javaSystemProperty() dedupe

Author: scivision

+stdlib/get_username.m

@@ -2,11 +2,7 @@
 
 function n = get_username()
 
-if stdlib.isoctave()
-  n = javaMethod("getProperty", "java.lang.System", "user.name");
-else
-  n = string(java.lang.System.getProperty('user.name'));
-end
+n = javaSystemProperty("user.name");
 
 end
 

+stdlib/homedir.m

@@ -9,10 +9,8 @@
   use_java (1,1) logical = false
 end
 
-if stdlib.isoctave()
-  h = javaMethod("getProperty", "java.lang.System", "user.home");
-elseif use_java
-  h = java.lang.System.getProperty("user.home");
+if use_java
+  h = javaSystemProperty("user.home");
 elseif ispc
   h = getenv("USERPROFILE");
 else

+stdlib/java_version.m

@@ -8,11 +8,7 @@
 
 function v = java_version()
 
-if stdlib.isoctave()
-  v = javaMethod("getProperty", "java.lang.System", "java.version");
-else
-  v = string(java.lang.System.getProperty("java.version"));
-end
+v = javaSystemProperty("java.version");
 
 end
 

+stdlib/private/javaSystemProperty.m

@@ -0,0 +1,11 @@
+function p = javaSystemProperty(k)
+
+try
+  p = string(java.lang.System.getProperty(k));
+catch e
+  if strcmp(e.identifier, "Octave:undefined-function")
+    p = javaMethod("getProperty", "java.lang.System", k);
+  else
+    rethrow(e);
+  end
+end

example/bench_homedir.m

@@ -0,0 +1,12 @@
+%% benchmark for exists()
+
+fno = @() stdlib.homedir(false);
+fjava = @() stdlib.homedir(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")