src/adaptation/icap/ModXact.h

   1
   2 /*
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  19  *  it under the terms of the GNU General Public License as published by
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  21  *  (at your option) any later version.
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  26  *  GNU General Public License for more details.
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  30  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
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  33
  34 #ifndef SQUID_ICAPMODXACT_H
  35 #define SQUID_ICAPMODXACT_H
  36
  37 #include "BodyPipe.h"
  38 #include "adaptation/icap/Xaction.h"
  39 #include "adaptation/icap/InOut.h"
  40 #include "adaptation/icap/Launcher.h"
  41
  42 /*
  43  * ICAPModXact implements ICAP REQMOD and RESPMOD transaction using
  44  * ICAPXaction as the base. The ICAPModXact receives a virgin HTTP message
  45  * from an ICAP vecoring point, (a.k.a., initiator), communicates with the
  46  * ICAP server, and sends the adapted HTTP message headers back.
  47  * Virgin/adapted HTTP message body is reveived/sent using BodyPipe
  48  * interface. The initiator (or its associate) is expected to send and/or
  49  * receive the HTTP body.
  50  */
  51
  52
  53 class ChunkedCodingParser;
  54
  55 namespace Adaptation
  56 {
  57 namespace Icap
  58 {
  59
  60 // estimated future presence and size of something (e.g., HTTP body)
  61
  62 class SizedEstimate
  63 {
  64
  65 public:
  66     SizedEstimate(); // not expected by default
  67     void expect(int64_t aSize); // expect with any, even unknown size
  68     bool expected() const;
  69
  70     /* other members can be accessed iff expected() */
  71
  72     bool knownSize() const;
  73     uint64_t size() const; // can be accessed iff knownSize()
  74
  75 private:
  76     enum { dtUnexpected = -2, dtUnknown = -1 };
  77     int64_t theData; // combines expectation and size info to save RAM
  78 };
  79
  80 // Virgin body may be used for two activities: (a) writing preview or prime
  81 // body to the ICAP server and (b) sending the body back in the echo mode.
  82 // Both activities use the same BodyPipe and may be active at the same time.
  83 // This class is used to maintain the state of body writing or sending
  84 // activity and to coordinate consumption of the shared virgin body buffer.
  85 class VirginBodyAct
  86 {
  87
  88 public:
  89     VirginBodyAct();
  90
  91     void plan(); // the activity may happen; do not consume at or above offset
  92     void disable(); // the activity wont continue; no consumption restrictions
  93
  94     bool active() const { return theState == stActive; }
  95     bool disabled() const { return theState == stDisabled; }
  96
  97     // methods below require active()
  98
  99     uint64_t offset() const; // the absolute beginning of not-yet-acted-on data
 100     void progress(size_t size); // note processed body bytes
 101
 102 private:
 103     int64_t theStart; // unprocessed virgin body data offset
 104
 105     typedef enum { stUndecided, stActive, stDisabled } State;
 106     State theState;
 107 };
 108
 109
 110 // maintains preview-related sizes
 111
 112 class Preview
 113 {
 114
 115 public:
 116     Preview();            // disabled
 117     void enable(size_t anAd); // enabled with advertised size
 118     bool enabled() const;
 119
 120     /* other members can be accessed iff enabled() */
 121
 122     size_t ad() const;      // advertised preview size
 123     size_t debt() const;    // remains to write
 124     bool done() const;      // wrote everything
 125     bool ieof() const;      // premature EOF
 126
 127     void wrote(size_t size, bool wroteEof);
 128
 129 private:
 130     size_t theWritten;
 131     size_t theAd;
 132     enum State { stDisabled, stWriting, stIeof, stDone } theState;
 133 };
 134
 135 class ModXact: public Xaction, public BodyProducer, public BodyConsumer
 136 {
 137
 138 public:
 139     ModXact(HttpMsg *virginHeader, HttpRequest *virginCause, ServiceRep::Pointer &s);
 140     virtual ~ModXact();
