Add EXIV2_ENABLE_FILESYSTEM_ACCESS option

Backport of d8d9f70

CMakeLists.txt

@@ -36,6 +36,7 @@ option( EXIV2_ENABLE_BMFF             "Build with BMFF support"
 option( EXIV2_ENABLE_BROTLI           "Use Brotli for JPEG XL compressed boxes (BMFF)"        ON  )
 option( EXIV2_ENABLE_VIDEO            "Build with video support"                              ON )
 option( EXIV2_ENABLE_INIH             "Use inih library"                                      ON  )
+option( EXIV2_ENABLE_FILESYSTEM_ACCESS "Build with filesystem access"                          ON)
 
 option( EXIV2_BUILD_SAMPLES           "Build sample applications"                             OFF )
 option( EXIV2_BUILD_EXIV2_COMMAND     "Build exiv2 command-line executable"                   ON  )
@@ -95,17 +96,21 @@ add_subdirectory( src )
 
 if( EXIV2_BUILD_UNIT_TESTS )
   add_subdirectory ( unitTests )
+  set(EXIV2_ENABLE_FILESYSTEM_ACCESS ON)
 endif()
 
 if( EXIV2_BUILD_FUZZ_TESTS )
   add_subdirectory ( fuzz )
+  set(EXIV2_ENABLE_FILESYSTEM_ACCESS ON)
 endif()
 
 if(EXIV2_BUILD_EXIV2_COMMAND)
   add_subdirectory ( app )
+  set(EXIV2_ENABLE_FILESYSTEM_ACCESS ON)
 
 if( EXIV2_BUILD_SAMPLES )
     add_subdirectory( samples )
+    set(EXIV2_ENABLE_FILESYSTEM_ACCESS ON)
     get_directory_property(SAMPLES DIRECTORY samples DEFINITION APPLICATIONS)
 
     if (Python3_Interpreter_FOUND)

