| #include "cache.h" |
| #include "config.h" |
| #include "dir.h" |
| #include "ewah/ewok.h" |
| #include "fsmonitor.h" |
| #include "fsmonitor-ipc.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 assert_index_minimum(struct index_state *istate, size_t pos) |
| { |
| if (pos > istate->cache_nr) |
| BUG("fsmonitor_dirty has more entries than the index (%"PRIuMAX" > %u)", |
| (uintmax_t)pos, istate->cache_nr); |
| } |
| |
| static void fsmonitor_ewah_callback(size_t pos, void *is) |
| { |
| struct index_state *istate = (struct index_state *)is; |
| struct cache_entry *ce; |
| |
| assert_index_minimum(istate, pos + 1); |
| |
| 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) |
| assert_index_minimum(istate, istate->fsmonitor_dirty->bit_size); |
| |
| trace2_data_string("index", NULL, "extension/fsmn/read/token", |
| istate->fsmonitor_last_update); |
| trace_printf_key(&trace_fsmonitor, |
| "read fsmonitor extension successful '%s'", |
| istate->fsmonitor_last_update); |
| 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) |
| assert_index_minimum(istate, istate->fsmonitor_dirty->bit_size); |
| |
| 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)); |
| |
| trace2_data_string("index", NULL, "extension/fsmn/write/token", |
| istate->fsmonitor_last_update); |
| trace_printf_key(&trace_fsmonitor, |
| "write fsmonitor extension successful '%s'", |
| istate->fsmonitor_last_update); |
| } |
| |
| /* |
| * Call the query-fsmonitor hook passing the last update token of the saved results. |
| */ |
| static int query_fsmonitor_hook(struct repository *r, |
| int version, |
| const char *last_update, |
| struct strbuf *query_result) |
| { |
| struct child_process cp = CHILD_PROCESS_INIT; |
| int result; |
| |
| if (fsm_settings__get_mode(r) != FSMONITOR_MODE_HOOK) |
| return -1; |
| |
| strvec_push(&cp.args, fsm_settings__get_hook_path(r)); |
| strvec_pushf(&cp.args, "%d", version); |
| strvec_pushf(&cp.args, "%s", last_update); |
| cp.use_shell = 1; |
| cp.dir = get_git_work_tree(); |
| |
| trace2_region_enter("fsm_hook", "query", NULL); |
| |
| result = capture_command(&cp, query_result, 1024); |
| |
| if (result) |
| trace2_data_intmax("fsm_hook", NULL, "query/failed", result); |
| else |
| trace2_data_intmax("fsm_hook", NULL, "query/response-length", |
| query_result->len); |
| |
| trace2_region_leave("fsm_hook", "query", NULL); |
| |
| return result; |
| } |
| |
| static void fsmonitor_refresh_callback(struct index_state *istate, char *name) |
| { |
| int i, len = strlen(name); |
| int pos = index_name_pos(istate, name, len); |
| |
| trace_printf_key(&trace_fsmonitor, |
| "fsmonitor_refresh_callback '%s' (pos %d)", |
| name, pos); |
| |
| if (name[len - 1] == '/') { |
| /* |
| * The daemon can decorate directory events, such as |
| * moves or renames, with a trailing slash if the OS |
| * FS Event contains sufficient information, such as |
| * MacOS. |
| * |
| * Use this to invalidate the entire cone under that |
| * directory. |
| * |
| * We do not expect an exact match because the index |
| * does not normally contain directory entries, so we |
| * start at the insertion point and scan. |
| */ |
| if (pos < 0) |
| pos = -pos - 1; |
| |
| /* Mark all entries for the folder invalid */ |
| for (i = pos; i < istate->cache_nr; i++) { |
| if (!starts_with(istate->cache[i]->name, name)) |
| break; |
| istate->cache[i]->ce_flags &= ~CE_FSMONITOR_VALID; |
| } |
| |
| /* |
| * We need to remove the traling "/" from the path |
| * for the untracked cache. |
| */ |
| name[len - 1] = '\0'; |
| } else if (pos >= 0) { |
| /* |
| * We have an exact match for this path and can just |
| * invalidate it. |
| */ |
| istate->cache[pos]->ce_flags &= ~CE_FSMONITOR_VALID; |
| } else { |
| /* |
| * The path is not a tracked file -or- it is a |
| * directory event on a platform that cannot |
| * distinguish between file and directory events in |
| * the event handler, such as Windows. |
| * |
| * Scan as if it is a directory and invalidate the |
| * cone under it. (But remember to ignore items |
| * between "name" and "name/", such as "name-" and |
| * "name.". |
| */ |
| pos = -pos - 1; |
| |
| for (i = pos; i < istate->cache_nr; i++) { |
| if (!starts_with(istate->cache[i]->name, name)) |
| break; |
| if ((unsigned char)istate->cache[i]->name[len] > '/') |
| break; |
| if (istate->cache[i]->name[len] == '/') |
| istate->cache[i]->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. |
