Source/cmFilePathChecksum.h

   1 /* Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
   2    file Copyright.txt or https://cmake.org/licensing for details.  */
   3 #pragma once
   4
   5 #include "cmConfigure.h" // IWYU pragma: keep
   6
   7 #include <array>
   8 #include <cstddef>
   9 #include <string>
  10 #include <utility>
  11
  12 class cmMakefile;
  13
  14 /** \class cmFilePathChecksum
  15  * @brief Generates a checksum for the parent directory of a file
  16  *
  17  * The checksum is calculated from the relative file path to the
  18  * closest known project directory. This guarantees reproducibility
  19  * when source and build directory differ e.g. for different project
  20  * build directories.
  21  */
  22 class cmFilePathChecksum
  23 {
  24 public:
  25   /// Maximum number of characters to use from the path checksum
  26   static const size_t partLengthDefault = 10;
  27
  28   /// @brief Parent directories are empty
  29   cmFilePathChecksum();
  30
  31   /// @brief Initializes the parent directories manually
  32   cmFilePathChecksum(std::string const& currentSrcDir,
  33                      std::string const& currentBinDir,
  34                      std::string const& projectSrcDir,
  35                      std::string const& projectBinDir);
  36
  37   /// @brief Initializes the parent directories from a makefile
  38   cmFilePathChecksum(cmMakefile* makefile);
  39
  40   /// @brief Allows parent directories setup after construction
  41   ///
  42   void setupParentDirs(std::string const& currentSrcDir,
  43                        std::string const& currentBinDir,
  44                        std::string const& projectSrcDir,
  45                        std::string const& projectBinDir);
  46
  47   /* @brief Calculates the path checksum for the parent directory of a file
  48    *
  49    */
  50   std::string get(std::string const& filePath) const;
  51
  52   /* @brief Same as get() but returns only the first length characters
  53    *
  54    */
  55   std::string getPart(std::string const& filePath,
  56                       size_t length = partLengthDefault) const;
  57
  58 private:
  59   /// List of (directory name, seed name) pairs
  60   std::array<std::pair<std::string, std::string>, 4> parentDirs;
  61 };