src/watch.c

   1 /* Copyright (c) 2006-2015 Jonas Fonseca <jonas.fonseca@gmail.com>
   2  *
   3  * This program is free software; you can redistribute it and/or
   4  * modify it under the terms of the GNU General Public License as
   5  * published by the Free Software Foundation; either version 2 of
   6  * the License, or (at your option) any later version.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  */
  13
  14 #include "tig/tig.h"
  15 #include "tig/repo.h"
  16 #include "tig/refdb.h"
  17 #include "tig/io.h"
  18 #include "tig/options.h"
  19 #include "tig/watch.h"
  20
  21 static struct watch *watches;
  22
  23 void
  24 watch_register(struct watch *watch, enum watch_trigger triggers)
  25 {
  26         watch_unregister(watch);
  27
  28         watch->next = watches;
  29         watches = watch;
  30
  31         watch->triggers = triggers;
  32         watch->changed = WATCH_NONE;
  33         watch->state = WATCH_NONE;
  34 }
  35
  36 void
  37 watch_unregister(struct watch *watch)
  38 {
  39         struct watch *pos, *prev = NULL;
  40
  41         for (pos = watches; pos; prev = pos, pos = pos->next) {
  42                 if (watch != pos)
  43                         continue;
  44                 if (!prev)
  45                         watches = watch->next;
  46                 else
  47                         prev->next = watch->next;
  48                 break;
  49         }
  50
  51         memset(watch, 0, sizeof(*watch));
  52 }
  53
  54 struct watch_handler {
  55         enum watch_trigger (*check)(struct watch_handler *handler, enum watch_event event, enum watch_trigger check);
  56         enum watch_trigger triggers;
  57         time_t last_modified;
  58 };
  59
  60 static bool
  61 check_file_mtime(time_t *last_modified, const char *path_fmt, ...)
  62 {
  63         char path[SIZEOF_STR];
  64         struct stat stat;
  65         int retval;
  66
  67         FORMAT_BUFFER(path, sizeof(path), path_fmt, retval, false);
  68
  69         if (retval < 0 ||
  70             lstat(path, &stat) < 0 ||
  71             stat.st_mtime <= *last_modified)
  72                 return false;
  73
  74         *last_modified = stat.st_mtime;
  75         return true;
  76 }
  77
  78 static enum watch_trigger
  79 watch_head_handler(struct watch_handler *handler, enum watch_event event, enum watch_trigger check)
  80 {
  81         const struct ref *head;
  82
  83         if (check_file_mtime(&handler->last_modified, "%s/HEAD", repo.git_dir))
  84                 return WATCH_HEAD;
  85
  86         // FIXME: check branch
  87         if ((head = get_ref_head()) &&
  88             check_file_mtime(&handler->last_modified, "%s/refs/head/%s", repo.git_dir, head->name))
  89                 return WATCH_HEAD;
  90
  91         return WATCH_NONE;
  92 }
  93
  94 static enum watch_trigger
  95 watch_stash_handler(struct watch_handler *handler, enum watch_event event, enum watch_trigger check)
  96 {
  97         if (check_file_mtime(&handler->last_modified, "%s/refs/stash", repo.git_dir))
  98                 return WATCH_STASH;
  99
 100         return WATCH_NONE;
 101 }
 102
 103 static enum watch_trigger
 104 watch_index_handler(struct watch_handler *handler, enum watch_event event, enum watch_trigger check)
 105 {
 106         enum watch_trigger changed = WATCH_NONE;
 107         struct index_diff diff;
 108
 109         if (event == WATCH_EVENT_AFTER_COMMAND)
 110                 return check_file_mtime(&handler->last_modified, "%s/index", repo.git_dir)
 111                         ? check : WATCH_NONE;
 112
 113         if (!check_file_mtime(&handler->last_modified, "%s/index", repo.git_dir) ||
 114             event == WATCH_EVENT_SWITCH_VIEW ||
 115             !index_diff(&diff, false, false))
 116                 return WATCH_NONE;
 117
 118         if (check & WATCH_INDEX_STAGED) {
 119                 if (diff.staged)
 120                         changed |= WATCH_INDEX_STAGED_YES;
 121                 else
 122                         changed |= WATCH_INDEX_STAGED_NO;
 123         }
 124
 125         if (check & WATCH_INDEX_UNSTAGED) {
 126                 if (diff.unstaged)
 127                         changed |= WATCH_INDEX_UNSTAGED_YES;
 128                 else
 129                         changed |= WATCH_INDEX_UNSTAGED_NO;
 130         }
 131
 132         if (changed)
 133                 handler->last_modified = time(NULL);
 134
 135         return changed;
 136 }
 137
 138 static enum watch_trigger
 139 watch_refs_handler(struct watch_handler *handler, enum watch_event event,
 140                    enum watch_trigger check)
 141 {
 142         if (event == WATCH_EVENT_AFTER_COMMAND)
 143                 load_refs(true);
 144
 145         return WATCH_NONE;
 146 }
 147
 148 static struct watch_handler watch_handlers[] = {
 149         { watch_index_handler, WATCH_INDEX },
