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RRawFileWin.cxx
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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#include "ROOT/RRawFileWin.hxx"
13
14#include "TError.h"
15
16#include <cerrno>
17#include <cstddef>
18#include <cstdint>
19#include <cstdio>
20#include <cstring>
21#include <memory>
22#include <stdexcept>
23#include <string>
24
25namespace {
26constexpr int kDefaultBlockSize = 4096; // Read files in 4k pages unless told otherwise
27} // anonymous namespace
28
30 : RRawFile(url, options), fFilePtr(nullptr)
31{
32}
33
35{
36 if (fFilePtr != nullptr)
37 fclose(fFilePtr);
38}
39
40std::unique_ptr<ROOT::Internal::RRawFile> ROOT::Internal::RRawFileWin::Clone() const
41{
42 return std::make_unique<RRawFileWin>(fUrl, fOptions);
43}
44
46{
47 Seek(0L, SEEK_END);
48 long size = ftell(fFilePtr);
49 if (size < 0)
50 throw std::runtime_error("Cannot tell position counter in '" + fUrl +
51 "', error: " + std::string(strerror(errno)));
52 Seek(fFilePos, SEEK_SET);
53 return size;
54}
55
57{
58 fFilePtr = fopen(GetLocation(fUrl).c_str(), "rb");
59 if (fFilePtr == nullptr)
60 throw std::runtime_error("Cannot open '" + fUrl + "', error: " + std::string(strerror(errno)));
61 // Prevent double buffering
62 int res = setvbuf(fFilePtr, nullptr, _IONBF, 0);
63 R__ASSERT(res == 0);
64 if (fOptions.fBlockSize < 0)
65 fOptions.fBlockSize = kDefaultBlockSize;
66}
67
68size_t ROOT::Internal::RRawFileWin::ReadAtImpl(void *buffer, size_t nbytes, std::uint64_t offset)
69{
70 Seek(offset, SEEK_SET);
71 size_t res = fread(buffer, 1, nbytes, fFilePtr);
72 if ((res < nbytes) && (ferror(fFilePtr) != 0)) {
73 clearerr(fFilePtr);
74 throw std::runtime_error("Cannot read from '" + fUrl + "', error: " + std::string(strerror(errno)));
75 }
76 return res;
77}
78
79void ROOT::Internal::RRawFileWin::Seek(long offset, int whence)
80{
81 int res = fseek(fFilePtr, offset, whence);
82 if (res != 0)
83 throw std::runtime_error("Cannot seek in '" + fUrl + "', error: " + std::string(strerror(errno)));
84}
size_t size(const MatrixT &matrix)
retrieve the size of a square matrix
#define R__ASSERT(e)
Definition: TError.h:118
RRawFileWin(std::string_view url, RRawFile::ROptions options)
Definition: RRawFileWin.cxx:29
size_t ReadAtImpl(void *buffer, size_t nbytes, std::uint64_t offset) final
Derived classes should implement low-level reading without buffering.
Definition: RRawFileWin.cxx:68
std::unique_ptr< RRawFile > Clone() const final
Create a new RawFile that accesses the same resource. The file pointer is reset to zero.
Definition: RRawFileWin.cxx:40
std::uint64_t GetSizeImpl() final
Derived classes should return the file size or kUnknownFileSize.
Definition: RRawFileWin.cxx:45
void Seek(long offset, int whence)
Definition: RRawFileWin.cxx:79
void OpenImpl() final
OpenImpl() is called at most once and before any call to either DoReadAt or DoGetSize.
Definition: RRawFileWin.cxx:56
The RRawFile provides read-only access to local and remote files.
Definition: RRawFile.hxx:43
basic_string_view< char > string_view
static constexpr double L
On construction, an ROptions parameter can customize the RRawFile behavior.
Definition: RRawFile.hxx:59