Preferences.h

/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Library General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Preferences.h
 * Interface for the Preferences class - this allows storing user preferences /
 * settings.
 * Copyright (C) 2005 Simon Newton
 */

#ifndef INCLUDE_OLAD_PREFERENCES_H_
#define INCLUDE_OLAD_PREFERENCES_H_

#include <ola/base/Macro.h>
#include <ola/Logging.h>
#include <ola/io/SelectServer.h>
// On MinGW, Thread.h pulls in pthread.h which pulls in Windows.h, which needs
// to be after WinSock2.h, hence this order
#include <ola/thread/Thread.h>

#include <map>
#include <vector>
#include <set>
#include <string>


namespace ola {

/*
 * Checks the value of a variable
 */
class Validator {
 public:
 Validator() {}
 virtual ~Validator() {}

 virtual bool IsValid(const std::string &value) const = 0;
};


/*
 * Check a value is a non-empty string
 */
class StringValidator: public Validator {
 public:
 explicit StringValidator(bool empty_ok = false)
 : Validator(),
 m_empty_ok(empty_ok) {
 }
 bool IsValid(const std::string &value) const;

 private:
 const bool m_empty_ok;
};


/*
 * Check that a value is one of a set of values
 */
template <class T>
class SetValidator: public Validator {
 public:
 explicit SetValidator(const std::set<T> &values) : m_values(values) {}
 bool IsValid(const std::string &value) const;

 private:
 std::set<T> m_values;
};


/*
 * Check that a value is a valid bool
 */
class BoolValidator: public Validator {
 public:
 BoolValidator(): Validator() {}
 bool IsValid(const std::string &value) const;

 // On win32 TRUE and FALSE are #define'd. We can #undef them here but that
 // doesn't fix the case in the calling code. So we use ENABLED and DISABLED
 // instead.
 static const char ENABLED[];
 static const char DISABLED[];
};


/*
 * Check that a value falls within a range of unsigned ints.
 */
class UIntValidator: public Validator {
 public:
 UIntValidator(unsigned int greater_than, unsigned int less_than)
 : m_gt(greater_than),
 m_lt(less_than) {}
 bool IsValid(const std::string &value) const;

 private:
 unsigned int m_gt, m_lt;
};


/*
 * Check that a value falls within a range of ints.
 */
class IntValidator: public Validator {
 public:
 IntValidator(int greater_than, int less_than)
 : m_gt(greater_than),
 m_lt(less_than) {}
 bool IsValid(const std::string &value) const;

 private:
 int m_gt, m_lt;
};


/*
 * Check an IPv4 address is valid
 */
class IPv4Validator: public Validator {
 public:
 explicit IPv4Validator(bool empty_ok = true):
 m_empty_ok(empty_ok) {}

 bool IsValid(const std::string &value) const;
 private:
 bool m_empty_ok;

 DISALLOW_COPY_AND_ASSIGN(IPv4Validator);
};


/*
 * The abstract Preferences class
 */
class Preferences {
 public:
 explicit Preferences(const std::string name): m_preference_name(name) {}

 virtual ~Preferences() {}

 virtual bool Load() = 0;

 virtual bool Save() const = 0;

 virtual void Clear() = 0;

 virtual std::string ConfigLocation() const = 0;

 virtual void SetValue(const std::string &key, const std::string &value) = 0;

 virtual void SetValue(const std::string &key, unsigned int value) = 0;

 virtual void SetValue(const std::string &key, int value) = 0;

 virtual void SetMultipleValue(const std::string &key,
 const std::string &value) = 0;

 virtual void SetMultipleValue(const std::string &key, unsigned int value) = 0;

 virtual void SetMultipleValue(const std::string &key, int value) = 0;

 virtual bool SetDefaultValue(const std::string &key,
 const Validator &validator,
 const std::string &value) = 0;

 virtual bool SetDefaultValue(const std::string &key,
 const Validator &validator,
 const char value[]) = 0;

 virtual bool SetDefaultValue(const std::string &key,
 const Validator &validator,
 unsigned int value) = 0;

 virtual bool SetDefaultValue(const std::string &key,
 const Validator &validator,
 int value) = 0;

 virtual bool SetDefaultValue(const std::string &key,
 const Validator &validator,
 bool value) = 0;

 virtual std::string GetValue(const std::string &key) const = 0;

 virtual std::vector<std::string> GetMultipleValue(
 const std::string &key) const = 0;

 virtual bool HasKey(const std::string &key) const = 0;

 virtual void RemoveValue(const std::string &key) = 0;

