[Python-checkins] cpython (3.2): Issue #1285086: Get rid of the refcounting hack and speed up

Thu Mar 14 20:43:30 CET 2013

http://hg.python.org/cpython/rev/3cb07925fcb9
changeset: 82659:3cb07925fcb9
branch: 3.2
parent: 82654:9b45873e5a68
user: Serhiy Storchaka <storchaka at gmail.com>
date: Thu Mar 14 21:31:37 2013 +0200
summary:
 Issue #1285086: Get rid of the refcounting hack and speed up
urllib.parse.unquote() and urllib.parse.unquote_to_bytes().
files:
 Lib/urllib/parse.py | 63 ++++++++++++++------------------
 Misc/NEWS | 3 +
 2 files changed, 30 insertions(+), 36 deletions(-)

diff --git a/Lib/urllib/parse.py b/Lib/urllib/parse.py
--- a/Lib/urllib/parse.py
+++ b/Lib/urllib/parse.py
@@ -27,6 +27,7 @@
 test_urlparse.py provides a good indicator of parsing behavior.
 """
 
+import re
 import sys
 import collections
 
@@ -470,6 +471,10 @@
 defrag = url
 return _coerce_result(DefragResult(defrag, frag))
 
+_hexdig = '0123456789ABCDEFabcdef'
+_hextobyte = {(a + b).encode(): bytes([int(a + b, 16)])
+ for a in _hexdig for b in _hexdig}
+
 def unquote_to_bytes(string):
 """unquote_to_bytes('abc%20def') -> b'abc def'."""
 # Note: strings are encoded as UTF-8. This is only an issue if it contains
@@ -480,16 +485,21 @@
 return b''
 if isinstance(string, str):
 string = string.encode('utf-8')
- res = string.split(b'%')
- if len(res) == 1:
+ bits = string.split(b'%')
+ if len(bits) == 1:
 return string
- string = res[0]
- for item in res[1:]:
+ res = [bits[0]]
+ append = res.append
+ for item in bits[1:]:
 try:
- string += bytes([int(item[:2], 16)]) + item[2:]
- except ValueError:
- string += b'%' + item
- return string
+ append(_hextobyte[item[:2]])
+ append(item[2:])
+ except KeyError:
+ append(b'%')
+ append(item)
+ return b''.join(res)
+
+_asciire = re.compile('([\x00-\x7f]+)')
 
 def unquote(string, encoding='utf-8', errors='replace'):
 """Replace %xx escapes by their single-character equivalent. The optional
@@ -501,39 +511,20 @@
 
 unquote('abc%20def') -> 'abc def'.
 """
- if string == '':
- return string
- res = string.split('%')
- if len(res) == 1:
+ if '%' not in string:
+ string.split
 return string
 if encoding is None:
 encoding = 'utf-8'
 if errors is None:
 errors = 'replace'
- # pct_sequence: contiguous sequence of percent-encoded bytes, decoded
- pct_sequence = b''
- string = res[0]
- for item in res[1:]:
- try:
- if not item:
- raise ValueError
- pct_sequence += bytes.fromhex(item[:2])
- rest = item[2:]
- if not rest:
- # This segment was just a single percent-encoded character.
- # May be part of a sequence of code units, so delay decoding.
- # (Stored in pct_sequence).
- continue
- except ValueError:
- rest = '%' + item
- # Encountered non-percent-encoded characters. Flush the current
- # pct_sequence.
- string += pct_sequence.decode(encoding, errors) + rest
- pct_sequence = b''
- if pct_sequence:
- # Flush the final pct_sequence
- string += pct_sequence.decode(encoding, errors)
- return string
+ bits = _asciire.split(string)
+ res = [bits[0]]
+ append = res.append
+ for i in range(1, len(bits), 2):
+ append(unquote_to_bytes(bits[i]).decode(encoding, errors))
+ append(bits[i + 1])
+ return ''.join(res)
 
 def parse_qs(qs, keep_blank_values=False, strict_parsing=False,
 encoding='utf-8', errors='replace'):
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -233,6 +233,9 @@
 Library
 -------
 
+- Issue #1285086: Get rid of the refcounting hack and speed up
+ urllib.parse.unquote() and urllib.parse.unquote_to_bytes().
+
 - Issue #17368: Fix an off-by-one error in the Python JSON decoder that caused
 a failure while decoding empty object literals when object_pairs_hook was
 specified.
-- 
Repository URL: http://hg.python.org/cpython
