From a307212cb8dcd1faf1f0a706930cf4e555f3b633 Mon Sep 17 00:00:00 2001
From: "Kyle J. McKay" <mackyle@gmail.com>
Date: Thu, 4 Jul 2013 19:38:26 -0700
Subject: [PATCH] Util.pm: new filedb_atomic_grep function

The filedb_atomic_grep function works similarly to the
perl grep function in that an array of the non-empty
values returned by the subroutine is the final result.
---
 Girocco/Util.pm | 33 ++++++++++++++++++++++++++++-----
 1 file changed, 28 insertions(+), 5 deletions(-)

diff --git a/Girocco/Util.pm b/Girocco/Util.pm
index 838c573..bada935 100644
--- a/Girocco/Util.pm
+++ b/Girocco/Util.pm
@@ -8,9 +8,9 @@ use Girocco::Config;
 BEGIN {
 	use base qw(Exporter);
 	our @EXPORT = qw(scrypt jailed_file
-	                 lock_file unlock_file
-	                 filedb_atomic_append filedb_atomic_edit
-	                 valid_email valid_email_multi
+			 lock_file unlock_file
+			 filedb_atomic_append filedb_atomic_edit filedb_atomic_grep
+			 valid_email valid_email_multi
 			 valid_repo_url valid_web_url);
 }
 
@@ -51,9 +51,13 @@ sub lock_file {
 }
 
 sub unlock_file {
-	my ($path) = @_;
+	my ($path, $noreplace) = @_;
 
-	rename "$path.lock", $path or die "$path unlock failed: $!";
+	if (!$noreplace) {
+		rename "$path.lock", $path or die "$path unlock failed: $!";
+	} else {
+		unlink "$path.lock" or die "$path unlock failed: $!";
+	}
 }
 
 sub filedb_atomic_append {
@@ -97,6 +101,25 @@ sub filedb_atomic_edit {
 	unlock_file($file);
 }
 
+sub filedb_atomic_grep {
+	my ($file, $fn) = @_;
+	my @results = ();
+
+	open my $src, $file or die "$file open for reading failed: $!";
+	my $dst = lock_file($file);
+
+	while (<$src>) {
+		my $result = $fn->($_);
+		push(@results, $result) if $result;
+	}
+
+	close $dst or die "$file(l) close failed: $!";
+	close $src;
+
+	unlock_file($file, 1);
+	return @results;
+}
+
 sub valid_email {
 	$_ = $_[0];
 	/^[a-zA-Z0-9+._-]+@[a-zA-Z0-9.-]+$/;
-- 
2.11.4.GIT