Author: Antonio Cuni <[email protected]>
Branch: fastjson
Changeset: r65089:55ed11b7b3be
Date: 2013-06-29 11:37 +0200
http://bitbucket.org/pypy/pypy/changeset/55ed11b7b3be/
Log: add an option to enable fast but less precise parsing of floats
diff --git a/pypy/module/_fastjson/interp_decoder.py
b/pypy/module/_fastjson/interp_decoder.py
--- a/pypy/module/_fastjson/interp_decoder.py
+++ b/pypy/module/_fastjson/interp_decoder.py
@@ -48,7 +48,7 @@
TYPE_UNKNOWN = 0
TYPE_STRING = 1
class JSONDecoder(object):
- def __init__(self, space, s):
+ def __init__(self, space, s, precise_float=True):
self.space = space
self.s = s
# we put our string in a raw buffer so:
@@ -59,6 +59,7 @@
self.end_ptr = lltype.malloc(rffi.CCHARPP.TO, 1, flavor='raw')
self.pos = 0
self.last_type = TYPE_UNKNOWN
+ self.precise_float = precise_float
def close(self):
rffi.free_charp(self.ll_chars)
@@ -144,9 +145,9 @@
if ch == '.':
if not self.ll_chars[i+1].isdigit():
self._raise("Expected digit at char %d", i+1)
- return self.parse_float(start)
+ return self.parse_float(start, i, intval, ovf_maybe)
elif ch == 'e' or ch == 'E':
- return self.parse_float(start)
+ return self.parse_float(start, i, intval, ovf_maybe)
elif ovf_maybe:
# apparently we get a ~30% slowdown on my microbenchmark if we
# return None instead of w_None, probably because the annotation
@@ -157,30 +158,12 @@
self.pos = i
return self.space.wrap(intval)
- ## if ch == '.':
- ## is_float = True
- ## i, frcval, frccount = self.parse_digits(i+1)
- ## frcval = neg_pow_10(frcval, frccount)
- ## ch = self.ll_chars[i]
- ## # check for the optional exponent part
- ## if ch == 'E' or ch == 'e':
- ## is_float = True
- ## i, ovf_maybe, exp = self.parse_integer(i+1,
allow_leading_0=True)
- ## #
- ## self.pos = i
- ## if is_float:
- ## # build the float
- ## floatval = intval + frcval
- ## if exp != 0:
- ## try:
- ## floatval = floatval * math.pow(10, exp)
- ## except OverflowError:
- ## floatval = rfloat.INFINITY
- ## return self.space.wrap(floatval)
- ## else:
- ## return self.space.wrap(intval)
+ def parse_float(self, start, i, intval, ovf_maybe):
+ if self.precise_float or ovf_maybe:
+ return self.parse_float_precise(start)
+ return self.parse_float_fast(i, intval)
- def parse_float(self, i):
+ def parse_float_precise(self, i):
from rpython.rlib import rdtoa
start = rffi.ptradd(self.ll_chars, i)
floatval = rdtoa.dg_strtod(start, self.end_ptr)
@@ -188,6 +171,27 @@
self.pos = i + diff
return self.space.wrap(floatval)
+ def parse_float_fast(self, i, intval):
+ exp = 0
+ frcval = 0
+ ch = self.ll_chars[i]
+ if ch == '.':
+ i, frcval, frccount = self.parse_digits(i+1)
+ frcval = neg_pow_10(frcval, frccount)
+ ch = self.ll_chars[i]
+ # check for the optional exponent part
+ if ch == 'E' or ch == 'e':
+ i, ovf_maybe, exp = self.parse_integer(i+1, allow_leading_0=True)
+ #
+ floatval = float(intval) + frcval
+ if exp != 0:
+ try:
+ floatval = floatval * math.pow(10, exp)
+ except OverflowError:
+ floatval = rfloat.INFINITY
+ self.pos = i
+ return self.space.wrap(floatval)
+
def decode_numeric_slow(self, i):
is_float = False
start = i
@@ -422,13 +426,13 @@
lowsurr = int(hexdigits, 16) # the possible ValueError is caugth by
the caller
return 0x10000 + (((highsurr - 0xd800) << 10) | (lowsurr - 0xdc00))
-
-def loads(space, w_s):
+@unwrap_spec(precise_float=bool)
+def loads(space, w_s, precise_float=True):
if space.isinstance_w(w_s, space.w_unicode):
raise OperationError(space.w_TypeError,
space.wrap("Expected utf8-encoded str, got
unicode"))
s = space.str_w(w_s)
- decoder = JSONDecoder(space, s)
+ decoder = JSONDecoder(space, s, precise_float)
try:
w_res = decoder.decode_any(0)
i = decoder.skip_whitespace(decoder.pos)
diff --git a/pypy/module/_fastjson/test/test__fastjson.py
b/pypy/module/_fastjson/test/test__fastjson.py
--- a/pypy/module/_fastjson/test/test__fastjson.py
+++ b/pypy/module/_fastjson/test/test__fastjson.py
@@ -105,6 +105,10 @@
res = _fastjson.loads(s)
assert type(res) is type(val)
assert res == val
+ #
+ res = _fastjson.loads(s, precise_float=False)
+ assert type(res) is type(val)
+ assert res == val
#
check('42', 42)
check('-42', -42)
@@ -135,6 +139,7 @@
import _fastjson
def error(s):
raises(ValueError, _fastjson.loads, s)
+ raises(ValueError, _fastjson.loads, s, False)
#
error(' 42 abc')
error('.123')
_______________________________________________
pypy-commit mailing list
[email protected]
http://mail.python.org/mailman/listinfo/pypy-commit
