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From jbel...@apache.org
Subject svn commit: r1063985 - /cassandra/trunk/src/java/org/apache/cassandra/db/CounterUpdateColumn.java
Date Thu, 27 Jan 2011 04:25:28 GMT
Author: jbellis
Date: Thu Jan 27 04:25:28 2011
New Revision: 1063985

URL: http://svn.apache.org/viewvc?rev=1063985&view=rev
Log:
add missing CounterUpdateColumn.java

Added:
    cassandra/trunk/src/java/org/apache/cassandra/db/CounterUpdateColumn.java

Added: cassandra/trunk/src/java/org/apache/cassandra/db/CounterUpdateColumn.java
URL: http://svn.apache.org/viewvc/cassandra/trunk/src/java/org/apache/cassandra/db/CounterUpdateColumn.java?rev=1063985&view=auto
==============================================================================
--- cassandra/trunk/src/java/org/apache/cassandra/db/CounterUpdateColumn.java (added)
+++ cassandra/trunk/src/java/org/apache/cassandra/db/CounterUpdateColumn.java Thu Jan 27 04:25:28
2011
@@ -0,0 +1,94 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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 org.apache.cassandra.db;
+
+import java.nio.ByteBuffer;
+
+import org.apache.cassandra.db.context.CounterContext;
+import org.apache.cassandra.utils.ByteBufferUtil;
+
+/**
+ * A counter update while it hasn't been applied yet by the leader replica.
+ *
+ * Contains a single counter update. When applied by the leader replica, this
+ * is transformed to a relevant CounterColumn. This Column is a temporary data
+ * structure that should never be stored inside a memtable or an sstable.
+ */
+public class CounterUpdateColumn extends Column
+{
+    public CounterUpdateColumn(ByteBuffer name, long value, long timestamp)
+    {
+        this(name, ByteBufferUtil.bytes(value), timestamp);
+    }
+
+    public CounterUpdateColumn(ByteBuffer name, ByteBuffer value, long timestamp)
+    {
+        super(name, value, timestamp);
+    }
+
+    public CounterColumn asCounterColumn()
+    {
+        return new CounterColumn(
+                ByteBufferUtil.clone(name()),
+                CounterContext.instance().create(delta()),
+                timestamp(),
+                Long.MIN_VALUE);
+    }
+
+    public long delta()
+    {
+        return value().getLong(value().position());
+    }
+
+    @Override
+    public IColumn diff(IColumn column)
+    {
+        // Diff is used during reads, but we should never read those columns
+        throw new UnsupportedOperationException("This operation is unsupported on CounterUpdateColumn.");
+    }
+
+    @Override
+    public IColumn reconcile(IColumn column)
+    {
+        // The only time this could happen is if a batchAdd ships two
+        // increment for the same column. Hence we simply sums the delta.
+
+        assert (column instanceof CounterUpdateColumn) || (column instanceof DeletedColumn)
: "Wrong class type.";
+
+        // tombstones take precedence
+        if (column.isMarkedForDelete())
+            return timestamp() > column.timestamp() ? this : column;
+
+        // neither is tombstoned
+        CounterUpdateColumn c = (CounterUpdateColumn)column;
+        return new CounterUpdateColumn(name(), delta() + c.delta(), Math.max(timestamp(),
c.timestamp()));
+    }
+
+    @Override
+    public int serializationFlags()
+    {
+        return ColumnSerializer.COUNTER_UPDATE_MASK;
+    }
+
+    @Override
+    public IColumn deepCopy()
+    {
+        return new CounterUpdateColumn(ByteBufferUtil.clone(name), ByteBufferUtil.clone(value),
timestamp);
+    }
+}



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