diff options
Diffstat (limited to 'debian/htdig/htdig-3.2.0b6/htlib/realloc.c')
| -rw-r--r-- | debian/htdig/htdig-3.2.0b6/htlib/realloc.c | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/debian/htdig/htdig-3.2.0b6/htlib/realloc.c b/debian/htdig/htdig-3.2.0b6/htlib/realloc.c new file mode 100644 index 00000000..2d31766a --- /dev/null +++ b/debian/htdig/htdig-3.2.0b6/htlib/realloc.c @@ -0,0 +1,146 @@ +/* Change the size of a block allocated by `malloc'. + Copyright 1990, 1991, 1992, 1993 Free Software Foundation, Inc. + Written May 1989 by Mike Haertel. + +This library 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 library 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; see the file COPYING.LIB. If +not, write to the Free Software Foundation, Inc., 675 Mass Ave, +Cambridge, MA 02139, USA. + + The author may be reached (Email) at the address mike@ai.mit.edu, + or (US mail) as Mike Haertel c/o Free Software Foundation. */ + +#ifndef _MALLOC_INTERNAL +#define _MALLOC_INTERNAL +#include <malloc.h> +#endif + +#define min(A, B) ((A) < (B) ? (A) : (B)) + +/* Debugging hook for realloc. */ +__ptr_t (*__realloc_hook) __P ((__ptr_t __ptr, size_t __size)); + +/* Resize the given region to the new size, returning a pointer + to the (possibly moved) region. This is optimized for speed; + some benchmarks seem to indicate that greater compactness is + achieved by unconditionally allocating and copying to a + new region. This module has incestuous knowledge of the + internals of both free and malloc. */ +__ptr_t +realloc (ptr, size) + __ptr_t ptr; + size_t size; +{ + __ptr_t result; + int type; + size_t block, blocks, oldlimit; + + if (size == 0) + { + free (ptr); + return malloc (0); + } + else if (ptr == NULL) + return malloc (size); + + if (__realloc_hook != NULL) + return (*__realloc_hook) (ptr, size); + + block = BLOCK (ptr); + + type = _heapinfo[block].busy.type; + switch (type) + { + case 0: + /* Maybe reallocate a large block to a small fragment. */ + if (size <= BLOCKSIZE / 2) + { + result = malloc (size); + if (result != NULL) + { + memcpy (result, ptr, size); + free (ptr); + return result; + } + } + + /* The new size is a large allocation as well; + see if we can hold it in place. */ + blocks = BLOCKIFY (size); + if (blocks < _heapinfo[block].busy.info.size) + { + /* The new size is smaller; return + excess memory to the free list. */ + _heapinfo[block + blocks].busy.type = 0; + _heapinfo[block + blocks].busy.info.size + = _heapinfo[block].busy.info.size - blocks; + _heapinfo[block].busy.info.size = blocks; + free (ADDRESS (block + blocks)); + result = ptr; + } + else if (blocks == _heapinfo[block].busy.info.size) + /* No size change necessary. */ + result = ptr; + else + { + /* Won't fit, so allocate a new region that will. + Free the old region first in case there is sufficient + adjacent free space to grow without moving. */ + blocks = _heapinfo[block].busy.info.size; + /* Prevent free from actually returning memory to the system. */ + oldlimit = _heaplimit; + _heaplimit = 0; + free (ptr); + _heaplimit = oldlimit; + result = malloc (size); + if (result == NULL) + { + /* Now we're really in trouble. We have to unfree + the thing we just freed. Unfortunately it might + have been coalesced with its neighbors. */ + if (_heapindex == block) + (void) malloc (blocks * BLOCKSIZE); + else + { + __ptr_t previous = malloc ((block - _heapindex) * BLOCKSIZE); + (void) malloc (blocks * BLOCKSIZE); + free (previous); + } + return NULL; + } + if (ptr != result) + memmove (result, ptr, blocks * BLOCKSIZE); + } + break; + + default: + /* Old size is a fragment; type is logarithm + to base two of the fragment size. */ + if (size > (size_t) (1 << (type - 1)) && size <= (size_t) (1 << type)) + /* The new size is the same kind of fragment. */ + result = ptr; + else + { + /* The new size is different; allocate a new space, + and copy the lesser of the new size and the old. */ + result = malloc (size); + if (result == NULL) + return NULL; + memcpy (result, ptr, min (size, (size_t) 1 << type)); + free (ptr); + } + break; + } + + return result; +} |