src/adaptation/icap/Xaction.h

   1
   2 /*
   3  * $Id$
   4  *
   5  *
   6  * SQUID Web Proxy Cache          http://www.squid-cache.org/
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  13  *  Copyrighted (C) 2001 by the Regents of the University of
  14  *  California; see the COPYRIGHT file for full details.  Squid
  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.
  27  *
  28  *  You should have received a copy of the GNU General Public License
  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_ICAPXACTION_H
  35 #define SQUID_ICAPXACTION_H
  36
  37 #include "comm/forward.h"
  38 #include "CommCalls.h"
  39 #include "MemBuf.h"
  40 #include "adaptation/icap/ServiceRep.h"
  41 #include "adaptation/Initiate.h"
  42 #include "AccessLogEntry.h"
  43 #include "HttpReply.h"
  44 #include "ipcache.h"
  45
  46 class CommConnectCbParams;
  47
  48 namespace Adaptation
  49 {
  50 namespace Icap
  51 {
  52
  53 /*
  54  * The ICAP Xaction implements common tasks for ICAP OPTIONS, REQMOD, and
  55  * RESPMOD transactions. It is started by an Initiator. It terminates
  56  * on its own, when done. Transactions communicate with Initiator using
  57  * asynchronous messages because a transaction or Initiator may be gone at
  58  * any time.
  59  */
  60
  61 // Note: Xaction must be the first parent for object-unaware cbdata to work
  62
  63 class Xaction: public Adaptation::Initiate
  64 {
  65
  66 public:
  67     Xaction(const char *aTypeName, ServiceRep::Pointer &aService);
  68     virtual ~Xaction();
  69
  70     void disableRetries();
  71     void disableRepeats(const char *reason);
  72     bool retriable() const { return isRetriable; }
  73     bool repeatable() const { return isRepeatable; }
  74
  75     // comm handler wrappers, treat as private
  76     void noteCommConnected(const CommConnectCbParams &io);
  77     void noteCommWrote(const CommIoCbParams &io);
  78     void noteCommRead(const CommIoCbParams &io);
  79     void noteCommTimedout(const CommTimeoutCbParams &io);
  80     void noteCommClosed(const CommCloseCbParams &io);
  81
  82     // TODO: create these only when actually sending/receiving
  83     HttpRequest *icapRequest; ///< sent (or at least created) ICAP request
  84     HttpReply::Pointer icapReply; ///< received ICAP reply, if any
  85
  86     /// the number of times we tried to get to the service, including this time
  87     int attempts;
  88
  89 protected:
  90     virtual void start();
  91     virtual void noteInitiatorAborted(); // TODO: move to Adaptation::Initiate
  92
  93     // comm hanndlers; called by comm handler wrappers
  94     virtual void handleCommConnected() = 0;
  95     virtual void handleCommWrote(size_t sz) = 0;
  96     virtual void handleCommRead(size_t sz) = 0;
  97     virtual void handleCommTimedout();
  98     virtual void handleCommClosed();
  99
 100     /// record error detail if possible
 101     virtual void detailError(int errDetail) {}
 102
 103     void openConnection();
 104     void closeConnection();
 105     void dieOnConnectionFailure();
 106     bool haveConnection() const;
 107
 108     void scheduleRead();
 109     void scheduleWrite(MemBuf &buf);
 110     void updateTimeout();
 111
 112     void cancelRead();
 113
 114     bool parseHttpMsg(HttpMsg *msg); // true=success; false=needMore; throw=err
 115     bool mayReadMore() const;
 116
 117     virtual bool doneReading() const;
 118     virtual bool doneWriting() const;
 119     bool doneWithIo() const;
 120     virtual bool doneAll() const;
 121
 122     // called just before the 'done' transaction is deleted
 123     virtual void swanSong();
 124
 125     // returns a temporary string depicting transaction status, for debugging
 126     virtual const char *status() const;
 127     virtual void fillPendingStatus(MemBuf &buf) const;
 128     virtual void fillDoneStatus(MemBuf &buf) const;
 129
 130     // useful for debugging
 131     virtual bool fillVirginHttpHeader(MemBuf&) const;
 132
 133 public:
 134     // custom exception handling and end-of-call checks
 135     virtual void callException(const std::exception  &e);
 136     virtual void callEnd();
 137     void dnsLookupDone(const ipcache_addrs *ia);
 138
 139 protected:
 140     // logging
 141     void setOutcome(const XactOutcome &xo);
 142     virtual void finalizeLogInfo();
 143
 144 public:
 145     ServiceRep &service();
 146
 147 private:
 148     void tellQueryAborted();
 149     void maybeLog();
 150
 151 protected:
 152     Comm::ConnectionPointer connection;     ///< ICAP server connection
 153     Adaptation::Icap::ServiceRep::Pointer theService;
 154
 155     /*
 156      * We have two read buffers.   We would prefer to read directly
 157      * into the MemBuf, but since comm_read isn't MemBuf-aware, and
 158      * uses event-delayed callbacks, it leaves the MemBuf in an
 159      * inconsistent state.  There would be data in the buffer, but
 160      * MemBuf.size won't be updated until the (delayed) callback
 161      * occurs.   To avoid that situation we use a plain buffer
 162      * (commBuf) and then copy (append) its contents to readBuf in
 163      * the callback.  If comm_read ever becomes MemBuf-aware, we
 164      * can eliminate commBuf and this extra buffer copy.
 165      */
 166     MemBuf readBuf;
 167     char *commBuf;
 168     size_t commBufSize;
 169     bool commEof;
 170     bool reuseConnection;
 171     bool isRetriable;  ///< can retry on persistent connection failures
 172     bool isRepeatable; ///< can repeat if no or unsatisfactory response
 173     bool ignoreLastWrite;
 174
 175     const char *stopReason;
 176
 177     // active (pending) comm callbacks for the ICAP server connection
 178     AsyncCall::Pointer connector;
 179     AsyncCall::Pointer reader;
 180     AsyncCall::Pointer writer;
 181     AsyncCall::Pointer closer;
 182
 183     AccessLogEntry::Pointer alep; ///< icap.log entry
 184     AccessLogEntry &al; ///< short for *alep
 185
 186     timeval icap_tr_start;     /*time when the ICAP transaction was created */
 187     timeval icap_tio_start;    /*time when the first ICAP request byte was scheduled for sending*/
 188     timeval icap_tio_finish;   /*time when the last byte of the ICAP responsewas received*/
 189
 190 private:
 191     //CBDATA_CLASS2(Xaction);
 192 };
 193
 194
 195 } // namespace Icap
 196 } // namespace Adaptation
 197
 198 #endif /* SQUID_ICAPXACTION_H */