content: /*
   * 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.beam.runners.dataflow.worker.streaming.harness;
  
  import java.io.PrintWriter;
  import java.util.Collection;
  import java.util.function.Consumer;
  import java.util.function.Supplier;
  import org.apache.beam.runners.dataflow.worker.status.StatusDataProvider;
  import org.apache.beam.runners.dataflow.worker.streaming.ComputationState;
  import org.apache.beam.runners.dataflow.worker.util.BoundedQueueExecutor;
  import org.apache.beam.sdk.annotations.Internal;
  
  @Internal
  class MetricsDataProvider implements StatusDataProvider {
  
    private final BoundedQueueExecutor workUnitExecutor;
    private final Supplier<Long> currentActiveCommitBytes;
    private final Consumer<PrintWriter> getDataStatusProvider;
    private final Supplier<Collection<ComputationState>> allComputationStates;
  
    MetricsDataProvider(
        BoundedQueueExecutor workUnitExecutor,
        Supplier<Long> currentActiveCommitBytes,
        Consumer<PrintWriter> getDataStatusProvider,
        Supplier<Collection<ComputationState>> allComputationStates) {
      this.workUnitExecutor = workUnitExecutor;
      this.currentActiveCommitBytes = currentActiveCommitBytes;
      this.getDataStatusProvider = getDataStatusProvider;
      this.allComputationStates = allComputationStates;
    }
  
    @Override
    public void appendSummaryHtml(PrintWriter writer) {
      writer.println(workUnitExecutor.summaryHtml());
  
      writer.print("Active commit: ");
      appendHumanizedBytes(currentActiveCommitBytes.get(), writer);
      writer.println("<br>");
  
      getDataStatusProvider.accept(writer);
  
      writer.println("<br>");
  
      writer.println("Active Keys: <br>");
      for (ComputationState computationState : allComputationStates.get()) {
        writer.print(computationState.getComputationId());
        writer.print(":<br>");
        computationState.printActiveWork(writer);
        writer.println("<br>");
      }
    }
  
    private void appendHumanizedBytes(long bytes, PrintWriter writer) {
      if (bytes < (4 << 10)) {
        writer.print(bytes);
        writer.print("B");
      } else if (bytes < (4 << 20)) {
        writer.print("~");
        writer.print(bytes >> 10);
        writer.print("KB");
      } else {
        writer.print("~");
        writer.print(bytes >> 20);
        writer.print("MB");
      }
    }
  }
  