/**
* 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.
*/
/**
* Runtime code-generation, compilation and bytecode-manipulation utilities.
*
* To achieve optimal performance in a dynamic schema environment, Drill
* includes a complete code generation system for generating type-specific Java
* code for most of its physical operators. This generated code is used for
* scalar expression evaluation as well as value transfers between record
* batches. As a new schema arrives at an operator, the schema change will be
* detected and prompt runtime code generation. This runtime-generated code will
* evaluate the expressions needed for the operator to process the incoming
* data. As the same code will often be run on a number of nodes in the cluster,
* compiled classes are stored in the distributed cache to avoid the need to re-
* compile and JIT-optimize the same code on every machine.
*/
package org.apache.drill.exec.compile;