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         unsigned 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         struct strbuf query_result = STRBUF_INIT;
 133         int query_success = 0;
 134         size_t bol; /* beginning of line */
 135         uint64_t last_update;
 136         char *buf;
 137         unsigned int i;
 138
 139         if (!core_fsmonitor || istate->fsmonitor_has_run_once)
 140                 return;
 141         istate->fsmonitor_has_run_once = 1;
 142
 143         trace_printf_key(&trace_fsmonitor, "refresh fsmonitor");
 144         /*
 145          * This could be racy so save the date/time now and query_fsmonitor
 146          * should be inclusive to ensure we don't miss potential changes.
 147          */
 148         last_update = getnanotime();
 149
 150         /*
 151          * If we have a last update time, call query_fsmonitor for the set of
 152          * changes since that time, else assume everything is possibly dirty
 153          * and check it all.
 154          */
 155         if (istate->fsmonitor_last_update) {
 156                 query_success = !query_fsmonitor(HOOK_INTERFACE_VERSION,
 157                         istate->fsmonitor_last_update, &query_result);
 158                 trace_performance_since(last_update, "fsmonitor process '%s'", core_fsmonitor);
 159                 trace_printf_key(&trace_fsmonitor, "fsmonitor process '%s' returned %s",
 160                         core_fsmonitor, query_success ? "success" : "failure");
 161         }
 162
 163         /* a fsmonitor process can return '/' to indicate all entries are invalid */
 164         if (query_success && query_result.buf[0] != '/') {
 165                 /* Mark all entries returned by the monitor as dirty */
 166                 buf = query_result.buf;
 167                 bol = 0;
 168                 for (i = 0; i < query_result.len; i++) {
 169                         if (buf[i] != '\0')
 170                                 continue;
 171                         fsmonitor_refresh_callback(istate, buf + bol);
 172                         bol = i + 1;
 173                 }
 174                 if (bol < query_result.len)
 175                         fsmonitor_refresh_callback(istate, buf + bol);
 176         } else {
 177                 /* Mark all entries invalid */
 178                 for (i = 0; i < istate->cache_nr; i++)
 179                         istate->cache[i]->ce_flags &= ~CE_FSMONITOR_VALID;
 180
 181                 /* If we're going to check every file, ensure we save the results */
 182                 istate->cache_changed |= FSMONITOR_CHANGED;
 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         unsigned 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         unsigned 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 }