fsmonitor.c

   1 #include "cache.h"
   2 #include "config.h"
   3 #include "dir.h"
   4 #include "ewah/ewok.h"
   5 #include "fsmonitor.h"
   6 #include "run-command.h"
   7 #include "strbuf.h"
   8
   9 #define INDEX_EXTENSION_VERSION (1)
  10 #define HOOK_INTERFACE_VERSION  (1)
  11
  12 struct trace_key trace_fsmonitor = TRACE_KEY_INIT(FSMONITOR);
  13
  14 static void fsmonitor_ewah_callback(size_t pos, void *is)
  15 {
  16         struct index_state *istate = (struct index_state *)is;
  17         struct cache_entry *ce;
  18
  19         if (pos >= istate->cache_nr)
  20                 BUG("fsmonitor_dirty has more entries than the index (%"PRIuMAX" >= %u)",
  21                     (uintmax_t)pos, istate->cache_nr);
  22
  23         ce = istate->cache[pos];
  24         ce->ce_flags &= ~CE_FSMONITOR_VALID;
  25 }
  26
  27 int read_fsmonitor_extension(struct index_state *istate, const void *data,
  28         unsigned long sz)
  29 {
  30         const char *index = data;
  31         uint32_t hdr_version;
  32         uint32_t ewah_size;
  33         struct ewah_bitmap *fsmonitor_dirty;
  34         int ret;
  35
  36         if (sz < sizeof(uint32_t) + sizeof(uint64_t) + sizeof(uint32_t))
  37                 return error("corrupt fsmonitor extension (too short)");
  38
  39         hdr_version = get_be32(index);
  40         index += sizeof(uint32_t);
  41         if (hdr_version != INDEX_EXTENSION_VERSION)
  42                 return error("bad fsmonitor version %d", hdr_version);
  43
  44         istate->fsmonitor_last_update = get_be64(index);
  45         index += sizeof(uint64_t);
  46
  47         ewah_size = get_be32(index);
  48         index += sizeof(uint32_t);
  49
  50         fsmonitor_dirty = ewah_new();
  51         ret = ewah_read_mmap(fsmonitor_dirty, index, ewah_size);
  52         if (ret != ewah_size) {
  53                 ewah_free(fsmonitor_dirty);
  54                 return error("failed to parse ewah bitmap reading fsmonitor index extension");
  55         }
  56         istate->fsmonitor_dirty = fsmonitor_dirty;
  57
  58         if (!istate->split_index &&
  59             istate->fsmonitor_dirty->bit_size > istate->cache_nr)
  60                 BUG("fsmonitor_dirty has more entries than the index (%"PRIuMAX" > %u)",
  61                     (uintmax_t)istate->fsmonitor_dirty->bit_size, istate->cache_nr);
  62
  63         trace_printf_key(&trace_fsmonitor, "read fsmonitor extension successful");
  64         return 0;
  65 }
  66
  67 void fill_fsmonitor_bitmap(struct index_state *istate)
  68 {
  69         unsigned int i, skipped = 0;
  70         istate->fsmonitor_dirty = ewah_new();
  71         for (i = 0; i < istate->cache_nr; i++) {
  72                 if (istate->cache[i]->ce_flags & CE_REMOVE)
  73                         skipped++;
  74                 else if (!(istate->cache[i]->ce_flags & CE_FSMONITOR_VALID))
  75                         ewah_set(istate->fsmonitor_dirty, i - skipped);
  76         }
  77 }
  78
  79 void write_fsmonitor_extension(struct strbuf *sb, struct index_state *istate)
  80 {
  81         uint32_t hdr_version;
  82         uint64_t tm;
  83         uint32_t ewah_start;
  84         uint32_t ewah_size = 0;
  85         int fixup = 0;
  86
  87         if (!istate->split_index &&
  88             istate->fsmonitor_dirty->bit_size > istate->cache_nr)
  89                 BUG("fsmonitor_dirty has more entries than the index (%"PRIuMAX" > %u)",
  90                     (uintmax_t)istate->fsmonitor_dirty->bit_size, istate->cache_nr);
  91
  92         put_be32(&hdr_version, INDEX_EXTENSION_VERSION);
  93         strbuf_add(sb, &hdr_version, sizeof(uint32_t));
  94
  95         put_be64(&tm, istate->fsmonitor_last_update);
  96         strbuf_add(sb, &tm, sizeof(uint64_t));
  97         fixup = sb->len;
  98         strbuf_add(sb, &ewah_size, sizeof(uint32_t)); /* we'll fix this up later */
  99
 100         ewah_start = sb->len;
 101         ewah_serialize_strbuf(istate->fsmonitor_dirty, sb);
 102         ewah_free(istate->fsmonitor_dirty);
 103         istate->fsmonitor_dirty = NULL;
 104
 105         /* fix up size field */
 106         put_be32(&ewah_size, sb->len - ewah_start);
 107         memcpy(sb->buf + fixup, &ewah_size, sizeof(uint32_t));
 108
 109         trace_printf_key(&trace_fsmonitor, "write fsmonitor extension successful");
 110 }
 111
 112 /*
 113  * Call the query-fsmonitor hook passing the time of the last saved results.
