diff options
| author | AlexSm <alex@ydb.tech> | 2024-03-05 10:40:59 +0100 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2024-03-05 12:40:59 +0300 |
| commit | 1ac13c847b5358faba44dbb638a828e24369467b (patch) | |
| tree | 07672b4dd3604ad3dee540a02c6494cb7d10dc3d /contrib/tools/python3/Lib/pickletools.py | |
| parent | ffcca3e7f7958ddc6487b91d3df8c01054bd0638 (diff) | |
| download | ydb-1ac13c847b5358faba44dbb638a828e24369467b.tar.gz | |
Library import 16 (#2433)
Co-authored-by: robot-piglet <robot-piglet@yandex-team.com>
Co-authored-by: deshevoy <deshevoy@yandex-team.com>
Co-authored-by: robot-contrib <robot-contrib@yandex-team.com>
Co-authored-by: thegeorg <thegeorg@yandex-team.com>
Co-authored-by: robot-ya-builder <robot-ya-builder@yandex-team.com>
Co-authored-by: svidyuk <svidyuk@yandex-team.com>
Co-authored-by: shadchin <shadchin@yandex-team.com>
Co-authored-by: robot-ratatosk <robot-ratatosk@yandex-team.com>
Co-authored-by: innokentii <innokentii@yandex-team.com>
Co-authored-by: arkady-e1ppa <arkady-e1ppa@yandex-team.com>
Co-authored-by: snermolaev <snermolaev@yandex-team.com>
Co-authored-by: dimdim11 <dimdim11@yandex-team.com>
Co-authored-by: kickbutt <kickbutt@yandex-team.com>
Co-authored-by: abdullinsaid <abdullinsaid@yandex-team.com>
Co-authored-by: korsunandrei <korsunandrei@yandex-team.com>
Co-authored-by: petrk <petrk@yandex-team.com>
Co-authored-by: miroslav2 <miroslav2@yandex-team.com>
Co-authored-by: serjflint <serjflint@yandex-team.com>
Co-authored-by: akhropov <akhropov@yandex-team.com>
Co-authored-by: prettyboy <prettyboy@yandex-team.com>
Co-authored-by: ilikepugs <ilikepugs@yandex-team.com>
Co-authored-by: hiddenpath <hiddenpath@yandex-team.com>
Co-authored-by: mikhnenko <mikhnenko@yandex-team.com>
Co-authored-by: spreis <spreis@yandex-team.com>
Co-authored-by: andreyshspb <andreyshspb@yandex-team.com>
Co-authored-by: dimaandreev <dimaandreev@yandex-team.com>
Co-authored-by: rashid <rashid@yandex-team.com>
Co-authored-by: robot-ydb-importer <robot-ydb-importer@yandex-team.com>
Co-authored-by: r-vetrov <r-vetrov@yandex-team.com>
Co-authored-by: ypodlesov <ypodlesov@yandex-team.com>
Co-authored-by: zaverden <zaverden@yandex-team.com>
Co-authored-by: vpozdyayev <vpozdyayev@yandex-team.com>
Co-authored-by: robot-cozmo <robot-cozmo@yandex-team.com>
Co-authored-by: v-korovin <v-korovin@yandex-team.com>
Co-authored-by: arikon <arikon@yandex-team.com>
Co-authored-by: khoden <khoden@yandex-team.com>
Co-authored-by: psydmm <psydmm@yandex-team.com>
Co-authored-by: robot-javacom <robot-javacom@yandex-team.com>
Co-authored-by: dtorilov <dtorilov@yandex-team.com>
Co-authored-by: sennikovmv <sennikovmv@yandex-team.com>
Co-authored-by: hcpp <hcpp@ydb.tech>
Diffstat (limited to 'contrib/tools/python3/Lib/pickletools.py')
| -rw-r--r-- | contrib/tools/python3/Lib/pickletools.py | 2901 |
1 files changed, 2901 insertions, 0 deletions
diff --git a/contrib/tools/python3/Lib/pickletools.py b/contrib/tools/python3/Lib/pickletools.py new file mode 100644 index 0000000000..95a77aeb2a --- /dev/null +++ b/contrib/tools/python3/Lib/pickletools.py @@ -0,0 +1,2901 @@ +'''"Executable documentation" for the pickle module. + +Extensive comments about the pickle protocols and pickle-machine opcodes +can be found here. Some functions meant for external use: + +genops(pickle) + Generate all the opcodes in a pickle, as (opcode, arg, position) triples. + +dis(pickle, out=None, memo=None, indentlevel=4) + Print a symbolic disassembly of a pickle. +''' + +import codecs +import io +import pickle +import re +import sys + +__all__ = ['dis', 'genops', 'optimize'] + +bytes_types = pickle.bytes_types + +# Other ideas: +# +# - A pickle verifier: read a pickle and check it exhaustively for +# well-formedness. dis() does a lot of this already. +# +# - A protocol identifier: examine a pickle and return its protocol number +# (== the highest .proto attr value among all the opcodes in the pickle). +# dis() already prints this info at the end. +# +# - A pickle optimizer: for example, tuple-building code is sometimes more +# elaborate than necessary, catering for the possibility that the tuple +# is recursive. Or lots of times a PUT is generated that's never accessed +# by a later GET. + + +# "A pickle" is a program for a virtual pickle machine (PM, but more accurately +# called an unpickling machine). It's a sequence of opcodes, interpreted by the +# PM, building an arbitrarily complex Python object. +# +# For the most part, the PM is very simple: there are no looping, testing, or +# conditional instructions, no arithmetic and no function calls. Opcodes are +# executed once each, from first to last, until a STOP opcode is reached. +# +# The PM has two data areas, "the stack" and "the memo". +# +# Many opcodes push Python objects onto the stack; e.g., INT pushes a Python +# integer object on the stack, whose value is gotten from a decimal string +# literal immediately following the INT opcode in the pickle bytestream. Other +# opcodes take Python objects off the stack. The result of unpickling is +# whatever object is left on the stack when the final STOP opcode is executed. +# +# The memo is simply an array of objects, or it can be implemented as a dict +# mapping little integers to objects. The memo serves as the PM's "long term +# memory", and the little integers indexing the memo are akin to variable +# names. Some opcodes pop a stack object into the memo at a given index, +# and others push a memo object at a given index onto the stack again. +# +# At heart, that's all the PM has. Subtleties arise for these reasons: +# +# + Object identity. Objects can be arbitrarily complex, and subobjects +# may be shared (for example, the list [a, a] refers to the same object a +# twice). It can be vital that unpickling recreate an isomorphic object +# graph, faithfully reproducing sharing. +# +# + Recursive objects. For example, after "L = []; L.append(L)", L is a +# list, and L[0] is the same list. This is related to the object identity +# point, and some sequences of pickle opcodes are subtle in order to +# get the right result in all cases. +# +# + Things pickle doesn't know everything about. Examples of things pickle +# does know everything about are Python's builtin scalar and container +# types, like ints and tuples. They generally have opcodes dedicated to +# them. For things like module references and instances of user-defined +# classes, pickle's knowledge is limited. Historically, many enhancements +# have been made to the pickle protocol in order to do a better (faster, +# and/or more compact) job on those. +# +# + Backward compatibility and micro-optimization. As explained below, +# pickle opcodes never go away, not even when better ways to do a thing +# get invented. The repertoire of the PM just keeps growing over time. +# For example, protocol 0 had two opcodes for building Python integers (INT +# and LONG), protocol 1 added three more for more-efficient pickling of short +# integers, and protocol 2 added two more for more-efficient pickling of +# long integers (before protocol 2, the only ways to pickle a Python long +# took time quadratic in the number of digits, for both pickling and +# unpickling). "Opcode bloat" isn't so much a subtlety as a source of +# wearying complication. +# +# +# Pickle protocols: +# +# For compatibility, the meaning of a pickle opcode never changes. Instead new +# pickle opcodes get added, and each version's unpickler can handle all the +# pickle opcodes in all protocol versions to date. So old pickles continue to +# be readable forever. The pickler can generally be told to restrict itself to +# the subset of opcodes available under previous protocol versions too, so that +# users can create pickles under the current version readable by older +# versions. However, a pickle does not contain its version number embedded +# within it. If an older unpickler tries to read a pickle using a later +# protocol, the result is most likely an exception due to seeing an unknown (in +# the older unpickler) opcode. +# +# The original pickle used what's now called "protocol 0", and what was called +# "text mode" before Python 2.3. The entire pickle bytestream is made up of +# printable 7-bit ASCII characters, plus the newline character, in protocol 0. +# That's why it was called text mode. Protocol 0 is small and elegant, but +# sometimes painfully inefficient. +# +# The second major set of additions is now called "protocol 1", and was called +# "binary mode" before Python 2.3. This added many opcodes with arguments +# consisting of arbitrary bytes, including NUL bytes and unprintable "high bit" +# bytes. Binary mode pickles can be substantially smaller than equivalent +# text mode pickles, and sometimes faster too; e.g., BININT represents a 4-byte +# int as 4 bytes following the opcode, which is cheaper to unpickle than the +# (perhaps) 11-character decimal string attached to INT. Protocol 1 also added +# a number of opcodes that operate on many stack elements at once (like APPENDS +# and SETITEMS), and "shortcut" opcodes (like EMPTY_DICT and EMPTY_TUPLE). +# +# The third major set of additions came in Python 2.3, and is called "protocol +# 2". This added: +# +# - A better way to pickle instances of new-style classes (NEWOBJ). +# +# - A way for a pickle to identify its protocol (PROTO). +# +# - Time- and space- efficient pickling of long ints (LONG{1,4}). +# +# - Shortcuts for small tuples (TUPLE{1,2,3}}. +# +# - Dedicated opcodes for bools (NEWTRUE, NEWFALSE). +# +# - The "extension registry", a vector of popular objects that can be pushed +# efficiently by index (EXT{1,2,4}). This is akin to the memo and GET, but +# the registry contents are predefined (there's nothing akin to the memo's +# PUT). +# +# Another independent change with Python 2.3 is the abandonment of any +# pretense that it might be safe to load pickles received from untrusted +# parties -- no sufficient security analysis has been done to guarantee +# this and there isn't a use case that warrants the expense of such an +# analysis. +# +# To this end, all tests for __safe_for_unpickling__ or for +# copyreg.safe_constructors are removed from the unpickling code. +# References to these variables in the descriptions below are to be seen +# as describing unpickling in Python 2.2 and before. + + +# Meta-rule: Descriptions are stored in instances of descriptor objects, +# with plain constructors. No meta-language is defined from which +# descriptors could be constructed. If you want, e.g., XML, write a little +# program to generate XML from the