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Jython is an implementation of the high-level, dynamic, object-oriented
language Python written in 100% Pure Java, and seamlessly integrated with
the Java platform. It thus allows you to run Python on any Java platform.
""" Standard "encodings" Package
Standard Python encoding modules are stored in this package
directory.
Codec modules must have names corresponding to normalized encoding
names as defined in the normalize_encoding() function below, e.g.
'utf-8' must be implemented by the module 'utf_8.py'.
Each codec module must export the following interface:
* getregentry() -> codecs.CodecInfo object
The getregentry() API must a CodecInfo object with encoder, decoder,
incrementalencoder, incrementaldecoder, streamwriter and streamreader
atttributes which adhere to the Python Codec Interface Standard.
In addition, a module may optionally also define the following
APIs which are then used by the package's codec search function:
* getaliases() -> sequence of encoding name strings to use as aliases
Alias names returned by getaliases() must be normalized encoding
names as defined by normalize_encoding().
Written by Marc-Andre Lemburg ([email protected]).
(c) Copyright CNRI, All Rights Reserved. NO WARRANTY.
"""#"
import codecs
from encodings import aliases, _java
import __builtin__
_cache = {}
_unknown = '--unknown--'
_import_tail = ['*']
_norm_encoding_map = (' . '
'0123456789 ABCDEFGHIJKLMNOPQRSTUVWXYZ '
' abcdefghijklmnopqrstuvwxyz '
' '
' '
' ')
_aliases = aliases.aliases
class CodecRegistryError(LookupError, SystemError):
pass
def normalize_encoding(encoding):
""" Normalize an encoding name.
Normalization works as follows: all non-alphanumeric
characters except the dot used for Python package names are
collapsed and replaced with a single underscore, e.g. ' -;#'
becomes '_'. Leading and trailing underscores are removed.
Note that encoding names should be ASCII only; if they do use
non-ASCII characters, these must be Latin-1 compatible.
"""
# Make sure we have an 8-bit string, because .translate() works
# differently for Unicode strings.
if hasattr(__builtin__, "unicode") and isinstance(encoding, unicode):
# Note that .encode('latin-1') does *not* use the codec
# registry, so this call doesn't recurse. (See unicodeobject.c
# PyUnicode_AsEncodedString() for details)
encoding = encoding.encode('latin-1')
return '_'.join(encoding.translate(_norm_encoding_map).split())
def search_function(encoding):
# Cache lookup
entry = _cache.get(encoding, _unknown)
if entry is not _unknown:
return entry
# Import the module:
#
# First try to find an alias for the normalized encoding
# name and lookup the module using the aliased name, then try to
# lookup the module using the standard import scheme, i.e. first
# try in the encodings package, then at top-level.
#
norm_encoding = normalize_encoding(encoding)
aliased_encoding = _aliases.get(norm_encoding) or \
_aliases.get(norm_encoding.replace('.', '_'))
if aliased_encoding is not None:
modnames = [aliased_encoding,
norm_encoding]
else:
modnames = [norm_encoding]
for modname in modnames:
if not modname or '.' in modname:
continue
try:
# Import is absolute to prevent the possibly malicious import of a
# module with side-effects that is not in the 'encodings' package.
mod = __import__('encodings.' + modname, fromlist=_import_tail,
level=0)
except ImportError:
pass
else:
break
else:
mod = None
try:
getregentry = mod.getregentry
except AttributeError:
# Not a codec module
mod = None
if mod is None:
# First, see if we can load the encoding using java.nio.Charset;
# FIXME this could include encodings not known to Python, so we should test that out as well
entry, codecaliases = _java._java_factory(encoding)
if entry is not None:
_cache[encoding] = entry
for alias in codecaliases:
if alias not in _aliases:
_aliases[alias] = modname
return entry
# Cache misses
_cache[encoding] = None
return None
# Now ask the module for the registry entry
entry = getregentry()
if not isinstance(entry, codecs.CodecInfo):
if not 4 <= len(entry) <= 7:
raise CodecRegistryError,\
'module "%s" (%s) failed to register' % \
(mod.__name__, mod.__file__)
if not hasattr(entry[0], '__call__') or \
not hasattr(entry[1], '__call__') or \
(entry[2] is not None and not hasattr(entry[2], '__call__')) or \
(entry[3] is not None and not hasattr(entry[3], '__call__')) or \
(len(entry) > 4 and entry[4] is not None and not hasattr(entry[4], '__call__')) or \
(len(entry) > 5 and entry[5] is not None and not hasattr(entry[5], '__call__')):
raise CodecRegistryError,\
'incompatible codecs in module "%s" (%s)' % \
(mod.__name__, mod.__file__)
if len(entry)<7 or entry[6] is None:
entry += (None,)*(6-len(entry)) + (mod.__name__.split(".", 1)[1],)
entry = codecs.CodecInfo(*entry)
# Cache the codec registry entry
_cache[encoding] = entry
# Register its aliases (without overwriting previously registered
# aliases)
try:
codecaliases = mod.getaliases()
except AttributeError:
pass
else:
for alias in codecaliases:
if alias not in _aliases:
_aliases[alias] = modname
# Return the registry entry
return entry
# Register the search_function in the Python codec registry
codecs.register(search_function)