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