objects. + +############################################################################## +# Some pickle opcodes have an argument, following the opcode in the +# bytestream. An argument is of a specific type, described by an instance +# of ArgumentDescriptor. These are not to be confused with arguments taken +# off the stack -- ArgumentDescriptor applies only to arguments embedded in +# the opcode stream, immediately following an opcode. + +# Represents the number of bytes consumed by an argument delimited by the +# next newline character. +UP_TO_NEWLINE = -1 + +# Represents the number of bytes consumed by a two-argument opcode where +# the first argument gives the number of bytes in the second argument. +TAKEN_FROM_ARGUMENT1 = -2 # num bytes is 1-byte unsigned int +TAKEN_FROM_ARGUMENT4 = -3 # num bytes is 4-byte signed little-endian int +TAKEN_FROM_ARGUMENT4U = -4 # num bytes is 4-byte unsigned little-endian int +TAKEN_FROM_ARGUMENT8U = -5 # num bytes is 8-byte unsigned little-endian int + +class ArgumentDescriptor(object): + __slots__ = ( + # name of descriptor record, also a module global name; a string + 'name', + + # length of argument, in bytes; an int; UP_TO_NEWLINE and + # TAKEN_FROM_ARGUMENT{1,4,8} are negative values for variable-length + # cases + 'n', + + # a function taking a file-like object, reading this kind of argument + # from the object at the current position, advancing the current + # position by n bytes, and returning the value of the argument + 'reader', + + # human-readable docs for this arg descriptor; a string + 'doc', + ) + + def __init__(self, name, n, reader, doc): + assert isinstance(name, str) + self.name = name + + assert isinstance(n, int) and (n >= 0 or + n in (UP_TO_NEWLINE, + TAKEN_FROM_ARGUMENT1, + TAKEN_FROM_ARGUMENT4, + TAKEN_FROM_ARGUMENT4U, + TAKEN_FROM_ARGUMENT8U)) + self.n = n + + self.reader = reader + + assert isinstance(doc, str) + self.doc = doc + +from struct import unpack as _unpack + +def read_uint1(f): + r""" + >>> import io + >>> read_uint1(io.BytesIO(b'\xff')) + 255 + """ + + data = f.read(1) + if data: + return data[0] + raise ValueError("not enough data in stream to read uint1") + +uint1 = ArgumentDescriptor( + name='uint1', + n=1, + reader=read_uint1, + doc="One-byte unsigned integer.") + + +def read_uint2(f): + r""" + >>> import io + >>> read_uint2(io.BytesIO(b'\xff\x00')) + 255 + >>> read_uint2(io.BytesIO(b'\xff\xff')) + 65535 + """ + + data = f.read(2) + if len(data) == 2: + return _unpack("<H", data)[0] + raise ValueError("not enough data in stream to read uint2") + +uint2 = ArgumentDescriptor( + name='uint2', + n=2, + reader=read_uint2, + doc="Two-byte unsigned integer, little-endian.") + + +def read_int4(f): + r""" + >>> import io + >>> read_int4(io.BytesIO(b'\xff\x00\x00\x00')) + 255 + >>> read_int4(io.BytesIO(b'\x00\x00\x00\x80')) == -(2**31) + True + """ + + data = f.read(4) + if len(data) == 4: + return _unpack("<i", data)[0] + raise ValueError("not enough data in stream to read int4") + +int4 = ArgumentDescriptor( + name='int4', + n=4, + reader=read_int4, + doc="Four-byte signed integer, little-endian, 2's complement.") + + +def read_uint4(f): + r""" + >>> import io + >>> read_uint4(io.BytesIO(b'\xff\x00\x00\x00')) + 255 + >>> read_uint4(io.BytesIO(b'\x00\x00\x00\x80')) == 2**31 + True + """ + + data = f.read(4) + if len(data) == 4: + return _unpack("<I", data)[0] + raise ValueError("not enough data in stream to read uint4") + +uint4 = ArgumentDescriptor( + name='uint4', + n=4, + reader=read_uint4, + doc="Four-byte unsigned integer, little-endian.") + + +def read_uint8(f): + r""" + >>> import io + >>> read_uint8(io.BytesIO(b'\xff\x00\x00\x00\x00\x00\x00\x00')) + 255 + >>> read_uint8(io.BytesIO(b'\xff' * 8)) == 2**64-1 + True + """ + + data = f.read(8) + if len(data) == 8: + return _unpack("<Q", data)[0] + raise ValueError("not enough data in stream to read uint8") + +uint8 = ArgumentDescriptor( + name='uint8', + n=8, + reader=read_uint8, + doc="Eight-byte unsigned integer, little-endian.") + + +def read_stringnl(f, decode=True, stripquotes=True): + r""" + >>> import io + >>> read_stringnl(io.BytesIO(b"'abcd'\nefg\n")) + 'abcd' + + >>> read_stringnl(io.BytesIO(b"\n")) + Traceback (most recent call last): + ... + ValueError: no string quotes around b'' + + >>> read_stringnl(io.BytesIO(b"\n"), stripquotes=False) + '' + + >>> read_stringnl(io.BytesIO(b"''\n")) + '' + + >>> read_stringnl(io.BytesIO(b'"abcd"')) + Traceback (most recent call last): + ... + ValueError: no newline found when trying to read stringnl + + Embedded escapes are undone in the result. + >>> read_stringnl(io.BytesIO(br"'a\n\\b\x00c\td'" + b"\n'e'")) + 'a\n\\b\x00c\td' + """ + + data = f.readline() + if not data.endswith(b'\n'): + raise ValueError("no newline found when trying to read stringnl") + data = data[:-1] # lose the newline + + if stripquotes: + for q in (b'"', b"'"): + if data.startswith(q): + if not data.endswith(q): + raise ValueError("strinq quote %r not found at both " + "ends of %r" % (q, data)) + data = data[1:-1] + break + else: + raise ValueError("no string quotes around %r" % data) + + if decode: + data = codecs.escape_decode(data)[0].decode("ascii") + return data + +stringnl = ArgumentDescriptor( + name='stringnl', + n=UP_TO_NEWLINE, + reader=read_stringnl, + doc="""A newline-terminated string. + + This is a repr-style string, with embedded escapes, and + bracketing quotes. + """) + +def read_stringnl_noescape(f): + return read_stringnl(f, stripquotes=False) + +stringnl_noescape = ArgumentDescriptor( + name='stringnl_noescape', + n=UP_TO_NEWLINE, + reader=read_stringnl_noescape, + doc="""A newline-terminated string. + + This is a str-style string, without embedded escapes, + or bracketing quotes. It should consist solely of + printable ASCII characters. + """) + +def read_stringnl_noescape_pair(f): + r""" + >>> import io + >>> read_stringnl_noescape_pair(io.BytesIO(b"Queue\nEmpty\njunk")) + 'Queue Empty' + """ + + return "%s %s" % (read_stringnl_noescape(f), read_stringnl_noescape(f)) + +stringnl_noescape_pair = ArgumentDescriptor( + name='stringnl_noescape_pair', + n=UP_TO_NEWLINE, + reader=read_stringnl_noescape_pair, + doc="""A pair of newline-terminated strings. + + These are str-style strings, without embedded + escapes, or bracketing quotes. They should + consist solely of printable ASCII characters. + The pair is returned as a single string, with + a single blank separating the two strings. + """) + + +def read_string1(f): + r""" + >>> import io + >>> read_string1(io.BytesIO(b"\x00")) + '' + >>> read_string1(io.BytesIO(b"\x03abcdef")) + 'abc' + """ + + n = read_uint1(f) + assert n >= 0 + data = f.read(n) + if len(data) == n: + return data.decode("latin-1") + raise ValueError("expected %d bytes in a string1, but only %d remain" % + (n, len(data))) + +string1 = ArgumentDescriptor( + name="string1", + n=TAKEN_FROM_ARGUMENT1, + reader=read_string1, + doc="""A counted string. + + The first argument is a 1-byte unsigned int giving the number + of bytes in the string, and the second argument is that many + bytes. + """) + + +def read_string4(f): + r""" + >>> import io + >>> read_string4(io.BytesIO(b"\x00\x00\x00\x00abc")) + '' + >>> read_string4(io.BytesIO(b"\x03\x00\x00\x00abcdef")) + 'abc' + >>> read_string4(io.BytesIO(b"\x00\x00\x00\x03abcdef")) + Traceback (most recent call last): + ... + ValueError: expected 50331648 bytes in a string4, but only 6 remain + """ + + n = read_int4(f) + if n < 0: + raise ValueError("string4 byte count < 0: %d" % n) + data = f.read(n) + if len(data) == n: + return data.decode("latin-1") + raise ValueError("expected %d bytes in a string4, but only %d remain" % + (n, len(data))) + +string4 = ArgumentDescriptor( + name="string4", + n=TAKEN_FROM_ARGUMENT4, + reader=read_string4, + doc="""A counted string. + + The first argument is a 4-byte little-endian signed int giving + the number of bytes in the string, and the second argument is + that many bytes. + """) + + +def read_bytes1(f): + r""" + >>> import io + >>> read_bytes1(io.BytesIO(b"\x00")) + b'' + >>> read_bytes1(io.BytesIO(b"\x03abcdef")) + b'abc' + """ + + n = read_uint1(f) + assert n >= 0 + data = f.read(n) + if len(data) == n: + return data + raise ValueError("expected %d bytes in a bytes1, but only %d remain" % + (n, len(data))) + +bytes1 = ArgumentDescriptor( + name="bytes1", + n=TAKEN_FROM_ARGUMENT1, + reader=read_bytes1, + doc="""A counted bytes string. + + The first argument is a 1-byte unsigned int giving the number + of bytes, and the second argument is that many bytes. + """) + + +def read_bytes4(f): + r""" + >>> import io + >>> read_bytes4(io.BytesIO(b"\x00\x00\x00\x00abc")) + b'' + >>> read_bytes4(io.BytesIO(b"\x03\x00\x00\x00abcdef")) + b'abc' + >>> read_bytes4(io.BytesIO(b"\x00\x00\x00\x03abcdef")) + Traceback (most recent call last): + ... + ValueError: expected 50331648 bytes in a bytes4, but only 6 remain + """ + + n = read_uint4(f) + assert n >= 0 + if n > sys.maxsize: + raise ValueError("bytes4 byte count > sys.maxsize: %d" % n) + data = f.read(n) + if len(data) == n: + return data + raise ValueError("expected %d bytes in a bytes4, but only %d remain" % + (n, len(data))) + +bytes4 = ArgumentDescriptor( + name="bytes4", + n=TAKEN_FROM_ARGUMENT4U, + reader=read_bytes4, + doc="""A counted bytes string. + + The first argument is a 4-byte little-endian unsigned int giving + the number of bytes, and the second argument is that many bytes. + """) + + +def read_bytes8(f): + r""" + >>> import io, struct, sys + >>> read_bytes8(io.BytesIO(b"\x00\x00\x00\x00\x00\x00\x00\x00abc")) + b'' + >>> read_bytes8(io.BytesIO(b"\x03\x00\x00\x00\x00\x00\x00\x00abcdef")) + b'abc' + >>> bigsize8 = struct.pack("<Q", sys.maxsize//3) + >>> read_bytes8(io.BytesIO(bigsize8 + b"abcdef")) #doctest: +ELLIPSIS + Traceback (most recent call last): + ... + ValueError: expected ... bytes in a bytes8, but only 6 remain + """ + + n = read_uint8(f) + assert n >= 0 + if n > sys.maxsize: + raise ValueError("bytes8 byte count > sys.maxsize: %d" % n) + data = f.read(n) + if len(data) == n: + return data + raise ValueError("expected %d bytes in a bytes8, but only %d remain" % + (n, len(data))) + +bytes8 = ArgumentDescriptor( + name="bytes8", + n=TAKEN_FROM_ARGUMENT8U, + reader=read_bytes8, + doc="""A counted bytes string. + + The first argument is an 8-byte little-endian unsigned int giving + the number of bytes, and the second argument is that many bytes. + """) + + +def read_bytearray8(f): + r""" + >>> import io, struct, sys + >>> read_bytearray8(io.BytesIO(b"\x00\x00\x00\x00\x00\x00\x00\x00abc")) + bytearray(b'') + >>> read_bytearray8(io.BytesIO(b"\x03\x00\x00\x00\x00\x00\x00\x00abcdef")) + bytearray(b'abc') + >>> bigsize8 = struct.pack("<Q", sys.maxsize//3) + >>> read_bytearray8(io.BytesIO(bigsize8 + b"abcdef")) #doctest: +ELLIPSIS + Traceback (most recent call last): + ... + ValueError: expected ... bytes in a bytearray8, but only 6 remain + """ + + n = read_uint8(f) + assert n >= 0 + if n > sys.maxsize: + raise ValueError("bytearray8 byte count > sys.maxsize: %d" % n) + data = f.read(n) + if len(data) == n: + return bytearray(data) + raise ValueError("expected %d bytes in a bytearray8, but only %d remain" % + (n, len(data))) + +bytearray8 = ArgumentDescriptor( + name="bytearray8", + n=TAKEN_FROM_ARGUMENT8U, + reader=read_bytearray8, + doc="""A counted bytearray. + + The first argument is an 8-byte little-endian unsigned int giving + the number of bytes, and the second argument is that many bytes. + """) + +def read_unicodestringnl(f): + r""" + >>> import io + >>> read_unicodestringnl(io.BytesIO(b"abc\\uabcd\njunk")) == 'abc\uabcd' + True + """ + + data = f.readline() + if not data.endswith(b'\n'): + raise ValueError("no newline found when trying to read " + "unicodestringnl") + data = data[:-1] # lose the newline + return str(data, 'raw-unicode-escape') + +unicodestringnl = ArgumentDescriptor( + name='unicodestringnl', + n=UP_TO_NEWLINE, + reader=read_unicodestringnl, + doc="""A newline-terminated Unicode string. + + This is raw-unicode-escape encoded, so consists of + printable ASCII characters, and may contain embedded + escape sequences. + """) + + +def read_unicodestring1(f): + r""" + >>> import io + >>> s = 'abcd\uabcd' + >>> enc = s.encode('utf-8') + >>> enc + b'abcd\xea\xaf\x8d' + >>> n = bytes([len(enc)]) # little-endian 1-byte length + >>> t = read_unicodestring1(io.BytesIO(n + enc + b'junk')) + >>> s == t + True + + >>> read_unicodestring1(io.BytesIO(n + enc[:-1])) + Traceback (most recent call last): + ... + ValueError: expected 7 bytes in a unicodestring1, but only 6 remain + """ + + n = read_uint1(f) + assert n >= 0 + data = f.read(n) + if len(data) == n: + return str(data, 'utf-8', 'surrogatepass') + raise ValueError("expected %d bytes in a unicodestring1, but only %d " + "remain" % (n, len(data))) + +unicodestring1 = ArgumentDescriptor( + name="unicodestring1", + n=TAKEN_FROM_ARGUMENT1, + reader=read_unicodestring1, + doc="""A counted Unicode string. + + The first argument is a 1-byte little-endian signed int + giving the number of bytes in the string, and the second + argument-- the UTF-8 encoding of the Unicode string -- + contains that many bytes. + """) + + +def read_unicodestring4(f): + r""" + >>> import io + >>> s = 'abcd\uabcd' + >>> enc = s.encode('utf-8') + >>> enc + b'abcd\xea\xaf\x8d' + >>> n = bytes([len(enc), 0, 0, 0]) # little-endian 4-byte length + >>> t = read_unicodestring4(io.BytesIO(n + enc + b'junk')) + >>> s == t + True + + >>> read_unicodestring4(io.BytesIO(n + enc[:-1])) + Traceback (most recent call last): + ... + ValueError: expected 7 bytes in a unicodestring4, but only 6 remain + """ + + n = read_uint4(f) + assert n >= 0 + if n > sys.maxsize: + raise ValueError("unicodestring4 byte count > sys.maxsize: %d" % n) + data = f.read(n) + if len(data) == n: + return str(data, 'utf-8', 'surrogatepass') + raise ValueError("expected %d bytes in a unicodestring4, but only %d " + "remain" % (n, len(data))) + +unicodestring4 = ArgumentDescriptor( + name="unicodestring4", + n=TAKEN_FROM_ARGUMENT4U, + reader=read_unicodestring4, + doc="""A counted Unicode string. + + The first argument is a 4-byte little-endian signed int + giving the number of bytes in the string, and the second + argument-- the UTF-8 encoding of the Unicode string -- + contains that many bytes. + """) + + +def read_unicodestring8(f): + r""" + >>> import io + >>> s = 'abcd\uabcd' + >>> enc = s.encode('utf-8') + >>> enc + b'abcd\xea\xaf\x8d' + >>> n = bytes([len(enc)]) + b'\0' * 7 # little-endian 8-byte length + >>> t = read_unicodestring8(io.BytesIO(n + enc + b'junk')) + >>> s == t + True + + >>> read_unicodestring8(io.BytesIO(n + enc[:-1])) + Traceback (most recent call last): + ... + ValueError: expected 7 bytes in a unicodestring8, but only 6 remain + """ + + n = read_uint8(f) + assert n >= 0 + if n > sys.maxsize: + raise ValueError("unicodestring8 byte count > sys.maxsize: %d" % n) + data = f.read(n) + if len(data) == n: + return str(data, 'utf-8', 'surrogatepass') + raise ValueError("expected %d bytes in a unicodestring8, but only %d " + "remain" % (n, len(data))) + +unicodestring8 = ArgumentDescriptor( + name="unicodestring8", + n=TAKEN_FROM_ARGUMENT8U, + reader=read_unicodestring8, + doc="""A counted Unicode string. + + The first argument is an 8-byte little-endian signed int + giving the number of bytes in the string, and the second + argument-- the UTF-8 encoding of the Unicode string -- + contains that many bytes. + """) + + +def read_decimalnl_short(f): + r""" + >>> import io + >>> read_decimalnl_short(io.BytesIO(b"1234\n56")) + 1234 + + >>> read_decimalnl_short(io.BytesIO(b"1234L\n56")) + Traceback (most recent call last): + ... + ValueError: invalid literal for int() with base 10: b'1234L' + """ + + s = read_stringnl(f, decode=False, stripquotes=False) + + # There's a hack for True and False here. + if s == b"00": + return False + elif s == b"01": + return True + + return int(s) + +def read_decimalnl_long(f): + r""" + >>> import io + + >>> read_decimalnl_long(io.BytesIO(b"1234L\n56")) + 1234 + + >>> read_decimalnl_long(io.BytesIO(b"123456789012345678901234L\n6")) + 123456789012345678901234 + """ + + s = read_stringnl(f, decode=False, stripquotes=False) + if s[-1:] == b'L': + s = s[:-1] + return int(s) + + +decimalnl_short = ArgumentDescriptor( + name='decimalnl_short', + n=UP_TO_NEWLINE, + reader=read_decimalnl_short, + doc="""A newline-terminated decimal integer literal. + + This never has a trailing 'L', and the integer fit + in a short Python int on the box where the pickle + was written -- but there's no guarantee it will fit + in a short Python int on the box where the pickle + is read. + """) + +decimalnl_long = ArgumentDescriptor( + name='decimalnl_long', + n=UP_TO_NEWLINE, + reader=read_decimalnl_long, + doc="""A newline-terminated decimal integer literal. + + This has a trailing 'L', and can represent integers + of any size. + """) + + +def read_floatnl(f): + r""" + >>> import io + >>> read_floatnl(io.BytesIO(b"-1.25\n6")) + -1.25 + """ + s = read_stringnl(f, decode=False, stripquotes=False) + return float(s) + +floatnl = ArgumentDescriptor( + name='floatnl', + n=UP_TO_NEWLINE, + reader=read_floatnl, + doc="""A newline-terminated decimal floating literal. + + In general this requires 17 significant digits for roundtrip + identity, and pickling then unpickling infinities, NaNs, and + minus zero doesn't work across boxes, or on some boxes even + on itself (e.g., Windows can't read the strings it produces + for infinities or NaNs). + """) + +def read_float8(f): + r""" + >>> import io, struct + >>> raw = struct.pack(">d", -1.25) + >>> raw + b'\xbf\xf4\x00\x00\x00\x00\x00\x00' + >>> read_float8(io.BytesIO(raw + b"\n")) + -1.25 + """ + + data = f.read(8) + if len(data) == 8: + return _unpack(">d", data)[0] + raise ValueError("not enough data in stream to read float8") + + +float8 = ArgumentDescriptor( + name='float8', + n=8, + reader=read_float8, + doc="""An 8-byte binary representation of a float, big-endian. + + The format is unique to Python, and shared with the struct + module (format string '>d') "in theory" (the struct and pickle + implementations don't share the code -- they should). It's + strongly related to the IEEE-754 double format, and, in normal + cases, is in fact identical to the big-endian 754 double format. + On other boxes the dynamic range is limited to that of a 754 + double, and "add a half and chop" rounding is used to reduce + the precision to 53 bits. However, even on a 754 box, + infinities, NaNs, and minus zero may not be handled correctly + (may not survive roundtrip pickling intact). + """) + +# Protocol 2 formats + +from pickle import decode_long + +def read_long1(f): + r""" + >>> import io + >>> read_long1(io.BytesIO(b"\x00")) + 0 + >>> read_long1(io.BytesIO(b"\x02\xff\x00")) + 255 + >>> read_long1(io.BytesIO(b"\x02\xff\x7f")) + 32767 + >>> read_long1(io.BytesIO(b"\x02\x00\xff")) + -256 + >>> read_long1(io.BytesIO(b"\x02\x00\x80")) + -32768 + """ + + n = read_uint1(f) + data = f.read(n) + if len(data) != n: + raise ValueError("not enough data in stream to read long1") + return decode_long(data) + +long1 = ArgumentDescriptor( + name="long1", + n=TAKEN_FROM_ARGUMENT1, + reader=read_long1, + doc="""A binary long, little-endian, using 1-byte size. + + This first reads one byte as an unsigned size, then reads that + many bytes and interprets them as a little-endian 2's-complement long. + If the size is 0, that's taken as a shortcut for the long 0L. + """) + +def read_long4(f): + r""" + >>> import io + >>> read_long4(io.BytesIO(b"\x02\x00\x00\x00\xff\x00")) + 255 + >>> read_long4(io.BytesIO(b"\x02\x00\x00\x00\xff\x7f")) + 32767 + >>> read_long4(io.BytesIO(b"\x02\x00\x00\x00\x00\xff")) + -256 + >>> read_long4(io.BytesIO(b"\x02\x00\x00\x00\x00\x80")) + -32768 + >>> read_long1(io.BytesIO(b"\x00\x00\x00\x00")) + 0 + """ + + n = read_int4(f) + if n < 0: + raise ValueError("long4 byte count < 0: %d" % n) + data = f.read(n) + if len(data) != n: + raise ValueError("not enough data in stream to read long4") + return decode_long(data) + +long4 = ArgumentDescriptor( + name="long4", + n=TAKEN_FROM_ARGUMENT4, + reader=read_long4, + doc="""A binary representation of a long, little-endian. + + This first reads four bytes as a signed size (but requires the + size to be >= 0), then reads that many bytes and interprets them + as a little-endian 2's-complement long. If the size is 0, that's taken + as a shortcut for the int 0, although LONG1 should really be used + then instead (and in any case where # of bytes < 256). + """) + + +############################################################################## +# Object descriptors. The stack used by the pickle machine holds objects, +# and in the stack_before and stack_after attributes of OpcodeInfo +# descriptors we need names to describe the various types of objects that can +# appear on the stack. + +class StackObject(object): + __slots__ = ( + # name of descriptor record, for info only + 'name', + + # type of object, or tuple of type objects (meaning the object can + # be of any type in the tuple) + 'obtype', + + # human-readable