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rq.py
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1464 lines (1093 loc) · 42.5 KB
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# Xlib.protocol.rq -- structure primitives for request, events and errors
#
# Copyright (C) 2000-2002 Peter Liljenberg <petli@ctrl-c.liu.se>
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public License
# as published by the Free Software Foundation; either version 2.1
# of the License, or (at your option) any later version.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
# See the GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the
# Free Software Foundation, Inc.,
# 59 Temple Place,
# Suite 330,
# Boston, MA 02111-1307 USA
# Standard modules
import sys
import traceback
import struct
from array import array
import types
# Python 2/3 compatibility.
from six import PY3, binary_type, byte2int, indexbytes, iterbytes
# Xlib modules
from .. import X
from ..support import lock
def decode_string(bs):
return bs.decode('latin1')
if PY3:
def encode_array(a):
return a.tobytes()
else:
def encode_array(a):
return a.tostring()
class BadDataError(Exception): pass
# These are struct codes, we know their byte sizes
signed_codes = { 1: 'b', 2: 'h', 4: 'l' }
unsigned_codes = { 1: 'B', 2: 'H', 4: 'L' }
# Unfortunately, we don't know the array sizes of B, H and L, since
# these use the underlying architecture's size for a char, short and
# long. Therefore we probe for their sizes, and additionally create
# a mapping that translates from struct codes to array codes.
#
# Bleah.
array_unsigned_codes = { }
struct_to_array_codes = { }
for c in 'bhil':
size = array(c).itemsize
array_unsigned_codes[size] = c.upper()
try:
struct_to_array_codes[signed_codes[size]] = c
struct_to_array_codes[unsigned_codes[size]] = c.upper()
except KeyError:
pass
# print array_unsigned_codes, struct_to_array_codes
class Field(object):
"""Field objects represent the data fields of a Struct.
Field objects must have the following attributes:
name -- the field name, or None
structcode -- the struct codes representing this field
structvalues -- the number of values encodes by structcode
Additionally, these attributes should either be None or real methods:
check_value -- check a value before it is converted to binary
parse_value -- parse a value after it has been converted from binary
If one of these attributes are None, no check or additional
parsings will be done one values when converting to or from binary
form. Otherwise, the methods should have the following behaviour:
newval = check_value(val)
Check that VAL is legal when converting to binary form. The
value can also be converted to another Python value. In any
case, return the possibly new value. NEWVAL should be a
single Python value if structvalues is 1, a tuple of
structvalues elements otherwise.
newval = parse_value(val, display)
VAL is an unpacked Python value, which now can be further
refined. DISPLAY is the current Display object. Return the
new value. VAL will be a single value if structvalues is 1,
a tuple of structvalues elements otherwise.
If `structcode' is None the Field must have the method
f.parse_binary_value() instead. See its documentation string for
details.
"""
name = None
default = None
structcode = None
structvalues = 0
check_value = None
parse_value = None
keyword_args = 0
def __init__(self):
pass
def parse_binary_value(self, data, display, length, format):
"""value, remaindata = f.parse_binary_value(data, display, length, format)
Decode a value for this field from the binary string DATA.
If there are a LengthField and/or a FormatField connected to this
field, their values will be LENGTH and FORMAT, respectively. If
there are no such fields the parameters will be None.
DISPLAY is the display involved, which is really only used by
the Resource fields.
The decoded value is returned as VALUE, and the remaining part
of DATA shold be returned as REMAINDATA.
"""
raise RuntimeError('Neither structcode or parse_binary_value ' \
'provided for {0}'.format(self))
class Pad(Field):
def __init__(self, size):
self.size = size
self.value = b'\0' * size
self.structcode = '{0}x'.format(size)
self.structvalues = 0
class ConstantField(Field):
def __init__(self, value):
self.value = value
class Opcode(ConstantField):
structcode = 'B'
structvalues = 1
class ReplyCode(ConstantField):
structcode = 'B'
structvalues = 1
def __init__(self):
self.value = 1
class LengthField(Field):
"""A LengthField stores the length of some other Field whose size
may vary, e.g. List and String8.
