Commit b19c80cc by Will Daly

Merge pull request #1957 from edx/fix/will/bug_392

Added unit tests for safe_key() to resolve bug 392.
parents fb4685fe aaa383b8
...@@ -8,15 +8,42 @@ import urllib ...@@ -8,15 +8,42 @@ import urllib
def fasthash(string): def fasthash(string):
m = hashlib.new("md4") """
m.update(string) Hashes `string` into a string representation of a 128-bit digest.
return m.hexdigest() """
md4 = hashlib.new("md4")
md4.update(string)
return md4.hexdigest()
def cleaned_string(val):
"""
Converts `val` to unicode and URL-encodes special characters
(including quotes and spaces)
"""
return urllib.quote_plus(smart_str(val))
def safe_key(key, key_prefix, version): def safe_key(key, key_prefix, version):
safe_key = urllib.quote_plus(smart_str(key)) """
Given a `key`, `key_prefix`, and `version`,
return a key that is safe to use with memcache.
`key`, `key_prefix`, and `version` can be numbers, strings, or unicode.
"""
# Clean for whitespace and control characters, which
# cause memcache to raise an exception
key = cleaned_string(key)
key_prefix = cleaned_string(key_prefix)
version = cleaned_string(version)
# Attempt to combine the prefix, version, and key
combined = ":".join([key_prefix, version, key])
if len(safe_key) > 250: # If the total length is too long for memcache, hash it
safe_key = fasthash(safe_key) if len(combined) > 250:
combined = fasthash(combined)
return ":".join([key_prefix, str(version), safe_key]) # Return the result
return combined
"""
Tests for memcache in util app
"""
from django.test import TestCase
from django.core.cache import get_cache
from django.conf import settings
from util.memcache import safe_key
class MemcacheTest(TestCase):
"""
Test memcache key cleanup
"""
# Test whitespace, control characters, and some non-ASCII UTF-16
UNICODE_CHAR_CODES = ([c for c in range(0, 30)] + [127] +
[129, 500, 2 ** 8 - 1, 2 ** 8 + 1, 2 ** 16 - 1])
def setUp(self):
self.cache = get_cache('default')
def test_safe_key(self):
key = safe_key('test', 'prefix', 'version')
self.assertEqual(key, 'prefix:version:test')
def test_numeric_inputs(self):
# Numeric key
self.assertEqual(safe_key(1, 'prefix', 'version'), 'prefix:version:1')
# Numeric prefix
self.assertEqual(safe_key('test', 5, 'version'), '5:version:test')
# Numeric version
self.assertEqual(safe_key('test', 'prefix', 5), 'prefix:5:test')
def test_safe_key_long(self):
# Choose lengths close to memcached's cutoff (250)
for length in [248, 249, 250, 251, 252]:
# Generate a key of that length
key = 'a' * length
# Make the key safe
key = safe_key(key, '', '')
# The key should now be valid
self.assertTrue(self._is_valid_key(key),
msg="Failed for key length {0}".format(length))
def test_long_key_prefix_version(self):
# Long key
key = safe_key('a' * 300, 'prefix', 'version')
self.assertTrue(self._is_valid_key(key))
# Long prefix
key = safe_key('key', 'a' * 300, 'version')
self.assertTrue(self._is_valid_key(key))
# Long version
key = safe_key('key', 'prefix', 'a' * 300)
self.assertTrue(self._is_valid_key(key))
def test_safe_key_unicode(self):
for unicode_char in self.UNICODE_CHAR_CODES:
# Generate a key with that character
key = unichr(unicode_char)
# Make the key safe
key = safe_key(key, '', '')
# The key should now be valid
self.assertTrue(self._is_valid_key(key),
msg="Failed for unicode character {0}".format(unicode_char))
def test_safe_key_prefix_unicode(self):
for unicode_char in self.UNICODE_CHAR_CODES:
# Generate a prefix with that character
prefix = unichr(unicode_char)
# Make the key safe
key = safe_key('test', prefix, '')
# The key should now be valid
self.assertTrue(self._is_valid_key(key),
msg="Failed for unicode character {0}".format(unicode_char))
def test_safe_key_version_unicode(self):
for unicode_char in self.UNICODE_CHAR_CODES:
# Generate a version with that character
version = unichr(unicode_char)
# Make the key safe
key = safe_key('test', '', version)
# The key should now be valid
self.assertTrue(self._is_valid_key(key),
msg="Failed for unicode character {0}".format(unicode_char))
def _is_valid_key(self, key):
"""
Test that a key is memcache-compatible.
Based on Django's validator in core.cache.backends.base
"""
# Check the length
if len(key) > 250:
return False
# Check that there are no spaces or control characters
for char in key:
if ord(char) < 33 or ord(char) == 127:
return False
return True
"""Tests for the util package""" """Tests for the Zendesk"""
from django.conf import settings from django.conf import settings
from django.contrib.auth.models import AnonymousUser from django.contrib.auth.models import AnonymousUser
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment