/** @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.
 */

/****************************************************************************

   HttpCacheSM.h

   Description:


 ****************************************************************************/

#ifndef _HTTP_CACHE_SM_H_
#define _HTTP_CACHE_SM_H_

#include "P_Cache.h"
#include "StatSystem.h"
#include "ProxyConfig.h"
#include "URL.h"
#include "HTTP.h"
#include "HttpConfig.h"

class HttpSM;
class HttpCacheSM;
class CacheLookupHttpConfig;

struct HttpCacheAction:public Action
{
  HttpCacheAction();
  virtual void cancel(Continuation * c = NULL);
  void init(HttpCacheSM * sm_arg)
  {
    sm = sm_arg;
  };
  HttpCacheSM *sm;
};

class HttpCacheSM:public Continuation
{
public:
  HttpCacheSM();

  void init(HttpSM * sm_arg, ProxyMutex * amutex)
  {
    master_sm = sm_arg;
    mutex = amutex;
    captive_action.init(this);
  }

  Action *open_read(URL * url, HTTPHdr * hdr, CacheLookupHttpConfig * params, time_t pin_in_cache);

  Action *open_write(URL * url,
                     HTTPHdr * request, CacheHTTPInfo * old_info, time_t pin_in_cache, bool retry, bool allow_multiple);

  CacheVConnection *cache_read_vc;
  CacheVConnection *cache_write_vc;
  CacheVConnection *cache_pre_write;

  bool read_locked;
  bool write_locked;
  // Flag to check whether read-while-write is in progress or not
  bool readwhilewrite_inprogress;

  HttpSM *master_sm;
  Action *pending_action;

  //Function to set readwhilewrite_inprogress flag
  inline void set_readwhilewrite_inprogress(bool value)
  {
    readwhilewrite_inprogress = value;
  }

  //Function to get the readwhilewrite_inprogress flag
  inline bool is_readwhilewrite_inprogress()
  {
    return readwhilewrite_inprogress;
  }

  inline void abort_read()
  {
    if (cache_read_vc) {
      HTTP_DECREMENT_DYN_STAT(http_current_cache_connections_stat);
      cache_read_vc->do_io(VIO::ABORT);
      cache_read_vc = NULL;
    }
  }
  inline void abort_write()
  {
    if (cache_write_vc) {
      HTTP_DECREMENT_DYN_STAT(http_current_cache_connections_stat);
      cache_write_vc->do_io(VIO::ABORT);
      cache_write_vc = NULL;
    }
    if (cache_pre_write) {
      cache_pre_write->do_io(VIO::ABORT);
      cache_pre_write = NULL;
    }
  }
  inline void close_write()
  {
    if (cache_write_vc) {
      HTTP_DECREMENT_DYN_STAT(http_current_cache_connections_stat);
      cache_write_vc->do_io(VIO::CLOSE);
      cache_write_vc = NULL;
    }
    ink_assert(!cache_pre_write);
  }
  inline void close_read()
  {
    if (cache_read_vc) {
      HTTP_DECREMENT_DYN_STAT(http_current_cache_connections_stat);
      cache_read_vc->do_io(VIO::CLOSE);
      cache_read_vc = NULL;
    }
  }
  inline void end_both()
  {
    // We close the read so that cache
    //   records its stats
    close_read();
    abort_write();
  }
  inline URL *get_lookup_url()
  {
    return lookup_url;
  }
  inline void set_lookup_url(URL * url)
  {
    lookup_url = url;
  }

private:

  void do_schedule_in();
  Action *do_cache_open_read();

  int state_cache_open_read(int event, void *data);
  int state_cache_open_write(int event, void *data);

  HttpCacheAction captive_action;
  bool open_read_cb;
  bool open_write_cb;

  // Open read parameters
  int open_read_tries;
  HTTPHdr *read_request_hdr;
  CacheLookupHttpConfig *read_config;
  time_t read_pin_in_cache;

  // Open write parameters
  bool retry_write;
  int open_write_tries;

  // Common parameters
  URL *lookup_url;

  // to keep track of multiple cache lookups
  int lookup_max_recursive;
  int current_lookup_level;
};

#endif
