OS dependent method.
  // This API is only available on Windows Vista or Linux.
  // Always return true on other operating systems.
  // See also: GetNamedPipeServerProcessId
  // http://msdn.microsoft.com/en-us/library/aa365446(VS.85).aspx
  // when pid of 0 is passed, IsValidServer() returns true.
  // when pid of static_cast<size_t>(-1) is passed, IsValidServer()
  // returns false.
  // To keep backward compatibility and other operationg system
  // having no support of getting peer's pid, you can set 0 pid.
  bool IsValidServer(uint32 pid, const string &server_path);

  // clear ipc_key;
  void Clear();

  // return singleton instance corresponding to "name"
  static IPCPathManager *GetIPCPathManager(const string &name);

  // do not call constructor directly.
  explicit IPCPathManager(const string &name);
  virtual ~IPCPathManager();

 private:

  // Load ipc name from ~/.mozc/.ipc
  // Note that this method overwrites the ipc_key_
  bool LoadPathName();

  scoped_ptr<ProcessMutex> path_mutex_;   // lock ipc path file
  scoped_ptr<Mutex> mutex_;   // mutex for methods
  scoped_ptr<ipc::IPCPathInfo> ipc_path_info_;
  string name_;
  string server_path_;   // cache for server_path
  uint32 server_pid_;    // cache for pid of server_path
};
}  // mozc

#endif  // MOZC_IPC_IPC_PATH_MANAGER_H_