diff options
Diffstat (limited to 'Lib/importlib/_bootstrap.py')
| -rw-r--r-- | Lib/importlib/_bootstrap.py | 57 |
1 files changed, 42 insertions, 15 deletions
diff --git a/Lib/importlib/_bootstrap.py b/Lib/importlib/_bootstrap.py index 520c10a..5bdd111 100644 --- a/Lib/importlib/_bootstrap.py +++ b/Lib/importlib/_bootstrap.py @@ -331,25 +331,40 @@ class _LoaderBasics: filename = self.get_filename(fullname).rpartition(path_sep)[2] return filename.rsplit('.', 1)[0] == '__init__' - def _bytes_from_bytecode(self, fullname, data, source_mtime): + def _bytes_from_bytecode(self, fullname, data, source_stats): """Return the marshalled bytes from bytecode, verifying the magic - number and timestamp along the way. + number, timestamp and source size along the way. - If source_mtime is None then skip the timestamp check. + If source_stats is None then skip the timestamp check. """ magic = data[:4] raw_timestamp = data[4:8] + raw_size = data[8:12] if len(magic) != 4 or magic != imp.get_magic(): raise ImportError("bad magic number in {}".format(fullname)) elif len(raw_timestamp) != 4: raise EOFError("bad timestamp in {}".format(fullname)) - elif source_mtime is not None: - if marshal._r_long(raw_timestamp) != source_mtime: - raise ImportError("bytecode is stale for {}".format(fullname)) + elif len(raw_size) != 4: + raise EOFError("bad size in {}".format(fullname)) + if source_stats is not None: + try: + source_mtime = int(source_stats['mtime']) + except KeyError: + pass + else: + if marshal._r_long(raw_timestamp) != source_mtime: + raise ImportError("bytecode is stale for {}".format(fullname)) + try: + source_size = source_stats['size'] & 0xFFFFFFFF + except KeyError: + pass + else: + if marshal._r_long(raw_size) != source_size: + raise ImportError("bytecode is stale for {}".format(fullname)) # Can't return the code object as errors from marshal loading need to # propagate even when source is available. - return data[8:] + return data[12:] @module_for_loader def _load_module(self, module, *, sourceless=False): @@ -377,11 +392,20 @@ class SourceLoader(_LoaderBasics): def path_mtime(self, path): """Optional method that returns the modification time (an int) for the specified path, where path is a str. + """ + raise NotImplementedError - Implementing this method allows the loader to read bytecode files. + def path_stats(self, path): + """Optional method returning a metadata dict for the specified path + to by the path (str). + Possible keys: + - 'mtime' (mandatory) is the numeric timestamp of last source + code modification; + - 'size' (optional) is the size in bytes of the source code. + Implementing this method allows the loader to read bytecode files. """ - raise NotImplementedError + return {'mtime': self.path_mtime(path)} def set_data(self, path, data): """Optional method which writes data (bytes) to a file path (a str). @@ -407,7 +431,7 @@ class SourceLoader(_LoaderBasics): def get_code(self, fullname): """Concrete implementation of InspectLoader.get_code. - Reading of bytecode requires path_mtime to be implemented. To write + Reading of bytecode requires path_stats to be implemented. To write bytecode, set_data must also be implemented. """ @@ -416,10 +440,11 @@ class SourceLoader(_LoaderBasics): source_mtime = None if bytecode_path is not None: try: - source_mtime = self.path_mtime(source_path) + st = self.path_stats(source_path) except NotImplementedError: pass else: + source_mtime = int(st['mtime']) try: data = self.get_data(bytecode_path) except IOError: @@ -427,7 +452,7 @@ class SourceLoader(_LoaderBasics): else: try: bytes_data = self._bytes_from_bytecode(fullname, data, - source_mtime) + st) except (ImportError, EOFError): pass else: @@ -448,6 +473,7 @@ class SourceLoader(_LoaderBasics): # throw an exception. data = bytearray(imp.get_magic()) data.extend(marshal._w_long(source_mtime)) + data.extend(marshal._w_long(len(source_bytes))) data.extend(marshal.dumps(code_object)) try: self.set_data(bytecode_path, data) @@ -492,9 +518,10 @@ class _SourceFileLoader(_FileLoader, SourceLoader): """Concrete implementation of SourceLoader using the file system.""" - def path_mtime(self, path): - """Return the modification time for the path.""" - return int(_os.stat(path).st_mtime) + def path_stats(self, path): + """Return the metadat for the path.""" + st = _os.stat(path) + return {'mtime': st.st_mtime, 'size': st.st_size} def set_data(self, path, data): """Write bytes data to a file.""" |