[thirdparty/git.git] / fsmonitor.c

#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;
	int result;

	if (!core_fsmonitor)
		return -1;

	strvec_push(&cp.args, core_fsmonitor);
	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' };
	int is_trivial = !memcmp(trivial_response,
				 &query_result->buf[query_result->len - 3], 3);

	return is_trivial;
}

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 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;
	}
}
Commit	Line	Data
883e248b BP	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
56c69100 KW	9	#define INDEX_EXTENSION_VERSION1 (1)
56c69100 KW	10	#define INDEX_EXTENSION_VERSION2 (2)
8da2c576 KW	11	#define HOOK_INTERFACE_VERSION1 (1)
8da2c576 KW	12	#define HOOK_INTERFACE_VERSION2 (2)
883e248b BP	13
	14	struct trace_key trace_fsmonitor = TRACE_KEY_INIT(FSMONITOR);
	15
	16	static void fsmonitor_ewah_callback(size_t pos, void *is)
	17	{
	18	struct index_state istate = (struct index_state )is;
3444ec2e	19	struct cache_entry *ce;
883e248b	20
3444ec2e WB	21	if (pos >= istate->cache_nr)
	22	BUG("fsmonitor_dirty has more entries than the index (%"PRIuMAX" >= %u)",
	23	(uintmax_t)pos, istate->cache_nr);
	24
	25	ce = istate->cache[pos];
883e248b BP	26	ce->ce_flags &= ~CE_FSMONITOR_VALID;
	27	}
	28
8da2c576 KW	29	static int fsmonitor_hook_version(void)
	30	{
	31	int hook_version;
	32
	33	if (git_config_get_int("core.fsmonitorhookversion", &hook_version))
	34	return -1;
	35
	36	if (hook_version == HOOK_INTERFACE_VERSION1 \|\|
	37	hook_version == HOOK_INTERFACE_VERSION2)
	38	return hook_version;
	39
	40	warning("Invalid hook version '%i' in core.fsmonitorhookversion. "
	41	"Must be 1 or 2.", hook_version);
	42	return -1;
	43	}
	44
883e248b BP	45	int read_fsmonitor_extension(struct index_state istate, const void data,
	46	unsigned long sz)
	47	{
	48	const char *index = data;
	49	uint32_t hdr_version;
	50	uint32_t ewah_size;
	51	struct ewah_bitmap *fsmonitor_dirty;
883e248b	52	int ret;
56c69100 KW	53	uint64_t timestamp;
56c69100 KW	54	struct strbuf last_update = STRBUF_INIT;
883e248b	55
56c69100	56	if (sz < sizeof(uint32_t) + 1 + sizeof(uint32_t))
883e248b BP	57	return error("corrupt fsmonitor extension (too short)");
	58
	59	hdr_version = get_be32(index);
	60	index += sizeof(uint32_t);
56c69100 KW	61	if (hdr_version == INDEX_EXTENSION_VERSION1) {
	62	timestamp = get_be64(index);
	63	strbuf_addf(&last_update, "%"PRIu64"", timestamp);
	64	index += sizeof(uint64_t);
	65	} else if (hdr_version == INDEX_EXTENSION_VERSION2) {
	66	strbuf_addstr(&last_update, index);
	67	index += last_update.len + 1;
	68	} else {
883e248b	69	return error("bad fsmonitor version %d", hdr_version);
56c69100	70	}
883e248b	71
56c69100	72	istate->fsmonitor_last_update = strbuf_detach(&last_update, NULL);
883e248b BP	73
	74	ewah_size = get_be32(index);
	75	index += sizeof(uint32_t);
	76
	77	fsmonitor_dirty = ewah_new();
	78	ret = ewah_read_mmap(fsmonitor_dirty, index, ewah_size);
	79	if (ret != ewah_size) {
	80	ewah_free(fsmonitor_dirty);
	81	return error("failed to parse ewah bitmap reading fsmonitor index extension");
	82	}
ba1b9cac	83	istate->fsmonitor_dirty = fsmonitor_dirty;
883e248b	84
61eea521 JH	85	if (!istate->split_index &&
61eea521 JH	86	istate->fsmonitor_dirty->bit_size > istate->cache_nr)
3444ec2e WB	87	BUG("fsmonitor_dirty has more entries than the index (%"PRIuMAX" > %u)",
	88	(uintmax_t)istate->fsmonitor_dirty->bit_size, istate->cache_nr);
	89
883e248b BP	90	trace_printf_key(&trace_fsmonitor, "read fsmonitor extension successful");
	91	return 0;
	92	}
	93
3bd28eb2 AV	94	void fill_fsmonitor_bitmap(struct index_state *istate)
