##// END OF EJS Templates
repository: teach addgroup() to receive data with missing parents...
repository: teach addgroup() to receive data with missing parents The way the narrow extension works today, the server rewrites outgoing changegroup data to lie about parents when the parents data is missing. It adds the ellipsis flag to the revision so it can be recorded as such in the revlog. In the new wire protocol, such rewriting does not occur on the server (at least not yet anyway). Instead, it is up to the client to recognize when it has received a revision without its parents. This means rewriting will be performed on the client. Furthermore, the mechanism for storing a shallow revision may differ from store to store. For example, the revlog store uses the ellipsis flag to denote a revision's parents have been rewritten. But a non-revlog store may wish to store things differently. And, some stores may not even support receiving shallow revision data! Therefore, it makes sense for the store itself to be making decisions about what to do when they receive revision data without their parents. This commit teaches the addgroup() bulk insert method to accept a boolean argument that indicates whether the incoming data may lack parent revisions. This flag can be set when receiving "shallow" data from a remote. The revlog implementation of this method has been taught to rewrite the missing parent(s) to nullid and to add the ellipsis flag to the revision when a missing parent is encountered. But it only does this if ellipsis flags are enabled on the repo and the incoming data is marked as possibly shallow. An error occurs otherwise. Differential Revision: https://phab.mercurial-scm.org/D5165

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pybser.py
484 lines | 16.6 KiB | text/x-python | PythonLexer
# Copyright 2015 Facebook, Inc.
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# * Redistributions of source code must retain the above copyright notice,
# this list of conditions and the following disclaimer.
#
# * Redistributions in binary form must reproduce the above copyright notice,
# this list of conditions and the following disclaimer in the documentation
# and/or other materials provided with the distribution.
#
# * Neither the name Facebook nor the names of its contributors may be used to
# endorse or promote products derived from this software without specific
# prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
# no unicode literals
import binascii
import collections
import ctypes
import struct
import sys
from . import (
compat,
)
BSER_ARRAY = b'\x00'
BSER_OBJECT = b'\x01'
BSER_BYTESTRING = b'\x02'
BSER_INT8 = b'\x03'
BSER_INT16 = b'\x04'
BSER_INT32 = b'\x05'
BSER_INT64 = b'\x06'
BSER_REAL = b'\x07'
BSER_TRUE = b'\x08'
BSER_FALSE = b'\x09'
BSER_NULL = b'\x0a'
BSER_TEMPLATE = b'\x0b'
BSER_SKIP = b'\x0c'
BSER_UTF8STRING = b'\x0d'
if compat.PYTHON3:
STRING_TYPES = (str, bytes)
unicode = str
def tobytes(i):
return str(i).encode('ascii')
long = int
else:
STRING_TYPES = (unicode, str)
tobytes = bytes
# Leave room for the serialization header, which includes
# our overall length. To make things simpler, we'll use an
# int32 for the header
EMPTY_HEADER = b"\x00\x01\x05\x00\x00\x00\x00"
EMPTY_HEADER_V2 = b"\x00\x02\x00\x00\x00\x00\x05\x00\x00\x00\x00"
def _int_size(x):
"""Return the smallest size int that can store the value"""
if -0x80 <= x <= 0x7F:
return 1
elif -0x8000 <= x <= 0x7FFF:
return 2
elif -0x80000000 <= x <= 0x7FFFFFFF:
return 4
elif long(-0x8000000000000000) <= x <= long(0x7FFFFFFFFFFFFFFF):
return 8
else:
raise RuntimeError('Cannot represent value: ' + str(x))
def _buf_pos(buf, pos):
ret = buf[pos]
