nucleus/library/configuration/config_watcher.cpp

   1 /*****************************************************************************\
   2 *                                                                             *
   3 *  Name   : config_watcher                                                    *
   4 *  Author : Chris Koeritz                                                     *
   5 *                                                                             *
   6 *******************************************************************************
   7 * Copyright (c) 2008-$now By Author.  This program is free software; you can  *
   8 * redistribute it and/or modify it under the terms of the GNU General Public  *
   9 * License as published by the Free Software Foundation; either version 2 of   *
  10 * the License or (at your option) any later version.  This is online at:      *
  11 *     http://www.fsf.org/copyleft/gpl.html                                    *
  12 * Please send any updates to: fred@gruntose.com                               *
  13 \*****************************************************************************/
  14
  15 #include "config_watcher.h"
  16
  17 #include <basis/functions.h>
  18 #include <configuration/table_configurator.h>
  19 #include <structures/set.h>
  20 #include <structures/string_table.h>
  21
  22 using namespace basis;
  23 using namespace structures;
  24
  25 namespace configuration {
  26
  27 config_watcher::config_watcher(configurator &to_watch)
  28 : _watching(to_watch),
  29   _current_config(new table_configurator),
  30   _previous_config(new table_configurator)
  31 {
  32   rescan();  // fill out our lists.
  33 }
  34
  35 config_watcher::~config_watcher()
  36 {
  37   WHACK(_current_config);
  38   WHACK(_previous_config);
  39 }
  40
  41 bool config_watcher::rescan()
  42 {
  43   // copy the current configuration into our previous config tracker.
  44   *_previous_config = *_current_config;
  45   // clean out any current items held.
  46   _current_config->reset();
  47
  48   // iterate across the sections in the watched config.
  49   string_set sects;
  50   _watching.section_set(sects);
  51   for (int sectindy = 0; sectindy < sects.length(); sectindy++) {
  52     // every entry in the current section gets added to our current config.
  53     astring curr_section = sects[sectindy];
  54     string_table entries;
  55         _watching.get_section(curr_section, entries);
  56     _current_config->put_section(curr_section, entries);
  57   }
  58
  59   return true;
  60 }
  61
  62 string_set config_watcher::new_sections() const
  63 {
  64   string_set before;
  65   _previous_config->section_set(before);
  66   string_set after;
  67   _current_config->section_set(before);
  68   return after - before;
  69 }
  70
  71 string_set config_watcher::deleted_sections() const
  72 {
  73   string_set before;
  74   _previous_config->section_set(before);
  75   string_set after;
  76   _current_config->section_set(before);
  77   return before - after;
  78 }
  79
  80 string_set config_watcher::changed_sections() const
  81 {
  82   string_set before;
  83   _previous_config->section_set(before);
  84   string_set after;
  85   _current_config->section_set(before);
  86   string_set possible_changes = before.intersection(after);
  87   string_set definite_changes;
  88   for (int i = 0; i < possible_changes.elements(); i++) {
  89     const astring &sect_name = possible_changes[i];
  90     string_table previous_section;
  91     _previous_config->get_section(sect_name, previous_section);
  92     string_table current_section;
  93     _current_config->get_section(sect_name, current_section);
  94     if (current_section != previous_section)
  95       definite_changes += sect_name;
  96   }
  97   return definite_changes;
  98 }
  99
 100 string_set config_watcher::deleted_items(const astring &section_name)
 101 {
 102   string_table previous_section;
 103   _previous_config->get_section(section_name, previous_section);
 104   string_set previous_names;
 105   previous_section.names(previous_names);
 106   string_table current_section;
 107   _current_config->get_section(section_name, current_section);
 108   string_set current_names;
 109   current_section.names(current_names);
 110   return previous_names - current_names;
 111 }
 112
 113 string_set config_watcher::new_items(const astring &section_name)
 114 {
 115   string_table previous_section;
 116   _previous_config->get_section(section_name, previous_section);
 117   string_set previous_names;
 118   previous_section.names(previous_names);
 119   string_table current_section;
 120   _current_config->get_section(section_name, current_section);
 121   string_set current_names;
 122   current_section.names(current_names);
 123   return current_names - previous_names;
 124 }
 125
 126 string_set config_watcher::changed_items(const astring &section_name)
 127 {
 128   string_table previous_section;
 129   _previous_config->get_section(section_name, previous_section);
 130   string_set previous_names;
 131   previous_section.names(previous_names);
 132   string_table current_section;
 133   _current_config->get_section(section_name, current_section);
 134   string_set current_names;
 135   current_section.names(current_names);
 136
 137   string_set possible_changes = current_names.intersection(previous_names);
 138   string_set definite_changes;
 139   for (int i = 0; i < possible_changes.elements(); i++) {
 140     const astring &curr_item = possible_changes[i];
 141     astring prev_value;
 142     _previous_config->get(section_name, curr_item, prev_value);
 143     astring curr_value;
 144     _current_config->get(section_name, curr_item, curr_value);
 145     if (prev_value != curr_value)
 146       definite_changes += curr_item;
 147   }
 148   return definite_changes;
 149 }
 150
 151 } //namespace.
 152
 153