diff options
Diffstat (limited to 'Lib/pickletools.py')
| -rw-r--r-- | Lib/pickletools.py | 31 |
1 files changed, 28 insertions, 3 deletions
diff --git a/Lib/pickletools.py b/Lib/pickletools.py index 0665cd0..1b6967a 100644 --- a/Lib/pickletools.py +++ b/Lib/pickletools.py @@ -14,9 +14,7 @@ import codecs import pickle import re -__all__ = ['dis', - 'genops', - ] +__all__ = ['dis', 'genops', 'optimize'] bytes_types = pickle.bytes_types @@ -1836,6 +1834,33 @@ def genops(pickle): break ############################################################################## +# A pickle optimizer. + +def optimize(p): + 'Optimize a pickle string by removing unused PUT opcodes' + gets = set() # set of args used by a GET opcode + puts = [] # (arg, startpos, stoppos) for the PUT opcodes + prevpos = None # set to pos if previous opcode was a PUT + for opcode, arg, pos in genops(p): + if prevpos is not None: + puts.append((prevarg, prevpos, pos)) + prevpos = None + if 'PUT' in opcode.name: + prevarg, prevpos = arg, pos + elif 'GET' in opcode.name: + gets.add(arg) + + # Copy the pickle string except for PUTS without a corresponding GET + s = [] + i = 0 + for arg, start, stop in puts: + j = stop if (arg in gets) else start + s.append(p[i:j]) + i = stop + s.append(p[i:]) + return ''.join(s) + +############################################################################## # A symbolic pickle disassembler. def dis(pickle, out=None, memo=None, indentlevel=4): |