| */ |
| untracked_cache_invalidate_path(istate, name, 0); |
| } |
| |
| /* |
| * The number of pathnames that we need to receive from FSMonitor |
| * before we force the index to be updated. |
| * |
| * Note that any pathname within the set of received paths MAY cause |
| * cache-entry or istate flag bits to be updated and thus cause the |
| * index to be updated on disk. |
| * |
| * However, the response may contain many paths (such as ignored |
| * paths) that will not update any flag bits. And thus not force the |
| * index to be updated. (This is fine and normal.) It also means |
| * that the token will not be updated in the FSMonitor index |
| * extension. So the next Git command will find the same token in the |
| * index, make the same token-relative request, and receive the same |
| * response (plus any newly changed paths). If this response is large |
| * (and continues to grow), performance could be impacted. |
| * |
| * For example, if the user runs a build and it writes 100K object |
| * files but doesn't modify any source files, the index would not need |
| * to be updated. The FSMonitor response (after the build and |
| * relative to a pre-build token) might be 5MB. Each subsequent Git |
| * command will receive that same 100K/5MB response until something |
| * causes the index to be updated. And `refresh_fsmonitor()` will |
| * have to iterate over those 100K paths each time. |
| * |
| * Performance could be improved if we optionally force update the |
| * index after a very large response and get an updated token into |
| * the FSMonitor index extension. This should allow subsequent |
| * commands to get smaller and more current responses. |
| * |
| * The value chosen here does not need to be precise. The index |
| * will be updated automatically the first time the user touches |
| * a tracked file and causes a command like `git status` to |
| * update an mtime to be updated and/or set a flag bit. |
| */ |
| static int fsmonitor_force_update_threshold = 100; |
| |
| 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; |
| int is_trivial = 0; |
| struct repository *r = istate->repo ? istate->repo : the_repository; |
| enum fsmonitor_mode fsm_mode = fsm_settings__get_mode(r); |
| |
| if (fsm_mode <= FSMONITOR_MODE_DISABLED || |
| istate->fsmonitor_has_run_once) |
| return; |
| |
| istate->fsmonitor_has_run_once = 1; |
| |
| trace_printf_key(&trace_fsmonitor, "refresh fsmonitor"); |
| |
| if (fsm_mode == FSMONITOR_MODE_IPC) { |
| query_success = !fsmonitor_ipc__send_query( |
| istate->fsmonitor_last_update ? |
| istate->fsmonitor_last_update : "builtin:fake", |
| &query_result); |
| if (query_success) { |
| /* |
| * The response contains a series of nul terminated |
| * strings. The first is the new token. |
| * |
| * Use `char *buf` as an interlude to trick the CI |
| * static analysis to let us use `strbuf_addstr()` |
| * here (and only copy the token) rather than |
| * `strbuf_addbuf()`. |
| */ |
| buf = query_result.buf; |
| strbuf_addstr(&last_update_token, buf); |
| bol = last_update_token.len + 1; |
| is_trivial = query_result.buf[bol] == '/'; |
| if (is_trivial) |
| trace2_data_intmax("fsm_client", NULL, |
| "query/trivial-response", 1); |
| } else { |
| /* |
| * The builtin daemon is not available on this |
| * platform -OR- we failed to get a response. |
| * |
| * Generate a fake token (rather than a V1 |
| * timestamp) for the index extension. (If |
| * they switch back to the hook API, we don't |
| * want ambiguous state.) |
| */ |
| strbuf_addstr(&last_update_token, "builtin:fake"); |
| } |
| |
| goto apply_results; |
| } |
| |
| assert(fsm_mode == FSMONITOR_MODE_HOOK); |
| |
| hook_version = fsmonitor_hook_version(); |
| |
| /* |
| * This could be racy so save the date/time now and query_fsmonitor_hook |
| * 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_hook 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( |
| r, 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 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; |
| is_trivial = query_result.buf[bol] == '/'; |
| } |
| } 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( |
| r, HOOK_INTERFACE_VERSION1, |
| istate->fsmonitor_last_update, &query_result); |
| if (query_success) |
| is_trivial = query_result.buf[0] == '/'; |
| } |
| |
| if (is_trivial) |
| trace2_data_intmax("fsm_hook", NULL, |
| "query/trivial-response", 1); |
| |
