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-rw-r--r--xpcom/ds/tools/perfecthash.py31
1 files changed, 10 insertions, 21 deletions
diff --git a/xpcom/ds/tools/perfecthash.py b/xpcom/ds/tools/perfecthash.py
index 929b643a30..2a5778e86d 100644
--- a/xpcom/ds/tools/perfecthash.py
+++ b/xpcom/ds/tools/perfecthash.py
@@ -24,18 +24,6 @@ small dataset it was designed for. In the future we may want to optimize further
import textwrap
from collections import namedtuple
-import six
-from mozbuild.util import ensure_bytes
-
-
-# Iteration over bytestrings works differently in Python 2 and 3; this function
-# captures the two possibilities. Returns an 'int' given the output of iterating
-# through a bytestring regardless of the input.
-def _ord(c):
- if six.PY3:
- return c
- return ord(c)
-
class PerfectHash(object):
"""PerfectHash objects represent a computed perfect hash function, which
@@ -88,7 +76,7 @@ class PerfectHash(object):
for bucket in buckets:
# Once we've reached an empty bucket, we're done.
- if len(bucket.entries) == 0:
+ if not bucket.entries:
break
# Try values for the basis until we find one with no conflicts.
@@ -103,7 +91,7 @@ class PerfectHash(object):
# There was a conflict, try the next basis.
basis += 1
idx = 0
- del slots[:]
+ slots.clear()
assert basis < self.U32_MAX, "table too small"
else:
slots.append(slot)
@@ -127,15 +115,16 @@ class PerfectHash(object):
32-bit FNV is used for indexing into the first table, and the value
stored in that table is used as the offset basis for indexing into the
values table."""
- for byte in memoryview(ensure_bytes(key)):
- obyte = _ord(byte)
+ FNV_PRIME = cls.FNV_PRIME
+ U32_MAX = cls.U32_MAX
+ for obyte in memoryview(key):
basis ^= obyte # xor-in the byte
- basis *= cls.FNV_PRIME # Multiply by the FNV prime
- basis &= cls.U32_MAX # clamp to 32-bits
+ basis *= FNV_PRIME # Multiply by the FNV prime
+ basis &= U32_MAX # clamp to 32-bits
return basis
def key(self, entry):
- return memoryview(ensure_bytes(self._key(entry)))
+ return memoryview(self._key(entry))
def get_raw_index(self, key):
"""Determine the index in self.entries without validating"""
@@ -145,7 +134,7 @@ class PerfectHash(object):
def get_index(self, key):
"""Given a key, determine the index in self.entries"""
idx = self.get_raw_index(key)
- if memoryview(ensure_bytes(key)) != self.key(self.entries[idx]):
+ if memoryview(key) != self.key(self.entries[idx]):
return None
return idx
@@ -334,7 +323,7 @@ class CGHelper(object):
not in the table."""
assert all(
- _ord(b) <= 0x7F for e in self.phf.entries for b in self.phf.key(e)
+ b <= 0x7F for e in self.phf.entries for b in self.phf.key(e)
), "non-ASCII key"
if return_type is None: