Andrew's git - gitweb.git/blob

   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
  12struct trace_key trace_fsmonitor = TRACE_KEY_INIT(FSMONITOR);
  13
  14static 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
  22int 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
  71void 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 */
 107static 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
 128static 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
 145void 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
 206void 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
 230void 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
 239void 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}