# HG changeset patch
# User Tomas Zeman <tzeman@volny.cz>
# Date 1333446422 -7200
# Node ID dbe9e8adddec1603958f1daedc981eaec5618e45
# Parent  3a1eb640ff95fab30f8d43ffbec3ba84a3b7b5f4
Sequencer

diff -r 3a1eb640ff95 -r dbe9e8adddec src/main/scala/fis/db/PgsqlSequencer.scala
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/main/scala/fis/db/PgsqlSequencer.scala	Tue Apr 03 11:47:02 2012 +0200
@@ -0,0 +1,79 @@
+/*
+ * Copyright 2012 Tomas Zeman <tzeman@volny.cz>
+ *
+ * Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package fis.db
+
+import net.liftweb.util.Helpers._
+import org.squeryl.Session
+import org.squeryl.internals.StatementWriter
+
+trait Sequencer {
+  def cur: Long
+  def next: Long
+  def name: String
+  def create(): Unit
+  def drop(): Unit
+}
+
+abstract class AbstractPgsqlSequencer extends Sequencer {
+
+  protected def sess = Session.currentSession
+
+  def create() {
+    val sw = new StatementWriter(sess.databaseAdapter)
+    sw.write("create sequence ", name)
+    exec(sw)
+  }
+
+  def drop() {
+    val sw = new StatementWriter(sess.databaseAdapter)
+    sw.write("drop sequence ", name)
+    exec(sw)
+  }
+
+  private def exec(sw: StatementWriter) {
+    val s = sess
+    val dba = s.databaseAdapter
+    tryo { dba.executeUpdate(s, sw) }
+  }
+
+  private def getLong(sw: StatementWriter): Long = {
+    val st = sess.connection.createStatement
+    val rs = st.executeQuery(sw.statement)
+    rs.next
+    rs.getLong(1)
+  }
+
+  def next: Long = {
+    val sw = new StatementWriter(sess.databaseAdapter)
+    sw.write("select nextval('" + name + "')")
+    getLong(sw)
+  }
+  
+  def cur: Long = {
+    val sw = new StatementWriter(sess.databaseAdapter)
+    sw.write("select currval('" + name + "')")
+    getLong(sw)
+  }
+  
+}
+
+class PgsqlSequencer(val name: String) extends AbstractPgsqlSequencer
+
+object PgsqlSequencer {
+  def apply(n: String) = new PgsqlSequencer(n)
+}
+
+// vim: set ts=2 sw=2 et: