Line data    Source code

       1             : /* Copyright (C) 2025 Robert Schiwon
       2             :  *
       3             :  * This file is part of libjdx.
       4             :  *
       5             :  * libjdx is free software: you can redistribute it and/or modify it under the
       6             :  * terms of the GNU Lesser General Public License as published by the Free
       7             :  * Software Foundation, either version 3 of the License, or (at your option) any
       8             :  * later version.
       9             :  *
      10             :  * libjdx is distributed in the hope that it will be useful, but WITHOUT ANY
      11             :  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
      12             :  * A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
      13             :  * details.
      14             :  *
      15             :  * You should have received a copy of the GNU Lesser General Public License
      16             :  * along with libjdx. If not, see <https://www.gnu.org/licenses/>.
      17             :  */
      18             : // determine the availability of the filesystem header
      19             : // inspired by:
      20             : // https://stackoverflow.com/questions/53365538/how-to-determine-whether-to-use-filesystem-or-experimental-filesystem
      21             : #ifndef JDX_USE_EXPERIMENTAL_FILESYSTEM
      22             : #if defined(__cpp_lib_filesystem)
      23             : // NOLINTNEXTLINE(cppcoreguidelines-macro-usage)
      24             : #define JDX_USE_EXPERIMENTAL_FILESYSTEM 0
      25             : #elif defined(__cpp_lib_experimental_filesystem)
      26             : // NOLINTNEXTLINE(cppcoreguidelines-macro-usage)
      27             : #define JDX_USE_EXPERIMENTAL_FILESYSTEM 1
      28             : #elif !defined(__has_include)
      29             : // NOLINTNEXTLINE(cppcoreguidelines-macro-usage)
      30             : #define JDX_USE_EXPERIMENTAL_FILESYSTEM 1
      31             : #elif __has_include(<filesystem>)
      32             : // NOLINTNEXTLINE(cppcoreguidelines-macro-usage)
      33             : #define JDX_USE_EXPERIMENTAL_FILESYSTEM 0
      34             : #elif __has_include(<experimental/filesystem>)
      35             : // NOLINTNEXTLINE(cppcoreguidelines-macro-usage)
      36             : #define JDX_USE_EXPERIMENTAL_FILESYSTEM 1
      37             : #endif
      38             : #endif
      39             : 
      40             : #ifndef JDX_USE_EXPERIMENTAL_FILESYSTEM
      41             : #error Required <filesystem> header not available.
      42             : #endif
      43             : 
      44             : #include "jdx/JdxParser.hpp"
      45             : #include "io/TextReader.hpp"
      46             : #include "util/LdrUtils.hpp"
      47             : #include "util/StringUtils.hpp"
      48             : 
      49             : #include <algorithm>
      50             : #include <array>
      51             : #include <climits>
      52             : #include <cstring>
      53             : #include <limits>
      54             : #include <sstream>
      55             : // include and alias filesystem header
      56             : #if JDX_USE_EXPERIMENTAL_FILESYSTEM
      57             : #include <experimental/filesystem>
      58             : namespace fs = std::experimental::filesystem;
      59             : #else
      60             : #include <filesystem>
      61             : namespace fs = std::filesystem;
      62             : #endif
      63             : 
      64          10 : bool libjdx::jdx::JdxParser::canParse(
      65             :     const std::string& filePath, std::istream& iStream)
      66             : {
      67             :     // check extension
      68          30 :     std::string extension = fs::path(filePath).extension();
      69          10 :     util::toLower(extension);
      70          10 :     if (std::find(std::begin(s_acceptedExtensions),
      71             :             std::end(s_acceptedExtensions), extension)
      72          10 :         == std::end(s_acceptedExtensions))
      73             :     {
      74           5 :         return false;
      75             :     }
      76             : 
      77             :     // read first few chars
      78           5 :     std::ios::pos_type position = iStream.tellg();
      79          10 :     std::string buffer(s_scanBufferSize, '\0');
      80           5 :     iStream.read(buffer.data(), s_scanBufferSize);
      81           5 :     const auto bytesRead = iStream.gcount();
      82           5 :     if (iStream.eof() || iStream.fail() || iStream.bad())
      83             :     {
      84           0 :         iStream.clear();
      85             :     }
      86           5 :     iStream.seekg(position, std::ios_base::beg);
      87           5 :     buffer.resize(bytesRead);
      88           5 :     if (util::isLdrStart(buffer))
      89             :     {
      90           8 :         auto label = util::parseLdrStart(buffer).first;
      91           4 :         return label == "TITLE";
      92             :     }
      93           1 :     return false;
      94             : }
      95             : 
      96           5 : libjdx::jdx::Block libjdx::jdx::JdxParser::parse(
      97             :     std::unique_ptr<std::istream> streamPtr)
      98             : {
      99          10 :     auto textReaderPtr = std::make_unique<io::TextReader>(std::move(streamPtr));
     100           6 :     libjdx::jdx::Block block{std::move(textReaderPtr)};
     101           8 :     return block;
     102             : }
     103             : 
     104          22 : libjdx::jdx::Block libjdx::jdx::JdxParser::parse(const std::string& filePath)
     105             : {
     106          42 :     auto textReaderPtr = std::make_unique<io::TextReader>(filePath);
     107          22 :     libjdx::jdx::Block block{std::move(textReaderPtr)};
     108          36 :     return block;
     109             : }