diff options
Diffstat (limited to 'third_party/git/t/t7519/fsmonitor-watchman')
| -rwxr-xr-x | third_party/git/t/t7519/fsmonitor-watchman | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/third_party/git/t/t7519/fsmonitor-watchman b/third_party/git/t/t7519/fsmonitor-watchman new file mode 100755 index 000000000000..5514edcf68be --- /dev/null +++ b/third_party/git/t/t7519/fsmonitor-watchman @@ -0,0 +1,133 @@ +#!/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; +#print STDERR "$0 $version $time\n"; + +# Check the hook interface version + +if ($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') + 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 + + open (my $fh, ">", ".git/watchman-query.json"); + print $fh $query; + close $fh; + + print CHLD_IN $query; + close CHLD_IN; + my $response = do {local $/; <CHLD_OUT>}; + + open ($fh, ">", ".git/watchman-response.json"); + print $fh $response; + close $fh; + + 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 $? != 0; + + # Watchman will always return all files on the first query so + # return the fast "everything is dirty" flag to git and do the + # Watchman query just to get it over with now so we won't pay + # the cost in git to look up each individual file. + + open ($fh, ">", ".git/watchman-output.out"); + print "/\0"; + close $fh; + + print "/\0"; + eval { launch_watchman() }; + exit 0; + } + + die "Watchman: $o->{error}.\n" . + "Falling back to scanning...\n" if $o->{error}; + + open ($fh, ">", ".git/watchman-output.out"); + binmode $fh, ":utf8"; + print $fh @{$o->{files}}; + close $fh; + + binmode STDOUT, ":utf8"; + local $, = "\0"; + print @{$o->{files}}; +} |