 114  */
 115 static int query_fsmonitor(int version, uint64_t last_update, struct strbuf *query_result)
 116 {
 117         struct child_process cp = CHILD_PROCESS_INIT;
 118
 119         if (!core_fsmonitor)
 120                 return -1;
 121
 122         argv_array_push(&cp.args, core_fsmonitor);
 123         argv_array_pushf(&cp.args, "%d", version);
 124         argv_array_pushf(&cp.args, "%" PRIuMAX, (uintmax_t)last_update);
 125         cp.use_shell = 1;
 126         cp.dir = get_git_work_tree();
 127
 128         return capture_command(&cp, query_result, 1024);
 129 }
 130
 131 static void fsmonitor_refresh_callback(struct index_state *istate, const char *name)
 132 {
 133         int pos = index_name_pos(istate, name, strlen(name));
 134
 135         if (pos >= 0) {
 136                 struct cache_entry *ce = istate->cache[pos];
 137                 ce->ce_flags &= ~CE_FSMONITOR_VALID;
 138         }
 139
 140         /*
 141          * Mark the untracked cache dirty even if it wasn't found in the index
 142          * as it could be a new untracked file.
 143          */
 144         trace_printf_key(&trace_fsmonitor, "fsmonitor_refresh_callback '%s'", name);
 145         untracked_cache_invalidate_path(istate, name, 0);
 146 }
 147
 148 void refresh_fsmonitor(struct index_state *istate)
 149 {
 150         struct strbuf query_result = STRBUF_INIT;
 151         int query_success = 0;
 152         size_t bol; /* beginning of line */
 153         uint64_t last_update;
 154         char *buf;
 155         unsigned int i;
 156
 157         if (!core_fsmonitor || istate->fsmonitor_has_run_once)
 158                 return;
 159         istate->fsmonitor_has_run_once = 1;
 160
 161         trace_printf_key(&trace_fsmonitor, "refresh fsmonitor");
 162         /*
 163          * This could be racy so save the date/time now and query_fsmonitor
 164          * should be inclusive to ensure we don't miss potential changes.
 165          */
 166         last_update = getnanotime();
 167
 168         /*
 169          * If we have a last update time, call query_fsmonitor for the set of
 170          * changes since that time, else assume everything is possibly dirty
 171          * and check it all.
