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Diffstat (limited to 'libmisc/high_water_alloc.c')
-rw-r--r-- | libmisc/high_water_alloc.c | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/libmisc/high_water_alloc.c b/libmisc/high_water_alloc.c new file mode 100644 index 0000000..db925d3 --- /dev/null +++ b/libmisc/high_water_alloc.c @@ -0,0 +1,45 @@ +/* + File: high_water_alloc.c + + Copyright (C) 2001-2002 Silicon Graphics, Inc. All Rights Reserved. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU Library 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 + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with this library; if not, write to the Free Software + Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. +*/ + +#include <stdio.h> +#include <stdlib.h> +#include "misc.h" + +int high_water_alloc(void **buf, size_t *bufsize, size_t newsize) +{ +#define CHUNK_SIZE 256 + /* + * Goal here is to avoid unnecessary memory allocations by + * using static buffers which only grow when necessary. + * Size is increased in fixed size chunks (CHUNK_SIZE). + */ + if (*bufsize < newsize) { + void *newbuf; + + newsize = (newsize + CHUNK_SIZE-1) & ~(CHUNK_SIZE-1); + newbuf = realloc(*buf, newsize); + if (!newbuf) + return 1; + + *buf = newbuf; + *bufsize = newsize; + } + return 0; +} |