pyembed: consolidate functions to load state

We want the code in Python land to be as simple as possible. Plus this
will make it easier to test, since we don't need to rely on having a
Python interpreter.

Author: indygreg

pyembed/src/importer.rs

@@ -475,22 +475,7 @@ fn module_setup(
 
     let mut importer_state = PythonImporterState::default();
 
-    // Populate our importer with entries from the interpreter then in-memory data
-    // structures. The last write wins. That's why we load builtins and frozens before
-    // data provided by us.
-    if let Err(e) = importer_state.load_interpreter_builtin_modules() {
-        return Err(PyErr::new::<ValueError, _>(py, e));
-    }
-
-    if let Err(e) = importer_state.load_interpreter_frozen_modules() {
-        return Err(PyErr::new::<ValueError, _>(py, e));
-    }
-
-    if let Err(e) = importer_state.load_modules_data(state.py_modules_data) {
-        return Err(PyErr::new::<ValueError, _>(py, e));
-    }
-
-    if let Err(e) = importer_state.load_resources_data(state.py_resources_data) {
+    if let Err(e) = importer_state.load(state.py_modules_data, state.py_resources_data) {
         return Err(PyErr::new::<ValueError, _>(py, e));
     }
 

pyembed/src/python_resources.rs

@@ -54,8 +54,24 @@ impl Default for PythonImporterState {
 }
 
 impl PythonImporterState {
+    /// Load state from the environment and by parsing data structures.
+    pub fn load(
+        &mut self,
+        modules_data: &'static [u8],
+        resources_data: &'static [u8],
+    ) -> Result<(), &'static str> {
+        // Last write wins. So start with core modules then move on to more
+        // local data.
+        self.load_interpreter_builtin_modules()?;
+        self.load_interpreter_frozen_modules()?;
+        self.load_modules_data(modules_data)?;
+        self.load_resources_data(resources_data)?;
+
+        Ok(())
+    }
+
     /// Load `builtin` modules from the Python interpreter.
-    pub fn load_interpreter_builtin_modules(&mut self) -> Result<(), &'static str> {
+    fn load_interpreter_builtin_modules(&mut self) -> Result<(), &'static str> {
         for i in 0.. {
             let record = unsafe { pyffi::PyImport_Inittab.offset(i) };
 
@@ -78,7 +94,7 @@ impl PythonImporterState {
     }
 
     /// Load `frozen` modules from the Python interpreter.
-    pub fn load_interpreter_frozen_modules(&mut self) -> Result<(), &'static str> {
+    fn load_interpreter_frozen_modules(&mut self) -> Result<(), &'static str> {
         for i in 0.. {
             let record = unsafe { pyffi::PyImport_FrozenModules.offset(i) };
 
@@ -101,7 +117,7 @@ impl PythonImporterState {
     }
 
     /// Parse binary modules data and update current data structure.
-    pub fn load_modules_data(&mut self, data: &'static [u8]) -> Result<(), &'static str> {
+    fn load_modules_data(&mut self, data: &'static [u8]) -> Result<(), &'static str> {
         let mut reader = Cursor::new(data);
 
         let count = reader
@@ -196,7 +212,7 @@ impl PythonImporterState {
         Ok(())
     }
 
-    pub fn load_resources_data(&mut self, data: &'static [u8]) -> Result<(), &'static str> {
+    fn load_resources_data(&mut self, data: &'static [u8]) -> Result<(), &'static str> {
         let mut reader = Cursor::new(data);
 
         let package_count = reader