docs for this kind of stack object; a string + 'doc', + ) + + def __init__(self, name, obtype, doc): + assert isinstance(name, str) + self.name = name + + assert isinstance(obtype, type) or isinstance(obtype, tuple) + if isinstance(obtype, tuple): + for contained in obtype: + assert isinstance(contained, type) + self.obtype = obtype + + assert isinstance(doc, str) + self.doc = doc + + def __repr__(self): + return self.name + + +pyint = pylong = StackObject( + name='int', + obtype=int, + doc="A Python integer object.") + +pyinteger_or_bool = StackObject( + name='int_or_bool', + obtype=(int, bool), + doc="A Python integer or boolean object.") + +pybool = StackObject( + name='bool', + obtype=bool, + doc="A Python boolean object.") + +pyfloat = StackObject( + name='float', + obtype=float, + doc="A Python float object.") + +pybytes_or_str = pystring = StackObject( + name='bytes_or_str', + obtype=(bytes, str), + doc="A Python bytes or (Unicode) string object.") + +pybytes = StackObject( + name='bytes', + obtype=bytes, + doc="A Python bytes object.") + +pybytearray = StackObject( + name='bytearray', + obtype=bytearray, + doc="A Python bytearray object.") + +pyunicode = StackObject( + name='str', + obtype=str, + doc="A Python (Unicode) string object.") + +pynone = StackObject( + name="None", + obtype=type(None), + doc="The Python None object.") + +pytuple = StackObject( + name="tuple", + obtype=tuple, + doc="A Python tuple object.") + +pylist = StackObject( + name="list", + obtype=list, + doc="A Python list object.") + +pydict = StackObject( + name="dict", + obtype=dict, + doc="A Python dict object.") + +pyset = StackObject( + name="set", + obtype=set, + doc="A Python set object.") + +pyfrozenset = StackObject( + name="frozenset", + obtype=set, + doc="A Python frozenset object.") + +pybuffer = StackObject( + name='buffer', + obtype=object, + doc="A Python buffer-like object.") + +anyobject = StackObject( + name='any', + obtype=object, + doc="Any kind of object whatsoever.") + +markobject = StackObject( + name="mark", + obtype=StackObject, + doc="""'The mark' is a unique object. + +Opcodes that operate on a variable number of objects +generally don't embed the count of objects in the opcode, +or pull it off the stack. Instead the MARK opcode is used +to push a special marker object on the stack, and then +some other opcodes grab all the objects from the top of +the stack down to (but not including) the topmost marker +object. +""") + +stackslice = StackObject( + name="stackslice", + obtype=StackObject, + doc="""An object representing a contiguous slice of the stack. + +This is used in conjunction with markobject, to represent all +of the stack following the topmost markobject. For example, +the POP_MARK opcode changes the stack from + + [..., markobject, stackslice] +to + [...] + +No matter how many object are on the stack after the topmost +markobject, POP_MARK gets rid of all of them (including the +topmost markobject too). +""") + +############################################################################## +# Descriptors for pickle opcodes. + +class OpcodeInfo(object): + + __slots__ = ( + # symbolic name of opcode; a string + 'name', + + # the code used in a bytestream to represent the opcode; a + # one-character string + 'code', + + # If the opcode has an argument embedded in the byte string, an + # instance of ArgumentDescriptor specifying its type. Note that + # arg.reader(s) can be used to read and decode the argument from + # the bytestream s, and arg.doc documents the format of the raw + # argument bytes. If the opcode doesn't have an argument embedded + # in the bytestream, arg should be None. + 'arg', + + # what the stack looks like before this opcode runs; a list + 'stack_before', + + # what the stack looks like after this opcode runs; a list + 'stack_after', + + # the protocol number in which this opcode was introduced; an int + 'proto', + + # human-readable docs for this opcode; a string + 'doc', + ) + + def __init__(self, name, code, arg, + stack_before, stack_after, proto, doc): + assert isinstance(name, str) + self.name = name + + assert isinstance(code, str) + assert len(code) == 1 + self.code = code + + assert arg is None or isinstance(arg, ArgumentDescriptor) + self.arg = arg + + assert isinstance(stack_before, list) + for x in stack_before: + assert isinstance(x, StackObject) + self.stack_before = stack_before + + assert isinstance(stack_after, list) + for x in stack_after: + assert isinstance(x, StackObject) + self.stack_after = stack_after + + assert isinstance(proto, int) and 0 <= proto <= pickle.HIGHEST_PROTOCOL + self.proto = proto + + assert isinstance(doc, str) + self.doc = doc + +I = OpcodeInfo +opcodes = [ + + # Ways to spell integers. + + I(name='INT', + code='I', + arg=decimalnl_short, + stack_before=[], + stack_after=[pyinteger_or_bool], + proto=0, + doc="""Push an integer or bool. + + The argument is a newline-terminated decimal literal string. + + The intent may have been that this always fit in a short Python int, + but INT can be generated in pickles written on a 64-bit box that + require a Python long on a 32-bit box. The difference between this + and LONG then is that INT skips a trailing 'L', and produces a short + int whenever possible. + + Another difference is due to that, when bool was introduced as a + distinct type in 2.3, builtin names True and False were also added to + 2.2.2, mapping to ints 1 and 0. For compatibility in both directions, + True gets pickled as INT + "I01\\n", and False as INT + "I00\\n". + Leading zeroes are never produced for a genuine integer. The 2.3 + (and later) unpicklers special-case these and return bool instead; + earlier unpicklers ignore the leading "0" and return the int. + """), + + I(name='BININT', + code='J', + arg=int4, + stack_before=[], + stack_after=[pyint], + proto=1, + doc="""Push a four-byte signed integer. + + This handles the full range of Python (short) integers on a 32-bit + box, directly as binary bytes (1 for the opcode and 4 for the integer). + If the integer is non-negative and fits in 1 or 2 bytes, pickling via + BININT1 or BININT2 saves space. + """), + + I(name='BININT1', + code='K', + arg=uint1, + stack_before=[], + stack_after=[pyint], + proto=1, + doc="""Push a one-byte unsigned integer. + + This is a space optimization for pickling very small non-negative ints, + in range(256). + """), + + I(name='BININT2', + code='M', + arg=uint2, + stack_before=[], + stack_after=[pyint], + proto=1, + doc="""Push a two-byte unsigned integer. + + This is a space optimization for pickling small positive ints, in + range(256, 2**16). Integers in range(256) can also be pickled via + BININT2, but BININT1 instead saves a byte. + """), + + I(name='LONG', + code='L', + arg=decimalnl_long, + stack_before=[], + stack_after=[pyint], + proto=0, + doc="""Push a long integer. + + The same as INT, except that the literal ends with 'L', and always + unpickles to a Python long. There doesn't seem a real purpose to the + trailing 'L'. + + Note that LONG takes time quadratic in the number of digits when + unpickling (this is simply due to the nature of decimal->binary + conversion). Proto 2 added linear-time (in C; still quadratic-time + in Python) LONG1 and LONG4 opcodes. + """), + + I(name="LONG1", + code='\x8a', + arg=long1, + stack_before=[], + stack_after=[pyint], + proto=2, + doc="""Long integer using one-byte length. + + A more efficient encoding of a Python long; the long1 encoding + says it all."""), + + I(name="LONG4", + code='\x8b', + arg=long4, + stack_before=[], + stack_after=[pyint], + proto=2, + doc="""Long integer using found-byte length. + + A more efficient encoding of a Python long; the long4 encoding + says it all."""), + + # Ways to spell strings (8-bit, not Unicode). + + I(name='STRING', + code='S', + arg=stringnl, + stack_before=[], + stack_after=[pybytes_or_str], + proto=0, + doc="""Push a Python string object. + + The argument is a repr-style string, with bracketing quote characters, + and perhaps embedded escapes. The argument extends until the next + newline character. These are usually decoded into a str instance + using the encoding given to the Unpickler constructor. or the default, + 'ASCII'. If the encoding given was 'bytes' however, they will be + decoded as bytes object instead. + """), + + I(name='BINSTRING', + code='T', + arg=string4, + stack_before=[], + stack_after=[pybytes_or_str], + proto=1, + doc="""Push a Python string object. + + There are two arguments: the first is a 4-byte little-endian + signed int giving the number of bytes in the string, and the + second is that many bytes, which are taken literally as the string + content. These are usually decoded into a str instance using the + encoding given to the Unpickler constructor. or the default, + 'ASCII'. If the encoding given was 'bytes' however, they will be + decoded as bytes object instead. + """), + + I(name='SHORT_BINSTRING', + code='U', + arg=string1, + stack_before=[], + stack_after=[pybytes_or_str], + proto=1, + doc="""Push a Python string object. + + There are two arguments: the first is a 1-byte unsigned int giving + the number of bytes in the string, and the second is that many + bytes, which are taken literally as the string content. These are + usually decoded into a str instance using the encoding given to + the Unpickler constructor. or the default, 'ASCII'. If the + encoding given was 'bytes' however, they will be decoded as bytes + object instead. + """), + + # Bytes (protocol 3 and higher) + + I(name='BINBYTES', + code='B', + arg=bytes4, + stack_before=[], + stack_after=[pybytes], + proto=3, + doc="""Push a Python bytes object. + + There are two arguments: the first is a 4-byte little-endian unsigned int + giving the number of bytes, and the second is that many bytes, which are + taken literally as the bytes content. + """), + + I(name='SHORT_BINBYTES', + code='C', + arg=bytes1, + stack_before=[], + stack_after=[pybytes], + proto=3, + doc="""Push a Python bytes object. + + There are two arguments: the first is a 1-byte unsigned int giving + the number of bytes, and the second is that many bytes, which are taken + literally as the string content. + """), + + I(name='BINBYTES8', + code='\x8e', + arg=bytes8, + stack_before=[], + stack_after=[pybytes], + proto=4, + doc="""Push a Python bytes object. + + There are two arguments: the first is an 8-byte unsigned int giving + the number of bytes in the string, and the second is that many bytes, + which are taken literally as the string content. + """), + + # Bytearray (protocol 5 and