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RRawFileDavix.hxx
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1// @(#)root/io:$Id$
2// Author: Jakob Blomer
3
4/*************************************************************************
5 * Copyright (C) 1995-2018, Rene Brun and Fons Rademakers. *
6 * All rights reserved. *
7 * *
8 * For the licensing terms see $ROOTSYS/LICENSE. *
9 * For the list of contributors see $ROOTSYS/README/CREDITS. *
10 *************************************************************************/
11
12#ifndef ROOT_RRawFileDavix
13#define ROOT_RRawFileDavix
14
15#include <ROOT/RRawFile.hxx>
16#include <string_view>
17
18#include <cstddef>
19#include <cstdint>
20#include <memory>
21
22namespace ROOT {
23namespace Internal {
24
25struct RDavixFileDes;
26
27/** \class RRawFileDavix RRawFileDavix.hxx
28
29The RRawFileDavix class provides read-only access to remote non-ROOT files. It uses the Davix library for
30the transport layer. It instructs the RRawFile base class to buffer in larger chunks than the default for
31local files, assuming that remote file access has high(er) latency.
32
33*/
34
35class RRawFileDavix : public RRawFile {
36private:
37 std::unique_ptr<Internal::RDavixFileDes> fFileDes;
38
39protected:
40 void OpenImpl() final;
41 size_t ReadAtImpl(void *buffer, size_t nbytes, std::uint64_t offset) final;
42 void ReadVImpl(RIOVec *ioVec, unsigned int nReq) final;
43 std::uint64_t GetSizeImpl() final;
44
45public:
46 RRawFileDavix(std::string_view url, RRawFile::ROptions options);
48 std::unique_ptr<RRawFile> Clone() const final;
49 int GetFeatures() const final { return kFeatureHasSize; }
50};
51
52} // namespace Internal
53} // namespace ROOT
54
55#endif
Option_t Option_t TPoint TPoint const char GetTextMagnitude GetFillStyle GetLineColor GetLineWidth GetMarkerStyle GetTextAlign GetTextColor GetTextSize void char Point_t Rectangle_t WindowAttributes_t Float_t Float_t Float_t Int_t Int_t UInt_t UInt_t Rectangle_t Int_t Int_t Window_t TString Int_t GCValues_t GetPrimarySelectionOwner GetDisplay GetScreen GetColormap GetNativeEvent const char const char dpyName wid window const char font_name cursor keysym reg const char only_if_exist regb h Point_t winding char text const char depth char const char Int_t count const char ColorStruct_t color const char Pixmap_t Pixmap_t PictureAttributes_t attr const char char ret_data h unsigned char height h offset
The RRawFileDavix class provides read-only access to remote non-ROOT files.
std::unique_ptr< Internal::RDavixFileDes > fFileDes
int GetFeatures() const final
Derived classes shall inform the user about the supported functionality, which can possibly depend on...
void ReadVImpl(RIOVec *ioVec, unsigned int nReq) final
By default implemented as a loop of ReadAt calls but can be overwritten, e.g. XRootD or DAVIX impleme...
size_t ReadAtImpl(void *buffer, size_t nbytes, std::uint64_t offset) final
Derived classes should implement low-level reading without buffering.
std::unique_ptr< RRawFile > Clone() const final
Create a new RawFile that accesses the same resource. The file pointer is reset to zero.
std::uint64_t GetSizeImpl() final
Derived classes should return the file size or kUnknownFileSize.
void OpenImpl() final
OpenImpl() is called at most once and before any call to either DoReadAt or DoGetSize.
The RRawFile provides read-only access to local and remote files.
Definition RRawFile.hxx:43
static constexpr int kFeatureHasSize
GetSize() does not return kUnknownFileSize.
Definition RRawFile.hxx:52
This file contains a specialised ROOT message handler to test for diagnostic in unit tests.
Used for vector reads from multiple offsets into multiple buffers.
Definition RRawFile.hxx:71
On construction, an ROptions parameter can customize the RRawFile behavior.
Definition RRawFile.hxx:59