Its name should be the same as the name of the field whose size
it stores. The other_fields attribute can be used to specify the
names of other fields whose sizes are stored by this field, so
a single length field can set the length of multiple fields.
The lf.get_binary_value() method of LengthFields is not used, instead
a lf.get_binary_length() should be provided.
Unless LengthField.get_binary_length() is overridden in child classes,
there should also be a lf.calc_length().
"""
structcode = 'L'
structvalues = 1
other_fields = None
def calc_length(self, length):
"""newlen = lf.calc_length(length)
Return a new length NEWLEN based on the provided LENGTH.
"""
return length
class TotalLengthField(LengthField):
pass
class RequestLength(TotalLengthField):
structcode = 'H'
structvalues = 1
def calc_length(self, length):
return length // 4
class ReplyLength(TotalLengthField):
structcode = 'L'
structvalues = 1
def calc_length(self, length):
return (length - 32) // 4
class LengthOf(LengthField):
def __init__(self, name, size):
if isinstance(name, (list, tuple)):
self.name = name[0]
self.other_fields = name[1:]
else:
self.name = name
self.structcode = unsigned_codes[size]
class OddLength(LengthField):
structcode = 'B'
structvalues = 1
def __init__(self, name):
self.name = name
def calc_length(self, length):
return length % 2
def parse_value(self, value, display):
if value == 0:
return 'even'
else:
return 'odd'
class FormatField(Field):
"""A FormatField encodes the format of some other field, in a manner
similar to LengthFields.
The ff.get_binary_value() method is not used, replaced by
ff.get_binary_format().
"""
structvalues = 1
def __init__(self, name, size):
self.name = name
self.structcode = unsigned_codes[size]
Format = FormatField
class ValueField(Field):
def __init__(self, name, default = None):
self.name = name
self.default = default
class Int8(ValueField):
structcode = 'b'
structvalues = 1
class Int16(ValueField):
structcode = 'h'
structvalues = 1
class Int32(ValueField):
structcode = 'l'
structvalues = 1
class Card8(ValueField):
structcode = 'B'
structvalues = 1
class Card16(ValueField):
structcode = 'H'
structvalues = 1
class Card32(ValueField):
structcode = 'L'
structvalues = 1
class Resource(Card32):
cast_function = '__resource__'
class_name = 'resource'
def __init__(self, name, codes = (), default = None):
Card32.__init__(self, name, default)
self.codes = codes
def check_value(self, value):
if hasattr(value, self.cast_function):
return getattr(value, self.cast_function)()
else:
return value
def parse_value(self, value, display):
# if not display:
# return value
if value in self.codes:
return value
c = display.get_resource_class(self.class_name)
if c:
return c(display, value)
else:
return value
class Window(Resource):
cast_function = '__window__'
class_name = 'window'
class Pixmap(Resource):
cast_function = '__pixmap__'
class_name = 'pixmap'
class Drawable(Resource):
cast_function = '__drawable__'
class_name = 'drawable'
class Fontable(Resource):
cast_function = '__fontable__'
class_name = 'fontable'
class Font(Resource):
cast_function = '__font__'
class_name = 'font'
class GC(Resource):
cast_function = '__gc__'
class_name = 'gc'
class Colormap(Resource):
cast_function = '__colormap__'
class_name = 'colormap'
class Cursor(Resource):
cast_function = '__cursor__'
class_name = 'cursor'
class Bool(ValueField):
structvalues = 1
structcode = 'B'
def check_value(self, value):
return not not value
class Set(ValueField):
structvalues = 1
def __init__(self, name, size, values, default = None):
ValueField.__init__(self, name, default)
self.structcode = unsigned_codes[size]
self.values = values
def check_value(self, val):
if val not in self.values:
