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substrate: Add basic file utility to read all the lines from a file
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// SPDX-License-Identifier: BSD-3-Clause | ||
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#ifndef SUBSTRATE_FILE_UTILS | ||
#define SUBSTRATE_FILE_UTILS | ||
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#include <algorithm> | ||
#include <iterator> | ||
#include <string> | ||
#include <vector> | ||
#include <substrate/fd> | ||
#include <substrate/mmap> | ||
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namespace substrate | ||
{ | ||
template<typename Str = std::string> | ||
std::vector<Str> read_lines(fd_t &file, typename Str::value_type separator = '\n') noexcept | ||
{ | ||
using char_t = typename Str::value_type; | ||
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if (!file.valid()) | ||
return {}; | ||
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const auto map{file.map(PROT_READ)}; | ||
if (!map.valid()) | ||
return {}; | ||
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std::vector<Str> result; | ||
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const auto *const cbegin{map.address<char_t>()}; | ||
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const auto *const cend | ||
{ | ||
[&]() | ||
{ | ||
const auto *begin{cbegin}; | ||
std::advance(begin, map.length() / sizeof(char_t)); | ||
return begin; | ||
}() | ||
}; | ||
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for (const auto *begin{cbegin}; begin < cend;) | ||
{ | ||
const auto *boundary | ||
{ | ||
std::find_if | ||
( | ||
begin, | ||
cend, | ||
[&](const auto chr) { return chr == separator || (separator == '\n' && chr == '\r'); } | ||
) | ||
}; | ||
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result.emplace_back(begin, boundary); | ||
if (separator == '\n' && *boundary == '\r' && (boundary + 1) != cend && *(boundary + 1) == '\n') | ||
std::advance(boundary, 2); | ||
else | ||
std::advance(boundary, 1); | ||
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begin = boundary; | ||
} | ||
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return result; | ||
} | ||
} // namespace substrate | ||
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#endif // SUBSTRATE_FILE_UTILS |
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// SPDX-License-Identifier: BSD-3-Clause | ||
#include <array> | ||
#include <substrate/file_utils> | ||
#include <substrate/indexed_iterator> | ||
#include <catch2/catch_test_macros.hpp> | ||
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using substrate::fd_t; | ||
using substrate::indexedIterator_t; | ||
using substrate::read_lines; | ||
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TEST_CASE("lines reader", "[boundedIterator_t]") | ||
{ | ||
const std::array<std::string, 6> lines | ||
{ | ||
{ | ||
"## Enforcement Responsibilities 1", | ||
"", | ||
"Community leaders are responsible for clarifying and enforcing our standards of", | ||
"acceptable behavior and will take appropriate and fair corrective action in", | ||
"response to any behavior that they deem inappropriate, threatening, offensive,", | ||
"or harmful." | ||
} | ||
}; | ||
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{ | ||
fd_t text{"info.txt", O_WRONLY | O_CREAT | O_EXCL | O_TEXT, substrate::normalMode}; | ||
REQUIRE(text.valid()); | ||
for (const auto &i : lines) | ||
{ | ||
REQUIRE(text.write(i)); | ||
REQUIRE(text.write('\n')); | ||
} | ||
} | ||
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{ | ||
fd_t text{"info.txt", O_RDONLY | O_TEXT}; | ||
REQUIRE(text.valid()); | ||
// Memory mapping here will cause the conversion to be skipped | ||
const auto input {read_lines(text)}; | ||
REQUIRE(lines.size() == input.size()); | ||
for (const auto &line : indexedIterator_t<decltype(lines)>{lines}) | ||
{ | ||
const auto &contents {line.second}; | ||
const auto &input_line {input[line.first]}; | ||
REQUIRE(input_line.find_first_of('\n', input_line.size() - 1) == std::string::npos); | ||
REQUIRE(input_line.find_first_of('\r', input_line.size() - 1) == std::string::npos); | ||
REQUIRE(input_line == contents); | ||
} | ||
} | ||
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{ | ||
const auto result{unlink("info.txt")}; | ||
if (result != 0) | ||
REQUIRE(errno == 0); | ||
else | ||
SUCCEED(); | ||
} | ||
} | ||
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TEST_CASE("lines reader with std::u16string", "[boundedIterator_t]") | ||
{ | ||
const std::array<std::u16string, 6> lines | ||
{{ | ||
u"## Enforcement Responsibilities 2", | ||
u"", | ||
u"Community leaders are responsible for clarifying and enforcing our standards of", | ||
u"acceptable behavior and will take appropriate and fair corrective action in", | ||
u"response to any behavior that they deem inappropriate, threatening, offensive,", | ||
u"or harmful." | ||
}}; | ||
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{ | ||
fd_t text{"info.txt", O_WRONLY | O_CREAT | O_EXCL | O_BINARY, substrate::normalMode}; | ||
REQUIRE(text.valid()); | ||
for (const auto &line : lines) | ||
{ | ||
REQUIRE(text.write(line.data(), line.size() * sizeof(std::u16string::value_type))); | ||
REQUIRE(text.write(u'\n')); | ||
} | ||
} | ||
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{ | ||
fd_t text{"info.txt", O_RDONLY | O_BINARY}; | ||
REQUIRE(text.valid()); | ||
const auto input{substrate::read_lines<std::u16string>(text)}; | ||
REQUIRE(lines.size() == input.size()); | ||
for (const auto &line : indexedIterator_t<decltype(lines)>{lines}) | ||
{ | ||
const auto &contents {line.second}; | ||
const auto &input_line {input[line.first]}; | ||
REQUIRE(input_line.find_first_of(u'\n', input_line.size() - 1) == std::u16string::npos); | ||
REQUIRE(input_line.find_first_of(u'\r', input_line.size() - 1) == std::u16string::npos); | ||
REQUIRE(input_line == contents); | ||
} | ||
} | ||
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{ | ||
const auto result{unlink("info.txt")}; | ||
if (result != 0) | ||
REQUIRE(errno == 0); | ||
else | ||
SUCCEED(); | ||
} | ||
} | ||
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TEST_CASE() | ||
{ | ||
unlink("info.txt"); | ||
SUCCEED(); | ||
} |
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