Added CachedFunctionDir

objects/util/CachedFunctionDir.m

@@ -0,0 +1,76 @@
+classdef CachedFunctionDir < handle
+    properties
+        cached_function
+        cache_filename
+        verbosity = 0;
+        version_tag = 0;
+    end
+
+
+    methods(Static)
+        function hashstr=get_hashstr(args)
+            % GET_HASHSTR Generate unique hash value from data
+            digest = java.security.MessageDigest.getInstance('SHA1');
+            for i=1:length(args)
+                data = typecast(args{i}, 'uint8');
+                digest.update(data)
+            end
+            hash = typecast(digest.digest(), 'uint8');
+            hashstr = sprintf('%.2X', hash);
+        end
+    end
+
+    methods
+        function cfunc=CachedFunctionDir(func, filename, varargin)
+            % CACHEDFUNCTION Create a CacheFunction object
+            options = varargin2options(varargin, mfilename);
+            [version_tag, options] = get_option(options, 'version_tag', 0);
+            [verbosity, options] = get_option(options, 'verbosity', 0);
+            check_unsupported_options(options);
+
+            cfunc.cache_filename = filename;
+            cfunc.cached_function = func;
+            cfunc.version_tag = version_tag;
+            cfunc.verbosity = verbosity;
+        end
+
+        function result=call(cfunc, varargin)
+            % CALL Call the function or get the result from the cache
+            args = varargin;
+            [result, found] = cfunc.retrieve(args);
+            if ~found
+                result = funcall(cfunc.cached_function, args{:});
+                cfunc.store(args, result);
+            end
+        end
+
+        function filename=get_filename(cfunc, basename)
+            filename = [fullfile(cfunc.cache_filename, basename), '.mat'];
+        end
+
+        function store(cfunc, args, result)
+            hashstr=cfunc.get_hashstr(args);
+            filename = cfunc.get_filename(hashstr);
+            makesavepath( filename );
+            save(filename, 'args', 'result');
+        end
+
+        function [result, found, origargs] = retrieve(cfunc, args)
+            hashstr=cfunc.get_hashstr(args);
+            filename = cfunc.get_filename(hashstr);
+
+            result = [];
+            origargs = [];
+            found = exist(filename, 'file');
+            if found
+                if cfunc.verbosity>0
+                    disp('Looking up response...');
+                end
+                load(filename, 'result', 'args');
+                % todo: compare args and origargs
+                origargs = args;
+            end
+        end
+    end
+
+end