README.md

@@ -254,6 +254,7 @@ option( EXIV2_ENABLE_PNG           "Build with png support (requires libz)"
 ...
 option( EXIV2_ENABLE_BMFF          "Build with BMFF support (brotli recommended)"    ON  )
 option( EXIV2_ENABLE_BROTLI        "Use Brotli for JPEG XL compressed boxes (BMFF)"  ON  )
+option( EXIV2_ENABLE_FILESYSTEM_ACCESS     "Build with filesystem access"            ON  )
 577 rmills@rmillsmm:~/gnu/github/exiv2/exiv2 $
 ```
 

cmake/config.h.cmake

@@ -6,6 +6,9 @@
 // Define to 1 if you want to use libcurl in httpIO.
 #cmakedefine EXV_USE_CURL
 
+// Define to 1 if you want to enable filesystem access
+#cmakedefine EXV_ENABLE_FILESYSTEM
+
 // Define if you require webready support.
 #cmakedefine EXV_ENABLE_WEBREADY
 

cmake/findDependencies.cmake

@@ -35,7 +35,9 @@ if (NOT Python3_Interpreter_FOUND)
     message(WARNING "Python3 was not found. Python tests under the 'tests' folder will not be executed")
 endif()
 
-find_package(Filesystem COMPONENTS Experimental Final REQUIRED)
+if(EXIV2_ENABLE_FILESYSTEM_ACCESS)
+  find_package(Filesystem COMPONENTS Experimental Final REQUIRED)
+endif()
 
 # don't use Frameworks on the Mac (#966)
 if (APPLE)

cmake/generateConfigFile.cmake

@@ -6,10 +6,11 @@ include(CheckCXXSymbolExists)
 if (${EXIV2_ENABLE_WEBREADY})
     set(EXV_USE_CURL  ${EXIV2_ENABLE_CURL})
 endif()
-set(EXV_ENABLE_BMFF      ${EXIV2_ENABLE_BMFF})
-set(EXV_ENABLE_WEBREADY  ${EXIV2_ENABLE_WEBREADY})
-set(EXV_HAVE_LENSDATA    ${EXIV2_ENABLE_LENSDATA})
-set(EXV_ENABLE_INIH      ${EXIV2_ENABLE_INIH})
+set(EXV_ENABLE_BMFF       ${EXIV2_ENABLE_BMFF})
+set(EXV_ENABLE_WEBREADY   ${EXIV2_ENABLE_WEBREADY})
+set(EXV_HAVE_LENSDATA     ${EXIV2_ENABLE_LENSDATA})
+set(EXV_ENABLE_INIH       ${EXIV2_ENABLE_INIH})
+set(EXV_ENABLE_FILESYSTEM ${EXIV2_ENABLE_FILESYSTEM_ACCESS})
 
 set(EXV_PACKAGE_NAME     ${PROJECT_NAME})
 set(EXV_PACKAGE_VERSION  ${PROJECT_VERSION})

cmake/printSummary.cmake

@@ -69,4 +69,5 @@ OptionOutput( "Building unit tests:                " EXIV2_BUILD_UNIT_TESTS
 OptionOutput( "Building fuzz tests:                " EXIV2_BUILD_FUZZ_TESTS             )
 OptionOutput( "Building doc:                       " EXIV2_BUILD_DOC                    )
 OptionOutput( "Building with coverage flags:       " BUILD_WITH_COVERAGE                )
+OptionOutput( "Building with filesystem access     " EXIV2_ENABLE_FILESYSTEM_ACCESS     )
 OptionOutput( "Using ccache:                       " BUILD_WITH_CCACHE                  )

include/exiv2/basicio.hpp

@@ -276,6 +276,7 @@ class EXIV2API IoCloser {
   IoCloser& operator=(const IoCloser&) = delete;
 };  // class IoCloser
 
+#ifdef EXV_ENABLE_FILESYSTEM
 /*!
   @brief Provides binary file IO by implementing the BasicIo
       interface.
@@ -479,6 +480,7 @@ class EXIV2API FileIo : public BasicIo {
   std::unique_ptr<Impl> p_;
 
 };  // class FileIo
+#endif
 
 /*!
   @brief Provides binary IO on blocks of memory by implementing the BasicIo
@@ -686,7 +688,7 @@ class EXIV2API XPathIo : public MemIo {
    */
   void ReadDataUri(const std::string& path);
 };  // class XPathIo
-#else
+#elif defined(EXV_ENABLE_FILESYSTEM)
 class EXIV2API XPathIo : public FileIo {
  public:
   /*!

include/exiv2/exif.hpp

@@ -229,6 +229,7 @@ class EXIV2API ExifThumbC {
            data buffer and %DataBuf ensures that it will be deleted.
    */
   [[nodiscard]] DataBuf copy() const;
+#ifdef EXV_ENABLE_FILESYSTEM
   /*!
     @brief Write the thumbnail image to a file.
 
@@ -240,6 +241,7 @@ class EXIV2API ExifThumbC {
     @return The number of bytes written.
   */
   [[nodiscard]] size_t writeFile(const std::string& path) const;
+#endif
   /*!
     @brief Return the MIME type of the thumbnail, either \c "image/tiff"
            or \c "image/jpeg".
@@ -279,6 +281,7 @@ class EXIV2API ExifThumb : public ExifThumbC {
 
