diff options
Diffstat (limited to 'third_party/git/fsmonitor.c')
| -rw-r--r-- | third_party/git/fsmonitor.c | 362 |
1 files changed, 362 insertions, 0 deletions
diff --git a/third_party/git/fsmonitor.c b/third_party/git/fsmonitor.c new file mode 100644 index 000000000000..932bd9012daf --- /dev/null +++ b/third_party/git/fsmonitor.c @@ -0,0 +1,362 @@ +#include "cache.h" +#include "config.h" +#include "dir.h" +#include "ewah/ewok.h" +#include "fsmonitor.h" +#include "run-command.h" +#include "strbuf.h" + +#define INDEX_EXTENSION_VERSION1 (1) +#define INDEX_EXTENSION_VERSION2 (2) +#define HOOK_INTERFACE_VERSION1 (1) +#define HOOK_INTERFACE_VERSION2 (2) + +struct trace_key trace_fsmonitor = TRACE_KEY_INIT(FSMONITOR); + +static void fsmonitor_ewah_callback(size_t pos, void *is) +{ + struct index_state *istate = (struct index_state *)is; + struct cache_entry *ce; + + if (pos >= istate->cache_nr) + BUG("fsmonitor_dirty has more entries than the index (%"PRIuMAX" >= %u)", + (uintmax_t)pos, istate->cache_nr); + + ce = istate->cache[pos]; + ce->ce_flags &= ~CE_FSMONITOR_VALID; +} + +static int fsmonitor_hook_version(void) +{ + int hook_version; + + if (git_config_get_int("core.fsmonitorhookversion", &hook_version)) + return -1; + + if (hook_version == HOOK_INTERFACE_VERSION1 || + hook_version == HOOK_INTERFACE_VERSION2) + return hook_version; + + warning("Invalid hook version '%i' in core.fsmonitorhookversion. " + "Must be 1 or 2.", hook_version); + return -1; +} + +int read_fsmonitor_extension(struct index_state *istate, const void *data, + unsigned long sz) +{ + const char *index = data; + uint32_t hdr_version; + uint32_t ewah_size; + struct ewah_bitmap *fsmonitor_dirty; + int ret; + uint64_t timestamp; + struct strbuf last_update = STRBUF_INIT; + + if (sz < sizeof(uint32_t) + 1 + sizeof(uint32_t)) + return error("corrupt fsmonitor extension (too short)"); + + hdr_version = get_be32(index); + index += sizeof(uint32_t); + if (hdr_version == INDEX_EXTENSION_VERSION1) { + timestamp = get_be64(index); + strbuf_addf(&last_update, "%"PRIu64"", timestamp); + index += sizeof(uint64_t); + } else if (hdr_version == INDEX_EXTENSION_VERSION2) { + strbuf_addstr(&last_update, index); + index += last_update.len + 1; + } else { + return error("bad fsmonitor version %d", hdr_version); + } + + istate->fsmonitor_last_update = strbuf_detach(&last_update, NULL); + + ewah_size = get_be32(index); + index += sizeof(uint32_t); + + fsmonitor_dirty = ewah_new(); + ret = ewah_read_mmap(fsmonitor_dirty, index, ewah_size); + if (ret != ewah_size) { + ewah_free(fsmonitor_dirty); + return error("failed to parse ewah bitmap reading fsmonitor index extension"); + } + istate->fsmonitor_dirty = fsmonitor_dirty; + + if (!istate->split_index && + istate->fsmonitor_dirty->bit_size > istate->cache_nr) + BUG("fsmonitor_dirty has more entries than the index (%"PRIuMAX" > %u)", + (uintmax_t)istate->fsmonitor_dirty->bit_size, istate->cache_nr); + + trace_printf_key(&trace_fsmonitor, "read fsmonitor extension successful"); + return 0; +} + +void fill_fsmonitor_bitmap(struct index_state *istate) +{ + unsigned int i, skipped = 0; + istate->fsmonitor_dirty = ewah_new(); + for (i = 0; i < istate->cache_nr; i++) { + if (istate->cache[i]->ce_flags & CE_REMOVE) + skipped++; + else if (!