raise ValueError('field %s: argument %s not in %s'
% (self.name, val, self.values))
return val
class Gravity(Set):
def __init__(self, name):
Set.__init__(self, name, 1, (X.ForgetGravity, X.StaticGravity,
X.NorthWestGravity, X.NorthGravity,
X.NorthEastGravity, X.WestGravity,
X.CenterGravity, X.EastGravity,
X.SouthWestGravity, X.SouthGravity,
X.SouthEastGravity))
class FixedBinary(ValueField):
structvalues = 1
def __init__(self, name, size):
ValueField.__init__(self, name)
self.structcode = '{0}s'.format(size)
class Binary(ValueField):
structcode = None
def __init__(self, name, pad = 1):
ValueField.__init__(self, name)
self.pad = pad
def pack_value(self, val):
val_bytes = val
slen = len(val_bytes)
if self.pad:
return val_bytes + b'\0' * ((4 - slen % 4) % 4), slen, None
else:
return val_bytes, slen, None
def parse_binary_value(self, data, display, length, format):
if length is None:
return data, b''
if self.pad:
slen = length + ((4 - length % 4) % 4)
else:
slen = length
return data[:length], data[slen:]
class String8(ValueField):
structcode = None
def __init__(self, name, pad = 1):
ValueField.__init__(self, name)
self.pad = pad
def pack_value(self, val):
if isinstance(val, bytes):
val_bytes = val
else:
val_bytes = val.encode()
slen = len(val_bytes)
if self.pad:
return val_bytes + b'\0' * ((4 - slen % 4) % 4), slen, None
else:
return val_bytes, slen, None
def parse_binary_value(self, data, display, length, format):
if length is None:
return decode_string(data), b''
if self.pad:
slen = length + ((4 - length % 4) % 4)
else:
slen = length
data_str = decode_string(data[:length])
return data_str, data[slen:]
class String16(ValueField):
structcode = None
def __init__(self, name, pad = 1):
ValueField.__init__(self, name)
self.pad = pad
def pack_value(self, val):
"""Convert 8-byte string into 16-byte list"""
if isinstance(val, bytes):
val = list(iterbytes(val))
slen = len(val)
if self.pad:
pad = b'\0\0' * (slen % 2)
else:
pad = b''
return struct.pack('>' + 'H' * slen, *val) + pad, slen, None
def parse_binary_value(self, data, display, length, format):
if length == 'odd':
length = len(data) // 2 - 1
elif length == 'even':
length = len(data) // 2
if self.pad:
slen = length + (length % 2)
else:
slen = length
return struct.unpack('>' + 'H' * length, data[:length * 2]), data[slen * 2:]
class List(ValueField):
"""The List, FixedList and Object fields store compound data objects.
The type of data objects must be provided as an object with the
following attributes and methods:
...
"""
structcode = None
def __init__(self, name, type, pad = 1):
ValueField.__init__(self, name)
self.type = type
self.pad = pad
def parse_binary_value(self, data, display, length, format):
if length is None:
ret = []
if self.type.structcode is None:
while data:
val, data = self.type.parse_binary(data, display)
ret.append(val)
else:
scode = '=' + self.type.structcode
slen = struct.calcsize(scode)
pos = 0
while pos + slen <= len(data):
v = struct.unpack(scode, data[pos: pos + slen])
if self.type.structvalues == 1:
v = v[0]
if self.type.parse_value is None:
ret.append(v)
else:
ret.append(self.type.parse_value(v, display))
pos = pos + slen
data = data[pos:]
else:
ret = [None] * int(length)
if self.type.structcode is None:
for i in range(0, length):
ret[i], data = self.type.parse_binary(data, display)
else:
scode = '=' + self.type.structcode
slen = struct.calcsize(scode)
pos = 0
for i in range(0, length):
v = struct.unpack(scode, data[pos: pos + slen])
if self.type.structvalues == 1:
v = v[0]
if self.type.parse_value is None:
ret[i] = v
else:
ret[i] = self.type.parse_value(v, display)
pos = pos + slen
data = data[pos:]
if self.pad:
data = data[len(data) % 4:]
return ret, data
def pack_value(self, val):
