Bug 569177 - Add support for eTag for WebServices

r/a=glob

1 files changed, 59 insertions, 1 deletions

diff --git a/Bugzilla/WebService/Server.pm b/Bugzilla/WebService/Server.pm
index 02226284c..5ffd965a5 100644
--- a/Bugzilla/WebService/Server.pm
+++ b/Bugzilla/WebService/Server.pm
@@ -14,6 +14,9 @@ use Bugzilla::Error;
 use Bugzilla::Util qw(datetime_from);
 
 use Scalar::Util qw(blessed);
+use Digest::MD5 qw(md5_base64);
+
+use Storable qw(freeze);
 
 sub handle_login {
     my ($self, $class, $method, $full_method) = @_;
@@ -29,7 +32,7 @@ sub handle_login {
 
 sub datetime_format_inbound {
     my ($self, $time) = @_;
-    
+
     my $converted = datetime_from($time, Bugzilla->local_timezone);
     if (!defined $converted) {
         ThrowUserError('illegal_date', { date => $time });
@@ -55,8 +58,63 @@ sub datetime_format_outbound {
     return $time->iso8601();
 }
 
+# ETag support
+sub bz_etag {
+    my ($self, $data) = @_;
+    my $cache = Bugzilla->request_cache;
+    if (defined $data) {
+        # Serialize the data if passed a reference
+        local $Storable::canonical = 1;
+        $data = freeze($data) if ref $data;
+
+        # Wide characters cause md5_base64() to die.
+        utf8::encode($data) if utf8::is_utf8($data);
+
+        # Append content_type to the end of the data
+        # string as we want the etag to be unique to
+        # the content_type. We do not need this for
+        # XMLRPC as text/xml is always returned.
+        if (blessed($self) && $self->can('content_type')) {
+            $data .= $self->content_type if $self->content_type;
+        }
+
+        $cache->{'bz_etag'} = md5_base64($data);
+    }
+    return $cache->{'bz_etag'};
+}
+
 1;
 
+=head1 NAME
+
+Bugzilla::WebService::Server - Base server class for the WebService API
+
+=head1 DESCRIPTION
+
+Bugzilla::WebService::Server is the base class for the individual WebService API
+servers such as XMLRPC, JSONRPC, and REST. You never actually create a
+Bugzilla::WebService::Server directly, you only make subclasses of it.
+
+=head1 FUNCTIONS
+
+=over
+
+=item C<bz_etag>
+
+This function is used to store an ETag value that will be used when returning
+the data by the different API server modules such as XMLRPC, or REST. The individual
+webservice methods can also set the value earlier in the process if needed such as
+before a unique update token is added. If a value is not set earlier, an etag will
+automatically be created using the returned data except in some cases when an error
+has occurred.
+
+=back
+
+=head1 SEE ALSO
+
+L<Bugzilla::WebService::Server::XMLRPC|XMLRPC>, L<Bugzilla::WebService::Server::JSONRPC|JSONRPC>,
+and L<Bugzilla::WebService::Server::REST|REST>.
+
 =head1 B<Methods in need of POD>
 
 =over