# HG changeset patch
# User emellor@ewan
# Node ID 59440a003278185ad0846ac571da107a0c141b4c
# Parent f15892b95965e1f7f2f636734c743c5919554cd7
Remove code seeding RNG from /dev/urandom. The random module's default RNG is
already seeded from the clock, so this is unnecessary, non-portable, and
expensive. This should improve start-up time of Xend. Replace twisty maze of
code with something sensible.
Signed-off-by: Ewan Mellor <ewan@xxxxxxxxxxxxx>
diff -r f15892b95965 -r 59440a003278 tools/python/xen/xend/uuid.py
--- a/tools/python/xen/xend/uuid.py Sun Oct 9 10:53:34 2005
+++ b/tools/python/xen/xend/uuid.py Sun Oct 9 10:57:24 2005
@@ -13,14 +13,19 @@
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#============================================================================
# Copyright (C) 2005 Mike Wray <mike.wray@xxxxxx>
+# Copyright (C) 2005 XenSource Ltd
#============================================================================
+
"""Universal(ly) Unique Identifiers (UUIDs).
"""
+
+
import commands
import random
-def uuidgen(random=True):
+
+def getUuidUuidgen(random = True):
"""Generate a UUID using the command uuidgen.
If random is true (default) generates a random uuid.
@@ -33,50 +38,21 @@
cmd += " -t"
return commands.getoutput(cmd)
-class UuidFactoryUuidgen:
- """A uuid factory using uuidgen."""
+def getUuidRandom():
+ """Generate a random UUID."""
+
+ bytes = [ random.randint(0, 255) for i in range(0, 16) ]
+ # Encode the variant.
+ bytes[6] = (bytes[6] & 0x0f) | 0x40
+ bytes[8] = (bytes[8] & 0x3f) | 0x80
+ f = "%02x"
+ return ( "-".join([f*4, f*2, f*2, f*2, f*6]) % tuple(bytes) )
- def __init__(self):
- pass
- def getUuid(self):
- return uuidgen()
+#uuidFactory = getUuidUuidgen
+uuidFactory = getUuidRandom
-class UuidFactoryRandom:
-
- """A random uuid factory."""
-
- def __init__(self):
- f = file("/dev/urandom", "r")
- seed = f.read(16)
- f.close()
- self.rand = random.Random(seed)
-
- def randBytes(self, n):
- return [ self.rand.randint(0, 255) for i in range(0, n) ]
-
- def getUuid(self):
- bytes = self.randBytes(16)
- # Encode the variant.
- bytes[6] = (bytes[6] & 0x0f) | 0x40
- bytes[8] = (bytes[8] & 0x3f) | 0x80
- f = "%02x"
- return ( "-".join([f*4, f*2, f*2, f*2, f*6]) % tuple(bytes) )
-
-def getFactory():
- """Get the factory to use for creating uuids.
- This is so it's easy to change the uuid factory.
- For example, for testing we might want repeatable uuids
- rather than the random ones we normally use.
- """
- global uuidFactory
- try:
- uuidFactory
- except:
- #uuidFactory = UuidFactoryUuidgen()
- uuidFactory = UuidFactoryRandom()
- return uuidFactory
def getUuid():
- return getFactory().getUuid()
+ return uuidFactory()
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