src/adaptation/icap/Launcher.h

   1
   2 /*
   3  * $Id$
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   5  *
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  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.
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  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.
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  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::Initiator *anInitiator, 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(HttpMsg *message);
  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     virtual void noteAdaptationQueryAbort(bool final);
  90
  91 protected:
  92     // Adaptation::Initiate API implementation
  93     virtual void start();
  94     virtual bool doneAll() const;
  95     virtual void swanSong();
  96
  97     // creates the right ICAP transaction using stored configuration params
  98     virtual Xaction *createXaction() = 0;
  99
 100     void launchXaction(const char *xkind);
 101
 102     Adaptation::ServicePointer theService; ///< ICAP service for all launches
 103     Adaptation::Initiate *theXaction; ///< current ICAP transaction
 104     int theLaunches; // the number of transaction launches
 105 };
 106
 107 /// helper class to pass information about aborted ICAP requests to
 108 /// the Adaptation::Icap::Launcher class
 109 class XactAbortInfo
 110 {
 111 public:
 112     XactAbortInfo(HttpRequest *anIcapRequest, HttpReply *anIcapReply,
 113                   bool beRetriable, bool beRepeatable);
 114     XactAbortInfo(const XactAbortInfo &);
 115     ~XactAbortInfo();
 116
 117     HttpRequest *icapRequest;
 118     HttpReply *icapReply;
 119     bool isRetriable;
 120     bool isRepeatable;
 121
 122 private:
 123     XactAbortInfo &operator =(const XactAbortInfo &); // undefined
 124 };
 125
 126 /* required by UnaryMemFunT */
 127 inline std::ostream &operator << (std::ostream &os, Adaptation::Icap::XactAbortInfo info)
 128 {
 129     // Nothing, it is unused
 130     return os;
 131 }
 132
 133 /// A Dialer class used to schedule the Adaptation::Icap::Launcher::noteXactAbort call
 134 class XactAbortCall: public UnaryMemFunT<Adaptation::Icap::Launcher, Adaptation::Icap::XactAbortInfo>
 135 {
 136 public:
 137     typedef void (Adaptation::Icap::Launcher::*DialMethod)(Adaptation::Icap::XactAbortInfo &);
 138     XactAbortCall(Adaptation::Icap::Launcher *launcer, DialMethod aMethod,
 139                   const Adaptation::Icap::XactAbortInfo &info):
 140             UnaryMemFunT<Adaptation::Icap::Launcher, Adaptation::Icap::XactAbortInfo>(launcer, NULL, info),
 141             dialMethod(aMethod) {}
 142     virtual void print(std::ostream &os) const {  os << '(' << "retriable:" << arg1.isRetriable << ", repeatable:" << arg1.isRepeatable << ')'; }
 143
 144 public:
 145     DialMethod dialMethod;
 146
 147 protected:
 148     virtual void doDial() { (object->*dialMethod)(arg1); }
 149 };
 150
 151 } // namespace Icap
 152 } // namespace Adaptation
 153
 154
 155 #endif /* SQUID_ICAPLAUNCHER_H */