 // bool helper methods
 virtual bool GetValueAsBool(const std::string &key) const = 0;

 virtual void SetValueAsBool(const std::string &key, bool value) = 0;

 protected:
 std::string m_preference_name;

 private:
 DISALLOW_COPY_AND_ASSIGN(Preferences);
};


class PreferencesFactory {
 public:
 PreferencesFactory() {}

 virtual ~PreferencesFactory();

 virtual Preferences *NewPreference(const std::string &name);

 virtual std::string ConfigLocation() const = 0;

 private:
 virtual Preferences *Create(const std::string &name) = 0;
 std::map<std::string, Preferences*> m_preferences_map;
};


/*
 * MemoryPreferences just stores the preferences in memory. Useful for testing.
 */
class MemoryPreferences: public Preferences {
 public:
 explicit MemoryPreferences(const std::string name): Preferences(name) {}
 virtual ~MemoryPreferences();
 virtual bool Load() { return true; }
 virtual bool Save() const { return true; }
 virtual void Clear();

 virtual std::string ConfigLocation() const { return "Not Saved"; }

 virtual void SetValue(const std::string &key, const std::string &value);
 virtual void SetValue(const std::string &key, unsigned int value);
 virtual void SetValue(const std::string &key, int value);
 virtual void SetMultipleValue(const std::string &key,
 const std::string &value);
 virtual void SetMultipleValue(const std::string &key, unsigned int value);
 virtual void SetMultipleValue(const std::string &key, int value);
 virtual bool SetDefaultValue(const std::string &key,
 const Validator &validator,
 const std::string &value);
 virtual bool SetDefaultValue(const std::string &key,
 const Validator &validator,
 const char value[]);
 virtual bool SetDefaultValue(const std::string &key,
 const Validator &validator,
 unsigned int value);
 virtual bool SetDefaultValue(const std::string &key,
 const Validator &validator,
 int value);
 virtual bool SetDefaultValue(const std::string &key,
 const Validator &validator,
 bool value);

 virtual std::string GetValue(const std::string &key) const;
 virtual std::vector<std::string> GetMultipleValue(
 const std::string &key) const;
 virtual bool HasKey(const std::string &key) const;

 virtual void RemoveValue(const std::string &key);

 // bool helper methods
 virtual bool GetValueAsBool(const std::string &key) const;
 virtual void SetValueAsBool(const std::string &key, bool value);

 bool operator==(const MemoryPreferences &other) {
 return m_pref_map == other.m_pref_map;
 }

 protected:
 typedef std::multimap<std::string, std::string> PreferencesMap;
 PreferencesMap m_pref_map;
};


class MemoryPreferencesFactory: public PreferencesFactory {
 public:
 virtual std::string ConfigLocation() const { return "Not Saved"; }

 private:
 MemoryPreferences *Create(const std::string &name) {
 return new MemoryPreferences(name);
 }
};


class FilePreferenceSaverThread: public ola::thread::Thread {
 public:
 typedef std::multimap<std::string, std::string> PreferencesMap;
 FilePreferenceSaverThread();

 void SavePreferences(const std::string &filename,
 const PreferencesMap &preferences);

 void *Run();

 bool Join(void *ptr = NULL);

 void Synchronize();

 private:
 ola::io::SelectServer m_ss;

 void CompleteSynchronization(ola::thread::ConditionVariable *condition,
 ola::thread::Mutex *mutex);
};


/*
 * FilePreferences uses one file per namespace
 */
class FileBackedPreferences: public MemoryPreferences {
 public:
 explicit FileBackedPreferences(const std::string &directory,
 const std::string &name,
 FilePreferenceSaverThread *saver_thread)
 : MemoryPreferences(name),
 m_directory(directory),
 m_saver_thread(saver_thread) {}

 virtual bool Load();
 virtual bool Save() const;

 bool LoadFromFile(const std::string &filename);

 std::string ConfigLocation() const { return FileName(); }

 private:
 const std::string m_directory;
 FilePreferenceSaverThread *m_saver_thread;

 bool ChangeDir() const;

 const std::string FileName() const;
 static const char OLA_CONFIG_PREFIX[];
 static const char OLA_CONFIG_SUFFIX[];
};


class FileBackedPreferencesFactory: public PreferencesFactory {
 public:
 explicit FileBackedPreferencesFactory(const std::string &directory)
 : m_directory(directory) {
 m_saver_thread.Start();
 }

 ~FileBackedPreferencesFactory() {
 m_saver_thread.Join();
 }

 virtual std::string ConfigLocation() const { return m_directory; }

 private:
 const std::string m_directory;
 FilePreferenceSaverThread m_saver_thread;

 FileBackedPreferences *Create(const std::string &name) {
 return new FileBackedPreferences(m_directory, name, &m_saver_thread);
 }
};
} // namespace ola
#endif // INCLUDE_OLAD_PREFERENCES_H_