src/Downloader.h

   1 /*
   2  * Copyright (C) 1996-2018 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_DOWNLOADER_H
  10 #define SQUID_DOWNLOADER_H
  11
  12 #include "base/AsyncJob.h"
  13 #include "defines.h"
  14 #include "http/forward.h"
  15 #include "http/StatusCode.h"
  16 #include "sbuf/SBuf.h"
  17 #include "XactionInitiator.h"
  18
  19 class ClientHttpRequest;
  20 class StoreIOBuffer;
  21 class clientStreamNode;
  22 class DownloaderContext;
  23 typedef RefCount<DownloaderContext> DownloaderContextPointer;
  24
  25 /// The Downloader class fetches SBuf-storable things for other Squid
  26 /// components/transactions using internal requests. For example, it is used
  27 /// to fetch missing intermediate certificates when validating origin server
  28 /// certificate chains.
  29 class Downloader: virtual public AsyncJob
  30 {
  31     CBDATA_CLASS(Downloader);
  32 public:
  33
  34     /// Callback data to use with Downloader callbacks.
  35     class CbDialer: public CallDialer {
  36     public:
  37         CbDialer(): status(Http::scNone) {}
  38         virtual ~CbDialer() {}
  39
  40         /* CallDialer API */
  41         virtual bool canDial(AsyncCall &call) = 0;
  42         virtual void dial(AsyncCall &call) = 0;
  43         virtual void print(std::ostream &os) const;
  44
  45         SBuf object;
  46         Http::StatusCode status;
  47     };
  48
  49     Downloader(SBuf &url, AsyncCall::Pointer &aCallback, const XactionInitiator initiator, unsigned int level = 0);
  50     virtual ~Downloader();
  51     virtual void swanSong();
  52
  53     /// delays destruction to protect doCallouts()
  54     void downloadFinished();
  55
  56     /// The nested level of Downloader object (downloads inside downloads).
  57     unsigned int nestedLevel() const {return level_;}
  58
  59     void handleReply(clientStreamNode *, ClientHttpRequest *, HttpReply *, StoreIOBuffer);
  60
  61 protected:
  62
  63     /* AsyncJob API */
  64     virtual bool doneAll() const;
  65     virtual void start();
  66
  67 private:
  68
  69     bool buildRequest();
  70     void callBack(Http::StatusCode const status);
  71
  72     /// The maximum allowed object size.
  73     static const size_t MaxObjectSize = 1*1024*1024;
  74
  75     SBuf url_; ///< the url to download
  76     AsyncCall::Pointer callback_; ///< callback to call when download finishes
  77     SBuf object_; ///< the object body data
  78     const unsigned int level_; ///< holds the nested downloads level
  79     /// The initiator of the download request.
  80     XactionInitiator initiator_;
  81
  82     /// Pointer to an object that stores the clientStream required info
  83     DownloaderContextPointer context_;
  84 };
  85
  86 #endif
  87