Fix get PYTHONHOME/PYTHONPATH marshal

vmuriart · yagweb · commit 790767c76bfc · 2017-04-07T20:42:00.000+08:00
Unlike pythonnet#413, the return type changes between PY2/PY3. Extended Custom Marshaler to convert IntPtr to Unicode String
diff --git a/src/runtime/CustomMarshaler.cs b/src/runtime/CustomMarshaler.cs
@@ -72,6 +72,33 @@ public static ICustomMarshaler GetInstance(string cookie)
         {
             return Instance;
         }
+
+        public static string PtrToStringUni(IntPtr p)
+        {
+            if (p == IntPtr.Zero)
+            {
+                return null;
+            }
+
+            int size = GetUnicodeByteLength(p);
+            var buffer = new byte[size];
+            Marshal.Copy(p, buffer, 0, size);
+            return PyEncoding.GetString(buffer, 0, size);
+        }
+
+        public static int GetUnicodeByteLength(IntPtr p)
+        {
+            var len = 0;
+            while (true)
+            {
+                int c = Runtime.UCS == 2
+                    ? Marshal.ReadInt16(p, len * 2)
+                    : Marshal.ReadInt32(p, len * 4);
+
+                if (c == 0) return len* Runtime.UCS;
+                checked{ ++len; }
+            }
+        }
     }
 
 
diff --git a/src/runtime/pythonengine.cs b/src/runtime/pythonengine.cs
@@ -57,12 +57,12 @@ public static string ProgramName
         {
             get
             {
-                string result = Runtime.Py_GetProgramName();
-                if (result == null)
-                {
-                    return "";
-                }
-                return result;
+                IntPtr p = Runtime.Py_GetProgramName();
+                string result = Runtime.IsPython3
+                    ? StrMarshaler.PtrToStringUni(p)
+                    : Marshal.PtrToStringAnsi(p);
+
+                return result ?? "";
             }
             set { Runtime.Py_SetProgramName(value); }
         }
@@ -71,12 +71,12 @@ public static string PythonHome
         {
             get
             {
-                string result = Runtime.Py_GetPythonHome();
-                if (result == null)
-                {
-                    return "";
-                }
-                return result;
+                IntPtr p = Runtime.Py_GetPythonHome();
+                string result = Runtime.IsPython3
+                    ? StrMarshaler.PtrToStringUni(p)
+                    : Marshal.PtrToStringAnsi(p);
+
+                return result ?? "";
             }
             set { Runtime.Py_SetPythonHome(value); }
         }
@@ -85,12 +85,12 @@ public static string PythonPath
         {
             get
             {
-                string result = Runtime.Py_GetPath();
-                if (result == null)
-                {
-                    return "";
-                }
-                return result;
+                IntPtr p = Runtime.Py_GetPath();
+                string result = Runtime.IsPython3
+                    ? StrMarshaler.PtrToStringUni(p)
+                    : Marshal.PtrToStringAnsi(p);
+
+                return result ?? "";
             }
             set { Runtime.Py_SetPath(value); }
         }
diff --git a/src/runtime/runtime.cs b/src/runtime/runtime.cs
@@ -683,46 +683,43 @@ public static extern int Py_Main(
 
 #if PYTHON3
         [DllImport(PythonDll)]
-        [return: MarshalAs(UnmanagedType.LPWStr)]
-        internal static extern string Py_GetProgramName();
+        internal static extern IntPtr Py_GetProgramName();
 
         [DllImport(PythonDll)]
         internal static extern void Py_SetProgramName(
             [MarshalAs(UnmanagedType.LPWStr)] string name
         );
 
         [DllImport(PythonDll)]
-        [return: MarshalAs(UnmanagedType.LPWStr)]
-        internal static extern string Py_GetPythonHome();
+        internal static extern IntPtr Py_GetPythonHome();
 
         [DllImport(PythonDll)]
         internal static extern void Py_SetPythonHome(
             [MarshalAs(UnmanagedType.LPWStr)] string home
         );
 
         [DllImport(PythonDll)]
-        [return: MarshalAs(UnmanagedType.LPWStr)]
-        internal static extern string Py_GetPath();
+        internal static extern IntPtr Py_GetPath();
 
         [DllImport(PythonDll)]
         internal static extern void Py_SetPath(
             [MarshalAs(UnmanagedType.LPWStr)] string home
         );
 #elif PYTHON2
         [DllImport(PythonDll)]
-        internal static extern string Py_GetProgramName();
+        internal static extern IntPtr Py_GetProgramName();
 
         [DllImport(PythonDll)]
         internal static extern void Py_SetProgramName(string name);
 
         [DllImport(PythonDll)]
-        internal static extern string Py_GetPythonHome();
+        internal static extern IntPtr Py_GetPythonHome();
 
         [DllImport(PythonDll)]
         internal static extern void Py_SetPythonHome(string home);
 
         [DllImport(PythonDll)]
-        internal static extern string Py_GetPath();
+        internal static extern IntPtr Py_GetPath();
 
         [DllImport(PythonDll)]
         internal static extern void Py_SetPath(string home);

Original file line number	Diff line number	Diff line change
`@@ -57,12 +57,12 @@ public static string ProgramName`
`57`	`57`	`{`
`58`	`58`	`get`
`59`	`59`	`{`
`60`		`- string result = Runtime.Py_GetProgramName();`
`61`		`- if (result == null)`
`62`		`- {`
`63`		`- return "";`
`64`		`- }`
`65`		`- return result;`
	`60`	`+ IntPtr p = Runtime.Py_GetProgramName();`
	`61`	`+ string result = Runtime.IsPython3`
	`62`	`+ ? StrMarshaler.PtrToStringUni(p)`
	`63`	`+ : Marshal.PtrToStringAnsi(p);`
	`64`	`+`
	`65`	`+ return result ?? "";`
`66`	`66`	`}`
`67`	`67`	`set { Runtime.Py_SetProgramName(value); }`
`68`	`68`	`}`
`@@ -71,12 +71,12 @@ public static string PythonHome`
`71`	`71`	`{`
`72`	`72`	`get`
`73`	`73`	`{`
`74`		`- string result = Runtime.Py_GetPythonHome();`
`75`		`- if (result == null)`
`76`		`- {`
`77`		`- return "";`
`78`		`- }`
`79`		`- return result;`
	`74`	`+ IntPtr p = Runtime.Py_GetPythonHome();`
	`75`	`+ string result = Runtime.IsPython3`
	`76`	`+ ? StrMarshaler.PtrToStringUni(p)`
	`77`	`+ : Marshal.PtrToStringAnsi(p);`
	`78`	`+`
	`79`	`+ return result ?? "";`
`80`	`80`	`}`
`81`	`81`	`set { Runtime.Py_SetPythonHome(value); }`
`82`	`82`	`}`
`@@ -85,12 +85,12 @@ public static string PythonPath`
`85`	`85`	`{`
`86`	`86`	`get`
`87`	`87`	`{`
`88`		`- string result = Runtime.Py_GetPath();`
`89`		`- if (result == null)`
`90`		`- {`
`91`		`- return "";`
`92`		`- }`
`93`		`- return result;`
	`88`	`+ IntPtr p = Runtime.Py_GetPath();`
	`89`	`+ string result = Runtime.IsPython3`
	`90`	`+ ? StrMarshaler.PtrToStringUni(p)`
	`91`	`+ : Marshal.PtrToStringAnsi(p);`
	`92`	`+`
	`93`	`+ return result ?? "";`
`94`	`94`	`}`
`95`	`95`	`set { Runtime.Py_SetPath(value); }`
`96`	`96`	`}`