3bd28eb2 AV	95	{
3444ec2e	96	unsigned int i, skipped = 0;
3bd28eb2	97	istate->fsmonitor_dirty = ewah_new();
3444ec2e WB	98	for (i = 0; i < istate->cache_nr; i++) {
	99	if (istate->cache[i]->ce_flags & CE_REMOVE)
	100	skipped++;
	101	else if (!(istate->cache[i]->ce_flags & CE_FSMONITOR_VALID))
	102	ewah_set(istate->fsmonitor_dirty, i - skipped);
	103	}
3bd28eb2 AV	104	}
3bd28eb2 AV	105
883e248b BP	106	void write_fsmonitor_extension(struct strbuf sb, struct index_state istate)
	107	{
	108	uint32_t hdr_version;
883e248b BP	109	uint32_t ewah_start;
	110	uint32_t ewah_size = 0;
	111	int fixup = 0;
	112
61eea521 JH	113	if (!istate->split_index &&
61eea521 JH	114	istate->fsmonitor_dirty->bit_size > istate->cache_nr)
3444ec2e WB	115	BUG("fsmonitor_dirty has more entries than the index (%"PRIuMAX" > %u)",
	116	(uintmax_t)istate->fsmonitor_dirty->bit_size, istate->cache_nr);
	117
56c69100	118	put_be32(&hdr_version, INDEX_EXTENSION_VERSION2);
883e248b BP	119	strbuf_add(sb, &hdr_version, sizeof(uint32_t));
883e248b BP	120
56c69100 KW	121	strbuf_addstr(sb, istate->fsmonitor_last_update);
	122	strbuf_addch(sb, 0); /* Want to keep a NUL */
	123
883e248b BP	124	fixup = sb->len;
	125	strbuf_add(sb, &ewah_size, sizeof(uint32_t)); /* we'll fix this up later */
	126
	127	ewah_start = sb->len;
3bd28eb2 AV	128	ewah_serialize_strbuf(istate->fsmonitor_dirty, sb);
	129	ewah_free(istate->fsmonitor_dirty);
	130	istate->fsmonitor_dirty = NULL;
883e248b BP	131
	132	/* fix up size field */
	133	put_be32(&ewah_size, sb->len - ewah_start);
	134	memcpy(sb->buf + fixup, &ewah_size, sizeof(uint32_t));
	135
	136	trace_printf_key(&trace_fsmonitor, "write fsmonitor extension successful");
	137	}
	138
	139	/*
56c69100	140	* Call the query-fsmonitor hook passing the last update token of the saved results.
883e248b	141	*/
56c69100	142	static int query_fsmonitor(int version, const char last_update, struct strbuf query_result)
883e248b BP	143	{
883e248b BP	144	struct child_process cp = CHILD_PROCESS_INIT;
940b94f3	145	int result;
883e248b	146
735e4173	147	if (!core_fsmonitor)
883e248b BP	148	return -1;
883e248b BP	149
ef8d7ac4 JK	150	strvec_push(&cp.args, core_fsmonitor);
	151	strvec_pushf(&cp.args, "%d", version);
	152	strvec_pushf(&cp.args, "%s", last_update);
883e248b	153	cp.use_shell = 1;
11cf33be	154	cp.dir = get_git_work_tree();
883e248b	155
940b94f3 JH	156	trace2_region_enter("fsm_hook", "query", NULL);
	157
	158	result = capture_command(&cp, query_result, 1024);
	159
	160	if (result)
	161	trace2_data_intmax("fsm_hook", NULL, "query/failed", result);
	162	else {
	163	trace2_data_intmax("fsm_hook", NULL, "query/response-length",
	164	query_result->len);
	165
	166	if (fsmonitor_is_trivial_response(query_result))
	167	trace2_data_intmax("fsm_hook", NULL,
	168	"query/trivial-response", 1);
	169	}
	170
	171	trace2_region_leave("fsm_hook", "query", NULL);
	172
	173	return result;
	174	}
	175
	176	int fsmonitor_is_trivial_response(const struct strbuf *query_result)
	177	{
	178	static char trivial_response[3] = { '\0', '/', '\0' };
	179	int is_trivial = !memcmp(trivial_response,
	180	&query_result->buf[query_result->len - 3], 3);
	181
	182	return is_trivial;
883e248b BP	183	}
	184
	185	static void fsmonitor_refresh_callback(struct index_state istate, const char name)
	186	{
	187	int pos = index_name_pos(istate, name, strlen(name));
	188
	189	if (pos >= 0) {
	190	struct cache_entry *ce = istate->cache[pos];
	191	ce->ce_flags &= ~CE_FSMONITOR_VALID;
	192	}
	193
	194	/*
	195	* Mark the untracked cache dirty even if it wasn't found in the index
	196	* as it could be a new untracked file.