# Single-char values, we'll assume that means integer lists.
if self.type.structcode and len(self.type.structcode) == 1:
if self.type.check_value is not None:
val = [self.type.check_value(v) for v in val]
a = array(struct_to_array_codes[self.type.structcode], val)
data = encode_array(a)
else:
data = []
for v in val:
data.append(self.type.pack_value(v))
data = b''.join(data)
if self.pad:
dlen = len(data)
data = data + b'\0' * ((4 - dlen % 4) % 4)
return data, len(val), None
class FixedList(List):
def __init__(self, name, size, type, pad = 1):
List.__init__(self, name, type, pad)
self.size = size
def parse_binary_value(self, data, display, length, format):
return List.parse_binary_value(self, data, display, self.size, format)
def pack_value(self, val):
if len(val) != self.size:
raise BadDataError('length mismatch for FixedList %s' % self.name)
return List.pack_value(self, val)
class Object(ValueField):
def __init__(self, name, type, default = None):
ValueField.__init__(self, name, default)
self.type = type
self.structcode = self.type.structcode
self.structvalues = self.type.structvalues
def parse_binary_value(self, data, display, length, format):
return self.type.parse_binary(data, display)
def parse_value(self, val, display):
return self.type.parse_value(val, display)
def pack_value(self, val):
return self.type.pack_value(val)
def check_value(self, val):
if isinstance(val, tuple):
vals = []
i = 0
for f in self.type.fields:
if f.name:
if f.check_value is None:
v = val[i]
else:
v = f.check_value(val[i])
if f.structvalues == 1:
vals.append(v)
else:
vals.extend(v)
i = i + 1
return vals
if isinstance(val, dict):
data = val
elif isinstance(val, DictWrapper):
data = val._data
else:
raise TypeError('Object value must be tuple, dictionary or DictWrapper: %s' % val)
vals = []
for f in self.type.fields:
if f.name:
if f.check_value is None:
v = data[f.name]
else:
v = f.check_value(data[f.name])
if f.structvalues == 1:
vals.append(v)
else:
vals.extend(v)
return vals
class PropertyData(ValueField):
structcode = None
def parse_binary_value(self, data, display, length, format):
if length is None:
length = len(data) // (format // 8)
else:
length = int(length)
if format == 0:
ret = None
elif format == 8:
ret = (8, data[:length])
data = data[length + ((4 - length % 4) % 4):]
elif format == 16:
ret = (16, array(array_unsigned_codes[2], data[:2 * length]))
data = data[2 * (length + length % 2):]
elif format == 32:
ret = (32, array(array_unsigned_codes[4], data[:4 * length]))
data = data[4 * length:]
return ret, data
def pack_value(self, value):
fmt, val = value
if fmt not in (8, 16, 32):
raise BadDataError('Invalid property data format {0}'.format(fmt))
if isinstance(val, binary_type):
size = fmt // 8
vlen = len(val)
if vlen % size:
vlen = vlen - vlen % size
data = val[:vlen]
else:
data = val
dlen = vlen // size
else:
if isinstance(val, tuple):
val = list(val)
size = fmt // 8
a = array(array_unsigned_codes[size], val)
data = encode_array(a)
dlen = len(val)
dl = len(data)
data = data + b'\0' * ((4 - dl % 4) % 4)
return data, dlen, fmt
class FixedPropertyData(PropertyData):
def __init__(self, name, size):
PropertyData.__init__(self, name)
self.size = size
def parse_binary_value(self, data, display, length, format):
return PropertyData.parse_binary_value(self, data, display,
self.size // (format // 8), format)
def pack_value(self, value):
data, dlen, fmt = PropertyData.pack_value(self, value)
if len(data) != self.size:
raise BadDataError('Wrong data length for FixedPropertyData: %s'
% (value, ))
return data, dlen, fmt
class ValueList(Field):
structcode = None
keyword_args = 1
default = 'usekeywords'
def __init__(self, name, mask, pad, *fields):
self.name = name
self.maskcode = '={0}{1}x'.format(unsigned_codes[mask], pad).encode()
self.maskcodelen = struct.calcsize(self.maskcode)
self.fields = []
flag = 1
for f in fields:
if f.name:
