summaryrefslogtreecommitdiff
path: root/t/t7519/fsmonitor-watchman
blob: 5514edcf68be8020ca94e8c51b9c9f2b3102bd09 (plain)
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
#!/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
	$time = int $time / 1000000000;
} else {
	die "Unsupported query-fsmonitor hook version '$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. Then we're using the "expression" term to
	# further constrain the results.
	#
	# The category of transient files that we want to ignore will have a
	# creation clock (cclock) newer than $time_t value and will also not
	# currently exist.
 
	my $query = <<"	END";
		["query", "$git_work_tree", {
			"since": $time,
			"fields": ["name"],
			"expression": ["not", ["allof", ["since", $time, "cclock"], ["not", "exists"]]]
		}]
	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}};
}