Raw
1 #!/usr/bin/perl
2
3 use strict;
4 use warnings;
5 use IPC::Open2;
6
7 # An example hook script to integrate Watchman
8 # (https://facebook.github.io/watchman/) with git to speed up detecting
9 # new and modified files.
10 #
11 # The hook is passed a version (currently 1) and a time in nanoseconds
12 # formatted as a string and outputs to stdout all files that have been
13 # modified since the given time. Paths must be relative to the root of
14 # the working tree and separated by a single NUL.
15 #
16 # To enable this hook, rename this file to "query-watchman" and set
17 # 'git config core.fsmonitor .git/hooks/query-watchman'
18 #
19 my ($version, $time) = @ARGV;
20 #print STDERR "$0 $version $time\n";
21
22 # Check the hook interface version
23
24 if ($version == 1) {
25 # convert nanoseconds to seconds
26 # subtract one second to make sure watchman will return all changes
27 $time = int ($time / 1000000000) - 1;
28 } else {
29 exit 1;
30 }
31
32 my $git_work_tree;
33 if ($^O =~ 'msys' || $^O =~ 'cygwin') {
34 $git_work_tree = Win32::GetCwd();
35 $git_work_tree =~ tr/\\/\//;
36 } else {
37 require Cwd;
38 $git_work_tree = Cwd::cwd();
39 }
40
41 launch_watchman();
42
43 sub launch_watchman {
44
45 my $pid = open2(\*CHLD_OUT, \*CHLD_IN, 'watchman -j')
46 or die "open2() failed: $!\n" .
47 "Falling back to scanning...\n";
48
49 # In the query expression below we're asking for names of files that
50 # changed since $time but were not transient (ie created after
51 # $time but no longer exist).
52 #
53 # To accomplish this, we're using the "since" generator to use the
54 # recency index to select candidate nodes and "fields" to limit the
55 # output to file names only.
56
57 my $query = <<" END";
58 ["query", "$git_work_tree", {
59 "since": $time,
60 "fields": ["name"]
61 }]
62 END
63
64 open (my $fh, ">", ".git/watchman-query.json");
65 print $fh $query;
66 close $fh;
67
68 print CHLD_IN $query;
69 close CHLD_IN;
70 my $response = do {local $/; <CHLD_OUT>};
71
72 open ($fh, ">", ".git/watchman-response.json");
73 print $fh $response;
74 close $fh;
75
76 die "Watchman: command returned no output.\n" .
77 "Falling back to scanning...\n" if $response eq "";
78 die "Watchman: command returned invalid output: $response\n" .
79 "Falling back to scanning...\n" unless $response =~ /^\{/;
80
81 my $json_pkg;
82 eval {
83 require JSON::XS;
84 $json_pkg = "JSON::XS";
85 1;
86 } or do {
87 require JSON::PP;
88 $json_pkg = "JSON::PP";
89 };
90
91 my $o = $json_pkg->new->utf8->decode($response);
92
93 if ($o->{error} and $o->{error} =~ m/unable to resolve root .* directory (.*) is not watched/) {
94 print STDERR "Adding '$git_work_tree' to watchman's watch list.\n";
95 qx/watchman watch "$git_work_tree"/;
96 die "Failed to make watchman watch '$git_work_tree'.\n" .
97 "Falling back to scanning...\n" if $? != 0;
98
99 # Watchman will always return all files on the first query so
100 # return the fast "everything is dirty" flag to git and do the
101 # Watchman query just to get it over with now so we won't pay
102 # the cost in git to look up each individual file.
103
104 open ($fh, ">", ".git/watchman-output.out");
105 print "/\0";
106 close $fh;
107
108 print "/\0";
109 exit 0;
110 }
111
112 die "Watchman: $o->{error}.\n" .
113 "Falling back to scanning...\n" if $o->{error};
114
115 open ($fh, ">", ".git/watchman-output.out");
116 binmode $fh, ":utf8";
117 print $fh @{$o->{files}};
118 close $fh;
119
120 binmode STDOUT, ":utf8";
121 local $, = "\0";
122 print @{$o->{files}};
123 }