fsmonitor updates for improved performance

cache.h

@@ -239,7 +239,7 @@ static inline unsigned create_ce_flags(unsigned stage)
 #define ce_namelen(ce) ((ce)->ce_namelen)
 #define ce_size(ce) cache_entry_size(ce_namelen(ce))
 #define ce_stage(ce) ((CE_STAGEMASK & (ce)->ce_flags) >> CE_STAGESHIFT)
-#define ce_uptodate(ce) ((ce)->ce_flags & CE_UPTODATE)
+#define ce_uptodate(ce) (((ce)->ce_flags & CE_UPTODATE) || ((ce)->ce_flags & CE_FSMONITOR_VALID))
 #define ce_skip_worktree(ce) ((ce)->ce_flags & CE_SKIP_WORKTREE)
 #define ce_mark_uptodate(ce) ((ce)->ce_flags |= CE_UPTODATE)
 #define ce_intent_to_add(ce) ((ce)->ce_flags & CE_INTENT_TO_ADD)

fsmonitor.c

@@ -55,7 +55,7 @@ int read_fsmonitor_extension(struct index_state *istate, const void *data,
 	}
 	istate->fsmonitor_dirty = fsmonitor_dirty;
 
-	if (istate->fsmonitor_dirty->bit_size > istate->cache_nr)
+	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);
 
@@ -83,7 +83,7 @@ void write_fsmonitor_extension(struct strbuf *sb, struct index_state *istate)
 	uint32_t ewah_size = 0;
 	int fixup = 0;
 
-	if (istate->fsmonitor_dirty->bit_size > istate->cache_nr)
+	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);
 
@@ -189,13 +189,29 @@ void refresh_fsmonitor(struct index_state *istate)
 		}
 		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++)
-			istate->cache[i]->ce_flags &= ~CE_FSMONITOR_VALID;
+		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 */
-		istate->cache_changed |= FSMONITOR_CHANGED;
+		/* If we're going to check every file, ensure we save results */
+		if (is_cache_changed)
+			istate->cache_changed |= FSMONITOR_CHANGED;
 
 		if (istate->untracked)
 			istate->untracked->use_fsmonitor = 0;
@@ -257,9 +273,7 @@ void tweak_fsmonitor(struct index_state *istate)
 				    (uintmax_t)istate->fsmonitor_dirty->bit_size, istate->cache_nr);
 			ewah_each_bit(istate->fsmonitor_dirty, fsmonitor_ewah_callback, istate);
 
-			/* Now mark the untracked cache for fsmonitor usage */
-			if (istate->untracked)
-				istate->untracked->use_fsmonitor = 1;
+			refresh_fsmonitor(istate);
 		}
 
 		ewah_free(istate->fsmonitor_dirty);

t/t7519-status-fsmonitor.sh

@@ -106,6 +106,8 @@ EOF
 
 # test that "update-index --fsmonitor-valid" sets the fsmonitor valid bit
 test_expect_success 'update-index --fsmonitor-valid" sets the fsmonitor valid bit' '
+	write_script .git/hooks/fsmonitor-test<<-\EOF &&
+	EOF
 	git update-index --fsmonitor &&
 	git update-index --fsmonitor-valid dir1/modified &&
 	git update-index --fsmonitor-valid dir2/modified &&
@@ -164,6 +166,8 @@ EOF
 
