src/esi/Element.h

   1 /*
   2  * Copyright (C) 1996-2017 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 #ifndef SQUID_ESIELEMENT_H
  10 #define SQUID_ESIELEMENT_H
  11
  12 #include "base/RefCount.h"
  13 #include "Debug.h"
  14 #include "esi/Segment.h"
  15
  16 typedef enum {
  17     ESI_PROCESS_COMPLETE = 0,
  18     ESI_PROCESS_PENDING_WONTFAIL = 1,
  19     ESI_PROCESS_PENDING_MAYFAIL = 2,
  20     ESI_PROCESS_FAILED = 3
  21 } esiProcessResult_t;
  22
  23 class ESIElement;
  24
  25 struct esiTreeParent : public RefCountable {
  26     virtual void provideData (ESISegment::Pointer data, ESIElement * source) {
  27         /* make abstract when all functionality complete */
  28         assert (0);
  29     }
  30
  31     virtual void fail(ESIElement * source, char const *reason = NULL) {}
  32
  33     virtual ~esiTreeParent() {}
  34 };
  35
  36 typedef RefCount<esiTreeParent> esiTreeParentPtr;
  37
  38 class ESIVarState;
  39
  40 class ESIElement : public esiTreeParent
  41 {
  42
  43 public:
  44     typedef RefCount<ESIElement> Pointer;
  45
  46     /* the types we have */
  47     enum ESIElementType_t {
  48         ESI_ELEMENT_NONE,
  49         ESI_ELEMENT_INCLUDE,
  50         ESI_ELEMENT_COMMENT,
  51         ESI_ELEMENT_REMOVE,
  52         ESI_ELEMENT_TRY,
  53         ESI_ELEMENT_ATTEMPT,
  54         ESI_ELEMENT_EXCEPT,
  55         ESI_ELEMENT_VARS,
  56         ESI_ELEMENT_CHOOSE,
  57         ESI_ELEMENT_WHEN,
  58         ESI_ELEMENT_OTHERWISE,
  59         ESI_ELEMENT_ASSIGN
  60     };
  61     static ESIElementType_t IdentifyElement (const char *);
  62     virtual bool addElement(ESIElement::Pointer) {
  63         /* Don't accept children */
  64         debugs(86,5, "ESIElement::addElement: Failed for " << this);
  65         return false;
  66     }
  67
  68     virtual void render (ESISegment::Pointer) = 0;
  69     /* process this element */
  70     virtual esiProcessResult_t process (int dovars) {
  71         debugs(86,5, "esiProcessComplete: Processed " << this);
  72         return ESI_PROCESS_COMPLETE;
  73     }
  74
  75     virtual bool mayFail() const {
  76         return true;
  77     }
  78
  79     virtual Pointer makeCacheable() const = 0;
  80     virtual Pointer makeUsable(esiTreeParentPtr, ESIVarState &) const = 0;
  81
  82     /* The top level no longer needs this element */
  83     virtual void finish() = 0;
  84 };
  85
  86 #endif /* SQUID_ESIELEMENT_H */
  87