extract redundant Message-ID handling code

Quit repeating ourselves and use a common MID module
instead.

1 files changed, 27 insertions, 0 deletions

diff --git a/lib/PublicInbox/MID.pm b/lib/PublicInbox/MID.pm
new file mode 100644
index 00000000..e5a30a1b
--- /dev/null
+++ b/lib/PublicInbox/MID.pm
@@ -0,0 +1,27 @@
+# Copyright (C) 2015, all contributors <meta@public-inbox.org>
+# License: AGPLv3 or later (https://www.gnu.org/licenses/agpl-3.0.txt)
+package PublicInbox::MID;
+use strict;
+use warnings;
+use base qw/Exporter/;
+our @EXPORT_OK = qw/mid_clean mid_compressed/;
+use Digest::SHA qw/sha1_hex/;
+use constant MID_MAX => 40; # SHA-1 hex length
+
+sub mid_clean {
+        my ($mid) = @_;
+        defined($mid) or die "no Message-ID";
+        # MDA->precheck did more checking for us
+        $mid =~ s/\A\s*<?//;
+        $mid =~ s/>?\s*\z//;
+        $mid;
+}
+
+# this is idempotent
+sub mid_compressed {
+        my ($mid) = @_;
+        return $mid if (length($mid) <= MID_MAX);
+        sha1_hex($mid);
+}
+
+1;