 172          */
 173         if (istate->fsmonitor_last_update) {
 174                 query_success = !query_fsmonitor(HOOK_INTERFACE_VERSION,
 175                         istate->fsmonitor_last_update, &query_result);
 176                 trace_performance_since(last_update, "fsmonitor process '%s'", core_fsmonitor);
 177                 trace_printf_key(&trace_fsmonitor, "fsmonitor process '%s' returned %s",
 178                         core_fsmonitor, query_success ? "success" : "failure");
 179         }
 180
 181         /* a fsmonitor process can return '/' to indicate all entries are invalid */
 182         if (query_success && query_result.buf[0] != '/') {
 183                 /* Mark all entries returned by the monitor as dirty */
 184                 buf = query_result.buf;
 185                 bol = 0;
 186                 for (i = 0; i < query_result.len; i++) {
 187                         if (buf[i] != '\0')
 188                                 continue;
 189                         fsmonitor_refresh_callback(istate, buf + bol);
 190                         bol = i + 1;
 191                 }
 192                 if (bol < query_result.len)
 193                         fsmonitor_refresh_callback(istate, buf + bol);
 194
 195                 /* Now mark the untracked cache for fsmonitor usage */
 196                 if (istate->untracked)
 197                         istate->untracked->use_fsmonitor = 1;
 198         } else {
 199
 200                 /* We only want to run the post index changed hook if we've actually changed entries, so keep track
 201                  * if we actually changed entries or not */
 202                 int is_cache_changed = 0;
 203                 /* Mark all entries invalid */
 204                 for (i = 0; i < istate->cache_nr; i++) {
 205                         if (istate->cache[i]->ce_flags & CE_FSMONITOR_VALID) {
 206                                 is_cache_changed = 1;
 207                                 istate->cache[i]->ce_flags &= ~CE_FSMONITOR_VALID;
 208                         }
 209                 }
 210
 211                 /* If we're going to check every file, ensure we save the results */
 212                 if (is_cache_changed)
 213                         istate->cache_changed |= FSMONITOR_CHANGED;
 214
 215                 if (istate->untracked)
 216                         istate->untracked->use_fsmonitor = 0;
 217         }
 218         strbuf_release(&query_result);
 219
 220         /* Now that we've updated istate, save the last_update time */
 221         istate->fsmonitor_last_update = last_update;
 222 }
 223
 224 void add_fsmonitor(struct index_state *istate)
 225 {
 226         unsigned int i;
 227
 228         if (!istate->fsmonitor_last_update) {
 229                 trace_printf_key(&trace_fsmonitor, "add fsmonitor");
 230                 istate->cache_changed |= FSMONITOR_CHANGED;
 231                 istate->fsmonitor_last_update = getnanotime();
 232
 233                 /* reset the fsmonitor state */
 234                 for (i = 0; i < istate->cache_nr; i++)
 235                         istate->cache[i]->ce_flags &= ~CE_FSMONITOR_VALID;
 236
 237                 /* reset the untracked cache */
 238                 if (istate->untracked) {
 239                         add_untracked_cache(istate);
 240                         istate->untracked->use_fsmonitor = 1;
 241                 }
 242
 243                 /* Update the fsmonitor state */
 244                 refresh_fsmonitor(istate);
 245         }
 246 }
 247
 248 void remove_fsmonitor(struct index_state *istate)
 249 {
 250         if (istate->fsmonitor_last_update) {
 251                 trace_printf_key(&trace_fsmonitor, "remove fsmonitor");
 252                 istate->cache_changed |= FSMONITOR_CHANGED;
 253                 istate->fsmonitor_last_update = 0;
 254         }
 255 }
 256
 257 void tweak_fsmonitor(struct index_state *istate)
 258 {
 259         unsigned int i;
 260         int fsmonitor_enabled = git_config_get_fsmonitor();
 261
 262         if (istate->fsmonitor_dirty) {
 263                 if (fsmonitor_enabled) {
 264                         /* Mark all entries valid */
 265                         for (i = 0; i < istate->cache_nr; i++) {
 266                                 istate->cache[i]->ce_flags |= CE_FSMONITOR_VALID;
 267                         }
 268
 269                         /* Mark all previously saved entries as dirty */
 270                         if (istate->fsmonitor_dirty->bit_size > istate->cache_nr)
 271                                 BUG("fsmonitor_dirty has more entries than the index (%"PRIuMAX" > %u)",
 272                                     (uintmax_t)istate->fsmonitor_dirty->bit_size, istate->cache_nr);
 273                         ewah_each_bit(istate->fsmonitor_dirty, fsmonitor_ewah_callback, istate);
 274
 275                         refresh_fsmonitor(istate);
 276                 }
 277
 278                 ewah_free(istate->fsmonitor_dirty);
 279                 istate->fsmonitor_dirty = NULL;
 280         }
 281
 282         switch (fsmonitor_enabled) {
 283         case -1: /* keep: do nothing */
 284                 break;
 285         case 0: /* false */
 286                 remove_fsmonitor(istate);
 287                 break;
 288         case 1: /* true */
 289                 add_fsmonitor(istate);
 290                 break;
 291         default: /* unknown value: do nothing */
 292                 break;
 293         }
 294 }