texinfo/info/nodes.h

   1 /* nodes.h -- How we represent nodes internally.
   2    $Id: nodes.h,v 1.1.1.2 1998/03/22 20:42:49 law Exp $
   3
   4    This file is part of GNU Info, a program for reading online documentation
   5    stored in Info format.
   6
   7    Copyright (C) 1993, 97 Free Software Foundation, Inc.
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 2, or (at your option)
  12    any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program; if not, write to the Free Software
  21    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  22
  23    Written by Brian Fox (bfox@ai.mit.edu). */
  24
  25 #if !defined (NODES_H)
  26 #define NODES_H
  27
  28 #include "info.h"
  29
  30 /* **************************************************************** */
  31 /*                                                                  */
  32 /*                    User Code Interface                           */
  33 /*                                                                  */
  34 /* **************************************************************** */
  35
  36 /* Callers generally only want the node itself.  This structure is used
  37    to pass node information around.  None of the information in this
  38    structure should ever be directly freed.  The structure itself can
  39    be passed to free ().  Note that NODE->parent is non-null if this
  40    node's file is a subfile.  In that case, NODE->parent is the logical
  41    name of the file containing this node.  Both names are given as full
  42    paths, so you might have: node->filename = "/usr/gnu/info/emacs-1",
  43    with node->parent = "/usr/gnu/info/emacs". */
  44 typedef struct {
  45   char *filename;               /* The physical file containing this node. */
  46   char *parent;                 /* Non-null is the logical file name. */
  47   char *nodename;               /* The name of this node. */
  48   char *contents;               /* Characters appearing in this node. */
  49   long nodelen;                 /* The length of the CONTENTS member. */
  50   int flags;                    /* See immediately below. */
  51 } NODE;
  52
  53 /* Defines that can appear in NODE->flags.  All informative. */
  54 #define N_HasTagsTable 0x01     /* This node was found through a tags table. */
  55 #define N_TagsIndirect 0x02     /* The tags table was an indirect one. */
  56 #define N_UpdateTags   0x04     /* The tags table is out of date. */
  57 #define N_IsCompressed 0x08     /* The file is compressed on disk. */
  58 #define N_IsInternal   0x10     /* This node was made by Info. */
  59 #define N_CannotGC     0x20     /* File buffer cannot be gc'ed. */
  60 #define N_IsManPage    0x40     /* This node is a Un*x manpage. */
  61 \f
  62 /* **************************************************************** */
  63 /*                                                                  */
  64 /*                     Internal Data Structures                     */
  65 /*                                                                  */
  66 /* **************************************************************** */
  67
  68 /* Some defines describing details about Info file contents. */
  69
  70 /* String Constants. */
  71 #define INFO_FILE_LABEL                 "File:"
  72 #define INFO_NODE_LABEL                 "Node:"
  73 #define INFO_PREV_LABEL                 "Prev:"
  74 #define INFO_ALTPREV_LABEL              "Previous:"
  75 #define INFO_NEXT_LABEL                 "Next:"
  76 #define INFO_UP_LABEL                   "Up:"
  77 #define INFO_MENU_LABEL                 "\n* Menu:"
  78 #define INFO_MENU_ENTRY_LABEL           "\n* "
  79 #define INFO_XREF_LABEL                 "*Note"
  80 #define TAGS_TABLE_END_LABEL            "\nEnd Tag Table"
  81 #define TAGS_TABLE_BEG_LABEL            "Tag Table:\n"
  82 #define INDIRECT_TAGS_TABLE_LABEL       "Indirect:\n"
  83 #define TAGS_TABLE_IS_INDIRECT_LABEL    "(Indirect)"
  84
  85 /* Character Constants. */
  86 #define INFO_COOKIE '\037'
  87 #define INFO_FF     '\014'
  88 #define INFO_TAGSEP '\177'
  89
  90 /* For each logical file that we have loaded, we keep a list of the names
  91    of the nodes that are found in that file.  A pointer to a node in an
  92    info file is called a "tag".  For split files, the tag pointer is
