is_readable,is_writable: default use Java true

Author: scivision

+stdlib/absolute.m

@@ -21,7 +21,7 @@
   p (1,1) string
   base (1,1) string = ""
   expand_tilde (1,1) logical = true
-  use_java (1,1) logical = true
+  use_java (1,1) logical = false
 end
 
 if expand_tilde

+stdlib/is_readable.m

@@ -5,24 +5,35 @@
 function ok = is_readable(file, use_java)
 arguments
   file (1,1) string
-  use_java (1,1) logical = false
+  use_java (1,1) logical = true
 end
 
+ok = false;
+if ~stdlib.exists(file, use_java), return, end
+% exists() check speeds up by factor of 50x on macOS for Java or non-Java
+
 if use_java
-  % java is about 10x slower than fileattrib
+  % https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/nio/file/Files.html#isReadable(java.nio.file.Path)
+  % java.nio.file.Files is about 10x slower than fileattrib
   % needs absolute()
-  file = stdlib.absolute(file, "", false, use_java);
+  % file = stdlib.absolute(file, "", false, true);
+  % ok = java.nio.file.Files.isReadable(java.io.File(file).toPath());
+try
+  ok = java.io.File(file).canRead();
+catch e
+  if strcmp(e.identifier, "Octave:undefined-function")
+    ok = javaObject("java.io.File", file).canRead();
+  else
+    rethrow(e);
+  end
+end
 
-  % https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/nio/file/Files.html#isReadable(java.nio.file.Path)
-  %ok = java.nio.file.Files.isReadable(java.io.File(file).toPath());
+else % use_java
 
-  % java.io.File().canRead() is about twice as fast as
-  % java.nio.file.Files.isReadable()
-  ok = java.io.File(file).canRead();
-else
-  [status, v] = fileattrib(file);
+[status, v] = fileattrib(file);
+
+ok = status ~= 0 && (v.UserRead || (~isnan(v.GroupRead) && v.GroupRead) || (~isnan(v.OtherRead) && v.OtherRead));
 
-  ok = status ~= 0 && (v.UserRead || (~isnan(v.GroupRead) && v.GroupRead) || (~isnan(v.OtherRead) && v.OtherRead));
 end
 
 end

+stdlib/is_writable.m

@@ -5,24 +5,37 @@
 function ok = is_writable(file, use_java)
 arguments
   file (1,1) string
-  use_java (1,1) logical = false
+  use_java (1,1) logical = true
 end
 
+ok = false;
+if ~stdlib.exists(file, use_java), return, end
+% exists() check speeds up by factor of 50x on macOS for Java or non-Java
 
-if use_java
-  % java is about 10x slower than fileattrib
-  % needs absolute()
-  file = stdlib.absolute(file, "", false, true);
 
+if use_java
   % https://docs.oracle.com/en/java/javase/22/docs/api/java.base/java/nio/file/Files.html#isWritable(java.nio.file.Path)
-  %ok = java.nio.file.Files.isWritable(java.io.File(file).toPath());
+  % java.nio.file.Files java is about 10x slower than fileattrib
+  % needs absolute()
+  % file = stdlib.absolute(file, "", false, true);
+  % ok = java.nio.file.Files.isWritable(java.io.File(file).toPath());
 
-  % java.io.File().canWrite() is about twice as fast
+try
   ok = java.io.File(file).canWrite();
+catch e
+  if strcmp(e.identifier, "Octave:undefined-function")
+    ok = javaObject("java.io.File", file).canWrite();
+  else
+    rethrow(e);
+  end
+end
+
 else
-  [status, v] = fileattrib(file);
 
-  ok = status ~= 0 && (v.UserWrite || (~isnan(v.GroupWrite) && v.GroupWrite) || (~isnan(v.OtherWrite) && v.OtherWrite));
+[status, v] = fileattrib(file);
+
+ok = status ~= 0 && (v.UserWrite || (~isnan(v.GroupWrite) && v.GroupWrite) || (~isnan(v.OtherWrite) && v.OtherWrite));
+
 end
 
 end

example/bench_is_writable.m

@@ -0,0 +1,17 @@
+%% benchmark
+
+f = mfilename("fullpath") + ".m";
+addpath(fullfile(fileparts(f), ".."))
+
+%f = tempname;
+
+fno = @() stdlib.is_writable(f, false);
+fjava = @() stdlib.is_writable(f, true);
+
+t_no = timeit(fno);
+t_java = timeit(fjava);
+
+disp("No Java: " + t_no + " s")
+disp("Java: " + t_java + " s")
+
+disp("Java is " + t_no/t_java + " times faster")

test/TestFileImpure.m

@@ -30,12 +30,12 @@ function test_file_size(tc)
 
 
 function test_is_readable(tc, p_exists)
-tc.verifyEqual(stdlib.is_readable(p_exists{1}), p_exists{2})
+tc.verifyEqual(stdlib.is_readable(p_exists{1}, stdlib.has_java()), p_exists{2})
 end
 
 
 function test_is_writable(tc, p_is_writable)
-tc.verifyEqual(stdlib.is_writable(p_is_writable{1}), p_is_writable{2})
+tc.verifyEqual(stdlib.is_writable(p_is_writable{1}, stdlib.has_java()), p_is_writable{2})
 end