higher) + + I(name='BYTEARRAY8', + code='\x96', + arg=bytearray8, + stack_before=[], + stack_after=[pybytearray], + proto=5, + doc="""Push a Python bytearray object. + + There are two arguments: the first is an 8-byte unsigned int giving + the number of bytes in the bytearray, and the second is that many bytes, + which are taken literally as the bytearray content. + """), + + # Out-of-band buffer (protocol 5 and higher) + + I(name='NEXT_BUFFER', + code='\x97', + arg=None, + stack_before=[], + stack_after=[pybuffer], + proto=5, + doc="Push an out-of-band buffer object."), + + I(name='READONLY_BUFFER', + code='\x98', + arg=None, + stack_before=[pybuffer], + stack_after=[pybuffer], + proto=5, + doc="Make an out-of-band buffer object read-only."), + + # Ways to spell None. + + I(name='NONE', + code='N', + arg=None, + stack_before=[], + stack_after=[pynone], + proto=0, + doc="Push None on the stack."), + + # Ways to spell bools, starting with proto 2. See INT for how this was + # done before proto 2. + + I(name='NEWTRUE', + code='\x88', + arg=None, + stack_before=[], + stack_after=[pybool], + proto=2, + doc="Push True onto the stack."), + + I(name='NEWFALSE', + code='\x89', + arg=None, + stack_before=[], + stack_after=[pybool], + proto=2, + doc="Push False onto the stack."), + + # Ways to spell Unicode strings. + + I(name='UNICODE', + code='V', + arg=unicodestringnl, + stack_before=[], + stack_after=[pyunicode], + proto=0, # this may be pure-text, but it's a later addition + doc="""Push a Python Unicode string object. + + The argument is a raw-unicode-escape encoding of a Unicode string, + and so may contain embedded escape sequences. The argument extends + until the next newline character. + """), + + I(name='SHORT_BINUNICODE', + code='\x8c', + arg=unicodestring1, + stack_before=[], + stack_after=[pyunicode], + proto=4, + doc="""Push a Python Unicode string object. + + There are two arguments: the first is a 1-byte little-endian signed int + giving the number of bytes in the string. The second is that many + bytes, and is the UTF-8 encoding of the Unicode string. + """), + + I(name='BINUNICODE', + code='X', + arg=unicodestring4, + stack_before=[], + stack_after=[pyunicode], + proto=1, + doc="""Push a Python Unicode string object. + + There are two arguments: the first is a 4-byte little-endian unsigned int + giving the number of bytes in the string. The second is that many + bytes, and is the UTF-8 encoding of the Unicode string. + """), + + I(name='BINUNICODE8', + code='\x8d', + arg=unicodestring8, + stack_before=[], + stack_after=[pyunicode], + proto=4, + doc="""Push a Python Unicode string object. + + There are two arguments: the first is an 8-byte little-endian signed int + giving the number of bytes in the string. The second is that many + bytes, and is the UTF-8 encoding of the Unicode string. + """), + + # Ways to spell floats. + + I(name='FLOAT', + code='F', + arg=floatnl, + stack_before=[], + stack_after=[pyfloat], + proto=0, + doc="""Newline-terminated decimal float literal. + + The argument is repr(a_float), and in general requires 17 significant + digits for roundtrip conversion to be an identity (this is so for + IEEE-754 double precision values, which is what Python float maps to + on most boxes). + + In general, FLOAT cannot be used to transport infinities, NaNs, or + minus zero across boxes (or even on a single box, if the platform C + library can't read the strings it produces for such things -- Windows + is like that), but may do less damage than BINFLOAT on boxes with + greater precision or dynamic range than IEEE-754 double. + """), + + I(name='BINFLOAT', + code='G', + arg=float8, + stack_before=[], + stack_after=[pyfloat], + proto=1, + doc="""Float stored in binary form, with 8 bytes of data. + + This generally requires less than half the space of FLOAT encoding. + In general, BINFLOAT cannot be used to transport infinities, NaNs, or + minus zero, raises an exception if the exponent exceeds the range of + an IEEE-754 double, and retains no more than 53 bits of precision (if + there are more than that, "add a half and chop" rounding is used to + cut it back to 53 significant bits). + """), + + # Ways to build lists. + + I(name='EMPTY_LIST', + code=']', + arg=None, + stack_before=[], + stack_after=[pylist], + proto=1, + doc="Push an empty list."), + + I(name='APPEND', + code='a', + arg=None, + stack_before=[pylist, anyobject], + stack_after=[pylist], + proto=0, + doc="""Append an object to a list. + + Stack before: ... pylist anyobject + Stack after: ... pylist+[anyobject] + + although pylist is really extended in-place. + """), + + I(name='APPENDS', + code='e', + arg=None, + stack_before=[pylist, markobject, stackslice], + stack_after=[pylist], + proto=1, + doc="""Extend a list by a slice of stack objects. + + Stack before: ... pylist markobject stackslice + Stack after: ... pylist+stackslice + + although pylist is really extended in-place. + """), + + I(name='LIST', + code='l', + arg=None, + stack_before=[markobject, stackslice], + stack_after=[pylist], + proto=0, + doc="""Build a list out of the topmost stack slice, after markobject. + + All the stack entries following the topmost markobject are placed into + a single Python list, which single list object replaces all of the + stack from the topmost markobject onward. For example, + + Stack before: ... markobject 1 2 3 'abc' + Stack after: ... [1, 2, 3, 'abc'] + """), + + # Ways to build tuples. + + I(name='EMPTY_TUPLE', + code=')', + arg=None, + stack_before=[], + stack_after=[pytuple], + proto=1, + doc="Push an empty tuple."), + + I(name='TUPLE', + code='t', + arg=None, + stack_before=[markobject, stackslice], + stack_after=[pytuple], + proto=0, + doc="""Build a tuple out of the topmost stack slice, after markobject. + + All the stack entries following the topmost markobject are placed into + a single Python tuple, which single tuple object replaces all of the + stack from the topmost markobject onward. For example, + + Stack before: ... markobject 1 2 3 'abc' + Stack after: ... (1, 2, 3, 'abc') + """), + + I(name='TUPLE1', + code='\x85', + arg=None, + stack_before=[anyobject], + stack_after=[pytuple], + proto=2, + doc="""Build a one-tuple out of the topmost item on the stack. + + This code pops one value off the stack and pushes a tuple of + length 1 whose one item is that value back onto it. In other + words: + + stack[-1] = tuple(stack[-1:]) + """), + + I(name='TUPLE2', + code='\x86', + arg=None, + stack_before=[anyobject, anyobject], + stack_after=[pytuple], + proto=2, + doc="""Build a two-tuple out of the top two items on the stack. + + This code pops two values off the stack and pushes a tuple of + length 2 whose items are those values back onto it. In other + words: + + stack[-2:] = [tuple(stack[-2:])] + """), + + I(name='TUPLE3', + code='\x87', + arg=None, + stack_before=[anyobject, anyobject, anyobject], + stack_after=[pytuple], + proto=2, + doc="""Build a three-tuple out of the top three items on the stack. + + This code pops three values off the stack and pushes a tuple of + length 3 whose items are those values back onto it. In other + words: + + stack[-3:] = [tuple(stack[-3:])] + """), + + # Ways to build dicts. + + I(name='EMPTY_DICT', + code='}', + arg=None, + stack_before=[], + stack_after=[pydict], + proto=1, + doc="Push an empty dict."), + + I(name='DICT', + code='d', + arg=None, + stack_before=[markobject, stackslice], + stack_after=[pydict], + proto=0, + doc="""Build a dict out of the topmost stack slice, after markobject. + + All the stack entries following the topmost markobject are placed into + a single Python dict, which single dict object replaces all of the + stack from the topmost markobject onward. The stack slice alternates + key, value, key, value, .... For example, + + Stack before: ... markobject 1 2 3 'abc' + Stack after: ... {1: 2, 3: 'abc'} + """), + + I(name='SETITEM', + code='s', + arg=None, + stack_before=[pydict, anyobject, anyobject], + stack_after=[pydict], + proto=0, + doc="""Add a key+value pair to an existing dict. + + Stack before: ... pydict key value + Stack after: ... pydict + + where pydict has been modified via pydict[key] = value. + """), + + I(name='SETITEMS', + code='u', + arg=None, + stack_before=[pydict, markobject, stackslice], + stack_after=[pydict], + proto=1, + doc="""Add an arbitrary number of key+value pairs to an existing dict. + + The slice of the stack following the topmost markobject is taken as + an alternating sequence of keys and values, added to the dict + immediately under the topmost markobject. Everything at and after the + topmost markobject is popped, leaving the mutated dict at the top + of the stack. + + Stack before: ... pydict markobject key_1 value_1 ... key_n value_n + Stack after: ... pydict + + where pydict has been modified via pydict[key_i] = value_i for i in + 1, 2, ..., n, and in that order. + """), + + # Ways to build sets + + I(name='EMPTY_SET', + code='\x8f', + arg=None, + stack_before=[], + stack_after=[pyset], + proto=4, + doc="Push an empty set."), + + I(name='ADDITEMS', + code='\x90', + arg=None, + stack_before=[pyset, markobject, stackslice], + stack_after=[pyset], + proto=4, + doc="""Add an arbitrary number of items to an existing set. + + The slice of the stack following the topmost markobject is taken as + a sequence of items, added to the set immediately under the topmost + markobject. Everything at and after the topmost markobject is popped, + leaving the mutated set at the top of the stack. + + Stack before: ... pyset markobject item_1 ... item_n + Stack after: ... pyset + + where pyset has been modified via pyset.add(item_i) = item_i for i in + 1, 2, ..., n, and in that order. + """), + + # Way to build frozensets + + I(name='FROZENSET', + code='\x91', + arg=None, + stack_before=[markobject, stackslice], + stack_after=[pyfrozenset], + proto=4, + doc="""Build a frozenset out of the topmost slice, after markobject. + + All the stack entries following the topmost markobject are placed into + a single Python frozenset, which single frozenset object replaces all + of the stack from the topmost markobject onward. For example, + + Stack before: ... markobject 1 2 3 + Stack after: ... frozenset({1, 2, 3}) + """), + + # Stack manipulation. + + I(name='POP', + code='0', + arg=None, + stack_before=[anyobject], + stack_after=[], + proto=0, + doc="Discard the top stack item, shrinking the stack by one item."), + + I(name='DUP', + code='2', + arg=None, + stack_before=[anyobject], + stack_after=[anyobject, anyobject], + proto=0, + doc="Push the top stack