	197	*/
	198	trace_printf_key(&trace_fsmonitor, "fsmonitor_refresh_callback '%s'", name);
0cacebf0	199	untracked_cache_invalidate_path(istate, name, 0);
883e248b BP	200	}
	201
	202	void refresh_fsmonitor(struct index_state *istate)
	203	{
883e248b	204	struct strbuf query_result = STRBUF_INIT;
8da2c576 KW	205	int query_success = 0, hook_version = -1;
8da2c576 KW	206	size_t bol = 0; /* beginning of line */
883e248b	207	uint64_t last_update;
56c69100	208	struct strbuf last_update_token = STRBUF_INIT;
883e248b	209	char *buf;
5d137fc2	210	unsigned int i;
883e248b	211
398a3b08	212	if (!core_fsmonitor \|\| istate->fsmonitor_has_run_once)
883e248b	213	return;
8da2c576 KW	214
	215	hook_version = fsmonitor_hook_version();
	216
398a3b08	217	istate->fsmonitor_has_run_once = 1;
883e248b BP	218
	219	trace_printf_key(&trace_fsmonitor, "refresh fsmonitor");
	220	/*
	221	* This could be racy so save the date/time now and query_fsmonitor
	222	* should be inclusive to ensure we don't miss potential changes.
	223	*/
	224	last_update = getnanotime();
8da2c576 KW	225	if (hook_version == HOOK_INTERFACE_VERSION1)
8da2c576 KW	226	strbuf_addf(&last_update_token, "%"PRIu64"", last_update);
883e248b BP	227
883e248b BP	228	/*
8da2c576 KW	229	* If we have a last update token, call query_fsmonitor for the set of
8da2c576 KW	230	* changes since that token, else assume everything is possibly dirty
883e248b BP	231	* and check it all.
	232	*/
	233	if (istate->fsmonitor_last_update) {
8da2c576 KW	234	if (hook_version == -1 \|\| hook_version == HOOK_INTERFACE_VERSION2) {
	235	query_success = !query_fsmonitor(HOOK_INTERFACE_VERSION2,
	236	istate->fsmonitor_last_update, &query_result);
	237
	238	if (query_success) {
	239	if (hook_version < 0)
	240	hook_version = HOOK_INTERFACE_VERSION2;
	241
	242	/*
	243	* First entry will be the last update token
	244	* Need to use a char * variable because static
	245	* analysis was suggesting to use strbuf_addbuf
	246	* but we don't want to copy the entire strbuf
6d12b533	247	* only the chars up to the first NUL
8da2c576 KW	248	*/
	249	buf = query_result.buf;
	250	strbuf_addstr(&last_update_token, buf);
	251	if (!last_update_token.len) {
	252	warning("Empty last update token.");
	253	query_success = 0;
	254	} else {
	255	bol = last_update_token.len + 1;
	256	}
	257	} else if (hook_version < 0) {
	258	hook_version = HOOK_INTERFACE_VERSION1;
	259	if (!last_update_token.len)
	260	strbuf_addf(&last_update_token, "%"PRIu64"", last_update);
	261	}
	262	}
	263
	264	if (hook_version == HOOK_INTERFACE_VERSION1) {
	265	query_success = !query_fsmonitor(HOOK_INTERFACE_VERSION1,
	266	istate->fsmonitor_last_update, &query_result);
	267	}
	268
883e248b BP	269	trace_performance_since(last_update, "fsmonitor process '%s'", core_fsmonitor);
	270	trace_printf_key(&trace_fsmonitor, "fsmonitor process '%s' returned %s",
	271	core_fsmonitor, query_success ? "success" : "failure");
	272	}
	273
	274	/* a fsmonitor process can return '/' to indicate all entries are invalid */
8da2c576	275	if (query_success && query_result.buf[bol] != '/') {
883e248b BP	276	/* Mark all entries returned by the monitor as dirty */
883e248b BP	277	buf = query_result.buf;
8da2c576	278	for (i = bol; i < query_result.len; i++) {
883e248b BP	279	if (buf[i] != '\0')
	280	continue;
	281	fsmonitor_refresh_callback(istate, buf + bol);
	282	bol = i + 1;
	283	}
	284	if (bol < query_result.len)
	285	fsmonitor_refresh_callback(istate, buf + bol);
679f2f9f US	286
	287	/* Now mark the untracked cache for fsmonitor usage */
