/**
* Copyright (C) 2014-2016 LinkedIn Corp. (pinot-core@linkedin.com)
*
* Licensed 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 com.linkedin.pinot.core.common;
import com.linkedin.pinot.core.operator.ExecutionStatistics;
public interface Operator {
/*
* allows the operator to set up/initialize processing
*/
boolean open();
/**
* Get the next non empty block, if there are additional predicates the
* operator is responsible to apply the predicate and return the block that
* has atleast one doc that satisfies the predicate
*
* @return
*/
Block nextBlock();
/**
* Same as nextBlock but the caller specifies the BlockId to start from
* TODO: Better to specify the docId and let the operator decide the block
* to return. This may not be a problem now but when we add join, blockId
* may not mean anything across different tables
* @param blockId
* @return
*/
Block nextBlock(BlockId blockId);
boolean close();
ExecutionStatistics getExecutionStatistics();
}