From 176b5600ed2a9a2653ec2b078dc417d3e8955a8e Mon Sep 17 00:00:00 2001 From: duane Date: Wed, 24 Jun 2009 01:54:25 +0000 Subject: Add a growable sprintf memory buffer library git-svn-id: svn://svn.berlios.de/openocd/trunk@2381 b42882b7-edfa-0310-969c-e2dbd0fdcd60 --- src/helper/membuf.c | 238 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 238 insertions(+) create mode 100644 src/helper/membuf.c (limited to 'src/helper/membuf.c') diff --git a/src/helper/membuf.c b/src/helper/membuf.c new file mode 100644 index 00000000..af396ca0 --- /dev/null +++ b/src/helper/membuf.c @@ -0,0 +1,238 @@ +/*************************************************************************** + * 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 +#include +#include +#include + +#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; +} + + + + + + -- cgit v1.2.3-18-g5258