Subversion Repositories Boeken.quickpython

#!/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;

# 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 --no-pretty')
      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

  print CHLD_IN $query;
  close CHLD_IN;
  my $response = do {local $/; <CHLD_OUT>};

  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.
    print "/\0";
    eval { launch_watchman() };
    exit 0;
  }

  die "Watchman: $o->{error}.\n" .
      "Falling back to scanning...\n" if $o->{error};

  binmode STDOUT, ":utf8";
  local $, = "\0";
  print @{$o->{files}};
}