Andrew's git - gitweb.git/blob

9eba8a740933dfa77d7155aca2ba1979e9d0fb68
   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, $time) = @ARGV;
  20
  21# Check the hook interface version
  22
  23if ($version == 1) {
  24        # convert nanoseconds to seconds
  25        $time = int $time / 1000000000;
  26} else {
  27        die "Unsupported query-fsmonitor hook version '$version'.\n" .
  28            "Falling back to scanning...\n";
  29}
  30
  31# Convert unix style paths to escaped Windows style paths when running
  32# in Windows command prompt
  33
  34my $system = `uname -s`;
  35$system =~ s/[\r\n]+//g;
  36my $git_work_tree;
  37
  38if ($system =~ m/^MSYS_NT/ || $system =~ m/^MINGW/) {
  39        $git_work_tree = `cygpath -aw "\$PWD"`;
  40        $git_work_tree =~ s/[\r\n]+//g;
  41        $git_work_tree =~ s,\\,/,g;
  42} else {
  43        $git_work_tree = $ENV{'PWD'};
  44}
  45
  46my $retry = 1;
  47
  48launch_watchman();
  49
  50sub launch_watchman {
  51
  52        my $pid = open2(\*CHLD_OUT, \*CHLD_IN, 'watchman -j')
  53            or die "open2() failed: $!\n" .
  54            "Falling back to scanning...\n";
  55
  56        # In the query expression below we're asking for names of files that
  57        # changed since $time but were not transient (ie created after
  58        # $time but no longer exist).
  59        #
  60        # To accomplish this, we're using the "since" generator to use the
  61        # recency index to select candidate nodes and "fields" to limit the
  62        # output to file names only. Then we're using the "expression" term to
  63        # further constrain the results.
  64        #
  65        # The category of transient files that we want to ignore will have a
  66        # creation clock (cclock) newer than $time_t value and will also not
  67        # currently exist.
  68
  69        my $query = <<" END";
  70                ["query", "$git_work_tree", {
  71                        "since": $time,
  72                        "fields": ["name"],
  73                        "expression": ["not", ["allof", ["since", $time, "cclock"], ["not", "exists"]]]
  74                }]
  75        END
  76
  77        print CHLD_IN $query;
  78        close CHLD_IN;
  79        my $response = do {local $/; <CHLD_OUT>};
  80
  81        die "Watchman: command returned no output.\n" .
  82            "Falling back to scanning...\n" if $response eq "";
  83        die "Watchman: command returned invalid output: $response\n" .
  84            "Falling back to scanning...\n" unless $response =~ /^\{/;
  85
  86        my $json_pkg;
  87        eval {
  88                require JSON::XS;
  89                $json_pkg = "JSON::XS";
  90                1;
  91        } or do {
  92                require JSON::PP;
  93                $json_pkg = "JSON::PP";
  94        };
  95
  96        my $o = $json_pkg->new->utf8->decode($response);
  97
  98        if ($retry > 0 and $o->{error} and $o->{error} =~ m/unable to resolve root .* directory (.*) is not watched/) {
  99                print STDERR "Adding '$git_work_tree' to watchman's watch list.\n";
 100                $retry--;
 101                qx/watchman watch "$git_work_tree"/;
 102                die "Failed to make watchman watch '$git_work_tree'.\n" .
 103                    "Falling back to scanning...\n" if $? != 0;
 104
 105                # Watchman will always return all files on the first query so
 106                # return the fast "everything is dirty" flag to git and do the
 107                # Watchman query just to get it over with now so we won't pay
 108                # the cost in git to look up each individual file.
 109                print "/\0";
 110                eval { launch_watchman() };
 111                exit 0;
 112        }
 113
 114        die "Watchman: $o->{error}.\n" .
 115            "Falling back to scanning...\n" if $o->{error};
 116
 117        binmode STDOUT, ":utf8";
 118        local $, = "\0";
 119        print @{$o->{files}};
 120}