 150         { watch_head_handler, WATCH_HEAD },
 151         { watch_stash_handler, WATCH_STASH },
 152         { watch_refs_handler, WATCH_HEAD | WATCH_REFS },
 153 };
 154
 155 static bool
 156 watch_no_refresh(enum watch_event event)
 157 {
 158         return opt_refresh_mode == REFRESH_MODE_MANUAL ||
 159                (opt_refresh_mode == REFRESH_MODE_AFTER_COMMAND &&
 160                 event != WATCH_EVENT_AFTER_COMMAND);
 161 }
 162
 163 static void
 164 watch_apply_changes(struct watch *source, enum watch_event event,
 165                     enum watch_trigger changed)
 166 {
 167         struct watch *watch;
 168
 169         if (watch_no_refresh(event))
 170                 return;
 171
 172         for (watch = watches; watch; watch = watch->next) {
 173                 enum watch_trigger triggers = changed & watch->triggers;
 174
 175                 if (source == watch) {
 176                         source->state |= triggers;
 177                         continue;
 178                 }
 179
 180                 if (event == WATCH_EVENT_AFTER_COMMAND) {
 181                         watch->state = WATCH_NONE;
 182                         triggers = watch->triggers;
 183                 }
 184
 185                 watch->changed |= triggers;
 186         }
 187 }
 188
 189 void
 190 watch_apply(struct watch *source, enum watch_trigger changed)
 191 {
 192         watch_apply_changes(source, WATCH_EVENT_LOAD, changed);
 193 }
 194
 195 static enum watch_trigger
 196 watch_update_event(enum watch_event event, enum watch_trigger trigger,
 197                    enum watch_trigger changed)
 198 {
 199         time_t timestamp = 0;
 200         int i;
 201
 202         if (watch_no_refresh(event))
 203                 return WATCH_NONE;
 204
 205         if (event == WATCH_EVENT_AFTER_COMMAND)
 206                 timestamp = time(NULL);
 207
 208         for (i = 0; i < ARRAY_SIZE(watch_handlers); i++) {
 209                 struct watch_handler *handler = &watch_handlers[i];
 210
 211                 if (event == WATCH_EVENT_AFTER_COMMAND) {
 212                         changed = handler->triggers;
 213                         handler->last_modified = timestamp;
 214                         continue;
 215                 }
 216
 217                 if (*repo.git_dir &&
 218                     (trigger & handler->triggers) &&
 219                     (changed | handler->triggers) != changed)
 220                         changed |= handler->check(handler, event, trigger);
 221         }
 222
 223         if (changed)
 224                 watch_apply_changes(NULL, event, changed);
 225
 226         return changed;
 227 }
 228
 229 #define watch_trigger_unmask(triggers, set) ((triggers) & ~(set))
 230
 231 static inline enum watch_trigger
 232 watch_unchanged_triggers(struct watch *watch)
 233 {
 234         return watch_trigger_unmask(watch->triggers, watch->changed);
 235 }
 236
 237 enum watch_trigger
 238 watch_update_single(struct watch *watch, enum watch_event event)
 239 {
 240         enum watch_trigger trigger = watch_unchanged_triggers(watch);
 241
 242         return watch_update_event(event, trigger, watch->changed);
 243 }
 244
 245 enum watch_trigger
 246 watch_update(enum watch_event event)
 247 {
 248         enum watch_trigger trigger = WATCH_NONE;
 249         struct watch *watch;
 250
 251         /* Collect triggers to check. Skkipping watches that are already
 252          * marked dirty to avoid unnecessary checks. */
 253         for (watch = watches; watch; watch = watch->next)
 254                 trigger |= watch_unchanged_triggers(watch);
 255
 256         return watch_update_event(event, trigger, WATCH_NONE);
 257 }
 258
 259 int
 260 watch_periodic(int interval)
 261 {
 262         static time_t last_update;
 263         int delay = -1;
 264
 265         if (watches && interval > 0) {
 266                 time_t now = time(NULL);
 267
 268                 if (!last_update)
 269                         last_update = now;
 270                 if (last_update + interval <= now) {
 271                         watch_update(WATCH_EVENT_PERIODIC);
 272                         last_update = now;
 273                 }
 274
 275                 delay = (now - last_update + interval) * 1000;
 276         }
 277
 278         return delay;
 279 }
 280
 281 bool
 282 watch_dirty(struct watch *watch)
 283 {
 284         enum watch_trigger old_index = watch->state & WATCH_INDEX;
 285         enum watch_trigger new_index = watch->changed & WATCH_INDEX;
 286         enum watch_trigger index = watch_trigger_unmask(new_index, old_index);
 287         enum watch_trigger other = watch_trigger_unmask(watch->changed, WATCH_INDEX);
 288         bool dirty = !!(index | other);
 289
 290         watch->changed = WATCH_NONE;
 291         return dirty;
 292 }
 293
 294 /* vim: set ts=8 sw=8 noexpandtab: */