freebsd-dev/gnu/usr.bin/texinfo/info/gc.c
1994-09-13 13:51:34 +00:00

96 lines
3.0 KiB
C

/* gc.c -- Functions to remember and garbage collect unused node contents. */
/* This file is part of GNU Info, a program for reading online documentation
stored in Info format.
Copyright (C) 1993 Free Software Foundation, Inc.
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, 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., 675 Mass Ave, Cambridge, MA 02139, USA.
Written by Brian Fox (bfox@ai.mit.edu). */
#include "info.h"
/* Array of pointers to the contents of gc-able nodes. A pointer on this
list can be garbage collected when no info window contains a node whose
contents member match the pointer. */
static char **gcable_pointers = (char **)NULL;
static int gcable_pointers_index = 0;
static int gcable_pointers_slots = 0;
/* Add POINTER to the list of garbage collectible pointers. A pointer
is not actually garbage collected until no info window contains a node
whose contents member is equal to the pointer. */
void
add_gcable_pointer (pointer)
char *pointer;
{
gc_pointers ();
add_pointer_to_array (pointer, gcable_pointers_index, gcable_pointers,
gcable_pointers_slots, 10, char *);
}
/* Grovel the list of info windows and gc-able pointers finding those
node->contents which are collectible, and free them. */
void
gc_pointers ()
{
register int i, j, k;
INFO_WINDOW *iw;
char **new = (char **)NULL;
int new_index = 0;
int new_slots = 0;
if (!info_windows || !gcable_pointers_index)
return;
for (i = 0; iw = info_windows[i]; i++)
{
for (j = 0; j < iw->nodes_index; j++)
{
NODE *node = iw->nodes[j];
/* If this node->contents appears in our list of gcable_pointers,
it is not gc-able, so save it. */
for (k = 0; k < gcable_pointers_index; k++)
if (gcable_pointers[k] == node->contents)
{
add_pointer_to_array
(node->contents, new_index, new, new_slots, 10, char *);
break;
}
}
}
/* We have gathered all of the pointers which need to be saved. Free any
of the original pointers which do not appear in the new list. */
for (i = 0; i < gcable_pointers_index; i++)
{
for (j = 0; j < new_index; j++)
if (gcable_pointers[i] == new[j])
break;
/* If we got all the way through the new list, then the old pointer
can be garbage collected. */
if (new && !new[j])
free (gcable_pointers[i]);
}
free (gcable_pointers);
gcable_pointers = new;
gcable_pointers_slots = new_slots;
gcable_pointers_index = new_index;
}