Cache Images for faster parsing subsequent images (or frames in animation) #396

source/core/support/imageutil.cpp

@@ -1388,11 +1388,17 @@ ImageData *Copy_Image(ImageData *Old)
 void Destroy_Image(ImageData *image)
 {
     if ((image == nullptr) || (--(image->References) > 0))
-        return;
+         return;
+
+    image->data = nullptr; // Prevent the image from being deleted. Images are now cached.
+    delete image;
+}
 
+void Remove_Cached_Image(Image* image) {
     delete image;
 }
 
+
 ImageData::~ImageData()
 {
 #ifdef POV_VIDCAP_IMPL

source/core/support/imageutil.h

@@ -143,6 +143,7 @@ int map_pos(const Vector3d& EPoint, const ImageData* pImage, DBL *xcoor, DBL *yc
 ImageData *Copy_Image(ImageData *old);
 ImageData *Create_Image(void);
 void Destroy_Image(ImageData *image);
+void Remove_Cached_Image(Image* image);
 
 /// @}
 ///

source/parser/ImageCache.cpp

@@ -0,0 +1,135 @@
+//******************************************************************************
+///
+/// @file parser/ImageCache.cpp
+///
+/// This module implements a cache for images used in a scene so they only heve
+/// to be loaded once during animation rendering or between manual renders
+///
+/// @copyright
+/// @parblock
+///
+/// Persistence of Vision Ray Tracer ('POV-Ray') version 3.8.
+/// Copyright 1991-2019 Persistence of Vision Raytracer Pty. Ltd.
+///
+/// POV-Ray is free software: you can redistribute it and/or modify
+/// it under the terms of the GNU Affero General Public License as
+/// published by the Free Software Foundation, either version 3 of the
+/// License, or (at your option) any later version.
+///
+/// POV-Ray is distributed in the hope that it will be useful,
+/// but WITHOUT ANY WARRANTY; without even the implied warranty of
+/// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+/// GNU Affero General Public License for more details.
+///
+/// You should have received a copy of the GNU Affero General Public License
+/// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+///
+/// ----------------------------------------------------------------------------
+///
+/// POV-Ray is based on the popular DKB raytracer version 2.12.
+/// DKBTrace was originally written by David K. Buck.
+/// DKBTrace Ver 2.0-2.12 were written by David K. Buck & Aaron A. Collins.
+///
+/// @endparblock
+///
+//******************************************************************************
+
+
+// C++ variants of C standard header files
+#include <map>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#ifndef WIN32
+#include <unistd.h> // Unix lib for getting last modified file date and time
+#endif
+#ifdef WIN32
+#define stat _stat // Windows lib for getting last modified file date and time
+#endif
+
+
+// POV-Ray header files (base module)
+#include "base/base_fwd.h"
+#include "base/messenger_fwd.h"
+#include "base/povassert.h"
+#include "base/stringtypes.h"
+#include "base/textstream_fwd.h"
+#include "base/textstreambuffer.h"
+#include "base/image/image_fwd.h"
+#include "base/stringutilities.h"
+#include "core/support/imageutil.h"
+
+// this must be the last file included
+#include "base/povdebug.h"
+
+
+namespace pov_image_cache
+{
+	using namespace pov_base;
+	using namespace std;
+	using namespace pov;
+
+	struct ImageCacheEntry final
+	{
+		Image* image;
+		long lastModified;
+	};
+
+	static std::map<std::string, ImageCacheEntry> Cache; // <- The actual cache
+
+	// Gets the last modified time from the filesystem
+	long GetLastModifiedTime(const std::string filename)
+	{
+		const char* cstrFilename = filename.c_str();
+
+		struct stat result;
+		if (stat(cstrFilename, &result) == 0)
+		{
+			return (long)result.st_mtime;
+		}
+		return 0;
+	}
+
+	// Try to get the image from the cache
+	Image* GetCachedImage(const UCS2* filename)
+	{
+		std::string lookupFilename = pov_base::UCS2toSysString(filename);
+
+		std::map<std::string, ImageCacheEntry>::iterator idx = Cache.find(lookupFilename);
+		if (idx != Cache.end()) 
+		{
+			long lastModified = GetLastModifiedTime(lookupFilename);
+			if (lastModified == Cache[lookupFilename].lastModified) 
+				return idx->second.image; //Cache[lookupFilename].image;
+
+			// Remove old image from cache and release memory so the newer version can be loaded
+			pov::Remove_Cached_Image(idx->second.image);
+			Cache.erase(idx);
+		}
+
+		return nullptr;
+	}
+
+	// Store a new image into cache
+	void StoreImageInCache(const UCS2* filename, Image* image)
+	{
+		std::string lookupFilename = pov_base::UCS2toSysString(filename);
+		long lastModified = GetLastModifiedTime(lookupFilename);
+		Cache[lookupFilename] = ImageCacheEntry{ image = image, lastModified = lastModified };
+	}
+
+	// May be called frome some menu item, personally, I'd just close PovRay and start a new process (different scenes often share resources in my case)
+	// Do not allow calling it while parsing or rendering!
+	void ClearCache() 
+	{
+		std::map<std::string, ImageCacheEntry>::iterator it = Cache.begin();
+
+		// Iterate over the map using Iterator till end.
+		while (it != Cache.end())
+		{
+			pov::Remove_Cached_Image(it->second.image);
+			Cache.erase(it);
+		}
+	}
+}