| trace_performance_since(last_update, "fsmonitor process '%s'", |
| fsm_settings__get_hook_path(r)); |
| trace_printf_key(&trace_fsmonitor, |
| "fsmonitor process '%s' returned %s", |
| fsm_settings__get_hook_path(r), |
| query_success ? "success" : "failure"); |
| } |
| |
| apply_results: |
| /* |
| * The response from FSMonitor (excluding the header token) is |
| * either: |
| * |
| * [a] a (possibly empty) list of NUL delimited relative |
| * pathnames of changed paths. This list can contain |
| * files and directories. Directories have a trailing |
| * slash. |
| * |
| * [b] a single '/' to indicate the provider had no |
| * information and that we should consider everything |
| * invalid. We call this a trivial response. |
| */ |
| trace2_region_enter("fsmonitor", "apply_results", istate->repo); |
| |
| if (query_success && !is_trivial) { |
| /* |
| * Mark all pathnames returned by the monitor as dirty. |
| * |
| * This updates both the cache-entries and the untracked-cache. |
| */ |
| int count = 0; |
| |
| 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; |
| count++; |
| } |
| if (bol < query_result.len) { |
| fsmonitor_refresh_callback(istate, buf + bol); |
| count++; |
| } |
| |
| /* Now mark the untracked cache for fsmonitor usage */ |
| if (istate->untracked) |
| istate->untracked->use_fsmonitor = 1; |
| |
| if (count > fsmonitor_force_update_threshold) |
| istate->cache_changed |= FSMONITOR_CHANGED; |
| |
| trace2_data_intmax("fsmonitor", istate->repo, "apply_count", |
| count); |
| |
| } else { |
| /* |
| * We failed to get a response or received a trivial response, |
| * so invalidate everything. |
| * |
| * 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; |
| |
| 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; |
| } |
| trace2_region_leave("fsmonitor", "apply_results", istate->repo); |
| |
| 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); |
| } |
| |
| /* |
| * The caller wants to turn on FSMonitor. And when the caller writes |
| * the index to disk, a FSMonitor extension should be included. This |
| * requires that `istate->fsmonitor_last_update` not be NULL. But we |
| * have not actually talked to a FSMonitor process yet, so we don't |
| * have an initial value for this field. |
| * |
| * For a protocol V1 FSMonitor process, this field is a formatted |
| * "nanoseconds since epoch" field. However, for a protocol V2 |
| * FSMonitor process, this field is an opaque token. |
| * |
| * Historically, `add_fsmonitor()` has initialized this field to the |
| * current time for protocol V1 processes. There are lots of race |
| * conditions here, but that code has shipped... |
| * |
| * The only true solution is to use a V2 FSMonitor and get a current |
| * or default token value (that it understands), but we cannot do that |
| * until we have actually talked to an instance of the FSMonitor process |
| * (but the protocol requires that we send a token first...). |
| * |
| * For simplicity, just initialize like we have a V1 process and require |
| * that V2 processes adapt. |
| */ |
| static void initialize_fsmonitor_last_update(struct index_state *istate) |
| { |
| struct strbuf last_update = STRBUF_INIT; |
| |
| strbuf_addf(&last_update, "%"PRIu64"", getnanotime()); |
| istate->fsmonitor_last_update = strbuf_detach(&last_update, NULL); |
| } |
| |
| void add_fsmonitor(struct index_state *istate) |
| { |
| unsigned int i; |
| |
| if (!istate->fsmonitor_last_update) { |
| trace_printf_key(&trace_fsmonitor, "add fsmonitor"); |
| istate->cache_changed |= FSMONITOR_CHANGED; |
| initialize_fsmonitor_last_update(istate); |
| |
| /* 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 = (fsm_settings__get_mode(istate->repo) |
| > FSMONITOR_MODE_DISABLED); |
| |
| if (istate->fsmonitor_dirty) { |
| if (fsmonitor_enabled) { |
| /* Mark all entries valid */ |
| for (i = 0; i < istate->cache_nr; i++) { |
| if (S_ISGITLINK(istate->cache[i]->ce_mode)) |
| continue; |
| istate->cache[i]->ce_flags |= CE_FSMONITOR_VALID; |
| } |
| |
| /* Mark all previously saved entries as dirty */ |
| assert_index_minimum(istate, istate->fsmonitor_dirty->bit_size); |
| ewah_each_bit(istate->fsmonitor_dirty, fsmonitor_ewah_callback, istate); |
| |
| refresh_fsmonitor(istate); |
| } |
| |
| ewah_free(istate->fsmonitor_dirty); |
| istate->fsmonitor_dirty = NULL; |
| } |
| |
| if (fsmonitor_enabled) |
| add_fsmonitor(istate); |
| else |
| remove_fsmonitor(istate); |
| } |