   //! @name Manipulators
   //@{
+#ifdef EXV_ENABLE_FILESYSTEM
   /*!
     @brief Set the Exif thumbnail to the JPEG image \em path. Set
            XResolution, YResolution and ResolutionUnit to \em xres,
@@ -297,6 +300,7 @@ class EXIV2API ExifThumb : public ExifThumbC {
            application that comes with OS X for one.) - David Harvey.
    */
   void setJpegThumbnail(const std::string& path, URational xres, URational yres, uint16_t unit);
+#endif
   /*!
     @brief Set the Exif thumbnail to the JPEG image pointed to by \em buf,
            and size \em size. Set XResolution, YResolution and
@@ -315,6 +319,7 @@ class EXIV2API ExifThumb : public ExifThumbC {
            application that comes with OS X for one.) - David Harvey.
    */
   void setJpegThumbnail(const byte* buf, size_t size, URational xres, URational yres, uint16_t unit);
+#ifdef EXV_ENABLE_FILESYSTEM
   /*!
     @brief Set the Exif thumbnail to the JPEG image \em path.
 
@@ -329,6 +334,7 @@ class EXIV2API ExifThumb : public ExifThumbC {
     @note  Additional existing Exif thumbnail tags are not modified.
    */
   void setJpegThumbnail(const std::string& path);
+#endif
   /*!
     @brief Set the Exif thumbnail to the JPEG image pointed to by \em buf,
            and size \em size.

include/exiv2/preview.hpp

@@ -68,6 +68,7 @@ class EXIV2API PreviewImage {
     @brief Return the size of the preview image in bytes.
    */
   [[nodiscard]] uint32_t size() const;
+#ifdef EXV_ENABLE_FILESYSTEM
   /*!
     @brief Write the thumbnail image to a file.
 
@@ -79,6 +80,7 @@ class EXIV2API PreviewImage {
     @return The number of bytes written.
   */
   [[nodiscard]] size_t writeFile(const std::string& path) const;
+#endif
   /*!
     @brief Return the MIME type of the preview image, usually either
            \c "image/tiff" or \c "image/jpeg".

meson.build

@@ -120,6 +120,7 @@ cdata.set('EXV_HAVE_LIBZ', zlib_dep.found())
 cdata.set('EXV_ENABLE_WEBREADY', web_dep.found())
 cdata.set('EXV_USE_CURL', curl_dep.found())
 cdata.set('EXV_ENABLE_NLS', intl_dep.found())
+cdata.set('EXV_ENABLE_FILESYSTEM', true)
 
 cfile = configure_file(
   input: 'cmake/config.h.cmake',

src/basicio.cpp

@@ -36,6 +36,7 @@
 #include <curl/curl.h>
 #endif
 
+#ifdef EXV_ENABLE_FILESYSTEM
 #ifdef _WIN32
 using mode_t = unsigned short;
 #include <io.h>
@@ -49,19 +50,7 @@ namespace fs = std::filesystem;
 #include <experimental/filesystem>
 namespace fs = std::experimental::filesystem;
 #endif
-
-// *****************************************************************************
-// class member definitions
-namespace {
-/// @brief replace each substring of the subject that matches the given search string with the given replacement.
-void ReplaceStringInPlace(std::string& subject, std::string_view search, std::string_view replace) {
-  auto pos = subject.find(search);
-  while (pos != std::string::npos) {
-    subject.replace(pos, search.length(), replace);
-    pos += subject.find(search, pos + replace.length());
-  }
-}
-}  // namespace
+#endif
 
 namespace Exiv2 {
 void BasicIo::readOrThrow(byte* buf, size_t rcount, ErrorCode err) {
@@ -75,6 +64,7 @@ void BasicIo::seekOrThrow(int64_t offset, Position pos, ErrorCode err) {
   Internal::enforce(r == 0, err);
 }
 
+#ifdef EXV_ENABLE_FILESYSTEM
 //! Internal Pimpl structure of class FileIo.
 class FileIo::Impl {
  public:
@@ -567,6 +557,7 @@ const std::string& FileIo::path() const noexcept {
 
 void FileIo::populateFakeData() {
 }
+#endif
 
 //! Internal Pimpl structure of class MemIo.
 class MemIo::Impl final {
@@ -915,7 +906,7 @@ void XPathIo::ReadDataUri(const std::string& path) {
   delete[] decodeData;
 }
 
-#else
+#elif defined(EXV_ENABLE_FILESYSTEM)
 XPathIo::XPathIo(const std::string& orgPath) : FileIo(XPathIo::writeDataToFile(orgPath)), tempFilePath_(path()) {
