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Check the magic number of bytecode files

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Kodi Arfer 2017-04-11 18:53:35 -07:00
parent 36324e9499
commit a87b23b4e8
1 changed files with 7 additions and 5 deletions
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12
hy/importer.py
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@ -86,14 +86,16 @@ def import_file_to_module(module_name, fpath, loader=None):
try: try:
source_mtime = int(os.stat(fpath).st_mtime) source_mtime = int(os.stat(fpath).st_mtime)
with open(bytecode_path, 'rb') as bc_f: with open(bytecode_path, 'rb') as bc_f:
# To get the bytecode file's internal timestamp, take the 4 bytes # The first 4 bytes are the magic number for the version of Python
# after the first 4 bytes and interpret them as a little-endian # that compiled this bytecode.
# 32-bit integer. bytecode_magic = bc_f.read(4)
bytecode_mtime = struct.unpack('<i', bc_f.read(8)[4:])[0] # The next 4 bytes, interpreted as a little-endian 32-bit integer,
# are the mtime of the corresponding source file.
bytecode_mtime, = struct.unpack('<i', bc_f.read(4))
except (IOError, OSError): except (IOError, OSError):
pass pass
else: else:
if bytecode_mtime >= source_mtime: if bytecode_magic == MAGIC and bytecode_mtime >= source_mtime:
# It's a cache hit. Load the byte-compiled version. # It's a cache hit. Load the byte-compiled version.
if PY3: if PY3:
# As of Python 3.6, imp.load_compiled still exists, but it's # As of Python 3.6, imp.load_compiled still exists, but it's