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/*
* $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
*/
#include "config.h"
#include <errno.h>
#include <limits.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.
*
* If extension failed, errno is set to indicate the error.
*
* 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;
/* Prevent signed integer overflows with large buffers. */
if (min_size > INT_MAX - 8)
{
errno = EFBIG;
return -1;
}
if (p->size > INT_MAX / 2)
new_size = min_size + 8;
else {
new_size = p->size * 2;
if (new_size < min_size + 8)
new_size = min_size + 8;
}
#ifdef PRINTBUF_DEBUG
MC_DEBUG("printbuf_extend: 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)
{
/* Prevent signed integer overflows with large buffers. */
if (size < 0 || size > INT_MAX - p->bpos - 1)
{
errno = EFBIG;
return -1;
}
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;
/* Prevent signed integer overflows with large buffers. */
if (len < 0 || offset < -1 || len > INT_MAX - offset)
{
errno = EFBIG;
return -1;
}
size_needed = offset + len;
if (pb->size < size_needed)
{
if (printbuf_extend(pb, size_needed) < 0)
return -1;
}
if (pb->bpos < offset)
memset(pb->buf + pb->bpos, '\0', offset - pb->bpos);
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];
/* use 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 implementations 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 < 0 || size > 127)
{
va_start(ap, msg);
if ((size = vasprintf(&t, msg, ap)) < 0)
{
va_end(ap);
return -1;
}
va_end(ap);
size = printbuf_memappend(p, t, size);
free(t);
}
else
{
size = 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);
}
}