/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #ifndef _LOG4CXX_MDC_H #define _LOG4CXX_MDC_H #if defined(_MSC_VER) #pragma warning (push) #pragma warning ( disable: 4231 4251 4275 4786 ) #endif #include #include #include namespace log4cxx { /** The MDC class is similar to the {@link log4cxx::NDC NDC} class except that it is based on a map instead of a stack. It provides mapped diagnostic contexts. A Mapped Diagnostic Context, or MDC in short, is an instrument for distinguishing interleaved log output from different sources. Log output is typically interleaved when a server handles multiple clients near-simultaneously.

The MDC is managed on a per thread basis. A child thread automatically inherits a copy of the mapped diagnostic context of its parent. */ class LOG4CXX_EXPORT MDC { public: /** String to string stl map. */ typedef std::map Map; /** * Places a key/value pair in the MDC for the current thread * which will be removed during the corresponding destructor. Both * construction and destruction are expected to be on the same thread. * @param key key * @param value value. */ MDC(const std::string& key, const std::string& value); ~MDC(); /** * Put a context value (the o parameter) as identified * with the key parameter into the current thread's * context map. * *

If the current thread does not have a context map it is * created as a side effect. * @param key key * @param value value. */ static void put(const std::string& key, const std::string& value); /** * Put a context value (the o parameter) as identified * with the key parameter into the current thread's * context map. * *

If the current thread does not have a context map it is * created as a side effect. * */ static void putLS(const LogString& key, const LogString& value); /** * Get the context identified by the key parameter. * *

This method has no side effects. * @param key key. * @return value for key, empty if not set. * */ static std::string get(const std::string& key); /** * Gets the context identified by the key parameter. * @param key context key. * @param dest destination to which value is appended. * @return true if key has associated value. */ static bool get(const LogString& key, LogString& dest); /** * Remove the the context identified by the key * parameter. * @param key key. * @return value if key had been set, empty if not. */ static std::string remove(const std::string& key); #if LOG4CXX_WCHAR_T_API /** * Places a key/value pair in the MDC for the current thread * which will be removed during the corresponding destructor. Both * construction and destruction are expected to be on the same thread. * @param key key * @param value value. */ MDC(const std::wstring& key, const std::wstring& value); /** * Put a context value (the o parameter) as identified * with the key parameter into the current thread's * context map. * *

If the current thread does not have a context map it is * created as a side effect. * @param key key * @param value value. */ static void put(const std::wstring& key, const std::wstring& value); /** * Get the context identified by the key parameter. * *

This method has no side effects. * @param key key. * @return value for key, empty if not set. * */ static std::wstring get(const std::wstring& key); /** * Remove the the context identified by the key * parameter. * @param key key. * @return value if key had been set, empty if not. */ static std::wstring remove(const std::wstring& key); #endif #if LOG4CXX_UNICHAR_API /** * Places a key/value pair in the MDC for the current thread * which will be removed during the corresponding destructor. Both * construction and destruction are expected to be on the same thread. * @param key key * @param value value. */ MDC(const std::basic_string& key, const std::basic_string& value); /** * Put a context value (the o parameter) as identified * with the key parameter into the current thread's * context map. * *

If the current thread does not have a context map it is * created as a side effect. * @param key key * @param value value. */ static void put(const std::basic_string& key, const std::basic_string& value); /** * Get the context identified by the key parameter. * *

This method has no side effects. * @param key key. * @return value for key, empty if not set. * */ static std::basic_string get(const std::basic_string& key); /** * Remove the the context identified by the key * parameter. * @param key key. * @return value if key had been set, empty if not. */ static std::basic_string remove(const std::basic_string& key); #endif #if LOG4CXX_CFSTRING_API /** * Places a key/value pair in the MDC for the current thread * which will be removed during the corresponding destructor. Both * construction and destruction are expected to be on the same thread. * @param key key * @param value value. */ MDC(const CFStringRef& key, const CFStringRef& value); /** * Put a context value (the o parameter) as identified * with the key parameter into the current thread's * context map. * *

If the current thread does not have a context map it is * created as a side effect. * @param key key * @param value value. */ static void put(const CFStringRef& key, const CFStringRef& value); /** * Get the context identified by the key parameter. * *

This method has no side effects. * @param key key. * @return value for key, empty if not set. * */ static CFStringRef get(const CFStringRef& key); /** * Remove the the context identified by the key * parameter. * @param key key. * @return value if key had been set, empty if not. */ static CFStringRef remove(const CFStringRef& key); #endif /** * Remove the the context identified by the key * parameter. * @param key key. * @param prevValue buffer to which previous value is appended. * @return true if key existed in MDC. */ static bool remove(const LogString& key, LogString& prevValue); /** * Clear all entries in the MDC. */ static void clear(); private: MDC(const MDC&); MDC& operator=(const MDC&); LogString key; }; // class MDC; } // namespace log4cxx #if defined(_MSC_VER) #pragma warning (pop) #endif #endif // _LOG4CXX_MDC_H