Bug 237862: New database layer for cross-database compatibility

Patch By Tomas Kopal <Tomas.Kopal@altap.cz> r=mkanat, a=myk


git-svn-id: svn://10.0.0.236/trunk@169270 18797224-902f-48f8-a5cc-f745e15eee43

mozilla/webtools/bugzilla/Bugzilla/DB/Pg.pm

@@ -0,0 +1,180 @@
+# -*- Mode: perl; indent-tabs-mode: nil -*-
+#
+# The contents of this file are subject to the Mozilla Public
+# License Version 1.1 (the "License"); you may not use this file
+# except in compliance with the License. You may obtain a copy of
+# the License at http://www.mozilla.org/MPL/
+#
+# Software distributed under the License is distributed on an "AS
+# IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
+# implied. See the License for the specific language governing
+# rights and limitations under the License.
+#
+# The Original Code is the Bugzilla Bug Tracking System.
+#
+# The Initial Developer of the Original Code is Netscape Communications
+# Corporation. Portions created by Netscape are
+# Copyright (C) 1998 Netscape Communications Corporation. All
+# Rights Reserved.
+#
+# Contributor(s): Dave Miller <davem00@aol.com>
+#                 Gayathri Swaminath <gayathrik00@aol.com>
+#                 Jeroen Ruigrok van der Werven <asmodai@wxs.nl>
+#                 Dave Lawrence <dkl@redhat.com>
+#                 Tomas Kopal <Tomas.Kopal@altap.cz>
+
+=head1 NAME
+
+Bugzilla::DB::Pg - Bugzilla database compatibility layer for PostgreSQL
+
+=head1 DESCRIPTION
+
+This module overrides methods of the Bugzilla::DB module with PostgreSQL
+specific implementation. It is instantiated by the Bugzilla::DB module
+and should never be used directly.
+
+For interface details see L<Bugzilla::DB> and L<DBI>.
+
+=cut
+
+package Bugzilla::DB::Pg;
+
+use strict;
+
+use Bugzilla::Error;
+use Carp;
+
+# This module extends the DB interface via inheritance
+use base qw(Bugzilla::DB);
+
+sub new {
+    my ($class, $user, $pass, $host, $dbname, $port) = @_;
+
+    # construct the DSN from the parameters we got
+    my $dsn = "DBI:Pg:host=$host;dbname=$dbname;port=$port";
+    
+    my $self = $class->db_new($dsn, $user, $pass);
+
+    # all class local variables stored in DBI derived class needs to have
+    # a prefix 'private_'. See DBI documentation.
+    $self->{private_bz_tables_locked} = 0;
+
+    bless ($self, $class);
+
+    return $self;
+}
+
+# if last_insert_id is supported on PostgreSQL by lowest DBI/DBD version
+# supported by Bugzilla, this implementation can be removed.
+sub bz_last_key {
+    my ($self, $table, $column) = @_;
+
+    my $seq = $table . "_" . $column . "_seq";
+    my ($last_insert_id) = $self->selectrow_array("SELECT CURRVAL('$seq')");
+
+    return $last_insert_id;
+}
+
+sub sql_regexp {
+    return "~";
+}
+
+sub sql_not_regexp {
+    return "!~" 
+}
+
+sub sql_limit {
+    my ($self, $limit,$offset) = @_;
+
+    if (defined($offset)) {
+        return "LIMIT $limit OFFSET $offset";
+    } else {
+        return "LIMIT $limit";
+    }
+}
+
+sub sql_to_days {
+    my ($self, $date) = @_;
+
+    return "TO_CHAR($date, 'J')::int";
+}
+
+sub sql_date_format {
+    my ($self, $date, $format) = @_;
+    
+    $format = "%Y.%m.%d %H:%i:%s" if !$format;
+
+    $format =~ s/\%Y/YYYY/g;
+    $format =~ s/\%y/YY/g;
+    $format =~ s/\%m/MM/g;
+    $format =~ s/\%d/DD/g;
+    $format =~ s/\%a/Dy/g;
+    $format =~ s/\%H/HH24/g;
+    $format =~ s/\%i/MI/g;
+    $format =~ s/\%s/SS/g;
+
+    return "TO_CHAR($date, " . $self->quote($format) . ")";
+}
+
+sub sql_interval {
+    my ($self, $interval) = @_;
+    
+    return "INTERVAL '$interval'";
+}
+
+sub bz_lock_tables {
+    my ($self, @tables) = @_;
+   
+    # Check first if there was no lock before
+    if ($self->{private_bz_tables_locked}) {
+        carp("Tables already locked");
+        ThrowCodeError("already_locked");
+    } else {
+        my %read_tables;
+        my %write_tables;
+        foreach my $table (@tables) {
+            $table =~ /^([\d\w]+)([\s]+AS[\s]+[\d\w]+)?[\s]+(WRITE|READ)$/i;
+            my $table_name = $1;
+            if ($3 =~ /READ/i) {
+                if (!exists $read_tables{$table_name}) {
+                    $read_tables{$table_name} = undef;
+                }
+            }
+            else {
+                if (!exists $write_tables{$table_name}) {
+                    $write_tables{$table_name} = undef;
+                }
+            }
+        }
+    
+        # Begin Transaction
+        $self->bz_start_transaction();
+        
+        Bugzilla->dbh->do('LOCK TABLE ' . join(', ', keys %read_tables) .
+                          ' IN ROW SHARE MODE') if keys %read_tables;
+        Bugzilla->dbh->do('LOCK TABLE ' . join(', ', keys %write_tables) .
+                          ' IN ROW EXCLUSIVE MODE') if keys %write_tables;
+    }
+}
+
+sub bz_unlock_tables {
+    my ($self, $abort) = @_;
+    
+    # Check first if there was previous matching lock
+    if (!$self->{private_bz_tables_locked}) {
+        # Abort is allowed even without previous lock for error handling
+        return if $abort;
+
+        carp("No matching lock");
+        ThrowCodeError("no_matching_lock");
+    } else {
+        # End transaction, tables will be unlocked automatically
+        if ($abort) {
+            $self->bz_rollback_transaction();
+        } else {
+            $self->bz_commit_transaction();
+        }
+    }
+}
+
+1;