src/main/java/org/apache/sysds/runtime/instructions/fed/CentralMomentFEDInstruction.java

/*
 * 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.sysds.runtime.instructions.fed;

import java.util.ArrayList;
import java.util.List;
import java.util.Optional;

import org.apache.sysds.common.Types;
import org.apache.sysds.runtime.DMLRuntimeException;
import org.apache.sysds.runtime.controlprogram.caching.MatrixObject;
import org.apache.sysds.runtime.controlprogram.context.ExecutionContext;
import org.apache.sysds.runtime.controlprogram.federated.FederatedRequest;
import org.apache.sysds.runtime.controlprogram.federated.FederatedResponse;
import org.apache.sysds.runtime.controlprogram.federated.FederatedUDF;
import org.apache.sysds.runtime.controlprogram.federated.FederationMap;
import org.apache.sysds.runtime.controlprogram.federated.FederationUtils;
import org.apache.sysds.runtime.functionobjects.CM;
import org.apache.sysds.runtime.instructions.InstructionUtils;
import org.apache.sysds.runtime.instructions.cp.CM_COV_Object;
import org.apache.sysds.runtime.instructions.cp.CPOperand;
import org.apache.sysds.runtime.instructions.cp.Data;
import org.apache.sysds.runtime.instructions.cp.DoubleObject;
import org.apache.sysds.runtime.instructions.cp.ScalarObject;
import org.apache.sysds.runtime.matrix.data.MatrixBlock;
import org.apache.sysds.runtime.matrix.operators.CMOperator;

public class CentralMomentFEDInstruction extends AggregateUnaryFEDInstruction {

    private CentralMomentFEDInstruction(CMOperator cm, CPOperand in1, CPOperand in2, CPOperand in3, CPOperand out,
                                       String opcode, String str) {
        super(cm, in1, in2, in3, out, opcode, str);
    }

    public static CentralMomentFEDInstruction parseInstruction(String str) {
        CPOperand in1 = new CPOperand("", Types.ValueType.UNKNOWN, Types.DataType.UNKNOWN);
        CPOperand in2 = null;
        CPOperand in3 = null;
        CPOperand out = new CPOperand("", Types.ValueType.UNKNOWN, Types.DataType.UNKNOWN);

        String[] parts = InstructionUtils.getInstructionPartsWithValueType(str);
        String opcode = parts[0];

        //check supported opcode
        if( !opcode.equalsIgnoreCase("cm") ) {
            throw new DMLRuntimeException("Unsupported opcode "+opcode);
        }

        if ( parts.length == 4 ) {
            // Example: CP.cm.mVar0.Var1.mVar2; (without weights)
            in2 = new CPOperand("", Types.ValueType.UNKNOWN, Types.DataType.UNKNOWN);
            parseUnaryInstruction(str, in1, in2, out);
        }
        else if ( parts.length == 5) {
            // CP.cm.mVar0.mVar1.Var2.mVar3; (with weights)
            in2 = new CPOperand("", Types.ValueType.UNKNOWN, Types.DataType.UNKNOWN);
            in3 = new CPOperand("", Types.ValueType.UNKNOWN, Types.DataType.UNKNOWN);
            parseUnaryInstruction(str, in1, in2, in3, out);
        }

        /*
         * Exact order of the central moment MAY NOT be known at compilation time.
         * We first try to parse the second argument as an integer, and if we fail,
         * we simply pass -1 so that getCMAggOpType() picks up AggregateOperationTypes.INVALID.
         * It must be updated at run time in processInstruction() method.
         */

        int cmOrder;
        try {
            if ( in3 == null ) {
                cmOrder = Integer.parseInt(in2.getName());
            }
            else {
                cmOrder = Integer.parseInt(in3.getName());
            }
        } catch(NumberFormatException e) {
            cmOrder = -1; // unknown at compilation time
        }

        CMOperator.AggregateOperationTypes opType = CMOperator.getCMAggOpType(cmOrder);
        CMOperator cm = new CMOperator(CM.getCMFnObject(opType), opType);
        return new CentralMomentFEDInstruction(cm, in1, in2, in3, out, opcode, str);
    }

    @Override
    public void processInstruction( ExecutionContext ec ) {
        MatrixObject mo = ec.getMatrixObject(input1.getName());
        ScalarObject order = ec.getScalarInput(input3==null ? input2 : input3);

        CMOperator cm_op = ((CMOperator) _optr);
        if(cm_op.getAggOpType() == CMOperator.AggregateOperationTypes.INVALID)
            cm_op = cm_op.setCMAggOp((int) order.getLongValue());

        FederationMap fedMapping = mo.getFedMapping();
        List<CM_COV_Object> globalCmobj = new ArrayList<>();

        long varID = FederationUtils.getNextFedDataID();
        CMOperator finalCm_op = cm_op;
        fedMapping.mapParallel(varID, (range, data) -> {

            FederatedResponse response;
            try {
                if (input3 == null ) {
                    response = data.executeFederatedOperation(
                        new FederatedRequest(FederatedRequest.RequestType.EXEC_UDF, -1,
                            new CentralMomentFEDInstruction.CMFunction(data.getVarID(), finalCm_op))).get();
                } else {
                    MatrixBlock wtBlock = ec.getMatrixInput(input2.getName());

                    response = data.executeFederatedOperation(
                        new FederatedRequest(FederatedRequest.RequestType.EXEC_UDF, -1,
                            new CentralMomentFEDInstruction.CMWeightsFunction(data.getVarID(), finalCm_op, wtBlock))).get();
                }

                if(!response.isSuccessful())
                    response.throwExceptionFromResponse();
               synchronized(globalCmobj) {
                   globalCmobj.add((CM_COV_Object) response.getData()[0]);
               }
            }
            catch(Exception e) {
                throw new DMLRuntimeException(e);
            }
            return null;
        });

        Optional<CM_COV_Object> res = globalCmobj.stream().reduce((arg0, arg1) -> (CM_COV_Object) finalCm_op.fn.execute(arg0, arg1));
        try {
            ec.setScalarOutput(output.getName(), new DoubleObject(res.get().getRequiredResult(finalCm_op)));
        }
        catch(Exception e) {
            throw new DMLRuntimeException(e);
        }
    }

    private static class CMFunction extends FederatedUDF {
        private static final long serialVersionUID = 7460149207607220994L;
        private final CMOperator _op;

        public CMFunction (long input, CMOperator op) {
            super(new long[] {input});
            _op = op;
        }

        @Override
        public FederatedResponse execute(ExecutionContext ec, Data... data) {
            MatrixBlock mb = ((MatrixObject) data[0]).acquireReadAndRelease();
            return new FederatedResponse(FederatedResponse.ResponseType.SUCCESS, mb.cmOperations(_op));
        }
    }


    private static class CMWeightsFunction extends FederatedUDF {
        private static final long serialVersionUID = -3685746246551622021L;
        private final CMOperator _op;
        private final MatrixBlock _weights;

        protected CMWeightsFunction(long input, CMOperator op, MatrixBlock weights) {
            super(new long[] {input});
            _op = op;
            _weights = weights;
        }

        @Override
        public FederatedResponse execute(ExecutionContext ec, Data... data) {
            MatrixBlock mb = ((MatrixObject) data[0]).acquireReadAndRelease();
            return new FederatedResponse(FederatedResponse.ResponseType.SUCCESS, mb.cmOperations(_op, _weights));
        }
    }
}