src/Downloader.h

   1 /*
   2  * Copyright (C) 1996-2023 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_SRC_DOWNLOADER_H
  10 #define SQUID_SRC_DOWNLOADER_H
  11
  12 #include "base/AsyncCallbacks.h"
  13 #include "base/AsyncJob.h"
  14 #include "defines.h"
  15 #include "http/forward.h"
  16 #include "http/StatusCode.h"
  17 #include "sbuf/SBuf.h"
  18
  19 class ClientHttpRequest;
  20 class StoreIOBuffer;
  21 class clientStreamNode;
  22 class DownloaderContext;
  23 typedef RefCount<DownloaderContext> DownloaderContextPointer;
  24 class MasterXaction;
  25 using MasterXactionPointer = RefCount<MasterXaction>;
  26
  27 /// download result
  28 class DownloaderAnswer {
  29 public:
  30     // The content of a successfully received HTTP 200 OK reply to our GET request.
  31     // Unused unless outcome is Http::scOkay.
  32     SBuf resource;
  33
  34     /// Download result summary.
  35     /// May differ from the status code of the downloaded HTTP reply.
  36     Http::StatusCode outcome = Http::scNone;
  37 };
  38
  39 std::ostream &operator <<(std::ostream &, const DownloaderAnswer &);
  40
  41 /// The Downloader class fetches SBuf-storable things for other Squid
  42 /// components/transactions using internal requests. For example, it is used
  43 /// to fetch missing intermediate certificates when validating origin server
  44 /// certificate chains.
  45 class Downloader: virtual public AsyncJob
  46 {
  47     CBDATA_CHILD(Downloader);
  48 public:
  49     using Answer = DownloaderAnswer;
  50
  51     Downloader(const SBuf &url, const AsyncCallback<Answer> &, const MasterXactionPointer &, unsigned int level = 0);
  52     ~Downloader() override;
  53     void swanSong() override;
  54
  55     /// delays destruction to protect doCallouts()
  56     void downloadFinished();
  57
  58     /// The nested level of Downloader object (downloads inside downloads).
  59     unsigned int nestedLevel() const {return level_;}
  60
  61     void handleReply(clientStreamNode *, ClientHttpRequest *, HttpReply *, StoreIOBuffer);
  62
  63 protected:
  64
  65     /* AsyncJob API */
  66     bool doneAll() const override;
  67     void start() override;
  68
  69 private:
  70
  71     bool buildRequest();
  72     void callBack(Http::StatusCode const status);
  73
  74     /// The maximum allowed object size.
  75     static const size_t MaxObjectSize = 1*1024*1024;
  76
  77     SBuf url_; ///< the url to download
  78
  79     /// answer destination
  80     AsyncCallback<Answer> callback_;
  81
  82     SBuf object_; ///< the object body data
  83     const unsigned int level_; ///< holds the nested downloads level
  84     MasterXactionPointer masterXaction_; ///< download transaction context
  85
  86     /// Pointer to an object that stores the clientStream required info
  87     DownloaderContextPointer context_;
  88 };
  89
  90 #endif /* SQUID_SRC_DOWNLOADER_H */
  91