  93    "indirect"; that is, the pointer also contains the name of the split
  94    file where the node can be found.  For non-split files, the filename
  95    member in the structure below simply contains the name of the current
  96    file.  The following structure describes a single node within a file. */
  97 typedef struct {
  98   char *filename;               /* The file where this node can be found. */
  99   char *nodename;               /* The node pointed to by this tag. */
 100   long nodestart;               /* The offset of the start of this node. */
 101   long nodelen;                 /* The length of this node. */
 102 } TAG;
 103
 104 /* The following structure is used to remember information about the contents
 105    of Info files that we have loaded at least once before.  The FINFO member
 106    is present so that we can reload the file if it has been modified since
 107    last being loaded.  All of the arrays appearing within this structure
 108    are NULL terminated, and each array which can change size has a
 109    corresponding SLOTS member which says how many slots have been allocated
 110    (with malloc ()) for this array. */
 111 typedef struct {
 112   char *filename;               /* The filename used to find this file. */
 113   char *fullpath;               /* The full pathname of this info file. */
 114   struct stat finfo;            /* Information about this file. */
 115   char *contents;               /* The contents of this particular file. */
 116   long filesize;                /* The number of bytes this file expands to. */
 117   char **subfiles;              /* If non-null, the list of subfiles. */
 118   TAG **tags;                   /* If non-null, the indirect tags table. */
 119   int tags_slots;               /* Number of slots allocated for TAGS. */
 120   int flags;                    /* Various flags.  Mimics of N_* flags. */
 121 } FILE_BUFFER;
 122
 123 /* **************************************************************** */
 124 /*                                                                  */
 125 /*                  Externally Visible Functions                    */
 126 /*                                                                  */
 127 /* **************************************************************** */
 128
 129 /* Array of FILE_BUFFER * which represents the currently loaded info files. */
 130 extern FILE_BUFFER **info_loaded_files;
 131
 132 /* The number of slots currently allocated to INFO_LOADED_FILES. */
 133 extern int info_loaded_files_slots;
 134
 135 /* Locate the file named by FILENAME, and return the information structure
 136    describing this file.  The file may appear in our list of loaded files
 137    already, or it may not.  If it does not already appear, find the file,
 138    and add it to the list of loaded files.  If the file cannot be found,
 139    return a NULL FILE_BUFFER *. */
 140 extern FILE_BUFFER *info_find_file ();
 141
 142 /* Force load the file named FILENAME, and return the information structure
 143    describing this file.  Even if the file was already loaded, this loads
 144    a new buffer, rebuilds tags and nodes, and returns a new FILE_BUFFER *. */
 145 extern FILE_BUFFER *info_load_file ();
 146
 147 /* Return a pointer to a NODE structure for the Info node (FILENAME)NODENAME.
 148    FILENAME can be passed as NULL, in which case the filename of "dir" is used.
 149    NODENAME can be passed as NULL, in which case the nodename of "Top" is used.
 150    If the node cannot be found, return a NULL pointer. */
 151 extern NODE *info_get_node ();
 152
 153 /* Return a pointer to a NODE structure for the Info node NODENAME in
 154    FILE_BUFFER.  NODENAME can be passed as NULL, in which case the
 155    nodename of "Top" is used.  If the node cannot be found, return a
 156    NULL pointer. */
 157 extern NODE *info_get_node_of_file_buffer ();
 158
 159 /* Grovel FILE_BUFFER->contents finding tags and nodes, and filling in the
 160    various slots.  This can also be used to rebuild a tag or node table. */
 161 extern void build_tags_and_nodes ();
 162
 163 /* When non-zero, this is a string describing the most recent file error. */
 164 extern char *info_recent_file_error;
 165
 166 /* Create a new, empty file buffer. */
 167 extern FILE_BUFFER *make_file_buffer ();
 168
 169 #endif /* !NODES_H */