libcxx/test/std/input.output/filesystems/fs.op.funcs/fs.op.copy_file/copy_file_large.pass.cpp

   1 //===----------------------------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 // UNSUPPORTED: c++03
  10 // REQUIRES: long_tests
  11 // UNSUPPORTED: no-filesystem
  12 // UNSUPPORTED: availability-filesystem-missing
  13
  14 // <filesystem>
  15
  16 // bool copy_file(const path& from, const path& to);
  17 // bool copy_file(const path& from, const path& to, error_code& ec) noexcept;
  18 // bool copy_file(const path& from, const path& to, copy_options options);
  19 // bool copy_file(const path& from, const path& to, copy_options options,
  20 //           error_code& ec) noexcept;
  21
  22 #include "filesystem_include.h"
  23 #include <cassert>
  24 #include <cstdio>
  25 #include <string>
  26
  27 #include "test_macros.h"
  28 #include "filesystem_test_helper.h"
  29
  30 using namespace fs;
  31
  32 // This test is intended to test 'sendfile's 2gb limit for a single call, and
  33 // to ensure that libc++ correctly copies files larger than that limit.
  34 // However it requires allocating ~5GB of filesystem space. This might not
  35 // be acceptable on all systems.
  36 static void large_file() {
  37   using namespace fs;
  38   constexpr std::uintmax_t sendfile_size_limit = 2147479552ull;
  39   constexpr std::uintmax_t additional_size = 1024;
  40   constexpr std::uintmax_t test_file_size = sendfile_size_limit + additional_size;
  41   static_assert(test_file_size > sendfile_size_limit, "");
  42
  43   scoped_test_env env;
  44
  45   // Check that we have more than sufficient room to create the files needed
  46   // to perform the test.
  47   if (space(env.test_root).available < 3 * test_file_size) {
  48     return;
  49   }
  50
  51   // Create a file right at the size limit. The file is full of '\0's.
  52   const path source = env.create_file("source", sendfile_size_limit);
  53   const std::string additional_data(additional_size, 'x');
  54   // Append known data to the end of the source file.
  55   {
  56     std::FILE* outf = std::fopen(source.string().c_str(), "a");
  57     assert(outf != nullptr);
  58     std::fputs(additional_data.c_str(), outf);
  59     std::fclose(outf);
  60   }
  61   assert(file_size(source) == test_file_size);
  62   const path dest = env.make_env_path("dest");
  63
  64   std::error_code ec = GetTestEC();
  65   assert(copy_file(source, dest, ec));
  66   assert(!ec);
  67
  68   assert(is_regular_file(dest));
  69   assert(file_size(dest) == test_file_size);
  70
  71   // Read the data from the end of the destination file, and ensure it matches
  72   // the data at the end of the source file.
  73   std::string out_data(additional_size, 'z');
  74   {
  75     std::FILE* dest_file = std::fopen(dest.string().c_str(), "rb");
  76     assert(dest_file != nullptr);
  77     assert(std::fseek(dest_file, sendfile_size_limit, SEEK_SET) == 0);
  78     assert(std::fread(&out_data[0], sizeof(out_data[0]), additional_size, dest_file) == additional_size);
  79     std::fclose(dest_file);
  80   }
  81   assert(out_data.size() == additional_data.size());
  82   assert(out_data == additional_data);
  83 }
  84
  85 int main(int, char**) {
  86   large_file();
  87
  88   return 0;
  89 }