string-buffer.h

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/*
 * string-buffer.h
 *
 * Copyright (C) 2010 Thomas A. Vaughan
 * All rights reserved.
 *
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the <organization> nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THOMAS A. VAUGHAN ''AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THOMAS A. VAUGHAN BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *
 * A way to store many strings all in a single contiguous buffer.
 */

#ifndef WAVEPACKET_STRING_BUFFER_H__
#define WAVEPACKET_STRING_BUFFER_H__


// includes --------------------------------------------------------------------
#include "common/common.h"
#include "threadsafe/smart_ptr.h"


/// \ingroup util
/*@{*/


////////////////////////////////////////////////////////////////////////////////
//
//      StringBuffer interface
//
//      The use case is to repeatedly call appendString() to add strings to the
//      buffer, and keep track of the offsets as they are returned.  You can
//      always look up appended strings again using their offset.  The internal
//      buffer will be resized as needed.
//
////////////////////////////////////////////////////////////////////////////////
class StringBuffer {
public:
        // public structs and typedefs -----------------------------------------
        struct iterator_t {
                byte_t  opaque[8];
        };

        // virtual destructor --------------------------------------------------
        virtual ~StringBuffer(void) throw();

        // StringBuffer class interface methods --------------------------------

        /// appends the given string to the end of the buffer, and returns the
        ///     offset into the buffer.
        virtual int appendString(IN const char * string) = 0;

        /// given an offset, returns the string
        virtual const char * getString(IN int offset) const throw() = 0;

        /// initialize an iterator to the beginning of the list of strings
        virtual void getIterator(OUT iterator_t& i) const throw() = 0;

        /// retrieve the current string, and advance the iterator.  Returns NULL
        ///     at the end.  Note that iterators remain valid even if
        ///     appendString() is repeatedly called and increases the buffer.
        /// However, iteration is NOT threadsafe.
        virtual const char * getNextString(IO iterator_t& i) const throw() = 0;

        /// for diagnostics: runs through and writes all strings to stream
        virtual void dumpStrings(IO std::ostream& stream) const = 0;

        // static factory methods ----------------------------------------------
        static smart_ptr<StringBuffer> create(IN int initialBytes = 4096);
};


#endif  // WAVEPACKET_STRING_BUFFER_H__