1 /* gc.c -- Functions to remember and garbage collect unused node contents. */ 2 3 /* This file is part of GNU Info, a program for reading online documentation 4 stored in Info format. 5 6 Copyright (C) 1993 Free Software Foundation, Inc. 7 8 This program is free software; you can redistribute it and/or modify 9 it under the terms of the GNU General Public License as published by 10 the Free Software Foundation; either version 2, or (at your option) 11 any later version. 12 13 This program is distributed in the hope that it will be useful, 14 but WITHOUT ANY WARRANTY; without even the implied warranty of 15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 GNU General Public License for more details. 17 18 You should have received a copy of the GNU General Public License 19 along with this program; if not, write to the Free Software 20 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 21 22 Written by Brian Fox (bfox@ai.mit.edu). */ 23 24 #include "info.h" 25 26 /* Array of pointers to the contents of gc-able nodes. A pointer on this 27 list can be garbage collected when no info window contains a node whose 28 contents member match the pointer. */ 29 static char **gcable_pointers = (char **)NULL; 30 static int gcable_pointers_index = 0; 31 static int gcable_pointers_slots = 0; 32 33 /* Add POINTER to the list of garbage collectible pointers. A pointer 34 is not actually garbage collected until no info window contains a node 35 whose contents member is equal to the pointer. */ 36 void 37 add_gcable_pointer (pointer) 38 char *pointer; 39 { 40 gc_pointers (); 41 add_pointer_to_array (pointer, gcable_pointers_index, gcable_pointers, 42 gcable_pointers_slots, 10, char *); 43 } 44 45 /* Grovel the list of info windows and gc-able pointers finding those 46 node->contents which are collectible, and free them. */ 47 void 48 gc_pointers () 49 { 50 register int i, j, k; 51 INFO_WINDOW *iw; 52 char **new = (char **)NULL; 53 int new_index = 0; 54 int new_slots = 0; 55 56 if (!info_windows || !gcable_pointers_index) 57 return; 58 59 for (i = 0; (iw = info_windows[i]); i++) 60 { 61 for (j = 0; j < iw->nodes_index; j++) 62 { 63 NODE *node = iw->nodes[j]; 64 65 /* If this node->contents appears in our list of gcable_pointers, 66 it is not gc-able, so save it. */ 67 for (k = 0; k < gcable_pointers_index; k++) 68 if (gcable_pointers[k] == node->contents) 69 { 70 add_pointer_to_array 71 (node->contents, new_index, new, new_slots, 10, char *); 72 break; 73 } 74 } 75 } 76 77 /* We have gathered all of the pointers which need to be saved. Free any 78 of the original pointers which do not appear in the new list. */ 79 for (i = 0; i < gcable_pointers_index; i++) 80 { 81 for (j = 0; j < new_index; j++) 82 if (gcable_pointers[i] == new[j]) 83 break; 84 85 /* If we got all the way through the new list, then the old pointer 86 can be garbage collected. */ 87 if (new && !new[j]) 88 free (gcable_pointers[i]); 89 } 90 91 free (gcable_pointers); 92 gcable_pointers = new; 93 gcable_pointers_slots = new_slots; 94 gcable_pointers_index = new_index; 95 } 96