src/ipc/Inquirer.h

   1 /*
   2  * Copyright (C) 1996-2022 The Squid Software Foundation and contributors
   3  *
   4  * Squid software is distributed under GPLv2+ license and includes
   5  * contributions from numerous individuals and organizations.
   6  * Please see the COPYING and CONTRIBUTORS files for details.
   7  */
   8
   9 /* DEBUG: section 54    Interprocess Communication */
  10
  11 #ifndef SQUID_IPC_INQUIRER_H
  12 #define SQUID_IPC_INQUIRER_H
  13
  14 #include "base/AsyncJob.h"
  15 #include "base/AsyncJobCalls.h"
  16 #include "base/forward.h"
  17 #include "ipc/forward.h"
  18 #include "ipc/Request.h"
  19 #include "ipc/Response.h"
  20 #include "ipc/StrandCoords.h"
  21
  22 namespace Ipc
  23 {
  24
  25 /// Coordinator's job that sends a cache manage request to each strand,
  26 /// aggregating individual strand responses and dumping the result if needed
  27 class Inquirer: public AsyncJob
  28 {
  29     CBDATA_CLASS(Inquirer);
  30
  31 public:
  32     Inquirer(Request::Pointer aRequest, const Ipc::StrandCoords& coords, double aTimeout);
  33     virtual ~Inquirer();
  34
  35     /// finds and calls the right Inquirer upon strand's response
  36     static void HandleRemoteAck(const Response& response);
  37
  38     /* has-to-be-public AsyncJob API */
  39     virtual void callException(const std::exception& e);
  40
  41     CodeContextPointer codeContext;
  42
  43 protected:
  44     /* AsyncJob API */
  45     virtual void start();
  46     virtual void swanSong();
  47     virtual bool doneAll() const;
  48     virtual const char *status() const;
  49
  50     /// inquire the next strand
  51     virtual void inquire();
  52     /// perform cleanup actions on completion of job
  53     virtual void cleanup();
  54     /// do specific exception handling
  55     virtual void handleException(const std::exception& e);
  56     /// send response to client
  57     virtual void sendResponse() = 0;
  58     /// perform aggregating of responses and returns true if need to continue
  59     virtual bool aggregate(Response::Pointer aResponse) = 0;
  60
  61 private:
  62     void handleRemoteAck(Response::Pointer response);
  63
  64     static void RequestTimedOut(void* param);
  65     void requestTimedOut();
  66     void removeTimeoutEvent();
  67
  68 protected:
  69     Request::Pointer request; ///< cache manager request received from client
  70
  71     Ipc::StrandCoords strands; ///< all strands we want to query, in order
  72     Ipc::StrandCoords::const_iterator pos; ///< strand we should query now
  73
  74     const double timeout; ///< number of seconds to wait for strand response
  75
  76     static RequestId::Index LastRequestId; ///< last requestId used
  77 };
  78
  79 } // namespace Ipc
  80
  81 #endif /* SQUID_IPC_INQUIRER_H */
  82