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
 101         if (!core_fsmonitor)
 102                 return -1;
 103
 104         argv_array_push(&cp.args, core_fsmonitor);
 105         argv_array_pushf(&cp.args, "%d", version);
 106         argv_array_pushf(&cp.args, "%" PRIuMAX, (uintmax_t)last_update);
 107         cp.use_shell = 1;
 108         cp.dir = get_git_work_tree();
 109
 110         return capture_command(&cp, query_result, 1024);
 111 }
 112
 113 static void fsmonitor_refresh_callback(struct index_state *istate, const char *name)
 114 {
 115         int pos = index_name_pos(istate, name, strlen(name));
 116
 117         if (pos >= 0) {
 118                 struct cache_entry *ce = istate->cache[pos];
 119                 ce->ce_flags &= ~CE_FSMONITOR_VALID;
 120         }
 121
 122         /*
 123          * Mark the untracked cache dirty even if it wasn't found in the index
 124          * as it could be a new untracked file.
 125          */
 126         trace_printf_key(&trace_fsmonitor, "fsmonitor_refresh_callback '%s'", name);
 127         untracked_cache_invalidate_path(istate, name, 0);
 128 }
 129
 130 void refresh_fsmonitor(struct index_state *istate)
 131 {
 132         static int has_run_once = 0;
 133         struct strbuf query_result = STRBUF_INIT;
 134         int query_success = 0;
 135         size_t bol; /* beginning of line */
 136         uint64_t last_update;
 137         char *buf;
 138         int i;
 139
 140         if (!core_fsmonitor || has_run_once)
 141                 return;
 142         has_run_once = 1;
 143
 144         trace_printf_key(&trace_fsmonitor, "refresh fsmonitor");
 145         /*
 146          * This could be racy so save the date/time now and query_fsmonitor
 147          * should be inclusive to ensure we don't miss potential changes.
 148          */
 149         last_update = getnanotime();
 150
 151         /*
 152          * If we have a last update time, call query_fsmonitor for the set of
 153          * changes since that time, else assume everything is possibly dirty
 154          * and check it all.
 155          */
 156         if (istate->fsmonitor_last_update) {
 157                 query_success = !query_fsmonitor(HOOK_INTERFACE_VERSION,
 158                         istate->fsmonitor_last_update, &query_result);
 159                 trace_performance_since(last_update, "fsmonitor process '%s'", core_fsmonitor);
 160                 trace_printf_key(&trace_fsmonitor, "fsmonitor process '%s' returned %s",
 161                         core_fsmonitor, query_success ? "success" : "failure");
 162         }
 163
 164         /* a fsmonitor process can return '/' to indicate all entries are invalid */
 165         if (query_success && query_result.buf[0] != '/') {
 166                 /* Mark all entries returned by the monitor as dirty */
 167                 buf = query_result.buf;
 168                 bol = 0;
 169                 for (i = 0; i < query_result.len; i++) {
 170                         if (buf[i] != '\0')
 171                                 continue;
 172                         fsmonitor_refresh_callback(istate, buf + bol);
 173                         bol = i + 1;
 174                 }
 175                 if (bol < query_result.len)
 176                         fsmonitor_refresh_callback(istate, buf + bol);
 177         } else {
 178                 /* Mark all entries invalid */
 179                 for (i = 0; i < istate->cache_nr; i++)
 180                         istate->cache[i]->ce_flags &= ~CE_FSMONITOR_VALID;
 181
 182                 /* If we're going to check every file, ensure we save the results */
 183                 istate->cache_changed |= FSMONITOR_CHANGED;
 184
 185                 if (istate->untracked)
 186                         istate->untracked->use_fsmonitor = 0;
 187         }
 188         strbuf_release(&query_result);
 189
 190         /* Now that we've updated istate, save the last_update time */
 191         istate->fsmonitor_last_update = last_update;
 192 }
 193
 194 void add_fsmonitor(struct index_state *istate)
 195 {
 196         int i;
 197
 198         if (!istate->fsmonitor_last_update) {
 199                 trace_printf_key(&trace_fsmonitor, "add fsmonitor");
 200                 istate->cache_changed |= FSMONITOR_CHANGED;
 201                 istate->fsmonitor_last_update = getnanotime();
 202
 203                 /* reset the fsmonitor state */
 204                 for (i = 0; i < istate->cache_nr; i++)
 205                         istate->cache[i]->ce_flags &= ~CE_FSMONITOR_VALID;
 206
 207                 /* reset the untracked cache */
 208                 if (istate->untracked) {
 209                         add_untracked_cache(istate);
 210                         istate->untracked->use_fsmonitor = 1;
 211                 }
 212
 213                 /* Update the fsmonitor state */
 214                 refresh_fsmonitor(istate);
 215         }
 216 }
 217
 218 void remove_fsmonitor(struct index_state *istate)
 219 {
 220         if (istate->fsmonitor_last_update) {
 221                 trace_printf_key(&trace_fsmonitor, "remove fsmonitor");
 222                 istate->cache_changed |= FSMONITOR_CHANGED;
 223                 istate->fsmonitor_last_update = 0;
 224         }
 225 }
 226
 227 void tweak_fsmonitor(struct index_state *istate)
 228 {
 229         int i;
 230         int fsmonitor_enabled = git_config_get_fsmonitor();
 231
 232         if (istate->fsmonitor_dirty) {
 233                 if (fsmonitor_enabled) {
 234                         /* Mark all entries valid */
 235                         for (i = 0; i < istate->cache_nr; i++) {
 236                                 istate->cache[i]->ce_flags |= CE_FSMONITOR_VALID;
 237                         }
 238
 239                         /* Mark all previously saved entries as dirty */
 240                         ewah_each_bit(istate->fsmonitor_dirty, fsmonitor_ewah_callback, istate);
 241
 242                         /* Now mark the untracked cache for fsmonitor usage */
 243                         if (istate->untracked)
 244                                 istate->untracked->use_fsmonitor = 1;
 245                 }
 246
 247                 ewah_free(istate->fsmonitor_dirty);
 248                 istate->fsmonitor_dirty = NULL;
 249         }
 250
 251         switch (fsmonitor_enabled) {
 252         case -1: /* keep: do nothing */
 253                 break;
 254         case 0: /* false */
 255                 remove_fsmonitor(istate);
 256                 break;
 257         case 1: /* true */
 258                 add_fsmonitor(istate);
 259                 break;
 260         default: /* unknown value: do nothing */
 261                 break;
 262         }
 263 }