 141
 142     // BodyProducer methods
 143     virtual void noteMoreBodySpaceAvailable(BodyPipe::Pointer);
 144     virtual void noteBodyConsumerAborted(BodyPipe::Pointer);
 145
 146     // BodyConsumer methods
 147     virtual void noteMoreBodyDataAvailable(BodyPipe::Pointer);
 148     virtual void noteBodyProductionEnded(BodyPipe::Pointer);
 149     virtual void noteBodyProducerAborted(BodyPipe::Pointer);
 150
 151     // comm handlers
 152     virtual void handleCommConnected();
 153     virtual void handleCommWrote(size_t size);
 154     virtual void handleCommRead(size_t size);
 155     void handleCommWroteHeaders();
 156     void handleCommWroteBody();
 157
 158     // service waiting
 159     void noteServiceReady();
 160     void noteServiceAvailable();
 161
 162 public:
 163     InOut virgin;
 164     InOut adapted;
 165
 166     // bypasses exceptions if needed and possible
 167     virtual void callException(const std::exception &e);
 168
 169     /// record error detail in the virgin request if possible
 170     virtual void detailError(int errDetail);
 171
 172 private:
 173     virtual void start();
 174
 175     /// locates the request, either as a cause or as a virgin message itself
 176     const HttpRequest &virginRequest() const; // Must always be available
 177
 178     void estimateVirginBody();
 179     void makeAdaptedBodyPipe(const char *what);
 180
 181     void waitForService();
 182
 183     // will not send anything [else] on the adapted pipe
 184     bool doneSending() const;
 185
 186     void startWriting();
 187     void writeMore();
 188     void writePreviewBody();
 189     void writePrimeBody();
 190     void writeSomeBody(const char *label, size_t size);
 191     void decideWritingAfterPreview(const char *previewKind);
 192
 193     void startReading();
 194     void readMore();
 195     virtual bool doneReading() const { return commEof || state.doneParsing(); }
 196     virtual bool doneWriting() const { return state.doneWriting(); }
 197
 198     size_t virginContentSize(const VirginBodyAct &act) const;
 199     const char *virginContentData(const VirginBodyAct &act) const;
 200     bool virginBodyEndReached(const VirginBodyAct &act) const;
 201
 202     void makeRequestHeaders(MemBuf &buf);
 203     void makeAllowHeader(MemBuf &buf);
 204     void makeUsernameHeader(const HttpRequest *request, MemBuf &buf);
 205     void addLastRequestChunk(MemBuf &buf);
 206     void openChunk(MemBuf &buf, size_t chunkSize, bool ieof);
 207     void closeChunk(MemBuf &buf);
 208     void virginConsume();
 209     void finishNullOrEmptyBodyPreview(MemBuf &buf);
 210
 211     void decideOnPreview();
 212     void decideOnRetries();
 213     bool shouldAllow204();
 214     bool shouldAllow206any();
 215     bool shouldAllow206in();
 216     bool shouldAllow206out();
 217     bool canBackupEverything() const;
 218
 219     void prepBackup(size_t expectedSize);
 220     void backup(const MemBuf &buf);
 221
 222     void parseMore();
 223
 224     void parseHeaders();
 225     void parseIcapHead();
 226     void parseHttpHead();
 227     bool parseHead(HttpMsg *head);
 228
 229     void decideOnParsingBody();
 230     void parseBody();
 231     void maybeAllocateHttpMsg();
 232
 233     void handle100Continue();
 234     bool validate200Ok();
 235     void handle200Ok();
 236     void handle204NoContent();
 237     void handle206PartialContent();
 238     void handleUnknownScode();
 239
 240     void bypassFailure();
 241
 242     void startSending();
 243     void disableBypass(const char *reason, bool includeGroupBypass);
 244
 245     void prepEchoing();
 246     void prepPartialBodyEchoing(uint64_t pos);
 247     void echoMore();
 248
 249     virtual bool doneAll() const;
 250     virtual void swanSong();
 251
 252     void stopReceiving();
 253     void stopSending(bool nicely);
 254     void stopWriting(bool nicely);
 255     void stopParsing();
 256     void stopBackup();
 257
 258     virtual void fillPendingStatus(MemBuf &buf) const;
 259     virtual void fillDoneStatus(MemBuf &buf) const;
 260     virtual bool fillVirginHttpHeader(MemBuf&) const;