(istate->cache[i]->ce_flags & CE_FSMONITOR_VALID)) + ewah_set(istate->fsmonitor_dirty, i - skipped); + } +} + +void write_fsmonitor_extension(struct strbuf *sb, struct index_state *istate) +{ + uint32_t hdr_version; + uint32_t ewah_start; + uint32_t ewah_size = 0; + int fixup = 0; + + if (!istate->split_index && + istate->fsmonitor_dirty->bit_size > istate->cache_nr) + BUG("fsmonitor_dirty has more entries than the index (%"PRIuMAX" > %u)", + (uintmax_t)istate->fsmonitor_dirty->bit_size, istate->cache_nr); + + put_be32(&hdr_version, INDEX_EXTENSION_VERSION2); + strbuf_add(sb, &hdr_version, sizeof(uint32_t)); + + strbuf_addstr(sb, istate->fsmonitor_last_update); + strbuf_addch(sb, 0); /* Want to keep a NUL */ + + fixup = sb->len; + strbuf_add(sb, &ewah_size, sizeof(uint32_t)); /* we'll fix this up later */ + + ewah_start = sb->len; + ewah_serialize_strbuf(istate->fsmonitor_dirty, sb); + ewah_free(istate->fsmonitor_dirty); + istate->fsmonitor_dirty = NULL; + + /* fix up size field */ + put_be32(&ewah_size, sb->len - ewah_start); + memcpy(sb->buf + fixup, &ewah_size, sizeof(uint32_t)); + + trace_printf_key(&trace_fsmonitor, "write fsmonitor extension successful"); +} + +/* + * Call the query-fsmonitor hook passing the last update token of the saved results. + */ +static int query_fsmonitor(int version, const char *last_update, struct strbuf *query_result) +{ + struct child_process cp = CHILD_PROCESS_INIT; + + if (!core_fsmonitor) + return -1; + + argv_array_push(&cp.args, core_fsmonitor); + argv_array_pushf(&cp.args, "%d", version); + argv_array_pushf(&cp.args, "%s", last_update); + cp.use_shell = 1; + cp.dir = get_git_work_tree(); + + return capture_command(&cp, query_result, 1024); +} + +static void fsmonitor_refresh_callback(struct index_state *istate, const char *name) +{ + int pos = index_name_pos(istate, name, strlen(name)); + + if (pos >= 0) { + struct cache_entry *ce = istate->cache[pos]; + ce->ce_flags &= ~CE_FSMONITOR_VALID; + } + + /* + * Mark the untracked cache dirty even if it wasn't found in the index + * as it could be a new untracked file. + */ + trace_printf_key(&trace_fsmonitor, "fsmonitor_refresh_callback '%s'", name); + untracked_cache_invalidate_path(istate, name, 0); +} + +void refresh_fsmonitor(struct index_state *istate) +{ + struct strbuf query_result = STRBUF_INIT; + int query_success = 0, hook_version = -1; + size_t bol = 0; /* beginning of line */ + uint64_t last_update; + struct strbuf last_update_token = STRBUF_INIT; + char *buf; + unsigned int i; + + if (!core_fsmonitor || istate->fsmonitor_has_run_once) + return; + + hook_version = fsmonitor_hook_version(); + + istate->fsmonitor_has_run_once = 1; + + trace_printf_key(&trace_fsmonitor, "refresh fsmonitor"); + /* + * This could be racy so save the date/time now and query_fsmonitor + * should be inclusive to ensure we don't miss potential changes. + */ + last_update = getnanotime(); + if (hook_version == HOOK_INTERFACE_VERSION1) + strbuf_addf(&last_update_token, "%"PRIu64"", last_update); + + /* + * If we have a last update token, call query_fsmonitor for the set of + * changes since that token, else assume everything is possibly dirty + * and check it all. + */ + if (istate->fsmonitor_last_update) { + if (hook_version == -1 || hook_version == HOOK_INTERFACE_VERSION2) { + query_success = !query_fsmonitor(HOOK_INTERFACE_VERSION2, + istate->fsmonitor_last_update, &query_result); + + if (query_success) { + if (hook_version < 0) + hook_version = HOOK_INTERFACE_VERSION2; + + /* + * First entry will be the last update token + * Need to use a char * variable because static + * analysis was suggesting to use strbuf_addbuf + * but we don't want to copy the entire strbuf + * only the the chars up to the first NUL + */ + buf = query_result.buf; + strbuf_addstr(&last_update_token, buf); + if (!last_update_token.len) { + warning("Empty last update token."); + query_success = 0; + } else { + bol = last_update_token.len + 1; + } + } else if (hook_version < 0) { + hook_version = HOOK_INTERFACE_VERSION1; + if (!last_update_token.len) + strbuf_addf(&last_update_token, "%"PRIu64"", last_update); + } + } + + if (hook_version == HOOK_INTERFACE_VERSION1) { + query_success = !query_fsmonitor(HOOK_INTERFACE_VERSION1, + istate->fsmonitor_last_update, &query_result); + } + + trace_performance_since(last_update, "fsmonitor process '%s'", core_fsmonitor); + trace_printf_key(&trace_fsmonitor, "fsmonitor process '%s' returned %s", + core_fsmonitor, query_success ? "success" : "failure"); + } + + /* a fsmonitor process can return '/' to indicate all entries are invalid */ + if (query_success && query_result.buf[bol] != '/') { + /* Mark all entries returned by the monitor as dirty */ + buf = query_result.buf; + for (i = bol; i < query_result.len; i++) { + if (buf[i] != '\0') + continue; + fsmonitor_refresh_callback(istate, buf + bol); + bol = i + 1; + } + if (bol < query_result.len) + fsmonitor_refresh_callback(istate, buf + bol); + + /* Now mark the untracked cache for fsmonitor usage */ + if (istate->untracked) + istate->untracked->use_fsmonitor = 1; + } else { + + /* We only want to run the post index changed hook if we've actually changed entries, so keep track + * if we actually changed entries or not */ + int is_cache_changed = 0; + /* Mark all entries invalid */ + for (i = 0; i < istate->cache_nr; i++) { + if (istate->cache[i]->ce_flags & CE_FSMONITOR_VALID) { + is_cache_changed = 1; + istate->cache[i]->ce_flags &= ~CE_FSMONITOR_VALID; + } + } + + /* If we're going to check every file, ensure we save the results */ + if (is_cache_changed) + istate->cache_changed |= FSMONITOR_CHANGED; + + if (istate->untracked) + istate->untracked->use_fsmonitor = 0; + } + strbuf_release(&query_result); + + /* Now that we've updated istate, save the last_update_token */ + FREE_AND_NULL(istate->fsmonitor_last_update); + istate->fsmonitor_last_update = strbuf_detach(&last_update_token, NULL); +} + +void add_fsmonitor(struct index_state *istate) +{ + unsigned int i; + struct strbuf last_update = STRBUF_INIT; + + if (!istate->fsmonitor_last_update) { + trace_printf_key(&trace_fsmonitor, "add fsmonitor"); + istate->cache_changed |= FSMONITOR_CHANGED; + strbuf_addf(&last_update, "%"PRIu64"", getnanotime()); + istate->fsmonitor_last_update = strbuf_detach(&last_update, NULL); + + /* reset the fsmonitor state */ + for (i = 0; i < istate->cache_nr; i++) + istate->cache[i]->ce_flags &= ~CE_FSMONITOR_VALID; + + /* reset the untracked cache */ + if (istate->untracked) { + add_untracked_cache(istate); + istate->untracked->use_fsmonitor = 1; + } + + /* Update the fsmonitor state */ + refresh_fsmonitor(istate); + } +} + +void remove_fsmonitor(struct index_state *istate) +{ + if (istate->fsmonitor_last_update) { + trace_printf_key(&trace_fsmonitor, "remove fsmonitor"); + istate->cache_changed |= FSMONITOR_CHANGED; + FREE_AND_NULL(istate->fsmonitor_last_update); + } +} + +void tweak_fsmonitor(struct index_state *istate) +{ + unsigned int i; + int fsmonitor_enabled = git_config_get_fsmonitor(); + + if (istate->fsmonitor_dirty) { + if (fsmonitor_enabled) { + /* Mark all entries valid */ + for (i = 0; i < istate->cache_nr; i++) { + istate->cache[i]->ce_flags |= CE_FSMONITOR_VALID; + } + + /* Mark all previously saved entries as dirty */ + if (istate->fsmonitor_dirty->bit_size > istate->cache_nr) + BUG("fsmonitor_dirty has more entries than the index (%"PRIuMAX" > %u)", + (uintmax_t)istate->fsmonitor_dirty->bit_size, istate->cache_nr); + ewah_each_bit(istate->fsmonitor_dirty, fsmonitor_ewah_callback, istate); + + refresh_fsmonitor(istate); + } + + ewah_free(istate->fsmonitor_dirty); + istate->fsmonitor_dirty = NULL; + } + + switch (fsmonitor_enabled) { + case -1: /* keep: do nothing */ + break; + case 0: /* false */ + remove_fsmonitor(istate); + break; + case 1: /* true */ + add_fsmonitor(istate); + break; + default: /* unknown value: do nothing */ + break; + } +} |