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