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Got rid of mdumps; I timed it, and struct.pack("<i", x) is more than 

40% faster than marshal.dumps(x)[1:]!  (That's not counting the
module attribute lookups, which can be avoided in either case.)
This commit is contained in:
Guido van Rossum 2003-01-28 03:03:08 +00:00
parent f558da0f90
commit 5c938d00a1
1 changed files with 26 additions and 30 deletions
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56
Lib/pickle.py
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@ -45,7 +45,6 @@ compatible_formats = ["1.0", # Original protocol 0
"2.0", # Protocol 2
] # Old format versions we can read
mdumps = marshal.dumps
mloads = marshal.loads
class PickleError(Exception):
@ -220,25 +219,22 @@ class Pickler:
self.memo[id(obj)] = memo_len, obj
# Return a PUT (BINPUT, LONG_BINPUT) opcode string, with argument i.
def put(self, i):
def put(self, i, pack=struct.pack):
if self.bin:
s = mdumps(i)[1:]
if i < 256:
return BINPUT + s[0]
return LONG_BINPUT + s
return BINPUT + chr(i)
else:
return LONG_BINPUT + pack("<i", i)
return PUT + `i` + '\n'
# Return a GET (BINGET, LONG_BINGET) opcode string, with argument i.
def get(self, i):
def get(self, i, pack=struct.pack):
if self.bin:
s = mdumps(i)[1:]
if i < 256:
return BINGET + s[0]
return LONG_BINGET + s
return BINGET + chr(i)
else:
return LONG_BINGET + pack("<i", i)
return GET + `i` + '\n'
@ -362,24 +358,25 @@ class Pickler:
self.write(object and TRUE or FALSE)
dispatch[bool] = save_bool
def save_int(self, object):
def save_int(self, object, pack=struct.pack):
if self.bin:
# If the int is small enough to fit in a signed 4-byte 2's-comp
# format, we can store it more efficiently than the general
# case.
# First one- and two-byte unsigned ints:
if object >= 0:
if object < 0xff:
self.write(BININT1 + chr(object))
return
if object < 0xffff:
self.write(BININT2 + chr(object&0xff) + chr(object>>8))
return
# Next check for 4-byte signed ints:
high_bits = object >> 31 # note that Python shift sign-extends
if high_bits == 0 or high_bits == -1:
# All high bits are copies of bit 2**31, so the value
# fits in a 4-byte signed int.
i = mdumps(object)[1:]
assert len(i) == 4
if i[-2:] == '\000\000': # fits in 2-byte unsigned int
if i[-3] == '\000': # fits in 1-byte unsigned int
self.write(BININT1 + i[0])
else:
self.write(BININT2 + i[:2])
else:
self.write(BININT + i)
self.write(BININT + pack("<i", object))
return
# Text pickle, or int too big to fit in signed 4-byte format.
self.write(INT + `object` + '\n')
@ -396,24 +393,23 @@ class Pickler:
self.write(FLOAT + `object` + '\n')
dispatch[FloatType] = save_float
def save_string(self, object):
def save_string(self, object, pack=struct.pack):
if self.bin:
n = len(object)
if n < 256:
self.write(SHORT_BINSTRING + chr(n) + object)
else:
self.write(BINSTRING + mdumps(n)[1:] + object)
self.write(BINSTRING + pack("<i", n) + object)
else:
self.write(STRING + `object` + '\n')
self.memoize(object)
dispatch[StringType] = save_string
def save_unicode(self, object):
def save_unicode(self, object, pack=struct.pack):
if self.bin:
encoding = object.encode('utf-8')
n = len(encoding)
s = mdumps(n)[1:]
self.write(BINUNICODE + s + encoding)
self.write(BINUNICODE + pack("<i", n) + encoding)
else:
object = object.replace("\\", "\\u005c")
object = object.replace("\n", "\\u000a")
@ -423,17 +419,17 @@ class Pickler:
if StringType == UnicodeType:
# This is true for Jython
def save_string(self, object):
def save_string(self, object, pack=struct.pack):
unicode = object.isunicode()
if self.bin:
if unicode:
object = object.encode("utf-8")
l = len(object)
s = mdumps(l)[1:]
if l < 256 and not unicode:
self.write(SHORT_BINSTRING + s[0] + object)
self.write(SHORT_BINSTRING + chr(l) + object)
else:
s = pack("<i", l)
if unicode:
self.write(BINUNICODE + s + object)
else: