text: /*
   * 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.
   */
  #pragma once
  
  #include "limiter.h"
  #include "ts/ts.h"
  
  ///////////////////////////////////////////////////////////////////////////////
  // TXN based limiters, for remap.config plugin instances.
  //
  class TxnRateLimiter : public RateLimiter<TSHttpTxn>
  {
  public:
    ~TxnRateLimiter()
    {
      if (_action) {
        TSActionCancel(_action);
      }
      if (_queue_cont) {
        TSContDestroy(_queue_cont);
      }
    }
  
    void setupTxnCont(TSHttpTxn txnp, TSHttpHookID hook);
    bool initialize(int argc, const char *argv[]);
  
    std::string header = "";  // Header to put the latency metrics in, e.g. @RateLimit-Delay
    unsigned error     = 429; // Error code when we decide not to allow a txn to be processed (e.g. queue full)
    unsigned retry     = 0;   // If > 0, we will also send a Retry-After: header with this retry value
  
  private:
    TSCont _queue_cont = nullptr; // Continuation processing the queue periodically
    TSAction _action   = nullptr; // The action associated with the queue continuation, needed to shut it down
  };
  