# In Python 2, buf is a str array so buf[pos] is a string. In Python 3, buf
# is a bytes array and buf[pos] is an integer.
if compat.PYTHON3:
ret = bytes((ret,))
return ret
class _bser_buffer(object):
def __init__(self, version):
self.bser_version = version
self.buf = ctypes.create_string_buffer(8192)
if self.bser_version == 1:
struct.pack_into(tobytes(len(EMPTY_HEADER)) + b's', self.buf, 0,
EMPTY_HEADER)
self.wpos = len(EMPTY_HEADER)
else:
assert self.bser_version == 2
struct.pack_into(tobytes(len(EMPTY_HEADER_V2)) + b's', self.buf, 0,
EMPTY_HEADER_V2)
self.wpos = len(EMPTY_HEADER_V2)
def ensure_size(self, size):
while ctypes.sizeof(self.buf) - self.wpos < size:
ctypes.resize(self.buf, ctypes.sizeof(self.buf) * 2)
def append_long(self, val):
size = _int_size(val)
to_write = size + 1
self.ensure_size(to_write)
if size == 1:
struct.pack_into(b'=cb', self.buf, self.wpos, BSER_INT8, val)
elif size == 2:
struct.pack_into(b'=ch', self.buf, self.wpos, BSER_INT16, val)
elif size == 4:
struct.pack_into(b'=ci', self.buf, self.wpos, BSER_INT32, val)
elif size == 8:
struct.pack_into(b'=cq', self.buf, self.wpos, BSER_INT64, val)
else:
raise RuntimeError('Cannot represent this long value')
self.wpos += to_write
def append_string(self, s):
if isinstance(s, unicode):
s = s.encode('utf-8')
s_len = len(s)
size = _int_size(s_len)
to_write = 2 + size + s_len
self.ensure_size(to_write)
if size == 1:
struct.pack_into(b'=ccb' + tobytes(s_len) + b's', self.buf,
self.wpos, BSER_BYTESTRING, BSER_INT8, s_len, s)
elif size == 2:
struct.pack_into(b'=cch' + tobytes(s_len) + b's', self.buf,
self.wpos, BSER_BYTESTRING, BSER_INT16, s_len, s)
elif size == 4:
struct.pack_into(b'=cci' + tobytes(s_len) + b's', self.buf,
self.wpos, BSER_BYTESTRING, BSER_INT32, s_len, s)
elif size == 8:
struct.pack_into(b'=ccq' + tobytes(s_len) + b's', self.buf,
self.wpos, BSER_BYTESTRING, BSER_INT64, s_len, s)
else:
raise RuntimeError('Cannot represent this string value')
self.wpos += to_write
def append_recursive(self, val):
if isinstance(val, bool):
needed = 1
self.ensure_size(needed)
if val:
to_encode = BSER_TRUE
else:
to_encode = BSER_FALSE
struct.pack_into(b'=c', self.buf, self.wpos, to_encode)
self.wpos += needed
elif val is None:
needed = 1
self.ensure_size(needed)
struct.pack_into(b'=c', self.buf, self.wpos, BSER_NULL)
self.wpos += needed
elif isinstance(val, (int, long)):
self.append_long(val)
elif isinstance(val, STRING_TYPES):
self.append_string(val)
elif isinstance(val, float):
needed = 9
self.ensure_size(needed)
struct.pack_into(b'=cd', self.buf, self.wpos, BSER_REAL, val)
self.wpos += needed
elif isinstance(val, collections.Mapping) and \
isinstance(val, collections.Sized):
val_len = len(val)
size = _int_size(val_len)
needed = 2 + size
self.ensure_size(needed)
if size == 1:
struct.pack_into(b'=ccb', self.buf, self.wpos, BSER_OBJECT,
BSER_INT8, val_len)
elif size == 2:
struct.pack_into(b'=cch', self.buf, self.wpos, BSER_OBJECT,
BSER_INT16, val_len)
elif size == 4:
struct.pack_into(b'=cci', self.buf, self.wpos, BSER_OBJECT,
BSER_INT32, val_len)
elif size == 8:
struct.pack_into(b'=ccq', self.buf, self.wpos, BSER_OBJECT,
BSER_INT64, val_len)
else:
raise RuntimeError('Cannot represent this mapping value')
self.wpos += needed
if compat.PYTHON3:
iteritems = val.items()
else:
iteritems = val.iteritems()
for k, v in iteritems:
self.append_string(k)
self.append_recursive(v)
elif isinstance(val, collections.Iterable) and \
isinstance(val, collections.Sized):
val_len = len(val)
size = _int_size(val_len)
