git-commit-vandalism/templates/hooks--fsmonitor-watchman.sample
Alex Vandiver 6f1dc21d98 fsmonitor: read from getcwd(), not the PWD environment variable
Though the process has chdir'd to the root of the working tree, the
PWD environment variable is only guaranteed to be updated accordingly
if a shell is involved -- which is not guaranteed to be the case.
That is, if `/usr/bin/perl` is a binary, $ENV{PWD} is unchanged from
whatever spawned `git` -- if `/usr/bin/perl` is a trivial shell
wrapper to the real `perl`, `$ENV{PWD}` will have been updated to the
root of the working copy.

Update to read from the Cwd module using the `getcwd` syscall, not the
PWD environment variable.  The Cygwin case is left unchanged, as it
necessarily _does_ go through a shell.

Signed-off-by: Alex Vandiver <alexmv@dropbox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-11-10 14:04:50 +09:00

122 lines
3.4 KiB
Perl
Executable File

#!/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";
}
# Convert unix style paths to escaped Windows style paths when running
# in Windows command prompt
my $system = `uname -s`;
$system =~ s/[\r\n]+//g;
my $git_work_tree;
if ($system =~ m/^MSYS_NT/ || $system =~ m/^MINGW/) {
$git_work_tree = `cygpath -aw "\$PWD"`;
$git_work_tree =~ s/[\r\n]+//g;
$git_work_tree =~ s,\\,/,g;
} 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}};
}