Commit 176b5600 authored by duane's avatar duane
Browse files

Add a growable sprintf memory buffer library

git-svn-id: svn://svn.berlios.de/openocd/trunk@2381 b42882b7-edfa-0310-969c-e2dbd0fdcd60
parent c97caebc
......@@ -23,6 +23,7 @@ libhelper_la_SOURCES = \
time_support.c \
replacements.c \
fileio.c \
membuf.c \
startup_tcl.c
if IOUTIL
......@@ -41,6 +42,7 @@ noinst_HEADERS = \
types.h \
log.h \
command.h \
membuf.h \
time_support.h \
replacements.h \
fileio.h \
......
/***************************************************************************
* Copyright (C) 2009 By Duane Ellis *
* openocd@duaneellis.com *
* *
* 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; either version 2 of the License, or *
* (at your option) any later version. *
* *
* 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 <stdio.h>
#include <stdarg.h>
#include <malloc.h>
#include <string.h>
#include "membuf.h"
struct membuf {
// buflen is alway "+1" bigger then
// what is shown here, the +1 is for
// the NULL string terminator
#define DEFAULT_BUFSIZE 100
size_t maxlen; // allocated size
size_t curlen; // where we are inserting at
char *_strtoklast;
void *buf;
};
#define space_avail( pBuf ) (pBuf->maxlen - pBuf->curlen)
#define dataend( pBuf ) ( ((char *)(pBuf->buf)) + pBuf->curlen )
size_t
membuf_len( struct membuf *pBuf )
{
return pBuf->curlen;
}
const void *
membuf_datapointer( struct membuf *pBuf )
{
return ((void *)(pBuf->buf));
}
const char *
membuf_strtok( struct membuf *pBuf, const char *sep, void **pLast )
{
if( pBuf ){
pBuf->_strtoklast = NULL;
*pLast = pBuf;
return strtok_r( ((char *)(pBuf->buf)), sep, &(pBuf->_strtoklast) );
} else {
// recover our pBuf
pBuf = *((struct membuf **)(pLast));
return strtok_r( NULL, sep, &(pBuf->_strtoklast) );
}
}
struct membuf *
membuf_new(void)
{
// by default - parameters are zero.
struct membuf *pBuf;
pBuf = calloc( 1, sizeof(*pBuf) );
if( pBuf ){
// we *ALWAYS* allocate +1 for null terminator.
pBuf->buf = calloc( DEFAULT_BUFSIZE+1, sizeof(char));
if( pBuf->buf == NULL ){
free(pBuf);
pBuf = NULL;
} else {
pBuf->maxlen = DEFAULT_BUFSIZE;
}
}
return pBuf;
}
struct membuf *
membuf_grow( struct membuf *pBuf, int n )
{
void *vp;
signed int newsize;
// this is a *SIGNED* value
newsize = ((int)(pBuf->maxlen)) + n;
// do not go negative, or too small
if( newsize < DEFAULT_BUFSIZE ){
newsize = DEFAULT_BUFSIZE;
}
// always alloc +1 for the null terminator
vp = realloc( pBuf->buf, newsize+1 );
if( vp ){
pBuf->buf = vp;
pBuf->maxlen = newsize;
return pBuf;
} else {
return NULL;
}
}
void membuf_reset( struct membuf *pBuf )
{
pBuf->curlen = 0;
}
void membuf_delete( struct membuf *pBuf )
{
if( pBuf ){
if( pBuf->buf){
// wack data so it cannot be reused
memset(pBuf->buf,0,pBuf->maxlen);
free(pBuf->buf);
}
// wack dat so it cannot be reused
memset(pBuf,0,sizeof(pBuf));
free(pBuf);
}
}
int
membuf_sprintf( struct membuf *pBuf , const char *fmt, ... )
{
int r;
va_list ap;
va_start( ap, fmt );
r = membuf_vsprintf( pBuf, fmt, ap );
va_end(ap);
return r;
}
int
membuf_vsprintf( struct membuf *pBuf, const char *fmt, va_list ap )
{
int r;
size_t sa;
int grew;
grew = 0;
for(;;) {
sa = space_avail(pBuf);
// do work
r = vsnprintf( dataend( pBuf ),
sa,
fmt,
ap );
if( (r > 0) && (((size_t)(r)) < sa) ){
// Success!
