text: /** @file
  
    A brief file description
  
    @section license License
  
    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.
   */
  
  //
  #include "libts.h"
  #include "Map.h"
  
  #ifndef _HTTP_CONNECTION_COUNT_H_
  
  /**
   * Singleton class to keep track of the number of connections per host
   */
  class ConnectionCount
  {
  public:
    /**
     * Static method to get the instance of the class
     * @return Returns a pointer to the instance of the class
     */
    static ConnectionCount *getInstance() {
      return &_connectionCount;
    }
  
    /**
     * Gets the number of connections for the host
     * @param ip IP address of the host
     * @return Number of connections
     */
    int getCount(const ts_ip_endpoint& addr) {
      ink_mutex_acquire(&_mutex);
      int count = _hostCount.get(ConnAddr(addr));
      ink_mutex_release(&_mutex);
      return count;
    }
  
    /**
     * Change (increment/decrement) the connection count
     * @param ip IP address of the host
     * @param delta Default is +1, can be set to negative to decrement
     */
    void incrementCount(const ts_ip_endpoint& addr, const int delta = 1) {
      ConnAddr caddr(addr);
      ink_mutex_acquire(&_mutex);
      int count = _hostCount.get(caddr);
      _hostCount.put(caddr, count + delta);
      ink_mutex_release(&_mutex);
    }
  
    struct ConnAddr {
      ts_ip_endpoint _addr;
  
      ConnAddr() { ink_zero(_addr); }
      ConnAddr(int x) { ink_release_assert(x == 0); ink_zero(_addr); }
      ConnAddr(const ts_ip_endpoint& addr) : _addr(addr) { }
      operator bool() { return ink_inet_is_ip(&_addr); }
    };
    
    class ConnAddrHashFns {
    public:
        static uintptr_t hash(ConnAddr& addr) { return (uintptr_t) ink_inet_hash(&addr._addr.sa); }
        static int equal(ConnAddr& a, ConnAddr& b) { return ink_inet_eq(&a._addr, &b._addr); }
    };
  
  private:
    // Hide the constructor and copy constructor
    ConnectionCount() { }
    ConnectionCount(const ConnectionCount & x) { NOWARN_UNUSED(x); }
  
    static ConnectionCount _connectionCount;
    HashMap<ConnAddr, ConnAddrHashFns, int> _hostCount;
    static ink_mutex _mutex;
  };
  
  #endif
  