--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/filecache.py Thu May 30 12:03:53 2019 +0300
@@ -0,0 +1,121 @@
+import datetime
+import parse
+import os
+from pathlib import Path
+import linetypes
+import math
+
+def find_ldraw_file(filename, libraries):
+ '''
+ Searches the LDraw libraries for the specified file.
+ `libraries` must be an iterable of LDraw library root paths.
+ '''
+ if os.path.sep != "\\":
+ filename = filename.replace("\\", os.path.sep)
+ for library in libraries:
+ for path in [
+ Path(library) / filename,
+ Path(library) / "parts" / filename,
+ Path(library) / "p" / filename,
+ ]:
+ if path.exists():
+ return path
+ raise FileNotFoundError(str.format(
+ '"{}" not found in the LDraw libraries',
+ filename,
+ ))
+
+class CyclicalReferenceError(Exception):
+ pass
+
+class SubfileCache:
+ class Subfile:
+ def __init__(self):
+ self.valid = None
+ self.flatness = None
+ self.description = None
+ self.problem = None
+ self.vertices = set()
+ def __init__(self, ldraw_directories):
+ '''
+ Initializes a new subfile cache
+ '''
+ self.cache = dict()
+ self.ldraw_directories = [
+ Path(os.path.expanduser(directory))
+ for directory in ldraw_directories
+ ]
+ self.reference_stack = []
+ def flatness_of(self, filename):
+ '''
+ Returns the set of all directiones the specified file is flat in.
+ '''
+ self.prepare_file(filename)
+ return self.cache[filename].flatness
+ def description_of(self, filename):
+ '''
+ Returns the description of the specified file
+ '''
+ self.prepare_file(filename)
+ return self.cache[filename].description
+ def find_file(self, filename):
+ return find_ldraw_file(
+ filename = filename,
+ libraries = self.ldraw_directories,
+ )
+ def prepare_file(self, filename):
+ '''
+ Loads the file if not loaded yet.
+ '''
+ if filename not in self.cache:
+ self._load_subfile(filename)
+ return self.cache[filename]
+ def _load_subfile(self, filename):
+ # ward against cyclical dependencies
+ if filename in self.reference_stack:
+ raise CyclicalReferenceError(
+ ' -> '.join(self.reference_stack + [filename]),
+ )
+ self.reference_stack.append(filename)
+ subfile = SubfileCache.Subfile()
+ self.cache[filename] = subfile
+ try:
+ path = self.find_file(filename)
+ with path.open() as file:
+ model = parse.read_ldraw(
+ file,
+ ldraw_directories = self.ldraw_directories,
+ )
+ except (FileNotFoundError, IOError, PermissionError) as error:
+ subfile.valid = False
+ subfile.problem = str(error)
+ else:
+ if isinstance(model.body[0], linetypes.MetaCommand):
+ subfile.valid = True
+ subfile.description = model.body[0].text
+ else:
+ subfile.valid = False
+ subfile.problem = 'Description not found'
+ if subfile.valid:
+ subfile.vertices = set(parse.model_vertices(model))
+ subfile.flatness = {'x', 'y', 'z'}
+ for vertex in subfile.vertices:
+ # Use list(subfile.flatness) for iteration because the
+ # actual set may be modified during the loop
+ for dimension in list(subfile.flatness):
+ if not math.isclose(
+ getattr(vertex, dimension),
+ 0.0,
+ abs_tol = 1e-05,
+ ):
+ subfile.flatness.remove(dimension)
+ if not subfile.flatness:
+ break
+ for subfile_reference in model.subfile_references:
+ # Go through all the subfile references so that we catch any
+ # cyclical references
+ self.prepare_file(subfile_reference.subfile_path)
+ self.reference_stack.pop()
+
+if __name__ == '__main__':
+ cache = SubfileCache(ldraw_directories = ["~/ldraw"])