needed = 2 + size
self.ensure_size(needed)
if size == 1:
struct.pack_into(b'=ccb', self.buf, self.wpos, BSER_ARRAY,
BSER_INT8, val_len)
elif size == 2:
struct.pack_into(b'=cch', self.buf, self.wpos, BSER_ARRAY,
BSER_INT16, val_len)
elif size == 4:
struct.pack_into(b'=cci', self.buf, self.wpos, BSER_ARRAY,
BSER_INT32, val_len)
elif size == 8:
struct.pack_into(b'=ccq', self.buf, self.wpos, BSER_ARRAY,
BSER_INT64, val_len)
else:
raise RuntimeError('Cannot represent this sequence value')
self.wpos += needed
for v in val:
self.append_recursive(v)
else:
raise RuntimeError('Cannot represent unknown value type')
def dumps(obj, version=1, capabilities=0):
bser_buf = _bser_buffer(version=version)
bser_buf.append_recursive(obj)
# Now fill in the overall length
if version == 1:
obj_len = bser_buf.wpos - len(EMPTY_HEADER)
struct.pack_into(b'=i', bser_buf.buf, 3, obj_len)
else:
obj_len = bser_buf.wpos - len(EMPTY_HEADER_V2)
struct.pack_into(b'=i', bser_buf.buf, 2, capabilities)
struct.pack_into(b'=i', bser_buf.buf, 7, obj_len)
return bser_buf.buf.raw[:bser_buf.wpos]
# This is a quack-alike with the bserObjectType in bser.c
# It provides by getattr accessors and getitem for both index
# and name.
class _BunserDict(object):
__slots__ = ('_keys', '_values')
def __init__(self, keys, values):
self._keys = keys
self._values = values
def __getattr__(self, name):
return self.__getitem__(name)
def __getitem__(self, key):
if isinstance(key, (int, long)):
return self._values[key]
elif key.startswith('st_'):
# hack^Wfeature to allow mercurial to use "st_size" to
# reference "size"
key = key[3:]
try:
return self._values[self._keys.index(key)]
except ValueError as ex:
raise KeyError('_BunserDict has no key %s' % key)
def __len__(self):
return len(self._keys)
class Bunser(object):
def __init__(self, mutable=True, value_encoding=None, value_errors=None):
self.mutable = mutable
self.value_encoding = value_encoding
if value_encoding is None:
self.value_errors = None
elif value_errors is None:
self.value_errors = 'strict'
else:
self.value_errors = value_errors
@staticmethod
def unser_int(buf, pos):
try:
int_type = _buf_pos(buf, pos)
except IndexError:
raise ValueError('Invalid bser int encoding, pos out of range')
if int_type == BSER_INT8:
needed = 2
fmt = b'=b'
elif int_type == BSER_INT16:
needed = 3
fmt = b'=h'
elif int_type == BSER_INT32:
needed = 5
fmt = b'=i'
elif int_type == BSER_INT64:
needed = 9
fmt = b'=q'
else:
raise ValueError('Invalid bser int encoding 0x%s' %
binascii.hexlify(int_type).decode('ascii'))
int_val = struct.unpack_from(fmt, buf, pos + 1)[0]
return (int_val, pos + needed)
def unser_utf8_string(self, buf, pos):
str_len, pos = self.unser_int(buf, pos + 1)
str_val = struct.unpack_from(tobytes(str_len) + b's', buf, pos)[0]
return (str_val.decode('utf-8'), pos + str_len)
def unser_bytestring(self, buf, pos):
str_len, pos = self.unser_int(buf, pos + 1)
str_val = struct.unpack_from(tobytes(str_len) + b's', buf, pos)[0]
if self.value_encoding is not None:
str_val = str_val.decode(self.value_encoding, self.value_errors)
# str_len stays the same because that's the length in bytes
return (str_val, pos + str_len)
def unser_array(self, buf, pos):
arr_len, pos = self.unser_int(buf, pos + 1)
arr = []
for i in range(arr_len):
arr_item, pos = self.loads_recursive(buf, pos)
arr.append(arr_item)
if not self.mutable:
arr = tuple(arr)
return arr, pos
def unser_object(self, buf, pos):
obj_len, pos = self.unser_int(buf, pos + 1)
if self.mutable:
obj = {}
else:
keys = []
vals = []
