HBASE-1130 PrefixRowFilter

git-svn-id: https://svn.apache.org/repos/asf/hadoop/hbase/trunk@735867 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/hadoop/hbase/filter/PrefixRowFilter.java

@@ -0,0 +1,102 @@
+/**
+ * Copyright 2009 The Apache Software Foundation
+ *
+ * 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.hadoop.hbase.filter;
+
+import java.io.DataInput;
+import java.io.DataOutput;
+import java.io.IOException;
+import java.util.SortedMap;
+
+import org.apache.hadoop.hbase.io.Cell;
+import org.apache.hadoop.hbase.util.Bytes;
+
+/**
+ * RowFilterInterface that filters everything that does not match a prefix
+ */
+public class PrefixRowFilter implements RowFilterInterface {
+  protected byte[] prefix;
+  
+  /**
+   * Constructor that takes a row prefix to filter on
+   */
+  public PrefixRowFilter(byte[] prefix) {
+    this.prefix = prefix;
+  }
+  
+  /**
+   * Default Constructor, filters nothing. Required for RPC
+   * deserialization
+   */
+  @SuppressWarnings("unused")
+  public PrefixRowFilter() { }
+  
+  @SuppressWarnings("unused")
+  public void reset() {
+    // Nothing to reset
+  }
+  
+  @SuppressWarnings("unused")
+  public void rowProcessed(boolean filtered, byte [] key) {
+    // does not care
+  }
+  
+  public boolean processAlways() {
+    return false;
+  }
+  
+  public boolean filterAllRemaining() {
+    return false;
+  }
+  
+  public boolean filterRowKey(final byte [] rowKey) {
+    if (rowKey == null)
+      return true;
+    if (rowKey.length < prefix.length)
+      return true;
+    for(int i = 0;i < prefix.length;i++)
+      if (prefix[i] != rowKey[i])
+        return true;
+    return false;
+  }
+
+  @SuppressWarnings("unused")
+  public boolean filterColumn(final byte [] rowKey, final byte [] colunmName,
+      final byte[] columnValue) {
+    return false;
+  }
+
+  @SuppressWarnings("unused")
+  public boolean filterRow(final SortedMap<byte [], Cell> columns) {
+    return false;
+  }
+
+  @SuppressWarnings("unused")
+  public void validate(final byte [][] columns) {
+    // does not do this
+  }
+  
+  public void readFields(final DataInput in) throws IOException {
+    prefix = Bytes.readByteArray(in);
+  }
+  
+  public void write(final DataOutput out) throws IOException {
+    Bytes.writeByteArray(out, prefix);
+  }
+}