[Python-checkins] r74479 - python/trunk/Lib/hashlib.py
gregory.p.smith
python-checkins at python.org
Sun Aug 16 23:54:45 CEST 2009
Author: gregory.p.smith
Date: Sun Aug 16 23:54:45 2009
New Revision: 74479
Log:
Clean up the C library import code (based on suggestions in issue6281).
Modified:
python/trunk/Lib/hashlib.py
Modified: python/trunk/Lib/hashlib.py
==============================================================================
--- python/trunk/Lib/hashlib.py (original)
+++ python/trunk/Lib/hashlib.py Sun Aug 16 23:54:45 2009
@@ -54,6 +54,12 @@
"""
+# This tuple and __get_builtin_constructor() must be modified if a new
+# always available algorithm is added.
+__always_supported = ('md5', 'sha1', 'sha224', 'sha256', 'sha384', 'sha512')
+
+__all__ = __always_supported + ('new',)
+
def __get_builtin_constructor(name):
if name in ('SHA1', 'sha1'):
@@ -77,7 +83,19 @@
elif bs == '384':
return _sha512.sha384
- raise ValueError, "unsupported hash type"
+ raise ValueError('unsupported hash type %s' % name)
+
+
+def __get_openssl_constructor(name):
+ try:
+ f = getattr(_hashlib, 'openssl_' + name)
+ # Allow the C module to raise ValueError. The function will be
+ # defined but the hash not actually available thanks to OpenSSL.
+ f()
+ # Use the C function directly (very fast)
+ return f
+ except (AttributeError, ValueError):
+ return __get_builtin_constructor(name)
def __py_new(name, string=''):
@@ -103,39 +121,21 @@
try:
import _hashlib
- # use the wrapper of the C implementation
new = __hash_new
-
- for opensslFuncName in filter(lambda n: n.startswith('openssl_'), dir(_hashlib)):
- funcName = opensslFuncName[len('openssl_'):]
- try:
- # try them all, some may not work due to the OpenSSL
- # version not supporting that algorithm.
- f = getattr(_hashlib, opensslFuncName)
- f()
- # Use the C function directly (very fast)
- exec funcName + ' = f'
- except ValueError:
- try:
- # Use the builtin implementation directly (fast)
- exec funcName + ' = __get_builtin_constructor(funcName)'
- except ValueError:
- # this one has no builtin implementation, don't define it
- pass
- # clean up our locals
- del f
- del opensslFuncName
- del funcName
-
+ __get_hash = __get_openssl_constructor
except ImportError:
- # We don't have the _hashlib OpenSSL module?
- # use the built in legacy interfaces via a wrapper function
new = __py_new
+ __get_hash = __get_builtin_constructor
+
+for __func_name in __always_supported:
+ # try them all, some may not work due to the OpenSSL
+ # version not supporting that algorithm.
+ try:
+ globals()[__func_name] = __get_hash(__func_name)
+ except ValueError:
+ import logging
+ logging.exception('code for hash %s was not found.', __func_name)
- # lookup the C function to use directly for the named constructors
- md5 = __get_builtin_constructor('md5')
- sha1 = __get_builtin_constructor('sha1')
- sha224 = __get_builtin_constructor('sha224')
- sha256 = __get_builtin_constructor('sha256')
- sha384 = __get_builtin_constructor('sha384')
- sha512 = __get_builtin_constructor('sha512')
+# Cleanup locals()
+del __always_supported, __func_name, __get_hash
+del __py_new, __hash_new, __get_openssl_constructor
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