Andrew's git - gitweb.git/blob - t/t7519/fsmonitor-watchman

   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
  32my $git_work_tree;
  33if ($^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
  41my $retry = 1;
  42
  43launch_watchman();
  44
  45sub launch_watchman {
  46
  47        my $pid = open2(\*CHLD_OUT, \*CHLD_IN, 'watchman -j')
  48            or die "open2() failed: $!\n" .
  49            "Falling back to scanning...\n";
  50
  51        # In the query expression below we're asking for names of files that
  52        # changed since $time but were not transient (ie created after
  53        # $time but no longer exist).
  54        #
  55        # To accomplish this, we're using the "since" generator to use the
  56        # recency index to select candidate nodes and "fields" to limit the
  57        # output to file names only. Then we're using the "expression" term to
  58        # further constrain the results.
  59        #
  60        # The category of transient files that we want to ignore will have a
  61        # creation clock (cclock) newer than $time_t value and will also not
  62        # currently exist.
  63
  64        my $query = <<" END";
  65                ["query", "$git_work_tree", {
  66                        "since": $time,
  67                        "fields": ["name"],
  68                        "expression": ["not", ["allof", ["since", $time, "cclock"], ["not", "exists"]]]
  69                }]
  70        END
  71        
  72        open (my $fh, ">", ".git/watchman-query.json");
  73        print $fh $query;
  74        close $fh;
  75
  76        print CHLD_IN $query;
  77        close CHLD_IN;
  78        my $response = do {local $/; <CHLD_OUT>};
  79
  80        open ($fh, ">", ".git/watchman-response.json");
  81        print $fh $response;
  82        close $fh;
  83
  84        die "Watchman: command returned no output.\n" .
  85            "Falling back to scanning...\n" if $response eq "";
  86        die "Watchman: command returned invalid output: $response\n" .
  87            "Falling back to scanning...\n" unless $response =~ /^\{/;
  88
  89        my $json_pkg;
  90        eval {
  91                require JSON::XS;
  92                $json_pkg = "JSON::XS";
  93                1;
  94        } or do {
  95                require JSON::PP;
  96                $json_pkg = "JSON::PP";
  97        };
  98
  99        my $o = $json_pkg->new->utf8->decode($response);
 100
 101        if ($retry > 0 and $o->{error} and $o->{error} =~ m/unable to resolve root .* directory (.*) is not watched/) {
 102                print STDERR "Adding '$git_work_tree' to watchman's watch list.\n";
 103                $retry--;
 104                qx/watchman watch "$git_work_tree"/;
 105                die "Failed to make watchman watch '$git_work_tree'.\n" .
 106                    "Falling back to scanning...\n" if $? != 0;
 107
 108                # Watchman will always return all files on the first query so
 109                # return the fast "everything is dirty" flag to git and do the
 110                # Watchman query just to get it over with now so we won't pay
 111                # the cost in git to look up each individual file.
 112
 113                open ($fh, ">", ".git/watchman-output.out");
 114                print "/\0";
 115                close $fh;
 116
 117                print "/\0";
 118                eval { launch_watchman() };
 119                exit 0;
 120        }
 121
 122        die "Watchman: $o->{error}.\n" .
 123            "Falling back to scanning...\n" if $o->{error};
 124
 125        open ($fh, ">", ".git/watchman-output.out");
 126        binmode $fh, ":utf8";
 127        print $fh @{$o->{files}};
 128        close $fh;
 129
 130        binmode STDOUT, ":utf8";
 131        local $, = "\0";
 132        print @{$o->{files}};
 133}