src/esi/Element.h

   1 /*
   2  * $Id$
   3  *
   4  *
   5  * SQUID Web Proxy Cache          http://www.squid-cache.org/
   6  * ----------------------------------------------------------
   7  *
   8  *  Squid is the result of efforts by numerous individuals from
   9  *  the Internet community; see the CONTRIBUTORS file for full
  10  *  details.   Many organizations have provided support for Squid's
  11  *  development; see the SPONSORS file for full details.  Squid is
  12  *  Copyrighted (C) 2001 by the Regents of the University of
  13  *  California; see the COPYRIGHT file for full details.  Squid
  14  *  incorporates software developed and/or copyrighted by other
  15  *  sources; see the CREDITS file for full details.
  16  *
  17  *  This program is free software; you can redistribute it and/or modify
  18  *  it under the terms of the GNU General Public License as published by
  19  *  the Free Software Foundation; either version 2 of the License, or
  20  *  (at your option) any later version.
  21  *
  22  *  This program is distributed in the hope that it will be useful,
  23  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  24  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  25  *  GNU General Public License for more details.
  26  *
  27  *  You should have received a copy of the GNU General Public License
  28  *  along with this program; if not, write to the Free Software
  29  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
  30  *
  31  */
  32
  33 #ifndef SQUID_ESIELEMENT_H
  34 #define SQUID_ESIELEMENT_H
  35
  36 #include "RefCount.h"
  37 #include "esi/Segment.h"
  38
  39 typedef enum {
  40     ESI_PROCESS_COMPLETE = 0,
  41     ESI_PROCESS_PENDING_WONTFAIL = 1,
  42     ESI_PROCESS_PENDING_MAYFAIL = 2,
  43     ESI_PROCESS_FAILED = 3
  44 } esiProcessResult_t;
  45
  46 class ESIElement;
  47
  48 struct esiTreeParent : public RefCountable {
  49     virtual void provideData (ESISegment::Pointer data, ESIElement * source) {
  50         /* make abstract when all functionality complete */
  51         assert (0);
  52     }
  53
  54     virtual void fail(ESIElement * source, char const *reason = NULL) {}
  55
  56     virtual ~esiTreeParent() {}
  57 };
  58
  59 typedef RefCount<esiTreeParent> esiTreeParentPtr;
  60
  61 class ESIVarState;
  62
  63 class ESIElement : public esiTreeParent
  64 {
  65
  66 public:
  67     typedef RefCount<ESIElement> Pointer;
  68
  69     /* the types we have */
  70     enum ESIElementType_t {
  71         ESI_ELEMENT_NONE,
  72         ESI_ELEMENT_INCLUDE,
  73         ESI_ELEMENT_COMMENT,
  74         ESI_ELEMENT_REMOVE,
  75         ESI_ELEMENT_TRY,
  76         ESI_ELEMENT_ATTEMPT,
  77         ESI_ELEMENT_EXCEPT,
  78         ESI_ELEMENT_VARS,
  79         ESI_ELEMENT_CHOOSE,
  80         ESI_ELEMENT_WHEN,
  81         ESI_ELEMENT_OTHERWISE,
  82         ESI_ELEMENT_ASSIGN
  83     };
  84     static ESIElementType_t IdentifyElement (const char *);
  85     virtual bool addElement(ESIElement::Pointer) {
  86         /* Don't accept children */
  87         debugs(86,5, "ESIElement::addElement: Failed for " << this);
  88         return false;
  89     }
  90
  91     virtual void render (ESISegment::Pointer) = 0;
  92     /* process this element */
  93     virtual esiProcessResult_t process (int dovars) {
  94         debugs(86,5, "esiProcessComplete: Processed " << this);
  95         return ESI_PROCESS_COMPLETE;
  96     }
  97
  98     virtual bool mayFail() const {
  99         return true;
 100     }
 101
 102     virtual Pointer makeCacheable() const = 0;
 103     virtual Pointer makeUsable(esiTreeParentPtr, ESIVarState &) const = 0;
 104
 105     /* The top level no longer needs this element */
 106     virtual void finish() = 0;
 107 };
 108
 109 #endif /* SQUID_ESIELEMENT_H */