 }
 
@@ -930,6 +921,16 @@ void XPathIo::transfer(BasicIo& src) {
   if (isTemp_) {
     // replace temp path to gent path.
     auto currentPath = path();
+
+    // replace each substring of the subject that matches the given search string with the given replacement.
+    auto ReplaceStringInPlace = [](std::string& subject, std::string_view search, std::string_view replace) {
+      auto pos = subject.find(search);
+      while (pos != std::string::npos) {
+        subject.replace(pos, search.length(), replace);
+        pos += subject.find(search, pos + replace.length());
+      }
+    };
+
     ReplaceStringInPlace(currentPath, XPathIo::TEMP_FILE_EXT, XPathIo::GEN_FILE_EXT);
     setPath(currentPath);
 
@@ -1725,7 +1726,7 @@ CurlIo::CurlIo(const std::string& url, size_t blockSize) {
 
 // *************************************************************************
 // free functions
-
+#ifdef EXV_ENABLE_FILESYSTEM
 DataBuf readFile(const std::string& path) {
   FileIo file(path);
   if (file.open("rb") != 0) {
@@ -1749,6 +1750,7 @@ size_t writeFile(const DataBuf& buf, const std::string& path) {
   }
   return file.write(buf.c_data(), buf.size());
 }
+#endif
 
 #ifdef EXV_USE_CURL
 size_t curlWriter(char* data, size_t size, size_t nmemb, std::string* writerData) {

src/exif.cpp

@@ -375,6 +375,7 @@ DataBuf ExifThumbC::copy() const {
   return thumbnail->copy(exifData_);
 }
 
+#ifdef EXV_ENABLE_FILESYSTEM
 size_t ExifThumbC::writeFile(const std::string& path) const {
   auto thumbnail = Thumbnail::create(exifData_);
   if (!thumbnail)
@@ -387,6 +388,7 @@ size_t ExifThumbC::writeFile(const std::string& path) const {
 
   return Exiv2::writeFile(buf, name);
 }
+#endif
 
 const char* ExifThumbC::mimeType() const {
   auto thumbnail = Thumbnail::create(exifData_);
@@ -405,10 +407,12 @@ const char* ExifThumbC::extension() const {
 ExifThumb::ExifThumb(ExifData& exifData) : ExifThumbC(exifData), exifData_(exifData) {
 }
 
+#ifdef EXV_ENABLE_FILESYSTEM
 void ExifThumb::setJpegThumbnail(const std::string& path, URational xres, URational yres, uint16_t unit) {
   DataBuf thumb = readFile(path);  // may throw
   setJpegThumbnail(thumb.c_data(), thumb.size(), xres, yres, unit);
 }
+#endif
 
 void ExifThumb::setJpegThumbnail(const byte* buf, size_t size, URational xres, URational yres, uint16_t unit) {
   setJpegThumbnail(buf, size);
@@ -417,10 +421,12 @@ void ExifThumb::setJpegThumbnail(const byte* buf, size_t size, URational xres, U
   exifData_["Exif.Thumbnail.ResolutionUnit"] = unit;
 }
 
+#ifdef EXV_ENABLE_FILESYSTEM
 void ExifThumb::setJpegThumbnail(const std::string& path) {
   DataBuf thumb = readFile(path);  // may throw
   setJpegThumbnail(thumb.c_data(), thumb.size());
 }
+#endif
 
 void ExifThumb::setJpegThumbnail(const byte* buf, size_t size) {
   exifData_["Exif.Thumbnail.Compression"] = static_cast<uint16_t>(6);

src/futils.cpp

@@ -16,13 +16,15 @@
 #include <sstream>
 #include <stdexcept>
 
+#ifdef EXV_ENABLE_FILESYSTEM
 #if __has_include(<filesystem>)
 #include <filesystem>
 namespace fs = std::filesystem;
 #else
 #include <experimental/filesystem>
 namespace fs = std::experimental::filesystem;
 #endif
+#endif
 
 #if defined(_WIN32)
 // clang-format off
@@ -231,7 +233,11 @@ bool fileExists(const std::string& path) {
   if (fileProtocol(path) != pFile) {
     return true;
   }
+#ifdef EXV_ENABLE_FILESYSTEM
   return fs::exists(path);
+#else
+  return false;
+#endif
 }
 
 std::string strError() {
@@ -341,6 +347,7 @@ Uri Uri::Parse(const std::string& uri) {
 }
 
 std::string getProcessPath() {
+#ifdef EXV_ENABLE_FILESYSTEM
 #if defined(__FreeBSD__)
   std::string ret("unknown");
   unsigned int n;
@@ -382,5 +389,8 @@ std::string getProcessPath() {
     return "unknown";
   }
 #endif
+#else
+  return "unknown";
+#endif
 }
 }  // namespace Exiv2