src/main/include/log4cxx/helpers/charsetencoder.h

/*
 * 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_HELPERS_CHARSETENCODER_H
#define _LOG4CXX_HELPERS_CHARSETENCODER_H

#include <log4cxx/helpers/objectimpl.h>
#include <log4cxx/helpers/pool.h>

namespace log4cxx
{

namespace helpers
{
class ByteBuffer;
class CharsetEncoder;
LOG4CXX_PTR_DEF(CharsetEncoder);

/**
*   An engine to transform LogStrings into bytes
*     for the specific character set.
*/
class LOG4CXX_EXPORT CharsetEncoder : public ObjectImpl
{
    public:
        DECLARE_ABSTRACT_LOG4CXX_OBJECT(CharsetEncoder)
        BEGIN_LOG4CXX_CAST_MAP()
        LOG4CXX_CAST_ENTRY(CharsetEncoder)
        END_LOG4CXX_CAST_MAP()

    protected:
        /**
        *  Protected constructor.
        */
        CharsetEncoder();

    public:
        /**
        * Destructor.
        */
        virtual ~CharsetEncoder();
        /**
         *  Get encoder for default charset.
         */
        static CharsetEncoderPtr getDefaultEncoder();

        /**
         *  Get encoder for specified character set.
         *  @param charset the following values should be recognized:
         *     "US-ASCII", "ISO-8859-1", "UTF-8",
         *     "UTF-16BE", "UTF-16LE".
         *  @return encoder.
         *  @throws IllegalArgumentException if encoding is not recognized.
         */
        static CharsetEncoderPtr getEncoder(const LogString& charset);


        /**
         *   Get encoder for UTF-8.
         */
        static CharsetEncoderPtr getUTF8Encoder();

        /**
        * Encodes a string replacing unmappable
        * characters with escape sequences.
        *
        */
        static void encode(CharsetEncoderPtr& enc,
                           const LogString& src,
                           LogString::const_iterator& iter,
                           ByteBuffer& dst);

        /**
         * Encodes as many characters from the input string as possible
         *   to the output buffer.
             *  @param in input string
         *  @param iter position in string to start.
         *  @param out output buffer.
         *  @return APR_SUCCESS unless a character can not be represented in
         *    the encoding.
         */
        virtual log4cxx_status_t encode(const LogString& in,
                                        LogString::const_iterator& iter,
                                        ByteBuffer& out) = 0;

        /**
         *   Resets any internal state.
         */
        virtual void reset();

        /**
         *   Flushes the encoder.
         */
        virtual void flush(ByteBuffer& out);

        /**
         *   Determines if the return value from encode indicates
         *     an unconvertable character.
         */
        inline static bool isError(log4cxx_status_t stat)
        {
            return (stat != 0);
        }


    private:
        /**
        *   Private copy constructor.
        */
        CharsetEncoder(const CharsetEncoder&);
        /**
         *   Private assignment operator.
         */
        CharsetEncoder& operator=(const CharsetEncoder&);

        static CharsetEncoder* createDefaultEncoder();
};

} // namespace helpers

}  //namespace log4cxx

#endif //_LOG4CXX_HELPERS_CHARSETENCODER_H