Commit: 9fe65bb610ffa90280b0ae3b8026bebfc9a070b5 - magickd (git)

D bindings to the GraphicsMagick library.

Commit MetaInfo

• Revisión: 9fe65bb610ffa90280b0ae3b8026bebfc9a070b5 (tree)
• Tiempo: 2023-05-27 11:04:51
• Autor: Mio <stigma@disr...>
• Commiter: Mio

Log Message

[magickd] Change how loading GraphicsMagick works

Cambiar Resumen

• modified: README.md
• add: source/magickd/initialisation.d
• modified: source/magickd/package.d

Diferencia incremental

--- a/README.md
+++ b/README.md
@@ -55,29 +55,32 @@ This requires loading the library at runtime and binding the symbols.
 import magickd;
 
 /* Attempt to load the GraphicsMagick library. */
-void *libgm = null;
-
-bool success = loadGraphicsMagick(libgm);
-if (false == success) {
-    /*
-     * We failed to load for some reason (errors are printed to stderr)
-     */
-    if (null is libgm) {
-        /*
-         * We failed to find the shared library, perhaps GraphicsMagick
-         * is not installed.
-         */
-    } else {
-        /*
-         * We just had some issues linking some of the dynamic functions,
-         * so proceed with caution. Again, any issues are printed to 
-         * stderr.
-         */
-    }
-} else {
-    /*
-     * We loaded the library without any issues!
-     */
+MDLoadStatus result = loadGraphicsMagick();
+
+/* Do we need to unload the library? */
+bool unload = false;
+
+switch (result) {
+   case MDLoadStatus.success:
+      // All Good!
+      unload = true;
+      break;
+   case MDLoadStatus.badLibrary:
+      // We have loaded the GraphicsMagick library, but some of the symbols
+      // that we expected to find, could not be found.
+      // Something may not work.
+      unload = true;
+      break;
+   case MDLoadStatus.noLibrary:
+      // We couldn't find the GraphicsMagick library on the system.
+      // Nothing will work.
+      break;
+   default:
+      assert(0);
+}
+
+if (unload) {
+   unloadGraphicsMagick();
 }
 ```
 

--- /dev/null
+++ b/source/magickd/initialisation.d
@@ -0,0 +1,99 @@
+/*
+  File:           magickd/initialisation.d
+  Contains:       Functions related to initialsing the GraphicsMagick C library.
+  Copyright:      (C) 2023 Mio
+
+  Permission is hereby granted, free of charge, to any person obtaining a copy
+  of this software and associated documentation files (the "Software"), to deal
+  in the Software without restriction, including without limitation the rights
+  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+  copies of the Software, and to permit persons to whom the Software is
+  furnished to do so, subject to the following conditions:
+
+  The above copyright notice and this permission notice shall be included in all
+  copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+  SOFTWARE.
+*/
+module magickd.initialisation;
+
+/// An enumeration for the potential return values of `loadGraphicsMagick`.
+enum MDLoadStatus
+{
+   /// Loading was successful.
+   success,
+   /// Some symbols could not be found in the libraries.
+   badLibrary,
+   /// We couldn't find all of the GraphicsMagick libraries.
+   noLibrary,
+}
+
+/// Load the GraphicsMagick/GraphicsMagickWand libraries.
+///
+/// Params:
+///    autoload = Should we automatically initialise the GraphicsMagick library
+///               via `InitializeMagick`.
+///
+/// Returns:
+///    A value of `MDLoadStatus`, depending on how successful the loading of the
+///    library was.
+///
+///    If loading was successful, then `MDLoadStatus.success` is returned.
+///
+///    If the libraries (GraphicsMagick and GraphicsMagickWand) could not be
+///    found on the system, then `MDLoadStatus.noLibrary` is returned.
+///
+///    `MDLoadStatus.badLibrary` is returned when the libraries *could* be found,
+///    but one or more of the symbols could not be found.
+///
+///    **NOTE**: When using the static version of magickd, this will always
+///    return `MDLoadStatus.success`.
+MDLoadStatus loadGraphicsMagick(bool autoload = true)
+{
+   import graphicsmagick_c.magick.magick : InitializeMagick;
+
+   version (GMagick_Dynamic) {
+      import graphicsmagick_c.config : _loadGraphicsMagick = loadGraphicsMagick,
+         loadGraphicsMagickWand;
+
+      void* lib;
+
+      bool success = _loadGraphicsMagick(lib);
+      if (null is lib) {
+         return MDLoadStatus.noLibrary;
+      }
+
+      success &= loadGraphicsMagickWand(lib);
+      if (null is lib) {
+         return MDLoadStatus.noLibrary;
+      }
+
+      if (autoload) {
+         InitializeMagick(null);
+      }
+
+      return success ? MDLoadStatus.success : MDLoadStatus.badLibrary;
+   } else {
+      if (autoload) {
+         InitializeMagick(null);
+      }
+
+      return MDLoadStatus.success;
+   }
+}
+
+/// Unload the GraphcisMagick library.
+///
+/// This is equivalent to calling `DestroyMagick`.
+void unloadGraphicsMagick()
+{
+   import graphicsmagick_c.magick.magick : DestroyMagick;
+
+   DestroyMagick();
+}

--- a/source/magickd/package.d
+++ b/source/magickd/package.d
@@ -1,7 +1,7 @@
 /*
   File:           magickd/package.d
   Contains:       Public imports for magickd.
-  Copyright:      (C) 2021, 2023 kaerou <[e-mail]>
+  Copyright:      (C) 2021, 2023 Mio
 
   Permission is hereby granted, free of charge, to any person obtaining a copy
   of this software and associated documentation files (the "Software"), to deal
@@ -25,13 +25,10 @@ module magickd;
 
 public
 {
-    version (GMagick_Dynamic) {
-        // MagickD only uses GraphicsMagick (not GraphicsMagickWand)
-        import graphicsmagick_c.config : loadGraphicsMagick;
-    }
-
     import graphicsmagick_c.magick.magick : InitializeMagick, DestroyMagick;
 
+    import magickd.initialisation;
+
     import magickd.image_info;
     import magickd.image;
     import magickd.exception;