/**
 * (C) Copyright IBM Corp. 2010, 2015
 *
 * 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.ibm.bi.dml.yarn.ropt;

import com.ibm.bi.dml.conf.ConfigurationManager;
import com.ibm.bi.dml.conf.DMLConfig;
import com.ibm.bi.dml.hops.OptimizerUtils;

public class YarnOptimizerUtils 
{
	public enum GridEnumType{
		EQUI_GRID,
		EXP_GRID,
		MEM_EQUI_GRID,
		HYBRID_MEM_EXP_GRID,
	}

	/**
	 * 
	 * @return
	 */
	public static double getRemoteMemBudgetMap(long jobLookupId)
	{
		return getRemoteMemBudgetMap(false, jobLookupId);
	}
	
	/**
	 * 
	 * @return
	 */
	public static double getRemoteMemBudgetMap(boolean substractSortBuffer, long jobLookupId)
	{
		double ret = YarnClusterAnalyzer.getRemoteMaxMemoryMap(jobLookupId);
		if( substractSortBuffer )
			ret -= YarnClusterAnalyzer.getRemoteMaxMemorySortBuffer();
		return ret * OptimizerUtils.MEM_UTIL_FACTOR;
	}
	
	/**
	 * 
	 * @return
	 */
	public static double getRemoteMemBudgetReduce(long jobLookupId)
	{
		double ret = YarnClusterAnalyzer.getRemoteMaxMemoryReduce(jobLookupId);
		return ret * OptimizerUtils.MEM_UTIL_FACTOR;
	}
	
	/**
	 * Returns the number of reducers that potentially run in parallel.
	 * This is either just the configured value (SystemML config) or
	 * the minimum of configured value and available reduce slots. 
	 * 
	 * @param configOnly
	 * @return
	 */
	public static int getNumReducers(boolean configOnly, long jobLookupId)
	{
		int ret = ConfigurationManager.getConfig().getIntValue(DMLConfig.NUM_REDUCERS);
		if( !configOnly )
			ret = Math.min(ret,YarnClusterAnalyzer.getRemoteParallelReduceTasks(jobLookupId));
		
		return ret;
	}
	
	/**
	 * 
	 * @param mb
	 * @return
	 */
	public static long toB( long mb )
	{
		return 1024 * 1024 * mb; 
	}
	
	/**
	 * 
	 * @param b
	 * @return
	 */
	public static long toMB( long b )
	{
		return b / (1024 * 1024); 
	}
	
	/**
	 * 
	 * @param minAlloc
	 * @param maxAlloc
	 * @param numCores
	 * @return
	 */
	public static long computeMinContraint( long minAlloc, long maxAlloc, long numCores )
	{
		return ((long)(Math.max(minAlloc, maxAlloc/numCores )/minAlloc)*minAlloc); 	
	}
}