	288	if (istate->untracked)
	289	istate->untracked->use_fsmonitor = 1;
883e248b	290	} else {
679f2f9f US	291
	292	/* We only want to run the post index changed hook if we've actually changed entries, so keep track
	293	* if we actually changed entries or not */
	294	int is_cache_changed = 0;
883e248b	295	/* Mark all entries invalid */
679f2f9f US	296	for (i = 0; i < istate->cache_nr; i++) {
	297	if (istate->cache[i]->ce_flags & CE_FSMONITOR_VALID) {
	298	is_cache_changed = 1;
	299	istate->cache[i]->ce_flags &= ~CE_FSMONITOR_VALID;
	300	}
	301	}
883e248b	302
ca598d5f	303	/* If we're going to check every file, ensure we save the results */
679f2f9f US	304	if (is_cache_changed)
679f2f9f US	305	istate->cache_changed \|= FSMONITOR_CHANGED;
ca598d5f	306
883e248b BP	307	if (istate->untracked)
	308	istate->untracked->use_fsmonitor = 0;
	309	}
	310	strbuf_release(&query_result);
	311
56c69100 KW	312	/* Now that we've updated istate, save the last_update_token */
	313	FREE_AND_NULL(istate->fsmonitor_last_update);
	314	istate->fsmonitor_last_update = strbuf_detach(&last_update_token, NULL);
883e248b BP	315	}
	316
	317	void add_fsmonitor(struct index_state *istate)
	318	{
5d137fc2	319	unsigned int i;
56c69100	320	struct strbuf last_update = STRBUF_INIT;
883e248b BP	321
	322	if (!istate->fsmonitor_last_update) {
	323	trace_printf_key(&trace_fsmonitor, "add fsmonitor");
	324	istate->cache_changed \|= FSMONITOR_CHANGED;
56c69100 KW	325	strbuf_addf(&last_update, "%"PRIu64"", getnanotime());
56c69100 KW	326	istate->fsmonitor_last_update = strbuf_detach(&last_update, NULL);
883e248b BP	327
	328	/* reset the fsmonitor state */
	329	for (i = 0; i < istate->cache_nr; i++)
	330	istate->cache[i]->ce_flags &= ~CE_FSMONITOR_VALID;
	331
	332	/* reset the untracked cache */
	333	if (istate->untracked) {
	334	add_untracked_cache(istate);
	335	istate->untracked->use_fsmonitor = 1;
	336	}
	337
	338	/* Update the fsmonitor state */
	339	refresh_fsmonitor(istate);
	340	}
	341	}
	342
	343	void remove_fsmonitor(struct index_state *istate)
	344	{
	345	if (istate->fsmonitor_last_update) {
	346	trace_printf_key(&trace_fsmonitor, "remove fsmonitor");
	347	istate->cache_changed \|= FSMONITOR_CHANGED;
56c69100	348	FREE_AND_NULL(istate->fsmonitor_last_update);
883e248b BP	349	}
	350	}
	351
	352	void tweak_fsmonitor(struct index_state *istate)
	353	{
5d137fc2	354	unsigned int i;
ba1b9cac AV	355	int fsmonitor_enabled = git_config_get_fsmonitor();
	356
	357	if (istate->fsmonitor_dirty) {
	358	if (fsmonitor_enabled) {
	359	/* Mark all entries valid */
	360	for (i = 0; i < istate->cache_nr; i++) {
	361	istate->cache[i]->ce_flags \|= CE_FSMONITOR_VALID;
	362	}
	363
	364	/* Mark all previously saved entries as dirty */
3444ec2e WB	365	if (istate->fsmonitor_dirty->bit_size > istate->cache_nr)
	366	BUG("fsmonitor_dirty has more entries than the index (%"PRIuMAX" > %u)",
	367	(uintmax_t)istate->fsmonitor_dirty->bit_size, istate->cache_nr);
ba1b9cac AV	368	ewah_each_bit(istate->fsmonitor_dirty, fsmonitor_ewah_callback, istate);
ba1b9cac AV	369
679f2f9f	370	refresh_fsmonitor(istate);
ba1b9cac AV	371	}
	372
	373	ewah_free(istate->fsmonitor_dirty);
	374	istate->fsmonitor_dirty = NULL;
	375	}
	376
	377	switch (fsmonitor_enabled) {
883e248b BP	378	case -1: /* keep: do nothing */
	379	break;
	380	case 0: /* false */
	381	remove_fsmonitor(istate);
	382	break;
	383	case 1: /* true */
	384	add_fsmonitor(istate);
	385	break;
	386	default: /* unknown value: do nothing */
	387	break;
	388	}
	389	}