/*

 * $Id: printbuf.c,v 1.5 2006/01/26 02:16:28 mclark Exp $

 *

 * Copyright (c) 2004, 2005 Metaparadigm Pte. Ltd.

 * Michael Clark <michael@metaparadigm.com>

 *

 * This library is free software; you can redistribute it and/or modify

 * it under the terms of the MIT license. See COPYING for details.

 *

 *

 * Copyright (c) 2008-2009 Yahoo! Inc.  All rights reserved.

 * The copyrights to the contents of this file are licensed under the MIT License

 * (http://www.opensource.org/licenses/mit-license.php)

 */

#include "config.h"

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#ifdef HAVE_STDARG_H

# include <stdarg.h>

#else /* !HAVE_STDARG_H */

# error Not enough var arg support!

#endif /* HAVE_STDARG_H */

#include "debug.h"

#include "printbuf.h"

#include "snprintf_compat.h"

#include "vasprintf_compat.h"

static int printbuf_extend(struct printbuf *p, int min_size);

struct printbuf* printbuf_new(void)

{

  struct printbuf *p;

  p = (struct printbuf*)calloc(1, sizeof(struct printbuf));

  if(!p) return NULL;

  p->size = 32;

  p->bpos = 0;

  if(!(p->buf = (char*)malloc(p->size))) {

    free(p);

    return NULL;

  }

  p->buf[0]= '\0';

  return p;

}

/**

 * Extend the buffer p so it has a size of at least min_size.

 *

 * If the current size is large enough, nothing is changed.

 *

 * Note: this does not check the available space!  The caller

 *  is responsible for performing those calculations.

 */

static int printbuf_extend(struct printbuf *p, int min_size)

{

	char *t;

	int new_size;

	if (p->size >= min_size)

		return 0;

	new_size = p->size * 2;

	if (new_size < min_size + 8)

		new_size =  min_size + 8;

#ifdef PRINTBUF_DEBUG

	MC_DEBUG("printbuf_memappend: realloc "

	  "bpos=%d min_size=%d old_size=%d new_size=%d\n",

	  p->bpos, min_size, p->size, new_size);

#endif /* PRINTBUF_DEBUG */

	if(!(t = (char*)realloc(p->buf, new_size)))

		return -1;

	p->size = new_size;

	p->buf = t;

	return 0;

}

int printbuf_memappend(struct printbuf *p, const char *buf, int size)

{

  if (p->size <= p->bpos + size + 1) {

    if (printbuf_extend(p, p->bpos + size + 1) < 0)

      return -1;

  }

  memcpy(p->buf + p->bpos, buf, size);

  p->bpos += size;

  p->buf[p->bpos]= '\0';

  return size;

}

int printbuf_memset(struct printbuf *pb, int offset, int charvalue, int len)

{

	int size_needed;

	if (offset == -1)

		offset = pb->bpos;

	size_needed = offset + len;

	if (pb->size < size_needed)

	{

		if (printbuf_extend(pb, size_needed) < 0)

			return -1;

	}

	memset(pb->buf + offset, charvalue, len);

	if (pb->bpos < size_needed)

		pb->bpos = size_needed;

	return 0;

}

int sprintbuf(struct printbuf *p, const char *msg, ...)

{

  va_list ap;

  char *t;

  int size;

  char buf[128];

  /* user stack buffer first */

  va_start(ap, msg);

  size = vsnprintf(buf, 128, msg, ap);

  va_end(ap);

  /* if string is greater than stack buffer, then use dynamic string

     with vasprintf.  Note: some implementation of vsnprintf return -1

     if output is truncated whereas some return the number of bytes that

     would have been written - this code handles both cases. */

  if(size == -1 || size > 127) {

    va_start(ap, msg);

    if((size = vasprintf(&t, msg, ap)) < 0) { va_end(ap); return -1; }

    va_end(ap);

    printbuf_memappend(p, t, size);

    free(t);

    return size;

  } else {

    printbuf_memappend(p, buf, size);

    return size;

  }

}

void printbuf_reset(struct printbuf *p)

{

  p->buf[0] = '\0';

  p->bpos = 0;

}

void printbuf_free(struct printbuf *p)

{

  if(p) {

    free(p->buf);

    free(p);

  }

}