merge(third_party/git): Merge squashed git subtree at v2.23.0

Merge commit '1b593e1ea4' as 'third_party/git'

third_party/git/perl/Git/SVN/Memoize/YAML.pm

@@ -0,0 +1,93 @@
+package Git::SVN::Memoize::YAML;
+use warnings;
+use strict;
+use YAML::Any ();
+
+# based on Memoize::Storable.
+
+sub TIEHASH {
+	my $package = shift;
+	my $filename = shift;
+	my $truehash = (-e $filename) ? YAML::Any::LoadFile($filename) : {};
+	my $self = {FILENAME => $filename, H => $truehash};
+	bless $self => $package;
+}
+
+sub STORE {
+	my $self = shift;
+	$self->{H}{$_[0]} = $_[1];
+}
+
+sub FETCH {
+	my $self = shift;
+	$self->{H}{$_[0]};
+}
+
+sub EXISTS {
+	my $self = shift;
+	exists $self->{H}{$_[0]};
+}
+
+sub DESTROY {
+	my $self = shift;
+	YAML::Any::DumpFile($self->{FILENAME}, $self->{H});
+}
+
+sub SCALAR {
+	my $self = shift;
+	scalar(%{$self->{H}});
+}
+
+sub FIRSTKEY {
+	'Fake hash from Git::SVN::Memoize::YAML';
+}
+
+sub NEXTKEY {
+	undef;
+}
+
+1;
+__END__
+
+=head1 NAME
+
+Git::SVN::Memoize::YAML - store Memoized data in YAML format
+
+=head1 SYNOPSIS
+
+    use Memoize;
+    use Git::SVN::Memoize::YAML;
+
+    tie my %cache => 'Git::SVN::Memoize::YAML', $filename;
+    memoize('slow_function', SCALAR_CACHE => [HASH => \%cache]);
+    slow_function(arguments);
+
+=head1 DESCRIPTION
+
+This module provides a class that can be used to tie a hash to a
+YAML file.  The file is read when the hash is initialized and
+rewritten when the hash is destroyed.
+
+The intent is to allow L<Memoize> to back its cache with a file in
+YAML format, just like L<Memoize::Storable> allows L<Memoize> to
+back its cache with a file in Storable format.  Unlike the Storable
+format, the YAML format is platform-independent and fairly stable.
+
+Carps on error.
+
+=head1 DIAGNOSTICS
+
+See L<YAML::Any>.
+
+=head1 DEPENDENCIES
+
+L<YAML::Any> from CPAN.
+
+=head1 INCOMPATIBILITIES
+
+None reported.
+
+=head1 BUGS
+
+The entire cache is read into a Perl hash when loading the file,
+so this is not very scalable.