/*
 * Copyright (C) 2007 Tildeslash Ltd. All rights reserved.
 *
 * 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.
 *
 * There are special exceptions to the terms and conditions of the GPL 
 * as it is applied to this software. View the full text of the exception
 * in the file EXCEPTIONS accompanying this software distribution.
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA 
 */


#include "Config.h"

#include <stdio.h>

#include "Util.h"
#include "StringBuffer.h"


/**
 * Implementation of the StringBuffer interface.
 *
 * @version \$Id: StringBuffer.c,v 1.16 2007/01/02 10:29:52 hauk Exp $
 * @file
 */


/* ----------------------------------------------------------- Definitions */


#define BUFFER_SIZE 256

#define T StringBuffer_T
struct T {
        int used;
        int length;
	uchar_T *buffer;
};


/* ------------------------------------------------------------ Prototypes */


static void doAppend(T S, const char *s, va_list ap);


/* ----------------------------------------------------- Protected methods */

#ifdef PACKAGE_PROTECTED
#pragma GCC visibility push(hidden)
#endif

T StringBuffer_new(const char *s) {
        T S;
        NEW(S);
        S->used= 0;
        S->length= BUFFER_SIZE;
        S->buffer= ALLOC(BUFFER_SIZE);
        return StringBuffer_append(S, s);
}


void StringBuffer_free(T *S) {
        assert(S && *S);
	FREE((*S)->buffer);
        FREE(*S);
}


T StringBuffer_append(T S, const char *s, ...) {
	va_list ap;
        assert(S);
        if(s && *s) {
                va_start(ap, s);
                doAppend(S, s, ap);
                va_end(ap);
        }
        return S;
}


T StringBuffer_vappend(T S, const char *s, va_list ap) {
        assert(S);
        if(s && *s)
                doAppend(S, s, ap);
        return S;
}


int StringBuffer_length(T S) {
        assert(S);
        return S->used;
}


void StringBuffer_clear(T S) {
        assert(S);
        S->used= 0;
        *S->buffer= 0;
}


const char *StringBuffer_toString(T S) {
        assert(S);
        return S->buffer;
}

#ifdef PACKAGE_PROTECTED
#pragma GCC visibility pop
#endif

/* ------------------------------------------------------- Private methods */


static void doAppend(T S, const char *s, va_list ap) {
        while(TRUE) {
                int n= vsnprintf(&S->buffer[S->used], S->length-S->used, s, ap);
                if(n > -1 && (S->used + n) < S->length) {
                        S->used+= n;
                        break;
                }
                if(n > -1)
                        S->length+= BUFFER_SIZE + n;
                else
                        S->length*= 2;
                RESIZE(S->buffer, S->length);
        }
}