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