HBASE-1420 add abliity to add and remove (table) indexes on existing tables

git-svn-id: https://svn.apache.org/repos/asf/hadoop/hbase/trunk@776418 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/hadoop/hbase/regionserver/tableindexed/IndexMaintenanceUtils.java

@@ -0,0 +1,73 @@
+/**
+ * Copyright 2008 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.regionserver.tableindexed;
+
+import java.util.SortedMap;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.hbase.client.tableindexed.IndexSpecification;
+import org.apache.hadoop.hbase.client.tableindexed.IndexedTable;
+import org.apache.hadoop.hbase.io.BatchUpdate;
+import org.apache.hadoop.hbase.util.Bytes;
+
+/**
+ * Singleton class for index maintence logic.
+ */
+public class IndexMaintenanceUtils {
+
+    private static final Log LOG = LogFactory.getLog(IndexMaintenanceUtils.class);
+
+    public static BatchUpdate createIndexUpdate(final IndexSpecification indexSpec, final byte[] row,
+            final SortedMap<byte[], byte[]> columnValues) {
+        byte[] indexRow = indexSpec.getKeyGenerator().createIndexKey(row, columnValues);
+        BatchUpdate update = new BatchUpdate(indexRow);
+
+        update.put(IndexedTable.INDEX_BASE_ROW_COLUMN, row);
+
+        for (byte[] col : indexSpec.getIndexedColumns()) {
+            byte[] val = columnValues.get(col);
+            if (val == null) {
+                throw new RuntimeException("Unexpected missing column value. [" + Bytes.toString(col) + "]");
+            }
+            update.put(col, val);
+        }
+
+        for (byte[] col : indexSpec.getAdditionalColumns()) {
+            byte[] val = columnValues.get(col);
+            if (val != null) {
+                update.put(col, val);
+            }
+        }
+
+        return update;
+    }
+
+    /**
+     * Ask if this update does apply to the index.
+     * 
+     * @param indexSpec
+     * @param b
+     * @return true if possibly apply.
+     */
+    public static boolean doesApplyToIndex(final IndexSpecification indexSpec,
+            final SortedMap<byte[], byte[]> columnValues) {
+
+        for (byte[] neededCol : indexSpec.getIndexedColumns()) {
+            if (!columnValues.containsKey(neededCol)) {
+                LOG.debug("Index [" + indexSpec.getIndexId() + "] can't be updated because ["
+                        + Bytes.toString(neededCol) + "] is missing");
+                return false;
+            }
+        }
+        return true;
+    }
+}