item onto the stack again, duplicating it."), + + I(name='MARK', + code='(', + arg=None, + stack_before=[], + stack_after=[markobject], + proto=0, + doc="""Push markobject onto the stack. + + markobject is a unique object, used by other opcodes to identify a + region of the stack containing a variable number of objects for them + to work on. See markobject.doc for more detail. + """), + + I(name='POP_MARK', + code='1', + arg=None, + stack_before=[markobject, stackslice], + stack_after=[], + proto=1, + doc="""Pop all the stack objects at and above the topmost markobject. + + When an opcode using a variable number of stack objects is done, + POP_MARK is used to remove those objects, and to remove the markobject + that delimited their starting position on the stack. + """), + + # Memo manipulation. There are really only two operations (get and put), + # each in all-text, "short binary", and "long binary" flavors. + + I(name='GET', + code='g', + arg=decimalnl_short, + stack_before=[], + stack_after=[anyobject], + proto=0, + doc="""Read an object from the memo and push it on the stack. + + The index of the memo object to push is given by the newline-terminated + decimal string following. BINGET and LONG_BINGET are space-optimized + versions. + """), + + I(name='BINGET', + code='h', + arg=uint1, + stack_before=[], + stack_after=[anyobject], + proto=1, + doc="""Read an object from the memo and push it on the stack. + + The index of the memo object to push is given by the 1-byte unsigned + integer following. + """), + + I(name='LONG_BINGET', + code='j', + arg=uint4, + stack_before=[], + stack_after=[anyobject], + proto=1, + doc="""Read an object from the memo and push it on the stack. + + The index of the memo object to push is given by the 4-byte unsigned + little-endian integer following. + """), + + I(name='PUT', + code='p', + arg=decimalnl_short, + stack_before=[], + stack_after=[], + proto=0, + doc="""Store the stack top into the memo. The stack is not popped. + + The index of the memo location to write into is given by the newline- + terminated decimal string following. BINPUT and LONG_BINPUT are + space-optimized versions. + """), + + I(name='BINPUT', + code='q', + arg=uint1, + stack_before=[], + stack_after=[], + proto=1, + doc="""Store the stack top into the memo. The stack is not popped. + + The index of the memo location to write into is given by the 1-byte + unsigned integer following. + """), + + I(name='LONG_BINPUT', + code='r', + arg=uint4, + stack_before=[], + stack_after=[], + proto=1, + doc="""Store the stack top into the memo. The stack is not popped. + + The index of the memo location to write into is given by the 4-byte + unsigned little-endian integer following. + """), + + I(name='MEMOIZE', + code='\x94', + arg=None, + stack_before=[anyobject], + stack_after=[anyobject], + proto=4, + doc="""Store the stack top into the memo. The stack is not popped. + + The index of the memo location to write is the number of + elements currently present in the memo. + """), + + # Access the extension registry (predefined objects). Akin to the GET + # family. + + I(name='EXT1', + code='\x82', + arg=uint1, + stack_before=[], + stack_after=[anyobject], + proto=2, + doc="""Extension code. + + This code and the similar EXT2 and EXT4 allow using a registry + of popular objects that are pickled by name, typically classes. + It is envisioned that through a global negotiation and + registration process, third parties can set up a mapping between + ints and object names. + + In order to guarantee pickle interchangeability, the extension + code registry ought to be global, although a range of codes may + be reserved for private use. + + EXT1 has a 1-byte integer argument. This is used to index into the + extension registry, and the object at that index is pushed on the stack. + """), + + I(name='EXT2', + code='\x83', + arg=uint2, + stack_before=[], + stack_after=[anyobject], + proto=2, + doc="""Extension code. + + See EXT1. EXT2 has a two-byte integer argument. + """), + + I(name='EXT4', + code='\x84', + arg=int4, + stack_before=[], + stack_after=[anyobject], + proto=2, + doc="""Extension code. + + See EXT1. EXT4 has a four-byte integer argument. + """), + + # Push a class object, or module function, on the stack, via its module + # and name. + + I(name='GLOBAL', + code='c', + arg=stringnl_noescape_pair, + stack_before=[], + stack_after=[anyobject], + proto=0, + doc="""Push a global object (module.attr) on the stack. + + Two newline-terminated strings follow the GLOBAL opcode. The first is + taken as a module name, and the second as a class name. The class + object module.class is pushed on the stack. More accurately, the + object returned by self.find_class(module, class) is pushed on the + stack, so unpickling subclasses can override this form of lookup. + """), + + I(name='STACK_GLOBAL', + code='\x93', + arg=None, + stack_before=[pyunicode, pyunicode], + stack_after=[anyobject], + proto=4, + doc="""Push a global object (module.attr) on the stack. + """), + + # Ways to build objects of classes pickle doesn't know about directly + # (user-defined classes). I despair of documenting this accurately + # and comprehensibly -- you really have to read the pickle code to + # find all the special cases. + + I(name='REDUCE', + code='R', + arg=None, + stack_before=[anyobject, anyobject], + stack_after=[anyobject], + proto=0, + doc="""Push an object built from a callable and an argument tuple. + + The opcode is named to remind of the __reduce__() method. + + Stack before: ... callable pytuple + Stack after: ... callable(*pytuple) + + The callable and the argument tuple are the first two items returned + by a __reduce__ method. Applying the callable to the argtuple is + supposed to reproduce the original object, or at least get it started. + If the __reduce__ method returns a 3-tuple, the last component is an + argument to be passed to the object's __setstate__, and then the REDUCE + opcode is followed by code to create setstate's argument, and then a + BUILD opcode to apply __setstate__ to that argument. + + If not isinstance(callable, type), REDUCE complains unless the + callable has been registered with the copyreg module's + safe_constructors dict, or the callable has a magic + '__safe_for_unpickling__' attribute with a true value. I'm not sure + why it does this, but I've sure seen this complaint often enough when + I didn't want to <wink>. + """), + + I(name='BUILD', + code='b', + arg=None, + stack_before=[anyobject, anyobject], + stack_after=[anyobject], + proto=0, + doc="""Finish building an object, via __setstate__ or dict update. + + Stack before: ... anyobject argument + Stack after: ... anyobject + + where anyobject may have been mutated, as follows: + + If the object has a __setstate__ method, + + anyobject.__setstate__(argument) + + is called. + + Else the argument must be a dict, the object must have a __dict__, and + the object is updated via + + anyobject.__dict__.update(argument) + """), + + I(name='INST', + code='i', + arg=stringnl_noescape_pair, + stack_before=[markobject, stackslice], + stack_after=[anyobject], + proto=0, + doc="""Build a class instance. + + This is the protocol 0 version of protocol 1's OBJ opcode. + INST is followed by two newline-terminated strings, giving a + module and class name, just as for the GLOBAL opcode (and see + GLOBAL for more details about that). self.find_class(module, name) + is used to get a class object. + + In addition, all the objects on the stack following the topmost + markobject are gathered into a tuple and popped (along with the + topmost markobject), just as for the TUPLE opcode. + + Now it gets complicated. If all of these are true: + + + The argtuple is empty (markobject was at the top of the stack + at the start). + + + The class object does not have a __getinitargs__ attribute. + + then we want to create an old-style class instance without invoking + its __init__() method (pickle has waffled on this over the years; not + calling __init__() is current wisdom). In this case, an instance of + an old-style dummy class is created, and then we try to rebind its + __class__ attribute to the desired class object. If this succeeds, + the new instance object is pushed on the stack, and we're done. + + Else (the argtuple is not empty, it's not an old-style class object, + or the class object does have a __getinitargs__ attribute), the code + first insists that the class object have a __safe_for_unpickling__ + attribute. Unlike as for the __safe_for_unpickling__ check in REDUCE, + it doesn't matter whether this attribute has a true or false value, it + only matters whether it exists (XXX this is a bug). If + __safe_for_unpickling__ doesn't exist, UnpicklingError is raised. + + Else (the class object does have a __safe_for_unpickling__ attr), + the class object obtained from INST's arguments is applied to the + argtuple obtained from the stack, and the resulting instance object + is pushed on the stack. + + NOTE: checks for __safe_for_unpickling__ went away in Python 2.3. + NOTE: the distinction between old-style and new-style classes does + not make sense in Python 3. + """), + + I(name='OBJ', + code='o', + arg=None, + stack_before=[markobject, anyobject, stackslice], + stack_after=[anyobject], + proto=1, + doc="""Build a class instance. + + This is the protocol 1 version of protocol 0's INST opcode, and is + very much like it. The major difference is that the class object + is taken off the stack, allowing it to be retrieved from the memo + repeatedly if several instances of the same class are created. This + can be much more efficient (in both time and space) than repeatedly + embedding the module and class names in INST opcodes. + + Unlike INST, OBJ takes no arguments from the opcode stream. Instead + the class object is taken off the stack, immediately above the + topmost markobject: + + Stack before: ... markobject classobject stackslice + Stack after: ... new_instance_object + + As for INST, the remainder of the stack above the markobject is + gathered into an argument tuple, and then the logic seems identical, + except that no __safe_for_unpickling__ check is done (XXX this is + a bug). See INST for the gory details. + + NOTE: In Python 2.3, INST and OBJ are identical except for how they + get the class object. That was always the intent; the implementations + had diverged for accidental reasons. + """), + + I(name='NEWOBJ', + code='\x81', + arg=None, + stack_before=[anyobject, anyobject], + stack_after=[anyobject], + proto=2, + doc="""Build an object instance. + + The stack before should be thought of as containing a class + object followed by an argument tuple (the tuple being the stack + top). Call these cls and args. They are popped off the stack, + and the value returned by cls.