source/parser/ImageCache.h

@@ -0,0 +1,79 @@
+//******************************************************************************
+///
+/// @file parser/ImageCache.h
+///
+/// Declarations related to the Image Cache.
+///
+/// @copyright
+/// @parblock
+///
+/// Persistence of Vision Ray Tracer ('POV-Ray') version 3.8.
+/// Copyright 1991-2019 Persistence of Vision Raytracer Pty. Ltd.
+///
+/// POV-Ray is free software: you can redistribute it and/or modify
+/// it under the terms of the GNU Affero General Public License as
+/// published by the Free Software Foundation, either version 3 of the
+/// License, or (at your option) any later version.
+///
+/// POV-Ray is distributed in the hope that it will be useful,
+/// but WITHOUT ANY WARRANTY; without even the implied warranty of
+/// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+/// GNU Affero General Public License for more details.
+///
+/// You should have received a copy of the GNU Affero General Public License
+/// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+///
+/// ----------------------------------------------------------------------------
+///
+/// POV-Ray is based on the popular DKB raytracer version 2.12.
+/// DKBTrace was originally written by David K. Buck.
+/// DKBTrace Ver 2.0-2.12 were written by David K. Buck & Aaron A. Collins.
+///
+/// @endparblock
+///
+//******************************************************************************
+
+#ifndef POVRAY_PARSER_IMAGE_CACHE_H
+#define POVRAY_PARSER_IMAGE_CACHE_H
+
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#ifndef WIN32
+#include <unistd.h> // Unix lib for getting last modified file date and time
+#endif
+#ifdef WIN32
+#define stat _stat // Windows lib for getting last modified file date and time
+#endif
+
+
+// POV-Ray header files (base module)
+#include "base/base_fwd.h"
+#include "base/messenger_fwd.h"
+#include "base/povassert.h"
+#include "base/stringtypes.h"
+#include "base/textstream_fwd.h"
+#include "base/textstreambuffer.h"
+#include "base/image/image_fwd.h"
+
+namespace pov
+{
+	class Blob_Element;
+	struct ContainedByShape;
+	struct GenericSpline;
+	class ImageData;
+	class Mesh;
+	struct PavementPattern;
+	struct TilingPattern;
+	struct TrueTypeFont;
+}
+
+namespace pov_image_cache
+{
+	using namespace pov_base;
+
+	Image* GetCachedImage(const UCS2* filename);
+	void StoreImageInCache(const UCS2* filename, Image* image);
+};
+
+#endif // POVRAY_PARSER_IMAGE_CACHE_H

source/parser/parser.cpp

@@ -113,7 +113,7 @@
 #include "vm/fnpovfpu.h"
 
 // POV-Ray header files (parser module)
-//  (none at the moment)
+#include "parser/ImageCache.h"
 
 // this must be the last file included
 #include "base/povdebug.h"
@@ -122,6 +122,7 @@ namespace pov_parser
 {
 
 using namespace pov;
+using namespace pov_image_cache;
 
 using std::min;
 using std::max;
@@ -9971,8 +9972,12 @@ OStream *Parser::CreateFile(const UCS2String& filename, unsigned int stype, bool
 
 //******************************************************************************
 
-Image *Parser::Read_Image(int filetype, const UCS2 *filename, const ImageReadOptions& options)
+Image *Parser::Read_Image(int filetype, const UCS2* filename, const ImageReadOptions& options)
 {
+    Image* img = pov_image_cache::GetCachedImage(filename);
+    if (img != nullptr)
+        return img;
+
     unsigned int stype;
     Image::ImageFileType type;
     UCS2String ign;
@@ -10040,7 +10045,11 @@ Image *Parser::Read_Image(int filetype, const UCS2 *filename, const ImageReadOpt
     if (file == nullptr)
         throw POV_EXCEPTION(kCannotOpenFileErr, "Cannot find image file.");
 
-    return Image::Read(type, file.get(), options);
+    img = Image::Read(type, file.get(), options);
+
+    pov_image_cache::StoreImageInCache(filename, img);
+
+    return img;
 }
 
 //******************************************************************************

windows/vs2015/povparser.vcxproj

@@ -400,6 +400,7 @@
   </ItemDefinitionGroup>
   <ItemGroup>
     <ClCompile Include="..\..\source\parser\fncode.cpp" />
+    <ClCompile Include="..\..\source\parser\ImageCache.cpp" />
     <ClCompile Include="..\..\source\parser\parser.cpp" />
     <ClCompile Include="..\..\source\parser\parsertypes.cpp" />
     <ClCompile Include="..\..\source\parser\parser_expressions.cpp" />
@@ -424,6 +425,7 @@
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="..\..\source\parser\fncode.h" />
+    <ClInclude Include="..\..\source\parser\ImageCache.h" />
     <ClInclude Include="..\..\source\parser\parser.h" />
     <ClInclude Include="..\..\source\parser\parsertypes.h" />
     <ClInclude Include="..\..\source\parser\parser_fwd.h" />

windows/vs2015/povparser.vcxproj.filters

@@ -46,6 +46,9 @@
     <ClInclude Include="..\..\source\parser\parser_fwd.h">
       <Filter>Parser Headers</Filter>
     </ClInclude>
+    <ClInclude Include="..\..\source\parser\ImageCache.h">
+      <Filter>Parser Headers</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="..\..\source\parser\parser.cpp">
@@ -93,5 +96,8 @@
     <ClCompile Include="..\..\source\parser\symboltable.cpp">
       <Filter>Parser Source</Filter>
     </ClCompile>
+    <ClCompile Include="..\..\source\parser\ImageCache.cpp">
+      <Filter>Parser Source</Filter>
+    </ClCompile>
   </ItemGroup>
 </Project>