content: /*
   * Tencent is pleased to support the open source community by making Angel available.
   *
   * Copyright (C) 2017-2018 THL A29 Limited, a Tencent company. All rights reserved.
   *
   * 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
   *
   * https://opensource.org/licenses/Apache-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.tencent.angel.graph.client.node2vec.updatefuncs.initwalkpath;
  
  import com.tencent.angel.PartitionKey;
  import com.tencent.angel.graph.client.node2vec.data.WalkPath;
  import com.tencent.angel.graph.client.node2vec.utils.PathQueue;
  import com.tencent.angel.ml.matrix.psf.update.base.PartitionUpdateParam;
  import com.tencent.angel.ml.matrix.psf.update.base.UpdateFunc;
  import com.tencent.angel.ml.matrix.psf.update.base.UpdateParam;
  import com.tencent.angel.ps.storage.vector.ServerLongAnyRow;
  import com.tencent.angel.ps.storage.vector.element.IElement;
  import com.tencent.angel.ps.storage.vector.element.LongArrayElement;
  import it.unimi.dsi.fastutil.longs.Long2ObjectMap;
  import it.unimi.dsi.fastutil.objects.ObjectIterator;
  import java.util.ArrayList;
  import java.util.Random;
  
  public class InitWalkPath extends UpdateFunc {
  
    /**
     * Create a new UpdateParam
     */
    public InitWalkPath(UpdateParam param) {
      super(param);
    }
  
    public InitWalkPath() {
      super(null);
    }
  
    @Override
    public void partitionUpdate(PartitionUpdateParam partParam) {
      InitWalkPathPartitionParam pparam = (InitWalkPathPartitionParam) partParam;
      PartitionKey partKey = pparam.getPartKey();
      ServerLongAnyRow walkPath = (ServerLongAnyRow) psContext.getMatrixStorageManager()
          .getRow(partKey, 0);
      ServerLongAnyRow rowNeighbor = (ServerLongAnyRow) psContext.getMatrixStorageManager().getRow(
          pparam.getNeighborMatrixId(), 0, partKey.getPartitionId());
      Random rand = new Random();
  
      ObjectIterator<Long2ObjectMap.Entry<IElement>> iter = rowNeighbor.iterator();
      walkPath.startWrite();
      walkPath.clear();
      PathQueue.init(partKey.getPartitionId());
      PathQueue.setThreshold(pparam.getThreshold());
      PathQueue.setKeepProba(pparam.getKeepProba());
      PathQueue.setNumParts(pparam.getNumParts());
      PathQueue.setIsTrunc(pparam.isTrunc());
      try {
        int count = 0;
        int batchSize = 1024;
        ArrayList<WalkPath> batchPath = new ArrayList<>();
        while (iter.hasNext()) {
          Long2ObjectMap.Entry<IElement> entry = iter.next();
          long key = entry.getLongKey() + partKey.getStartCol();
          LongArrayElement value = (LongArrayElement) entry.getValue();
  
          long[] neighbor = value.getData();
          long neigh = neighbor[rand.nextInt(neighbor.length)];
  
          WalkPath wPath = new WalkPath(pparam.getWalkLength(), key, neigh);
          walkPath.set(key, wPath);
  
          batchPath.add(wPath);
          count++;
          if (count % batchSize == 0) {
            PathQueue.initPushBatch(partKey.getPartitionId(), batchPath);
            batchPath.clear();
          }
        }
  
        if (!batchPath.isEmpty()) {
          PathQueue.initPushBatch(partKey.getPartitionId(), batchPath);
          batchPath.clear();
        }
      } finally {
        walkPath.endWrite();
      }
    }
  }
  