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 = istate->cache[pos];
  18
  19         ce->ce_flags &= ~CE_FSMONITOR_VALID;
  20 }
  21
  22 int read_fsmonitor_extension(struct index_state *istate, const void *data,
  23         unsigned long sz)
  24 {
  25         const char *index = data;
  26         uint32_t hdr_version;
  27         uint32_t ewah_size;
  28         struct ewah_bitmap *fsmonitor_dirty;
  29         int i;
  30         int ret;
  31
  32         if (sz < sizeof(uint32_t) + sizeof(uint64_t) + sizeof(uint32_t))
  33                 return error("corrupt fsmonitor extension (too short)");
  34
  35         hdr_version = get_be32(index);
  36         index += sizeof(uint32_t);
  37         if (hdr_version != INDEX_EXTENSION_VERSION)
  38                 return error("bad fsmonitor version %d", hdr_version);
  39
  40         istate->fsmonitor_last_update = get_be64(index);
  41         index += sizeof(uint64_t);
  42
  43         ewah_size = get_be32(index);
  44         index += sizeof(uint32_t);
  45
  46         fsmonitor_dirty = ewah_new();
  47         ret = ewah_read_mmap(fsmonitor_dirty, index, ewah_size);
  48         if (ret != ewah_size) {
  49                 ewah_free(fsmonitor_dirty);
  50                 return error("failed to parse ewah bitmap reading fsmonitor index extension");
  51         }
  52
  53         if (git_config_get_fsmonitor()) {
  54                 /* Mark all entries valid */
  55                 for (i = 0; i < istate->cache_nr; i++)
  56                         istate->cache[i]->ce_flags |= CE_FSMONITOR_VALID;
  57
  58                 /* Mark all previously saved entries as dirty */
  59                 ewah_each_bit(fsmonitor_dirty, fsmonitor_ewah_callback, istate);
  60
  61                 /* Now mark the untracked cache for fsmonitor usage */
  62                 if (istate->untracked)
  63                         istate->untracked->use_fsmonitor = 1;
  64         }
  65         ewah_free(fsmonitor_dirty);
  66
  67         trace_printf_key(&trace_fsmonitor, "read fsmonitor extension successful");
  68         return 0;
  69 }
  70
  71 void write_fsmonitor_extension(struct strbuf *sb, struct index_state *istate)
  72 {
  73         uint32_t hdr_version;
  74         uint64_t tm;
  75         struct ewah_bitmap *bitmap;
  76         int i;
  77         uint32_t ewah_start;
  78         uint32_t ewah_size = 0;
  79         int fixup = 0;
  80
  81         put_be32(&hdr_version, INDEX_EXTENSION_VERSION);
  82         strbuf_add(sb, &hdr_version, sizeof(uint32_t));
  83
  84         put_be64(&tm, istate->fsmonitor_last_update);
  85         strbuf_add(sb, &tm, sizeof(uint64_t));
  86         fixup = sb->len;
  87         strbuf_add(sb, &ewah_size, sizeof(uint32_t)); /* we'll fix this up later */
  88
  89         ewah_start = sb->len;
  90         bitmap = ewah_new();
  91         for (i = 0; i < istate->cache_nr; i++)
  92                 if (!(istate->cache[i]->ce_flags & CE_FSMONITOR_VALID))
  93                         ewah_set(bitmap, i);
  94         ewah_serialize_strbuf(bitmap, sb);
  95         ewah_free(bitmap);
  96
  97         /* fix up size field */
  98         put_be32(&ewah_size, sb->len - ewah_start);
  99         memcpy(sb->buf + fixup, &ewah_size, sizeof(uint32_t));
 100
 101         trace_printf_key(&trace_fsmonitor, "write fsmonitor extension successful");
 102 }
 103
 104 /*
 105  * Call the query-fsmonitor hook passing the time of the last saved results.
 106  */
 107 static int query_fsmonitor(int version, uint64_t last_update, struct strbuf *query_result)
 108 {
 109         struct child_process cp = CHILD_PROCESS_INIT;
 110         char ver[64];
 111         char date[64];
 112         const char *argv[4];
 113
 114         if (!(argv[0] = core_fsmonitor))
 115                 return -1;
 116
 117         snprintf(ver, sizeof(version), "%d", version);
 118         snprintf(date, sizeof(date), "%" PRIuMAX, (uintmax_t)last_update);
 119         argv[1] = ver;
 120         argv[2] = date;
 121         argv[3] = NULL;
 122         cp.argv = argv;
 123         cp.use_shell = 1;
 124
 125         return capture_command(&cp, query_result, 1024);
 126 }
 127
 128 static void fsmonitor_refresh_callback(struct index_state *istate, const char *name)
 129 {
 130         int pos = index_name_pos(istate, name, strlen(name));
 131
 132         if (pos >= 0) {
 133                 struct cache_entry *ce = istate->cache[pos];
 134                 ce->ce_flags &= ~CE_FSMONITOR_VALID;
 135         }
 136
 137         /*
 138          * Mark the untracked cache dirty even if it wasn't found in the index
 139          * as it could be a new untracked file.
 140          */
 141         trace_printf_key(&trace_fsmonitor, "fsmonitor_refresh_callback '%s'", name);
 142         untracked_cache_invalidate_path(istate, name);
 143 }
 144
 145 void refresh_fsmonitor(struct index_state *istate)
 146 {
 147         static int has_run_once = 0;
 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         int i;
 154
 155         if (!core_fsmonitor || has_run_once)
 156                 return;
 157         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 (istate->untracked)
 198                         istate->untracked->use_fsmonitor = 0;
 199         }
 200         strbuf_release(&query_result);
 201
 202         /* Now that we've updated istate, save the last_update time */
 203         istate->fsmonitor_last_update = last_update;
 204 }
 205
 206 void add_fsmonitor(struct index_state *istate)
 207 {
 208         int i;
 209
 210         if (!istate->fsmonitor_last_update) {
 211                 trace_printf_key(&trace_fsmonitor, "add fsmonitor");
 212                 istate->cache_changed |= FSMONITOR_CHANGED;
 213                 istate->fsmonitor_last_update = getnanotime();
 214
 215                 /* reset the fsmonitor state */
 216                 for (i = 0; i < istate->cache_nr; i++)
 217                         istate->cache[i]->ce_flags &= ~CE_FSMONITOR_VALID;
 218
 219                 /* reset the untracked cache */
 220                 if (istate->untracked) {
 221                         add_untracked_cache(istate);
 222                         istate->untracked->use_fsmonitor = 1;
 223                 }
 224
 225                 /* Update the fsmonitor state */
 226                 refresh_fsmonitor(istate);
 227         }
 228 }
 229
 230 void remove_fsmonitor(struct index_state *istate)
 231 {
 232         if (istate->fsmonitor_last_update) {
 233                 trace_printf_key(&trace_fsmonitor, "remove fsmonitor");
 234                 istate->cache_changed |= FSMONITOR_CHANGED;
 235                 istate->fsmonitor_last_update = 0;
 236         }
 237 }
 238
 239 void tweak_fsmonitor(struct index_state *istate)
 240 {
 241         switch (git_config_get_fsmonitor()) {
 242         case -1: /* keep: do nothing */
 243                 break;
 244         case 0: /* false */
 245                 remove_fsmonitor(istate);
 246                 break;
 247         case 1: /* true */
 248                 add_fsmonitor(istate);
 249                 break;
 250         default: /* unknown value: do nothing */
 251                 break;
 252         }
 253 }