pBuf->curlen += ((size_t)(r));
// remember: We always alloc'ed +1
// so this does not overflow
((char *)(pBuf->buf))[ pBuf->curlen ] = 0;
r = 0;
break;
}
// failure
if( r < 0 ){
// Option(A) format error
// Option(B) glibc2.0 bug
// assume (B).
r = (4 * DEFAULT_BUFSIZE);
}
// don't do this again
if( grew ){
r = -1;
break;
}
grew = 1;
pBuf = membuf_grow( pBuf, r );
if(pBuf == NULL){
// grow failed
r = -1;
break;
}
}
return r;
}
struct membuf *
membuf_strcat( struct membuf *pBuf, const char *pStr )
{
return membuf_append( pBuf, pStr, strlen( pStr ) );
}
struct membuf *
membuf_append( struct membuf *pBuf, const void *pData, size_t len )
{
size_t sa;
int r;
// how much room is there?
sa = space_avail( pBuf );
// will it fit?
if( sa < len ){
// if not, how much do we need?
r = ((int)(sa - len));
// do the grow.
pBuf = membuf_grow( pBuf, r );
// failed?
if(pBuf==NULL){
return pBuf;
}
}
// append
memcpy( dataend(pBuf),
pData,
len );
pBuf->curlen += len;
return pBuf;
}
#ifndef HELPER_MEMBUF_H
#define HELPER_MEMBUF_H
/** @file */
/** @page MEMBUF - an auto-growing string buffer
*
* With OpenOCD often, one must write code that sends text to
* different places.. the historical command_ctx, or JIM output,
* and/or other places.
*
* This is a simple 'string buffer' that auto-grows.
*
* More correctly put, this is a "memory buffer"
* it may contain binary data
*
* Note: Internally the buffer always has a 'null terminator'
*/
/* contents of this structure are 'opaque' */
struct membuf;
/** Create a new membuf
* By default the memory buffer has "some non-zero-size"
* (couple hundred bytes, exact amount is opaque)
*/
struct membuf *membuf_new(void);
/** delete (destroy) the mem buffer
* @param pBuf - buffer to release
*/
void membuf_delete( struct membuf *pBuf );
/** grow/shrink a membuf by specified amount.
* @param pBuf - the buffer
* @param amount - the amount to grow or shrink by.
*
* Symantics of 'realloc()' return NULL on failure
*/
struct membuf *membuf_grow( struct membuf *pBuf, int amount );
/** how long is this buffer (memlen(), strlen())
* @param pBuf - the buffer
*
* @returns: length of current buffer.
*/
size_t membuf_len( struct membuf *pBuf );
/** reset an membuf to zero length.
* @param pBuf - buffer to reset
*
* Note this does not 'release' the memory buffer
*/
void membuf_reset( struct membuf *pBuf );
/** sprintf() to the string buffer
* @param pBuf - buffer to capture sprintf() data into
* @param fmt - printf format
*
* Returns 0 on success
* Returns non-zero on failure
*/
int membuf_sprintf( struct membuf *pBuf , const char *fmt, ... );
/** vsprintf() to the string buffer
* @param pBuf - buffer to capture sprintf() data into
* @param fmt - printf format
* @param ap - va_list for fmt
*
* Returns 0 on success
* Returns non-zero on failure
*/
int membuf_vsprintf( struct membuf *pBuf , const char *fmt, va_list ap);
/** Tokenize lines using strtok()
* @param pBuf - buffer to tokenize
* @param delim - delimiter parameter for strtok_r()
*
* Identical to "strtok()" - pass "pBuff=NULL" on second call
*
* NOTE: This call is <b>destructive</b> to the buffer.
*/
const char *membuf_strtok( struct membuf *pBuf, const char *delim, void **pSave );
/** Return pointer to the memory in the buffer
* @param pBuf - buffer
*
* NOTE: Thou shall not modify this pointer, it is <b>CONST</b>
*/
const void *membuf_datapointer( struct membuf *pBuf );
/** Append data to the buffer
* @param pBuf - buffer to append
* @param pData - pointer to data to append
* @param len - length of data to append
*
* Modified symantics of "memcpy()". On memory allocation failure
* returns NULL. On success, returns pointer to orginal membuf.
*/
struct membuf *membuf_append( struct membuf *pBuf, const void *pData, size_t len );
/** Append string to the buffer
* @param pBuf - buffer to append
* @param str - string to append
*
* Modified symantics of "strcat()". On memory allocation failure
* returns NULL. On success, returns pointer to orginal membuf.
*/
struct membuf *membuf_strcat( struct membuf *pBuf, const char *s );
#endif
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