__new__(cls, *args) is pushed back + onto the stack. + """), + + I(name='NEWOBJ_EX', + code='\x92', + arg=None, + stack_before=[anyobject, anyobject, anyobject], + stack_after=[anyobject], + proto=4, + doc="""Build an object instance. + + The stack before should be thought of as containing a class + object followed by an argument tuple and by a keyword argument dict + (the dict being the stack top). Call these cls and args. They are + popped off the stack, and the value returned by + cls.__new__(cls, *args, *kwargs) is pushed back onto the stack. + """), + + # Machine control. + + I(name='PROTO', + code='\x80', + arg=uint1, + stack_before=[], + stack_after=[], + proto=2, + doc="""Protocol version indicator. + + For protocol 2 and above, a pickle must start with this opcode. + The argument is the protocol version, an int in range(2, 256). + """), + + I(name='STOP', + code='.', + arg=None, + stack_before=[anyobject], + stack_after=[], + proto=0, + doc="""Stop the unpickling machine. + + Every pickle ends with this opcode. The object at the top of the stack + is popped, and that's the result of unpickling. The stack should be + empty then. + """), + + # Framing support. + + I(name='FRAME', + code='\x95', + arg=uint8, + stack_before=[], + stack_after=[], + proto=4, + doc="""Indicate the beginning of a new frame. + + The unpickler may use this opcode to safely prefetch data from its + underlying stream. + """), + + # Ways to deal with persistent IDs. + + I(name='PERSID', + code='P', + arg=stringnl_noescape, + stack_before=[], + stack_after=[anyobject], + proto=0, + doc="""Push an object identified by a persistent ID. + + The pickle module doesn't define what a persistent ID means. PERSID's + argument is a newline-terminated str-style (no embedded escapes, no + bracketing quote characters) string, which *is* "the persistent ID". + The unpickler passes this string to self.persistent_load(). Whatever + object that returns is pushed on the stack. There is no implementation + of persistent_load() in Python's unpickler: it must be supplied by an + unpickler subclass. + """), + + I(name='BINPERSID', + code='Q', + arg=None, + stack_before=[anyobject], + stack_after=[anyobject], + proto=1, + doc="""Push an object identified by a persistent ID. + + Like PERSID, except the persistent ID is popped off the stack (instead + of being a string embedded in the opcode bytestream). The persistent + ID is passed to self.persistent_load(), and whatever object that + returns is pushed on the stack. See PERSID for more detail. + """), +] +del I + +# Verify uniqueness of .name and .code members. +name2i = {} +code2i = {} + +for i, d in enumerate(opcodes): + if d.name in name2i: + raise ValueError("repeated name %r at indices %d and %d" % + (d.name, name2i[d.name], i)) + if d.code in code2i: + raise ValueError("repeated code %r at indices %d and %d" % + (d.code, code2i[d.code], i)) + + name2i[d.name] = i + code2i[d.code] = i + +del name2i, code2i, i, d + +############################################################################## +# Build a code2op dict, mapping opcode characters to OpcodeInfo records. +# Also ensure we've got the same stuff as pickle.py, although the +# introspection here is dicey. + +code2op = {} +for d in opcodes: + code2op[d.code] = d +del d + +def assure_pickle_consistency(verbose=False): + + copy = code2op.copy() + for name in pickle.__all__: + if not re.match("[A-Z][A-Z0-9_]+$", name): + if verbose: + print("skipping %r: it doesn't look like an opcode name" % name) + continue + picklecode = getattr(pickle, name) + if not isinstance(picklecode, bytes) or len(picklecode) != 1: + if verbose: + print(("skipping %r: value %r doesn't look like a pickle " + "code" % (name, picklecode))) + continue + picklecode = picklecode.decode("latin-1") + if picklecode in copy: + if verbose: + print("checking name %r w/ code %r for consistency" % ( + name, picklecode)) + d = copy[picklecode] + if d.name != name: + raise ValueError("for pickle code %r, pickle.py uses name %r " + "but we're using name %r" % (picklecode, + name, + d.name)) + # Forget this one. Any left over in copy at the end are a problem + # of a different kind. + del copy[picklecode] + else: + raise ValueError("pickle.py appears to have a pickle opcode with " + "name %r and code %r, but we don't" % + (name, picklecode)) + if copy: + msg = ["we appear to have pickle opcodes that pickle.py doesn't have:"] + for code, d in copy.items(): + msg.append(" name %r with code %r" % (d.name, code)) + raise ValueError("\n".join(msg)) + +assure_pickle_consistency() +del assure_pickle_consistency + +############################################################################## +# A pickle opcode generator. + +def _genops(data, yield_end_pos=False): + if isinstance(data, bytes_types): + data = io.BytesIO(data) + + if hasattr(data, "tell"): + getpos = data.tell + else: + getpos = lambda: None + + while True: + pos = getpos() + code = data.read(1) + opcode = code2op.get(code.decode("latin-1")) + if opcode is None: + if code == b"": + raise ValueError("pickle exhausted before seeing STOP") + else: + raise ValueError("at position %s, opcode %r unknown" % ( + "<unknown>" if pos is None else pos, + code)) + if opcode.arg is None: + arg = None + else: + arg = opcode.arg.reader(data) + if yield_end_pos: + yield opcode, arg, pos, getpos() + else: + yield opcode, arg, pos + if code == b'.': + assert opcode.name == 'STOP' + break + +def genops(pickle): + """Generate all the opcodes in a pickle. + + 'pickle' is a file-like object, or string, containing the pickle. + + Each opcode in the pickle is generated, from the current pickle position, + stopping after a STOP opcode is delivered. A triple is generated for + each opcode: + + opcode, arg, pos + + opcode is an OpcodeInfo record, describing the current opcode. + + If the opcode has an argument embedded in the pickle, arg is its decoded + value, as a Python object. If the opcode doesn't have an argument, arg + is None. + + If the pickle has a tell() method, pos was the value of pickle.tell() + before reading the current opcode. If the pickle is a bytes object, + it's wrapped in a BytesIO object, and the latter's tell() result is + used. Else (the pickle doesn't have a tell(), and it's not obvious how + to query its current position) pos is None. + """ + return _genops(pickle) + +############################################################################## +# A pickle optimizer. + +def optimize(p): + 'Optimize a pickle string by removing unused PUT opcodes' + put = 'PUT' + get = 'GET' + oldids = set() # set of all PUT ids + newids = {} # set of ids used by a GET opcode + opcodes = [] # (op, idx) or (pos, end_pos) + proto = 0 + protoheader = b'' + for opcode, arg, pos, end_pos in _genops(p, yield_end_pos=True): + if 'PUT' in opcode.name: + oldids.add(arg) + opcodes.append((put, arg)) + elif opcode.name == 'MEMOIZE': + idx = len(oldids) + oldids.add(idx) + opcodes.append((put, idx)) + elif 'FRAME' in opcode.name: + pass + elif 'GET' in opcode.name: + if opcode.proto > proto: + proto = opcode.proto + newids[arg] = None + opcodes.append((get, arg)) + elif opcode.name == 'PROTO': + if arg > proto: + proto = arg + if pos == 0: + protoheader = p[pos:end_pos] + else: + opcodes.append((pos, end_pos)) + else: + opcodes.append((pos, end_pos)) + del oldids + + # Copy the opcodes except for PUTS without a corresponding GET + out = io.BytesIO() + # Write the PROTO header before any framing + out.write(protoheader) + pickler = pickle._Pickler(out, proto) + if proto >= 4: + pickler.framer.start_framing() + idx = 0 + for op, arg in opcodes: + frameless = False + if op is put: + if arg not in newids: + continue + data = pickler.put(idx) + newids[arg] = idx + idx += 1 + elif op is get: + data = pickler.get(newids[arg]) + else: + data = p[op:arg] + frameless = len(data) > pickler.framer._FRAME_SIZE_TARGET + pickler.framer.commit_frame(force=frameless) + if frameless: + pickler.framer.file_write(data) + else: + pickler.write(data) + pickler.framer.end_framing() + return out.getvalue() + +############################################################################## +# A symbolic pickle disassembler. + +def dis(pickle, out=None, memo=None, indentlevel=4, annotate=0): + """Produce a symbolic disassembly of a pickle. + + 'pickle' is a file-like object, or string, containing a (at least one) + pickle. The pickle is disassembled from the current position, through + the first STOP opcode encountered. + + Optional arg 'out' is a file-like object to which the disassembly is + printed. It defaults to sys.stdout. + + Optional arg 'memo' is a Python dict, used as the pickle's memo. It + may be mutated by dis(), if the pickle contains PUT or BINPUT opcodes. + Passing the same memo object to another dis() call then allows disassembly + to proceed across multiple pickles that were all created by the same + pickler with the same memo. Ordinarily you don't need to worry about this. + + Optional arg 'indentlevel' is the number of blanks by which to indent + a new MARK level. It defaults to 4. + + Optional arg 'annotate' if nonzero instructs dis() to add short + description of the opcode on each line of disassembled output. + The value given to 'annotate' must be an integer and is used as a + hint for the column where annotation should start. The default + value is 0, meaning no annotations. + + In addition to printing the disassembly, some sanity checks are made: + + + All embedded opcode arguments "make sense". + + + Explicit and implicit pop operations have enough items on the stack. + + + When an opcode implicitly refers to a markobject, a markobject is + actually on the stack. + + + A memo entry isn't referenced before it's defined. + + + The markobject isn't stored in the memo. + + + A memo entry isn't redefined. + """ + + # Most of the hair here is for sanity checks, but most of it is needed + # anyway to detect when a protocol 0 POP takes a MARK off the stack + # (which in turn is needed to indent MARK blocks correctly). + + stack = [] # crude emulation of unpickler stack + if memo is None: + memo = {} # crude emulation of unpickler memo + maxproto = -1 # max protocol number seen + markstack = [] # bytecode positions of MARK opcodes + indentchunk = ' ' * indentlevel + errormsg = None + annocol = annotate # column hint for annotations + for opcode, arg, pos