src/esi/Context.h

   1 /*
   2  *
   3  * SQUID Web Proxy Cache          http://www.squid-cache.org/
   4  * ----------------------------------------------------------
   5  *
   6  *  Squid is the result of efforts by numerous individuals from
   7  *  the Internet community; see the CONTRIBUTORS file for full
   8  *  details.   Many organizations have provided support for Squid's
   9  *  development; see the SPONSORS file for full details.  Squid is
  10  *  Copyrighted (C) 2001 by the Regents of the University of
  11  *  California; see the COPYRIGHT file for full details.  Squid
  12  *  incorporates software developed and/or copyrighted by other
  13  *  sources; see the CREDITS file for full details.
  14  *
  15  *  This program is free software; you can redistribute it and/or modify
  16  *  it under the terms of the GNU General Public License as published by
  17  *  the Free Software Foundation; either version 2 of the License, or
  18  *  (at your option) any later version.
  19  *
  20  *  This program is distributed in the hope that it will be useful,
  21  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  22  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  23  *  GNU General Public License for more details.
  24  *
  25  *  You should have received a copy of the GNU General Public License
  26  *  along with this program; if not, write to the Free Software
  27  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
  28  *
  29  * Copyright (c) 2003, Robert Collins <robertc@squid-cache.org>
  30  */
  31
  32 #ifndef SQUID_ESICONTEXT_H
  33 #define SQUID_ESICONTEXT_H
  34
  35 #include "esi/Parser.h"
  36 #include "esi/Element.h"
  37 #include "clientStream.h"
  38 #include "err_type.h"
  39 #include "HttpStatusCode.h"
  40
  41 class ESIVarState;
  42 class ClientHttpRequest;
  43
  44 /* ESIContext */
  45
  46 class ESIContext : public esiTreeParent, public ESIParserClient
  47 {
  48
  49 public:
  50     typedef RefCount<ESIContext> Pointer;
  51     void *operator new (size_t byteCount);
  52     void operator delete (void *address);
  53     ESIContext() :
  54             thisNode(NULL),
  55             http(NULL),
  56             errorpage(ERR_NONE),
  57             errorstatus(HTTP_STATUS_NONE),
  58             errormessage(NULL),
  59             rep(NULL),
  60             outbound_offset(0),
  61             readpos(0),
  62             pos(0),
  63             varState(NULL),
  64             cachedASTInUse(false),
  65             reading_(true),
  66             processing(false) {
  67         memset(&flags, 0, sizeof(flags));
  68     }
  69
  70     ~ESIContext();
  71
  72     enum esiKick_t {
  73         ESI_KICK_FAILED,
  74         ESI_KICK_PENDING,
  75         ESI_KICK_SENT,
  76         ESI_KICK_INPROGRESS
  77     };
  78
  79     /* when esi processing completes */
  80     void provideData(ESISegment::Pointer, ESIElement *source);
  81     void fail (ESIElement *source, char const*anError = NULL);
  82     void startRead();
  83     void finishRead();
  84     bool reading() const;
  85     void setError();
  86     void setErrorMessage(char const *);
  87
  88     void addStackElement (ESIElement::Pointer element);
  89     void addLiteral (const char *s, int len);
  90
  91     void finishChildren ();
  92
  93     clientStreamNode *thisNode; /* our stream node */
  94     /* the request we are processing. HMM: cbdataReferencing this will result
  95      * in a circular reference, so we don't. Note: we are automatically freed
  96      * when it is, so thats ok. */
  97     ClientHttpRequest *http;
  98
  99     struct {
 100         int passthrough:1;
 101         int oktosend:1;
 102         int finished:1;
 103
 104         /* an error has occured, send full body replies
 105          * regardless. Note that we don't fail midstream
 106          * because we buffer until we can not fail
 107          */
 108         int error:1;
 109
 110         int finishedtemplate:1; /* we've read the entire template */
 111         int clientwantsdata:1; /* we need to satisfy a read request */
 112         int kicked:1; /* note on reentering the kick routine */
 113         int detached:1; /* our downstream has detached */
 114     } flags;
 115
 116     err_type errorpage; /* if we error what page to use */
 117     http_status errorstatus; /* if we error, what code to return */
 118     char *errormessage; /* error to pass to error page */
 119     HttpReply *rep; /* buffered until we pass data downstream */
 120     ESISegment::Pointer buffered; /* unprocessed data - for whatever reason */
 121     ESISegment::Pointer incoming;
 122     /* processed data we are waiting to send, or for
 123      * potential errors to be resolved
 124      */
 125     ESISegment::Pointer outbound;
 126     ESISegment::Pointer outboundtail; /* our write segment */
 127     /* the offset to the next character to send -
 128      * non zero if we haven't sent the entire segment
 129      * for some reason
 130      */
 131     size_t outbound_offset;
 132     int64_t readpos; /* the logical position we are reading from */
 133     int64_t pos; /* the logical position of outbound_offset in the data stream */
 134
 135     class ParserState
 136     {
 137
 138     public:
 139         ESIElement::Pointer stack[10]; /* a stack of esi elements that are open */
 140         int stackdepth; /* self explanatory */
 141         ESIParser::Pointer theParser;
 142         ESIElement::Pointer top();
 143         void init (ESIParserClient *);
 144         bool inited() const;
 145         ParserState();
 146         void freeResources();
 147         void popAll();
 148         int parsing:1; /* libexpat is not reentrant on the same context */
 149
 150     private:
 151         bool inited_;
 152     }
 153
 154     parserState; /* todo factor this off somewhere else; */
 155     ESIVarState *varState;
 156     ESIElement::Pointer tree;
 157
 158     esiKick_t kick ();
 159     RefCount<ESIContext> cbdataLocker;
 160     bool failed() const {return flags.error != 0;}
 161
 162     bool cachedASTInUse;
 163
 164 private:
 165     void fail ();
 166     void freeResources();
 167     void fixupOutboundTail();
 168     void trimBlanks();
 169     size_t send ();
 170     bool reading_;
 171     void appendOutboundData(ESISegment::Pointer theData);
 172     esiProcessResult_t process ();
 173     void parse();
 174     void parseOneBuffer();
 175     void updateCachedAST();
 176     bool hasCachedAST() const;
 177     void getCachedAST();
 178     virtual void start(const char *el, const char **attr, size_t attrCount);
 179     virtual void end(const char *el);
 180     virtual void parserDefault (const char *s, int len);
 181     virtual void parserComment (const char *s);
 182     bool processing;
 183
 184     CBDATA_CLASS(ESIContext);
 185 };
 186
 187 #endif /* SQUID_ESICONTEXT_H */