 261
 262 private:
 263     void packHead(MemBuf &httpBuf, const HttpMsg *head);
 264     void encapsulateHead(MemBuf &icapBuf, const char *section, MemBuf &httpBuf, const HttpMsg *head);
 265     bool gotEncapsulated(const char *section) const;
 266     void checkConsuming();
 267
 268     virtual void finalizeLogInfo();
 269
 270     SizedEstimate virginBody;
 271     VirginBodyAct virginBodyWriting; // virgin body writing state
 272     VirginBodyAct virginBodySending;  // virgin body sending state
 273     uint64_t virginConsumed;        // virgin data consumed so far
 274     Preview preview; // use for creating (writing) the preview
 275
 276     ChunkedCodingParser *bodyParser; // ICAP response body parser
 277
 278     bool canStartBypass; // enables bypass of transaction failures
 279     bool protectGroupBypass; // protects ServiceGroup-wide bypass of failures
 280
 281     /**
 282      * size of HTTP header in ICAP reply or -1 if there is not any encapsulated
 283      * message data
 284      */
 285     int64_t replyHttpHeaderSize;
 286     /**
 287      * size of dechunked HTTP body in ICAP reply or -1 if there is not any
 288      * encapsulated message data
 289      */
 290     int64_t replyHttpBodySize;
 291
 292     int adaptHistoryId; ///< adaptation history slot reservation
 293
 294     class State
 295     {
 296
 297     public:
 298         State();
 299
 300     public:
 301
 302         bool serviceWaiting; // waiting for ICAP service options
 303         bool allowedPostview204; // mmust handle 204 No Content outside preview
 304         bool allowedPostview206; // must handle 206 Partial Content outside preview
 305         bool allowedPreview206; // must handle 206 Partial Content inside preview
 306         bool readyForUob; ///< got a 206 response and expect a use-origin-body
 307         bool waitedForService; ///< true if was queued at least once
 308
 309         // will not write anything [else] to the ICAP server connection
 310         bool doneWriting() const { return writing == writingReallyDone; }
 311
 312         // will not use virgin.body_pipe
 313         bool doneConsumingVirgin() const {
 314             return writing >= writingAlmostDone
 315                    && ((sending == sendingAdapted && !readyForUob) ||
 316                        sending == sendingDone);
 317         }
 318
 319         // parsed entire ICAP response from the ICAP server
 320         bool doneParsing() const { return parsing == psDone; }
 321
 322         // is parsing ICAP or HTTP headers read from the ICAP server
 323         bool parsingHeaders() const {
 324             return parsing == psIcapHeader ||
 325                    parsing == psHttpHeader;
 326         }
 327
 328         enum Parsing { psIcapHeader, psHttpHeader, psBody, psDone } parsing;
 329
 330         // measures ICAP request writing progress
 331         enum Writing { writingInit, writingConnect, writingHeaders,
 332                        writingPreview, writingPaused, writingPrime,
 333                        writingAlmostDone, // waiting for the last write() call to finish
 334                        writingReallyDone
 335                      } writing;
 336
 337         enum Sending { sendingUndecided, sendingVirgin, sendingAdapted,
 338                        sendingDone
 339                      } sending;
 340     } state;
 341
 342     CBDATA_CLASS2(ModXact);
 343 };
 344
 345 // An Launcher that stores ModXact construction info and
 346 // creates ModXact when needed
 347 class ModXactLauncher: public Launcher
 348 {
 349 public:
 350     ModXactLauncher(HttpMsg *virginHeader, HttpRequest *virginCause, Adaptation::ServicePointer s);
 351
 352 protected:
 353     virtual Xaction *createXaction();
 354
 355     virtual void swanSong();
 356
 357     /// starts or stops transaction accounting in ICAP history
 358     void updateHistory(bool start);
 359
 360     InOut virgin;
 361
 362 private:
 363     CBDATA_CLASS2(ModXactLauncher);
 364 };
 365
 366
 367 } // namespace Icap
 368 } // namespace Adaptation
 369
 370 #endif /* SQUID_ICAPMOD_XACT_H */