Andrew's git / gitweb.git /
5fe72cefaf89da7bc8d592fa264353ae992f1ed7
   1#!/usr/bin/perl
   2
   3use strict;
   4use warnings;
   5use 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#
  19my ($version, $time) = @ARGV;
  20#print STDERR "$0 $version $time\n";
  21
  22# Check the hook interface version
  23
  24if ($version == 1) {
  25        # convert nanoseconds to seconds
  26        $time = int $time / 1000000000;
  27} else {
  28        die "Unsupported query-fsmonitor hook version '$version'.\n" .
  29            "Falling back to scanning...\n";
  30}
  31
  32# Convert unix style paths to escaped Windows style paths when running
  33# in Windows command prompt
  34
  35my $system = `uname -s`;
  36$system =~ s/[\r\n]+//g;
  37my $git_work_tree;
  38
  39if ($system =~ m/^MSYS_NT/ || $system =~ m/^MINGW/) {
  40        $git_work_tree = `cygpath -aw "\$PWD"`;
  41        $git_work_tree =~ s/[\r\n]+//g;
  42        $git_work_tree =~ s,\\,/,g;
  43} else {
  44        require Cwd;
  45        $git_work_tree = Cwd::cwd();
  46}
  47
  48my $retry = 1;
  49
  50launch_watchman();
  51
  52sub launch_watchman {
  53
  54        my $pid = open2(\*CHLD_OUT, \*CHLD_IN, 'watchman -j')
  55            or die "open2() failed: $!\n" .
  56            "Falling back to scanning...\n";
  57
  58        # In the query expression below we're asking for names of files that
  59        # changed since $time but were not transient (ie created after
  60        # $time but no longer exist).
  61        #
  62        # To accomplish this, we're using the "since" generator to use the
  63        # recency index to select candidate nodes and "fields" to limit the
  64        # output to file names only. Then we're using the "expression" term to
  65        # further constrain the results.
  66        #
  67        # The category of transient files that we want to ignore will have a
  68        # creation clock (cclock) newer than $time_t value and will also not
  69        # currently exist.
  70
  71        my $query = <<" END";
  72                ["query", "$git_work_tree", {
  73                        "since": $time,
  74                        "fields": ["name"],
  75                        "expression": ["not", ["allof", ["since", $time, "cclock"], ["not", "exists"]]]
  76                }]
  77        END
  78        
  79        open (my $fh, ">", ".git/watchman-query.json");
  80        print $fh $query;
  81        close $fh;
  82
  83        print CHLD_IN $query;
  84        close CHLD_IN;
  85        my $response = do {local $/; <CHLD_OUT>};
  86
  87        open ($fh, ">", ".git/watchman-response.json");
  88        print $fh $response;
  89        close $fh;
  90
  91        die "Watchman: command returned no output.\n" .
  92            "Falling back to scanning...\n" if $response eq "";
  93        die "Watchman: command returned invalid output: $response\n" .
  94            "Falling back to scanning...\n" unless $response =~ /^\{/;
  95
  96        my $json_pkg;
  97        eval {
  98                require JSON::XS;
  99                $json_pkg = "JSON::XS";
 100                1;
 101        } or do {
 102                require JSON::PP;
 103                $json_pkg = "JSON::PP";
 104        };
 105
 106        my $o = $json_pkg->new->utf8->decode($response);
 107
 108        if ($retry > 0 and $o->{error} and $o->{error} =~ m/unable to resolve root .* directory (.*) is not watched/) {
 109                print STDERR "Adding '$git_work_tree' to watchman's watch list.\n";
 110                $retry--;
 111                qx/watchman watch "$git_work_tree"/;
 112                die "Failed to make watchman watch '$git_work_tree'.\n" .
 113                    "Falling back to scanning...\n" if $? != 0;
 114
 115                # Watchman will always return all files on the first query so
 116                # return the fast "everything is dirty" flag to git and do the
 117                # Watchman query just to get it over with now so we won't pay
 118                # the cost in git to look up each individual file.
 119
 120                open ($fh, ">", ".git/watchman-output.out");
 121                print "/\0";
 122                close $fh;
 123
 124                print "/\0";
 125                eval { launch_watchman() };
 126                exit 0;
 127        }
 128
 129        die "Watchman: $o->{error}.\n" .
 130            "Falling back to scanning...\n" if $o->{error};
 131
 132        open ($fh, ">", ".git/watchman-output.out");
 133        binmode $fh, ":utf8";
 134        print $fh @{$o->{files}};
 135        close $fh;
 136
 137        binmode STDOUT, ":utf8";
 138        local $, = "\0";
 139        print @{$o->{files}};
 140}