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