Changes in sasmodels/custom/__init__.py [0f48f1e:d321747] in sasmodels

File:

• sasmodels/custom/__init__.py (modified) (4 diffs)

sasmodels/custom/__init__.py

@@ -12 +12 @@
 import sys
 import os
-from os.path import basename, splitext
+from os.path import basename, splitext, join as joinpath, exists, dirname
 
 try:
@@ -18 +18 @@
     from importlib.util import spec_from_file_location, module_from_spec  # type: ignore
     def load_module_from_path(fullname, path):
+        # type: (str, str) -> "module"
         """load module from *path* as *fullname*"""
         spec = spec_from_file_location(fullname, os.path.expanduser(path))
@@ -27 +28 @@
     import imp
     def load_module_from_path(fullname, path):
+        # type: (str, str) -> "module"
         """load module from *path* as *fullname*"""
         # Clear out old definitions, if any
@@ -37 +39 @@
         return module
 
+_MODULE_CACHE = {} # type: Dict[str, Tuple("module", int)]
+_MODULE_DEPENDS = {} # type: Dict[str, List[str]]
+_MODULE_DEPENDS_STACK = [] # type: List[str]
 def load_custom_kernel_module(path):
+    # type: str -> "module"
     """load SAS kernel from *path* as *sasmodels.custom.modelname*"""
     # Pull off the last .ext if it exists; there may be others
     name = basename(splitext(path)[0])
-    # Placing the model in the 'sasmodels.custom' name space.
-    kernel_module = load_module_from_path('sasmodels.custom.'+name,
-                                          os.path.expanduser(path))
-    return kernel_module
+    path = os.path.expanduser(path)
+
+    # Reload module if necessary.
+    if need_reload(path):
+        # Assume the module file is the only dependency
+        _MODULE_DEPENDS[path] = set([path])
+
+        # Load the module while pushing it onto the dependency stack.  If
+        # this triggers any submodules, then they will add their dependencies
+        # to this module as the "working_on" parent.  Pop the stack when the
+        # module is loaded.
+        _MODULE_DEPENDS_STACK.append(path)
+        module = load_module_from_path('sasmodels.custom.'+name, path)
+        _MODULE_DEPENDS_STACK.pop()
+
+        # Include external C code in the dependencies.  We are looking
+        # for module.source and assuming that it is a list of C source files
+        # relative to the module itself.  Any files that do not exist,
+        # such as those in the standard libraries, will be ignored.
+        # TODO: look in builtin module path for standard c sources
+        # TODO: share code with generate.model_sources
+        c_sources = getattr(module, 'source', None)
+        if isinstance(c_sources, (list, tuple)):
+            _MODULE_DEPENDS[path].update(_find_sources(path, c_sources))
+
+        # Cache the module, and tag it with the newest timestamp
+        timestamp = max(os.path.getmtime(f) for f in _MODULE_DEPENDS[path])
+        _MODULE_CACHE[path] = module, timestamp
+
+        #print("loading", os.path.basename(path), _MODULE_CACHE[path][1],
+        #    [os.path.basename(p) for p in _MODULE_DEPENDS[path]])
+
+    # Add path and all its dependence to the parent module, if there is one.
+    if _MODULE_DEPENDS_STACK:
+        working_on = _MODULE_DEPENDS_STACK[-1]
+        _MODULE_DEPENDS[working_on].update(_MODULE_DEPENDS[path])
+
+    return _MODULE_CACHE[path][0]
+
+def need_reload(path):
+    # type: str -> bool
+    """
+    Return True if any path dependencies have a timestamp newer than the time
+    when the path was most recently loaded.
+    """
+    # TODO: fails if a dependency has a modification time in the future
+    # If the newest dependency has a time stamp in the future, then this
+    # will be recorded as the cached time.  When a second dependency
+    # is updated to the current time stamp, it will still be considered
+    # older than the current build and the reload will not be triggered.
+    # Could instead treat all future times as 0 here and in the code above
+    # which records the newest timestamp.  This will force a reload when
+    # the future time is reached, but other than that should perform
+    # correctly.  Probably not worth the extra code...
+    _, cache_time = _MODULE_CACHE.get(path, (None, -1))
+    depends = _MODULE_DEPENDS.get(path, [path])
+    #print("reload", any(cache_time < os.path.getmtime(p) for p in depends))
+    #for f in depends: print(">>>  ", f, os.path.getmtime(f))
+    return any(cache_time < os.path.getmtime(p) for p in depends)
+
+def _find_sources(path, source_list):
+    # type: (str, List[str]) -> List[str]
+    """
+    Return a list of the sources relative to base file; ignore any that
+    are not found.
+    """
+    root = dirname(path)
+    found = []
+    for source_name in source_list:
+        source_path = joinpath(root, source_name)
+        if exists(source_path):
+            found.append(source_path)
+    return found