| /* |
| * 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.phoenix.compile; |
| |
| import java.util.List; |
| |
| import org.apache.hadoop.hbase.filter.CompareFilter.CompareOp; |
| import org.apache.phoenix.expression.Expression; |
| import org.apache.phoenix.query.KeyRange; |
| import org.apache.phoenix.schema.PColumn; |
| import org.apache.phoenix.schema.PTable; |
| |
| /** |
| * |
| * Interface that determines how a key part contributes to |
| * the forming of the key (start/stop of scan and SkipScanFilter) |
| * for each part of a multi-part primary key. It acts as the glue |
| * between a built-in function and the setting of the scan key |
| * during query compilation. |
| * |
| * |
| * @since 0.12 |
| */ |
| public interface KeyPart { |
| /** |
| * Calculate the key range given an operator and the key on |
| * the RHS of an expression. For example, given the expression |
| * SUBSTR(foo,1,3) = 'bar', the key range would be ['bar','bas'), |
| * and if foo was fixed length, the upper and lower key range |
| * bytes would be filled out to the fixed length. |
| * @param op comparison operator (=, <=, <, >=, >, !=) |
| * @param rhs the constant on the RHS of an expression. |
| * @return the key range that encompasses the range for the |
| * expression for which this keyPart is associated |
| * |
| * @see org.apache.phoenix.expression.function.ScalarFunction#newKeyPart(KeyPart) |
| */ |
| public KeyRange getKeyRange(CompareOp op, Expression rhs); |
| |
| /** |
| * Determines whether an expression gets extracted from the |
| * WHERE clause if it contributes toward the building of the |
| * scan key. For example, the SUBSTR built-in function may |
| * be extracted, since it may be completely represented |
| * through a key range. However, the REGEXP_SUBSTR must be |
| * left in the WHERE clause, since only the constant prefix |
| * part of the evaluation can be represented through a key |
| * range (i.e. rows may pass through that will fail when |
| * the REGEXP_SUBSTR is evaluated). |
| * |
| * @return an empty list if the expression should remain in |
| * the WHEERE clause for post filtering or a singleton list |
| * containing the expression if it should be removed. |
| */ |
| public List<Expression> getExtractNodes(); |
| |
| /** |
| * Gets the primary key column associated with the start of this key part. |
| * @return the primary key column for this key part |
| */ |
| public PColumn getColumn(); |
| |
| /** |
| * Gets the table metadata object associated with this key part |
| * @return the table for this key part |
| */ |
| public PTable getTable(); |
| } |