for i in range(obj_len):
key, pos = self.unser_utf8_string(buf, pos)
val, pos = self.loads_recursive(buf, pos)
if self.mutable:
obj[key] = val
else:
keys.append(key)
vals.append(val)
if not self.mutable:
obj = _BunserDict(keys, vals)
return obj, pos
def unser_template(self, buf, pos):
val_type = _buf_pos(buf, pos + 1)
if val_type != BSER_ARRAY:
raise RuntimeError('Expect ARRAY to follow TEMPLATE')
# force UTF-8 on keys
keys_bunser = Bunser(mutable=self.mutable, value_encoding='utf-8')
keys, pos = keys_bunser.unser_array(buf, pos + 1)
nitems, pos = self.unser_int(buf, pos)
arr = []
for i in range(nitems):
if self.mutable:
obj = {}
else:
vals = []
for keyidx in range(len(keys)):
if _buf_pos(buf, pos) == BSER_SKIP:
pos += 1
ele = None
else:
ele, pos = self.loads_recursive(buf, pos)
if self.mutable:
key = keys[keyidx]
obj[key] = ele
else:
vals.append(ele)
if not self.mutable:
obj = _BunserDict(keys, vals)
arr.append(obj)
return arr, pos
def loads_recursive(self, buf, pos):
val_type = _buf_pos(buf, pos)
if (val_type == BSER_INT8 or val_type == BSER_INT16 or
val_type == BSER_INT32 or val_type == BSER_INT64):
return self.unser_int(buf, pos)
elif val_type == BSER_REAL:
val = struct.unpack_from(b'=d', buf, pos + 1)[0]
return (val, pos + 9)
elif val_type == BSER_TRUE:
return (True, pos + 1)
elif val_type == BSER_FALSE:
return (False, pos + 1)
elif val_type == BSER_NULL:
return (None, pos + 1)
elif val_type == BSER_BYTESTRING:
return self.unser_bytestring(buf, pos)
elif val_type == BSER_UTF8STRING:
return self.unser_utf8_string(buf, pos)
elif val_type == BSER_ARRAY:
return self.unser_array(buf, pos)
elif val_type == BSER_OBJECT:
return self.unser_object(buf, pos)
elif val_type == BSER_TEMPLATE:
return self.unser_template(buf, pos)
else:
raise ValueError('unhandled bser opcode 0x%s' %
binascii.hexlify(val_type).decode('ascii'))
def _pdu_info_helper(buf):
bser_version = -1
if buf[0:2] == EMPTY_HEADER[0:2]:
bser_version = 1
bser_capabilities = 0
expected_len, pos2 = Bunser.unser_int(buf, 2)
elif buf[0:2] == EMPTY_HEADER_V2[0:2]:
if len(buf) < 8:
raise ValueError('Invalid BSER header')
bser_version = 2
bser_capabilities = struct.unpack_from("I", buf, 2)[0]
expected_len, pos2 = Bunser.unser_int(buf, 6)
else:
raise ValueError('Invalid BSER header')
return bser_version, bser_capabilities, expected_len, pos2
def pdu_info(buf):
info = _pdu_info_helper(buf)
return info[0], info[1], info[2] + info[3]
def pdu_len(buf):
info = _pdu_info_helper(buf)
return info[2] + info[3]
def loads(buf, mutable=True, value_encoding=None, value_errors=None):
"""Deserialize a BSER-encoded blob.
@param buf: The buffer to deserialize.
@type buf: bytes
@param mutable: Whether to return mutable results.
@type mutable: bool
@param value_encoding: Optional codec to use to decode values. If
unspecified or None, return values as bytestrings.
@type value_encoding: str
@param value_errors: Optional error handler for codec. 'strict' by default.
The other most common argument is 'surrogateescape' on
Python 3. If value_encoding is None, this is ignored.
@type value_errors: str
"""
info = _pdu_info_helper(buf)
expected_len = info[2]
pos = info[3]
if len(buf) != expected_len + pos:
raise ValueError('bser data len != header len')
bunser = Bunser(mutable=mutable, value_encoding=value_encoding,
value_errors=value_errors)
return bunser.loads_recursive(buf, pos)[0]
def load(fp, mutable=True, value_encoding=None, value_errors=None):
from . import load
return load.load(fp, mutable, value_encoding, value_errors)