src/adaptation/icap/Launcher.h

   1
   2 /*
   3  * $Id$
   4  *
   5  *
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  15  *  incorporates software developed and/or copyrighted by other
  16  *  sources; see the CREDITS file for full details.
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  18  *  This program is free software; you can redistribute it and/or modify
  19  *  it under the terms of the GNU General Public License as published by
  20  *  the Free Software Foundation; either version 2 of the License, or
  21  *  (at your option) any later version.
  22  *
  23  *  This program is distributed in the hope that it will be useful,
  24  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  25  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  26  *  GNU General Public License for more details.
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  29  *  along with this program; if not, write to the Free Software
  30  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
  31  *
  32  */
  33
  34 #ifndef SQUID_ICAPLAUNCHER_H
  35 #define SQUID_ICAPLAUNCHER_H
  36
  37 #include "adaptation/Initiator.h"
  38 #include "adaptation/Initiate.h"
  39 #include "adaptation/icap/ServiceRep.h"
  40
  41 /*
  42  * The ICAP Launcher starts an ICAP transaction. If the transaction fails
  43  * due to what looks like a persistent connection race condition, the launcher
  44  * starts a new ICAP transaction using a freshly opened connection.
  45  *
  46  * ICAPLauncher and one or more ICAP transactions initiated by it form an
  47  * ICAP "query".
  48  *
  49  * An ICAP Initiator deals with the ICAP Launcher and not an individual ICAP
  50  * transaction because the latter may disappear and be replaced by another
  51  * transaction.
  52  *
  53  * Specific ICAP launchers implement the createXaction() method to create
  54  * REQMOD, RESPMOD, or OPTIONS transaction from initiator-supplied data.
  55  *
  56  * TODO: This class might be the right place to initiate ICAP ACL checks or
  57  * implement more sophisticated ICAP transaction handling like chaining of
  58  * ICAP transactions.
  59  */
  60
  61
  62 namespace Adaptation
  63 {
  64 namespace Icap
  65 {
  66
  67 class Xaction;
  68 class XactAbortInfo;
  69
  70 // Note: Initiate must be the first parent for cbdata to work. We use
  71 // a temporary InitaitorHolder/toCbdata hacks and do not call cbdata
  72 // operations on the initiator directly.
  73 class Launcher: public Adaptation::Initiate, public Adaptation::Initiator
  74 {
  75 public:
  76     Launcher(const char *aTypeName, Adaptation::ServicePointer &aService);
  77     virtual ~Launcher();
  78
  79     // Adaptation::Initiate: asynchronous communication with the initiator
  80     void noteInitiatorAborted();
  81
  82     // Adaptation::Initiator: asynchronous communication with the current transaction
  83     virtual void noteAdaptationAnswer(const Answer &answer);
  84     virtual void noteXactAbort(XactAbortInfo info);
  85
  86 private:
  87     bool canRetry(XactAbortInfo &info) const; //< true if can retry in the case of persistent connection failures
  88     bool canRepeat(XactAbortInfo &info) const; //< true if can repeat in the case of no or unsatisfactory response
  89
  90 protected:
  91     // Adaptation::Initiate API implementation
  92     virtual void start();
  93     virtual bool doneAll() const;
  94     virtual void swanSong();
  95
  96     // creates the right ICAP transaction using stored configuration params
  97     virtual Xaction *createXaction() = 0;
  98
  99     void launchXaction(const char *xkind);
 100
 101     Adaptation::ServicePointer theService; ///< ICAP service for all launches
 102     CbcPointer<Initiate> theXaction; ///< current ICAP transaction
 103     int theLaunches; // the number of transaction launches
 104 };
 105
 106 /// helper class to pass information about aborted ICAP requests to
 107 /// the Adaptation::Icap::Launcher class
 108 class XactAbortInfo
 109 {
 110 public:
 111     XactAbortInfo(HttpRequest *anIcapRequest, HttpReply *anIcapReply,
 112                   bool beRetriable, bool beRepeatable);
 113     XactAbortInfo(const XactAbortInfo &);
 114     ~XactAbortInfo();
 115
 116     std::ostream &print(std::ostream &os) const {
 117         return os << isRetriable << ',' << isRepeatable;
 118     }
 119
 120     HttpRequest *icapRequest;
 121     HttpReply *icapReply;
 122     bool isRetriable;
 123     bool isRepeatable;
 124
 125 private:
 126     XactAbortInfo &operator =(const XactAbortInfo &); // undefined
 127 };
 128
 129 inline
 130 std::ostream &
 131 operator <<(std::ostream &os, const XactAbortInfo &xai)
 132 {
 133     return xai.print(os);
 134 }
 135
 136 } // namespace Icap
 137 } // namespace Adaptation
 138
 139
 140 #endif /* SQUID_ICAPLAUNCHER_H */