 # test that newly added files are marked valid
 test_expect_success 'newly added files are marked valid' '
+	write_script .git/hooks/fsmonitor-test<<-\EOF &&
+	EOF
 	git add new &&
 	git add dir1/new &&
 	git add dir2/new &&
@@ -218,11 +222,12 @@ test_expect_success '*only* files returned by the integration script get flagged
 # Ensure commands that call refresh_index() to move the index back in time
 # properly invalidate the fsmonitor cache
 test_expect_success 'refresh_index() invalidates fsmonitor cache' '
-	write_script .git/hooks/fsmonitor-test<<-\EOF &&
-	EOF
 	clean_repo &&
 	dirty_repo &&
+	write_integration_script &&
 	git add . &&
+	write_script .git/hooks/fsmonitor-test<<-\EOF &&
+	EOF
 	git commit -m "to reset" &&
 	git reset HEAD~1 &&
 	git status >actual &&

t/t7519/fsmonitor-watchman

@@ -17,7 +17,6 @@ use IPC::Open2;
 # 'git config core.fsmonitor .git/hooks/query-watchman'
 #
 my ($version, $time) = @ARGV;
-#print STDERR "$0 $version $time\n";
 
 # Check the hook interface version
 
@@ -45,7 +44,7 @@ launch_watchman();
 
 sub launch_watchman {
 
-	my $pid = open2(\*CHLD_OUT, \*CHLD_IN, 'watchman -j')
+	my $pid = open2(\*CHLD_OUT, \*CHLD_IN, 'watchman -j --no-pretty')
 	    or die "open2() failed: $!\n" .
 	    "Falling back to scanning...\n";
 
@@ -63,19 +62,11 @@ sub launch_watchman {
 			"fields": ["name"]
 		}]
 	END
-
-	open (my $fh, ">", ".git/watchman-query.json");
-	print $fh $query;
-	close $fh;
 
 	print CHLD_IN $query;
 	close CHLD_IN;
 	my $response = do {local $/; <CHLD_OUT>};
 
-	open ($fh, ">", ".git/watchman-response.json");
-	print $fh $response;
-	close $fh;
-
 	die "Watchman: command returned no output.\n" .
 	    "Falling back to scanning...\n" if $response eq "";
 	die "Watchman: command returned invalid output: $response\n" .
@@ -94,7 +85,6 @@ sub launch_watchman {
 	my $o = $json_pkg->new->utf8->decode($response);
 
 	if ($retry > 0 and $o->{error} and $o->{error} =~ m/unable to resolve root .* directory (.*) is not watched/) {
-		print STDERR "Adding '$git_work_tree' to watchman's watch list.\n";
 		$retry--;
 		qx/watchman watch "$git_work_tree"/;
 		die "Failed to make watchman watch '$git_work_tree'.\n" .
@@ -104,11 +94,6 @@ sub launch_watchman {
 		# return the fast "everything is dirty" flag to git and do the
 		# Watchman query just to get it over with now so we won't pay
 		# the cost in git to look up each individual file.
-
-		open ($fh, ">", ".git/watchman-output.out");
-		print "/\0";
-		close $fh;
-
 		print "/\0";
 		eval { launch_watchman() };
 		exit 0;
@@ -117,11 +102,6 @@ sub launch_watchman {
 	die "Watchman: $o->{error}.\n" .
 	    "Falling back to scanning...\n" if $o->{error};
 
-	open ($fh, ">", ".git/watchman-output.out");
-	binmode $fh, ":utf8";
-	print $fh @{$o->{files}};
-	close $fh;
-
 	binmode STDOUT, ":utf8";
 	local $, = "\0";
 	print @{$o->{files}};

