content: /*
   * Copyright 2021-2024 Aklivity Inc.
   *
   * Aklivity 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 io.aklivity.zilla.runtime.binding.tcp.internal;
  
  import static io.aklivity.zilla.runtime.engine.EngineConfiguration.ENGINE_WORKER_CAPACITY_LIMIT;
  
  import java.util.function.LongConsumer;
  
  import io.aklivity.zilla.runtime.engine.EngineContext;
  
  public final class TcpUsageTracker
  {
      private final int capacity;
      private final LongConsumer recordUsage;
  
      private int usage;
  
      public TcpUsageTracker(
          TcpConfiguration config,
          EngineContext context)
      {
          this.capacity = ENGINE_WORKER_CAPACITY_LIMIT.getAsInt(config);
          this.recordUsage = context.supplyUtilizationMetric();
      }
  
      public int available()
      {
          return capacity - usage;
      }
  
      public void claim()
      {
          int newUsage = ++usage;
          assert newUsage <= capacity : "newUsage = %d, capacity = %d".formatted(newUsage, capacity);
  
          record(newUsage);
      }
  
      public void released()
      {
          int newUsage = --usage;
          assert newUsage >= 0 : "newUsage = %d".formatted(newUsage);
  
          record(newUsage);
      }
  
      private void record(
          int newUsage)
      {
          recordUsage.accept(newUsage);
      }
  }
  