in genops(pickle): + if pos is not None: + print("%5d:" % pos, end=' ', file=out) + + line = "%-4s %s%s" % (repr(opcode.code)[1:-1], + indentchunk * len(markstack), + opcode.name) + + maxproto = max(maxproto, opcode.proto) + before = opcode.stack_before # don't mutate + after = opcode.stack_after # don't mutate + numtopop = len(before) + + # See whether a MARK should be popped. + markmsg = None + if markobject in before or (opcode.name == "POP" and + stack and + stack[-1] is markobject): + assert markobject not in after + if __debug__: + if markobject in before: + assert before[-1] is stackslice + if markstack: + markpos = markstack.pop() + if markpos is None: + markmsg = "(MARK at unknown opcode offset)" + else: + markmsg = "(MARK at %d)" % markpos + # Pop everything at and after the topmost markobject. + while stack[-1] is not markobject: + stack.pop() + stack.pop() + # Stop later code from popping too much. + try: + numtopop = before.index(markobject) + except ValueError: + assert opcode.name == "POP" + numtopop = 0 + else: + errormsg = markmsg = "no MARK exists on stack" + + # Check for correct memo usage. + if opcode.name in ("PUT", "BINPUT", "LONG_BINPUT", "MEMOIZE"): + if opcode.name == "MEMOIZE": + memo_idx = len(memo) + markmsg = "(as %d)" % memo_idx + else: + assert arg is not None + memo_idx = arg + if memo_idx in memo: + errormsg = "memo key %r already defined" % arg + elif not stack: + errormsg = "stack is empty -- can't store into memo" + elif stack[-1] is markobject: + errormsg = "can't store markobject in the memo" + else: + memo[memo_idx] = stack[-1] + elif opcode.name in ("GET", "BINGET", "LONG_BINGET"): + if arg in memo: + assert len(after) == 1 + after = [memo[arg]] # for better stack emulation + else: + errormsg = "memo key %r has never been stored into" % arg + + if arg is not None or markmsg: + # make a mild effort to align arguments + line += ' ' * (10 - len(opcode.name)) + if arg is not None: + line += ' ' + repr(arg) + if markmsg: + line += ' ' + markmsg + if annotate: + line += ' ' * (annocol - len(line)) + # make a mild effort to align annotations + annocol = len(line) + if annocol > 50: + annocol = annotate + line += ' ' + opcode.doc.split('\n', 1)[0] + print(line, file=out) + + if errormsg: + # Note that we delayed complaining until the offending opcode + # was printed. + raise ValueError(errormsg) + + # Emulate the stack effects. + if len(stack) < numtopop: + raise ValueError("tries to pop %d items from stack with " + "only %d items" % (numtopop, len(stack))) + if numtopop: + del stack[-numtopop:] + if markobject in after: + assert markobject not in before + markstack.append(pos) + + stack.extend(after) + + print("highest protocol among opcodes =", maxproto, file=out) + if stack: + raise ValueError("stack not empty after STOP: %r" % stack) + +# For use in the doctest, simply as an example of a class to pickle. +class _Example: + def __init__(self, value): + self.value = value + +_dis_test = r""" +>>> import pickle +>>> x = [1, 2, (3, 4), {b'abc': "def"}] +>>> pkl0 = pickle.dumps(x, 0) +>>> dis(pkl0) + 0: ( MARK + 1: l LIST (MARK at 0) + 2: p PUT 0 + 5: I INT 1 + 8: a APPEND + 9: I INT 2 + 12: a APPEND + 13: ( MARK + 14: I INT 3 + 17: I INT 4 + 20: t TUPLE (MARK at 13) + 21: p PUT 1 + 24: a APPEND + 25: ( MARK + 26: d DICT (MARK at 25) + 27: p PUT 2 + 30: c GLOBAL '_codecs encode' + 46: p PUT 3 + 49: ( MARK + 50: V UNICODE 'abc' + 55: p PUT 4 + 58: V UNICODE 'latin1' + 66: p PUT 5 + 69: t TUPLE (MARK at 49) + 70: p PUT 6 + 73: R REDUCE + 74: p PUT 7 + 77: V UNICODE 'def' + 82: p PUT 8 + 85: s SETITEM + 86: a APPEND + 87: . STOP +highest protocol among opcodes = 0 + +Try again with a "binary" pickle. + +>>> pkl1 = pickle.dumps(x, 1) +>>> dis(pkl1) + 0: ] EMPTY_LIST + 1: q BINPUT 0 + 3: ( MARK + 4: K BININT1 1 + 6: K BININT1 2 + 8: ( MARK + 9: K BININT1 3 + 11: K BININT1 4 + 13: t TUPLE (MARK at 8) + 14: q BINPUT 1 + 16: } EMPTY_DICT + 17: q BINPUT 2 + 19: c GLOBAL '_codecs encode' + 35: q BINPUT 3 + 37: ( MARK + 38: X BINUNICODE 'abc' + 46: q BINPUT 4 + 48: X BINUNICODE 'latin1' + 59: q BINPUT 5 + 61: t TUPLE (MARK at 37) + 62: q BINPUT 6 + 64: R REDUCE + 65: q BINPUT 7 + 67: X BINUNICODE 'def' + 75: q BINPUT 8 + 77: s SETITEM + 78: e APPENDS (MARK at 3) + 79: . STOP +highest protocol among opcodes = 1 + +Exercise the INST/OBJ/BUILD family. + +>>> import pickletools +>>> dis(pickle.dumps(pickletools.dis, 0)) + 0: c GLOBAL 'pickletools dis' + 17: p PUT 0 + 20: . STOP +highest protocol among opcodes = 0 + +>>> from pickletools import _Example +>>> x = [_Example(42)] * 2 +>>> dis(pickle.dumps(x, 0)) + 0: ( MARK + 1: l LIST (MARK at 0) + 2: p PUT 0 + 5: c GLOBAL 'copy_reg _reconstructor' + 30: p PUT 1 + 33: ( MARK + 34: c GLOBAL 'pickletools _Example' + 56: p PUT 2 + 59: c GLOBAL '__builtin__ object' + 79: p PUT 3 + 82: N NONE + 83: t TUPLE (MARK at 33) + 84: p PUT 4 + 87: R REDUCE + 88: p PUT 5 + 91: ( MARK + 92: d DICT (MARK at 91) + 93: p PUT 6 + 96: V UNICODE 'value' + 103: p PUT 7 + 106: I INT 42 + 110: s SETITEM + 111: b BUILD + 112: a APPEND + 113: g GET 5 + 116: a APPEND + 117: . STOP +highest protocol among opcodes = 0 + +>>> dis(pickle.dumps(x, 1)) + 0: ] EMPTY_LIST + 1: q BINPUT 0 + 3: ( MARK + 4: c GLOBAL 'copy_reg _reconstructor' + 29: q BINPUT 1 + 31: ( MARK + 32: c GLOBAL 'pickletools _Example' + 54: q BINPUT 2 + 56: c GLOBAL '__builtin__ object' + 76: q BINPUT 3 + 78: N NONE + 79: t TUPLE (MARK at 31) + 80: q BINPUT 4 + 82: R REDUCE + 83: q BINPUT 5 + 85: } EMPTY_DICT + 86: q BINPUT 6 + 88: X BINUNICODE 'value' + 98: q BINPUT 7 + 100: K BININT1 42 + 102: s SETITEM + 103: b BUILD + 104: h BINGET 5 + 106: e APPENDS (MARK at 3) + 107: . STOP +highest protocol among opcodes = 1 + +Try "the canonical" recursive-object test. + +>>> L = [] +>>> T = L, +>>> L.append(T) +>>> L[0] is T +True +>>> T[0] is L +True +>>> L[0][0] is L +True +>>> T[0][0] is T +True +>>> dis(pickle.dumps(L, 0)) + 0: ( MARK + 1: l LIST (MARK at 0) + 2: p PUT 0 + 5: ( MARK + 6: g GET 0 + 9: t TUPLE (MARK at 5) + 10: p PUT 1 + 13: a APPEND + 14: . STOP +highest protocol among opcodes = 0 + +>>> dis(pickle.dumps(L, 1)) + 0: ] EMPTY_LIST + 1: q BINPUT 0 + 3: ( MARK + 4: h BINGET 0 + 6: t TUPLE (MARK at 3) + 7: q BINPUT 1 + 9: a APPEND + 10: . STOP +highest protocol among opcodes = 1 + +Note that, in the protocol 0 pickle of the recursive tuple, the disassembler +has to emulate the stack in order to realize that the POP opcode at 16 gets +rid of the MARK at 0. + +>>> dis(pickle.dumps(T, 0)) + 0: ( MARK + 1: ( MARK + 2: l LIST (MARK at 1) + 3: p PUT 0 + 6: ( MARK + 7: g GET 0 + 10: t TUPLE (MARK at 6) + 11: p PUT 1 + 14: a APPEND + 15: 0 POP + 16: 0 POP (MARK at 0) + 17: g GET 1 + 20: . STOP +highest protocol among opcodes = 0 + +>>> dis(pickle.dumps(T, 1)) + 0: ( MARK + 1: ] EMPTY_LIST + 2: q BINPUT 0 + 4: ( MARK + 5: h BINGET 0 + 7: t TUPLE (MARK at 4) + 8: q BINPUT 1 + 10: a APPEND + 11: 1 POP_MARK (MARK at 0) + 12: h BINGET 1 + 14: . STOP +highest protocol among opcodes = 1 + +Try protocol 2. + +>>> dis(pickle.dumps(L, 2)) + 0: \x80 PROTO 2 + 2: ] EMPTY_LIST + 3: q BINPUT 0 + 5: h BINGET 0 + 7: \x85 TUPLE1 + 8: q BINPUT 1 + 10: a APPEND + 11: . STOP +highest protocol among opcodes = 2 + +>>> dis(pickle.dumps(T, 2)) + 0: \x80 PROTO 2 + 2: ] EMPTY_LIST + 3: q BINPUT 0 + 5: h BINGET 0 + 7: \x85 TUPLE1 + 8: q BINPUT 1 + 10: a APPEND + 11: 0 POP + 12: h BINGET 1 + 14: . STOP +highest protocol among opcodes = 2 + +Try protocol 3 with annotations: + +>>> dis(pickle.dumps(T, 3), annotate=1) + 0: \x80 PROTO 3 Protocol version indicator. + 2: ] EMPTY_LIST Push an empty list. + 3: q BINPUT 0 Store the stack top into the memo. The stack is not popped. + 5: h BINGET 0 Read an object from the memo and push it on the stack. + 7: \x85 TUPLE1 Build a one-tuple out of the topmost item on the stack. + 8: q BINPUT 1 Store the stack top into the memo. The stack is not popped. + 10: a APPEND Append an object to a list. + 11: 0 POP Discard the top stack item, shrinking the stack by one item. + 12: h BINGET 1 Read an object from the memo and push it on the stack. + 14: . STOP Stop the unpickling machine. +highest protocol among opcodes = 2 + +""" + +_memo_test = r""" +>>> import pickle +>>> import io +>>> f = io.BytesIO() +>>> p = pickle.Pickler(f, 2) +>>> x = [1, 2, 3] +>>> p.dump(x) +>>> p.dump(x) +>>> f.seek(0) +0 +>>> memo = {} +>>> dis(f, memo=memo) + 0: \x80 PROTO 2 + 2: ] EMPTY_LIST + 3: q BINPUT 0 + 5: ( MARK + 6: K BININT1 1 + 8: K BININT1 2 + 10: K BININT1 3 + 12: e APPENDS (MARK at 5) + 13: . STOP +highest protocol among opcodes = 2 +>>> dis(f, memo=memo) + 14: \x80 PROTO 2 + 16: h BINGET 0 + 18: . STOP +highest protocol among opcodes = 2 +""" + +__test__ = {'disassembler_test': _dis_test, + 'disassembler_memo_test': _memo_test, + } + +def _test(): + import doctest + return doctest.testmod() + +if __name__ == "__main__": + import argparse + parser = argparse.ArgumentParser( + description='disassemble one or more pickle files') + parser.add_argument( + 'pickle_file', + nargs='*', help='the pickle file') + parser.add_argument( + '-o', '--output', + help='the file where the output should be written') + parser.add_argument( + '-m', '--memo', action='store_true', + help='preserve memo between disassemblies') + parser.add_argument( + '-l', '--indentlevel', default=4, type=int, + help='the number of blanks by which to indent a new MARK level') + parser.add_argument( + '-a', '--annotate', action='store_true', + help='annotate each line with a short opcode description') + parser.add_argument( + '-p', '--preamble', default="==> {name} <==", + help='if more than one pickle file is specified, print this before' + ' each disassembly') + parser.add_argument( + '-t', '--test', action='store_true', + help='run self-test suite') + parser.add_argument( + '-v', action='store_true', + help='run verbosely; only affects self-test run') + args = parser.parse_args() + if args.test: + _test() + else: + if not args.pickle_file: + parser.print_help() + else: + annotate = 30 if args.annotate else 0 + memo = {} if args.memo else None + if args.output is None: + output = sys.stdout + else: + output = open(args.output, 'w') + try: + for arg in args.pickle_file: + if len(args.pickle_file) > 1: + name = '<stdin>' if arg == '-' else arg + preamble = args.preamble.format(name=name) + output.write(preamble + '\n') + if arg == '-': + dis(sys.stdin.buffer, output, memo, args.indentlevel, annotate) + else: + with open(arg, 'rb') as f: + dis(f, output, memo, args.indentlevel, annotate) + finally: + if output is not sys.stdout: + output.close() |