t/t7519/fsmonitor-watchman-debug

@@ -0,0 +1,128 @@
+#!/usr/bin/perl
+
+use strict;
+use warnings;
+use IPC::Open2;
+
+# An example hook script to integrate Watchman
+# (https://facebook.github.io/watchman/) with git to speed up detecting
+# new and modified files.
+#
+# The hook is passed a version (currently 1) and a time in nanoseconds
+# formatted as a string and outputs to stdout all files that have been
+# modified since the given time. Paths must be relative to the root of
+# the working tree and separated by a single NUL.
+#
+# To enable this hook, rename this file to "query-watchman" and set
+# 'git config core.fsmonitor .git/hooks/query-watchman'
+#
+my ($version, $time) = @ARGV;
+#print STDERR "$0 $version $time\n";
+
+# Check the hook interface version
+
+if ($version == 1) {
+	# convert nanoseconds to seconds
+	# subtract one second to make sure watchman will return all changes
+	$time = int ($time / 1000000000) - 1;
+} else {
+	die "Unsupported query-fsmonitor hook version '$version'.\n" .
+	    "Falling back to scanning...\n";
+}
+
+my $git_work_tree;
+if ($^O =~ 'msys' || $^O =~ 'cygwin') {
+	$git_work_tree = Win32::GetCwd();
+	$git_work_tree =~ tr/\\/\//;
+} else {
+	require Cwd;
+	$git_work_tree = Cwd::cwd();
+}
+
+my $retry = 1;
+
+launch_watchman();
+
+sub launch_watchman {
+
+	my $pid = open2(\*CHLD_OUT, \*CHLD_IN, 'watchman -j')
+	    or die "open2() failed: $!\n" .
+	    "Falling back to scanning...\n";
+
+	# In the query expression below we're asking for names of files that
+	# changed since $time but were not transient (ie created after
+	# $time but no longer exist).
+	#
+	# To accomplish this, we're using the "since" generator to use the
+	# recency index to select candidate nodes and "fields" to limit the
+	# output to file names only.
+
+	my $query = <<"	END";
+		["query", "$git_work_tree", {
+			"since": $time,
+			"fields": ["name"]
+		}]
+	END
+
+	open (my $fh, ">", ".git/watchman-query.json");
+	print $fh $query;
+	close $fh;
+
+	print CHLD_IN $query;
+	close CHLD_IN;
+	my $response = do {local $/; <CHLD_OUT>};
+
+	open ($fh, ">", ".git/watchman-response.json");
+	print $fh $response;
+	close $fh;
+
+	die "Watchman: command returned no output.\n" .
+	    "Falling back to scanning...\n" if $response eq "";
+	die "Watchman: command returned invalid output: $response\n" .
+	    "Falling back to scanning...\n" unless $response =~ /^\{/;
+
+	my $json_pkg;
+	eval {
+		require JSON::XS;
+		$json_pkg = "JSON::XS";
+		1;
+	} or do {
+		require JSON::PP;
+		$json_pkg = "JSON::PP";
+	};
+
+	my $o = $json_pkg->new->utf8->decode($response);
+
+	if ($retry > 0 and $o->{error} and $o->{error} =~ m/unable to resolve root .* directory (.*) is not watched/) {
+		print STDERR "Adding '$git_work_tree' to watchman's watch list.\n";
+		$retry--;
+		qx/watchman watch "$git_work_tree"/;
+		die "Failed to make watchman watch '$git_work_tree'.\n" .
+		    "Falling back to scanning...\n" if $? != 0;
+
+		# Watchman will always return all files on the first query so
+		# return the fast "everything is dirty" flag to git and do the
+		# Watchman query just to get it over with now so we won't pay
+		# the cost in git to look up each individual file.
+
+		open ($fh, ">", ".git/watchman-output.out");
+		print "/\0";
+		close $fh;
+
+		print "/\0";
+		eval { launch_watchman() };
+		exit 0;
+	}
+
+	die "Watchman: $o->{error}.\n" .
+	    "Falling back to scanning...\n" if $o->{error};
+
+	open ($fh, ">", ".git/watchman-output.out");
+	binmode $fh, ":utf8";
+	print $fh @{$o->{files}};
+	close $fh;
+
+	binmode STDOUT, ":utf8";
+	local $, = "\0";
+	print @{$o->{files}};
+}

unpack-trees.c

@@ -1584,6 +1584,9 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
 	o->merge_size = len;
 	mark_all_ce_unused(o->src_index);
 
+	if (o->src_index->fsmonitor_last_update)
+		o->result.fsmonitor_last_update = o->src_index->fsmonitor_last_update;
+
 	/*
 	 * Sparse checkout loop #1: set NEW_SKIP_WORKTREE on existing entries
 	 */