git@vger.kernel.org list mirror (unofficial, one of many)
 help / color / mirror / code / Atom feed
63174630c0e2b5dbcef32f6c683e8fa81f92dddb blob 14282 bytes (raw)

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
 
#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);

		if (fsmonitor_is_trivial_response(query_result))
			trace2_data_intmax("fsm_hook", NULL,
					   "query/trivial-response", 1);
	}

	trace2_region_leave("fsm_hook", "query", NULL);

	return result;
}

int fsmonitor_is_trivial_response(const struct strbuf *query_result)
{
	static char trivial_response[3] = { '\0', '/', '\0' };

	return query_result->len >= 3 &&
		!memcmp(trivial_response,
			&query_result->buf[query_result->len - 3], 3);
}

static void fsmonitor_refresh_callback(struct index_state *istate, char *name)
{
	int i, len = strlen(name);
	if (name[len - 1] == '/') {

		/*
		 * TODO We should binary search to find the first path with
		 * TODO this directory prefix.  Then linearly update entries
		 * TODO while the prefix matches.  Taking care to search without
		 * TODO the trailing slash -- because '/' sorts after a few
		 * TODO interesting special chars, like '.' and ' '.
		 */

		/* Mark all entries for the folder invalid */
		for (i = 0; i < istate->cache_nr; i++) {
			if (istate->cache[i]->ce_flags & CE_FSMONITOR_VALID &&
			    starts_with(istate->cache[i]->name, name))
				istate->cache[i]->ce_flags &= ~CE_FSMONITOR_VALID;
		}
		/* Need to remove the / from the path for the untracked cache */
		name[len - 1] = '\0';
	} else {
		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;
	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) {
		/* TODO */
		return;
	}

	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;
				}
			} 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);
		}

		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");
	}

	/*
	 * 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.
	 */
	if (query_success && query_result.buf[bol] != '/') {
		/*
		 * Mark all pathnames returned by the monitor as dirty.
		 *
		 * This updates both the cache-entries and the untracked-cache.
		 */
		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 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;
	}
	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;
	struct repository *r = istate->repo ? istate->repo : the_repository;
	int fsmonitor_enabled = (fsm_settings__get_mode(r) > FSMONITOR_MODE_DISABLED);

	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 */
			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);
}
debug log:

solving 63174630c0e ...
found 63174630c0e in https://80x24.org/mirrors/git.git

Code repositories for project(s) associated with this inbox:

	https://80x24.org/mirrors/git.git

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).