mariadb-columnstore-engine/utils/configcpp/configcpp.h

/* Copyright (C) 2014 InfiniDB, Inc.

   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; version 2 of
   the License.

   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 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. */

/******************************************************************************************
* $Id: configcpp.h 3495 2013-01-21 14:09:51Z rdempsey $
*
******************************************************************************************/
/**
 * @file
 */
#ifndef CONFIG_CONFIGCPP_H
#define CONFIG_CONFIGCPP_H

#include <string>
#include <map>
#include <vector>
#include <stdint.h>
#include <boost/thread.hpp>

#include <sys/types.h>
#include <libxml/parser.h>

#include "xmlparser.h"

namespace messageqcpp

{

class ByteStream;

}

#if defined(_MSC_VER) && defined(LIBCONFIG_DLLEXPORT)
#define EXPORT __declspec(dllexport)
#else
#define EXPORT
#endif

namespace config {

/** @brief a config file I/F class
 *
 * This is a singleton pattern: you must use the makeConfig() factory method to get a
 * pointer to the config file. You can have as many config files open at the same time as you like,
 * but you need different pointers to each. This class handles locking internally using an NFS-compatible
 * fcntl() call.
 */
class Config
{
public:
	/** @brief Config factory method
	 *
	 * Creates a singleton Config object
	 */
	EXPORT static Config* makeConfig(const char* cf=0);

	/** @brief Config factory method
	 *
	 * Creates a singleton Config object
	 */
	EXPORT static Config* makeConfig(const std::string& cf);

	/** @brief dtor
	*/
	EXPORT virtual ~Config();

	/** @brief get name's value from section
	*
	* get name's value from section in the current config file.
	* @param section the name of the config file section to search
	* @param name the param name whose value is to be returned
	*/
	EXPORT const std::string getConfig(const std::string& section, const std::string& name);

	/** @brief get all name's values from a section
	*
	* get name's values from section in the current config file.
	* @param section the name of the config file section to search
	* @param name the param name whose value is to be returned
	* @param values the values in the section are returned in this vector
	*/
	EXPORT void getConfig(const std::string& section, const std::string& name,
													std::vector<std::string>& values);

	/** @brief set name's value in section
	*
	* set name's value in section in the current config file.
	* @param section the name of the config file section to update
	* @param name the param name whose value is to be updated
	* @param value the param value
	*/
	EXPORT void setConfig(const std::string& section, const std::string& name, const std::string& value);

	/** @brief delete name from section
	*
	* delete name from section in the current config file.
	* @param section the name of the config file section to search
	* @param name the param name whose entry is to be deleted
	* @note if you delete the last param from a section, the section will still remain
	*/
	EXPORT void delConfig(const std::string& section, const std::string& name);

	/** @brief write the config file back out to disk
	*
	* write the config file back out to disk using the current filename.
	*/
	EXPORT void write(void) const;

	/** @brief write the config file back out to disk as fileName
	*
	* write the config file out to disk as a new file fileName. Does not affect the current
	* config filename.
	*/
	EXPORT void write(const std::string& fileName) const;

	/** @brief write a stream copy of config file to disk
	*
	* write a stream copy of config file to disk. used to distributed mass updates to system nodes
	* 
	*/
	EXPORT void writeConfigFile(messageqcpp::ByteStream msg) const;

	/** @brief return the name of this config file
	*
	* return the name of this config file.
	*/
	EXPORT inline const std::string& configFile() const { return fConfigFile; }

	/** @brief delete all config file instances
	*
	* deletes \b all config file maps
	*/
	EXPORT static void deleteInstanceMap();

	/** @brief parse config file numerics
	*
	* Convert human-friendly number formats to machine-friendly. Handle suffixes 'K', 'M', 'G'.
	* Handle decimal, hex and octal notation in the same way as the C compiler.
	* Ignore any 'B' following [KMG]. Ignore case in suffixes.
	* An empty string or an unparseable string returns 0.
	* Return a signed numeric value.
	*/
	EXPORT static int64_t fromText(const std::string& text);

	/** @brief parse config file numerics
	*
	* Return an unsigned numeric value.
	*/
	EXPORT static inline uint64_t uFromText(const std::string& text) { return static_cast<uint64_t>(fromText(text)); }

	/** @brief Used externally to check whether there has been a config change without loading everything
	 *
	 */
	inline time_t getLastMTime() const { return fMtime; }

	/** @brief Used externally to check whether there has been a config change without loading everything
	 *
	 */
	EXPORT time_t getCurrentMTime();

	/** @brief Enumerate all the sections in the config file
	 *
	 */
	EXPORT const std::vector<std::string> enumConfig();

	/** @brief Enumerate all the names in a section in the config file
	 *
	 */
	EXPORT const std::vector<std::string> enumSection(const std::string& section);

protected:
	/** @brief parse the XML file
	*
	*/
	void parseDoc(void);

	/** @brief write the XML tree to disk
	*
	*/
	EXPORT void writeConfig(const std::string& fileName) const;

	/** @brief stop processing this XML file
	*
	*/
	void closeConfig(void);

private:
	typedef std::map<std::string, Config*> configMap_t;

	/*
	*/
	Config(const Config& rhs);
	/*
	*/
	Config& operator=(const Config& rhs);

	/** @brief ctor with config file specified
	*/
	Config(const std::string& configFile, const std::string& installDir);

	static configMap_t fInstanceMap;
	static boost::mutex fInstanceMapMutex;
	static boost::mutex fXmlLock;
	static boost::mutex fWriteXmlLock;

	xmlDocPtr fDoc;
	const std::string fConfigFile;
	time_t fMtime;
	mutable boost::mutex fLock;
	const std::string fInstallDir;
	XMLParser fParser;

};

}

#undef EXPORT

#endif
// vim:ts=4 sw=4: