is_{exe,readable,writable} 40x faster than native

Author: scivision

+stdlib/+legacy/file_attributes.m

@@ -4,11 +4,17 @@
 end
 % need arguments and stdlib.strempty for Matlab < R2020b
 
-assert(~stdlib.strempty(p), 'Path must not be empty.');
+a = struct.empty;
+
+if stdlib.strempty(p)
+  return
+end
 
 [status, s] = fileattrib(p);
 
-assert(status == 1, "'%s' is not a file or directory.", p);
+if status ~= 1
+  return
+end
 
 a = s;
 for n = ["GroupRead", "GroupWrite", "GroupExecute", "OtherRead", "OtherWrite", "OtherExecute"]

+stdlib/+legacy/is_exe.m

@@ -6,11 +6,10 @@
   return
 end
 
-if ~isfile(file)
-  return
-end
-
 a = stdlib.legacy.file_attributes(file);
-y = a.UserExecute || a.GroupExecute || a.OtherExecute;
+
+if ~isempty(a) && ~a.directory
+  y = a.UserExecute || a.GroupExecute || a.OtherExecute;
+end
 
 end

+stdlib/+legacy/is_readable.m

@@ -1,13 +1,11 @@
 function y = is_readable(file)
-arguments
-  file (1,1) string
-end
 
-if stdlib.exists(file)
-  a = stdlib.legacy.file_attributes(file);
+y = false;
+
+a = stdlib.legacy.file_attributes(file);
+
+if ~isempty(a)
   y = a.UserRead || a.GroupRead || a.OtherRead;
-else
-  y = false;
 end
 
 end

+stdlib/+legacy/is_writable.m

@@ -1,13 +1,11 @@
 function y = is_writable(file)
-arguments
-  file (1,1) string
-end
 
-if stdlib.exists(file)
-  a = stdlib.legacy.file_attributes(file);
+y = false;
+
+a = stdlib.legacy.file_attributes(file);
+
+if ~isempty(a)
   y = a.UserWrite || a.GroupWrite || a.OtherWrite;
-else
-  y = false;
 end
 
 end

+stdlib/is_exe.m

@@ -6,7 +6,7 @@
 %%% Outputs
 % ok: true if path is a file and has executable permissions
 %
-% the legacy backend is actually significantly faster for single files
+% the legacy backend is like 40x faster than native.
 
 function [ok, b] = is_exe(file)
 arguments

+stdlib/is_readable.m

@@ -5,7 +5,7 @@
 %%% Outputs
 % ok: true if file is readable
 %
-% the legacy backend is actually significantly faster for single files
+% the legacy backend is like 40x faster than native
 
 function [ok, b] = is_readable(file)
 arguments

+stdlib/is_writable.m

@@ -5,7 +5,7 @@
 %%% Outputs
 % * ok: true if file is writable
 %
-% the legacy backend is actually significantly faster for single files
+% the legacy backend is like 40x faster than native
 
 function [ok, b] = is_writable(file)
 arguments

example/BenchmarkIsExe.m

@@ -17,9 +17,9 @@ function bench_exist(tc, fun)
   e = e + ".exe";
 end
 
-tc.startMeasuring()
-y = fun(e);
-tc.stopMeasuring()
+while tc.keepMeasuring()
+  y = fun(e);
+end
 
 tc.verifyEqual(y, true)
 end

example/BenchmarkIsExeRun.m

@@ -11,6 +11,6 @@
 
 function result = run_bench(name)
 suite = testsuite(name);
-exp = matlab.perftest.TimeExperiment.limitingSamplingError(MaxSamples=150, RelativeMarginOfError=0.1);
+exp = matlab.perftest.TimeExperiment.limitingSamplingError(RelativeMarginOfError=0.1);
 result = exp.run(suite);
 end