text: /** @file
  
    ProxyClientSession - Base class for protocol client sessions.
  
    @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.
   */
  
  #ifndef __PROXY_CLIENT_SESSION_H__
  #define __PROXY_CLIENT_SESSION_H__
  
  #include "libts.h"
  #include "P_Net.h"
  #include "InkAPIInternal.h"
  
  // Emit a debug message conditional on whether this particular client session
  // has debugging enabled. This should only be called from within a client session
  // member function.
  #define DebugSsn(ssn, tag, ...) DebugSpecific((ssn)->debug(), tag, __VA_ARGS__)
  
  class ProxyClientSession : public VConnection
  {
  public:
    ProxyClientSession();
  
    virtual void destroy() = 0;
    virtual void start() = 0;
  
    virtual void new_connection(NetVConnection *new_vc, MIOBuffer *iobuf, IOBufferReader *reader, bool backdoor) = 0;
  
    virtual void
    ssn_hook_append(TSHttpHookID id, INKContInternal *cont)
    {
      this->api_hooks.prepend(id, cont);
    }
  
    virtual void
    ssn_hook_prepend(TSHttpHookID id, INKContInternal *cont)
    {
      this->api_hooks.prepend(id, cont);
    }
  
    APIHook *
    ssn_hook_get(TSHttpHookID id) const
    {
      return this->api_hooks.get(id);
    }
  
    void *
    get_user_arg(unsigned ix) const
    {
      ink_assert(ix < countof(user_args));
      return this->user_args[ix];
    }
  
    void
    set_user_arg(unsigned ix, void *arg)
    {
      ink_assert(ix < countof(user_args));
      user_args[ix] = arg;
    }
  
    // Return whether debugging is enabled for this session.
    bool
    debug() const
    {
      return this->debug_on;
    }
  
    bool
    hooks_enabled() const
    {
      return this->hooks_on;
    }
  
    bool
    has_hooks() const
    {
      return this->api_hooks.has_hooks() || http_global_hooks->has_hooks();
    }
  
    // Initiate an API hook invocation.
    void do_api_callout(TSHttpHookID id);
  
    void cleanup();
  
    static int64_t next_connection_id();
  
  protected:
    // XXX Consider using a bitwise flags variable for the following flags, so that we can make the best
    // use of internal alignment padding.
  
    // Session specific debug flag.
    bool debug_on;
    bool hooks_on;
  
  private:
    APIHookScope api_scope;
    TSHttpHookID api_hookid;
    APIHook *api_current;
    HttpAPIHooks api_hooks;
    void *user_args[HTTP_SSN_TXN_MAX_USER_ARG];
  
    ProxyClientSession(ProxyClientSession &);                  // noncopyable
    ProxyClientSession &operator=(const ProxyClientSession &); // noncopyable
  
    int state_api_callout(int event, void *edata);
    void handle_api_return(int event);
  
    friend void TSHttpSsnDebugSet(TSHttpSsn, int);
  };
  
  #endif // __PROXY_CLIENT_SESSION_H__
  