self.fields.append((f, flag))
flag = flag << 1
def pack_value(self, arg, keys):
mask = 0
data = b''
if arg == self.default:
arg = keys
for field, flag in self.fields:
if field.name in arg:
mask = mask | flag
val = arg[field.name]
if field.check_value is not None:
val = field.check_value(val)
d = struct.pack('=' + field.structcode, val)
data = data + d + b'\0' * (4 - len(d))
return struct.pack(self.maskcode, mask) + data, None, None
def parse_binary_value(self, data, display, length, format):
r = {}
mask = int(struct.unpack(self.maskcode, data[:self.maskcodelen])[0])
data = data[self.maskcodelen:]
for field, flag in self.fields:
if mask & flag:
if field.structcode:
vals = struct.unpack('=' + field.structcode,
data[:struct.calcsize('=' + field.structcode)])
if field.structvalues == 1:
vals = vals[0]
if field.parse_value is not None:
vals = field.parse_value(vals, display)
else:
vals, d = field.parse_binary_value(data[:4], display, None, None)
r[field.name] = vals
data = data[4:]
return DictWrapper(r), data
class KeyboardMapping(ValueField):
structcode = None
def parse_binary_value(self, data, display, length, format):
if length is None:
dlen = len(data)
else:
dlen = 4 * length * format
a = array(array_unsigned_codes[4], bytes(data[:dlen]))
ret = []
for i in range(0, len(a), format):
ret.append(a[i : i + format])
return ret, data[dlen:]
def pack_value(self, value):
keycodes = 0
for v in value:
keycodes = max(keycodes, len(v))
a = array(array_unsigned_codes[4])
for v in value:
for k in v:
a.append(k)
for i in range(len(v), keycodes):
a.append(X.NoSymbol)
return encode_array(a), len(value), keycodes
class ModifierMapping(ValueField):
structcode = None
def parse_binary_value(self, data, display, length, format):
a = array(array_unsigned_codes[1], data[:8 * format])
ret = []
for i in range(0, 8):
ret.append(a[i * format : (i + 1) * format])
return ret, data[8 * format:]
def pack_value(self, value):
if len(value) != 8:
raise BadDataError('ModifierMapping list should have eight elements')
keycodes = 0
for v in value:
keycodes = max(keycodes, len(v))
a = array(array_unsigned_codes[1])
for v in value:
for k in v:
a.append(k)
for i in range(len(v), keycodes):
a.append(0)
return encode_array(a), len(value), keycodes
class EventField(ValueField):
structcode = None
def pack_value(self, value):
if not isinstance(value, Event):
raise BadDataError('%s is not an Event for field %s' % (value, self.name))
return value._binary, None, None
def parse_binary_value(self, data, display, length, format):
from . import event
estruct = display.event_classes.get(byte2int(data) & 0x7f, event.AnyEvent)
if type(estruct) == dict:
# this etype refers to a set of sub-events with individual subcodes
estruct = estruct[indexbytes(data, 1)]
return estruct(display = display, binarydata = data[:32]), data[32:]
#
# Objects usable for List and FixedList fields.
# Struct is also usable.
#
class ScalarObj(object):
def __init__(self, code):
self.structcode = code
self.structvalues = 1
self.parse_value = None
self.check_value = None
Card8Obj = ScalarObj('B')
Card16Obj = ScalarObj('H')
Card32Obj = ScalarObj('L')
class ResourceObj(object):
structcode = 'L'
structvalues = 1
def __init__(self, class_name):
self.class_name = class_name
9ABB
self.check_value = None
def parse_value(self, value, display):
# if not display:
# return value
c = display.get_resource_class(self.class_name)
if c:
return c(display, value)
else:
return value
WindowObj = ResourceObj('window')
ColormapObj = ResourceObj('colormap')
class StrClass(object):
structcode = None
def pack_value(self, val):
return (chr(len(val)) + val).encode()
def parse_binary(self, data, display):
slen = byte2int(data) + 1
return decode_string(data[1:slen]), data[slen:]
Str = StrClass()
class Struct(object):
"""Struct objects represents a binary data structure. It can
contain both fields with static and dynamic sizes. However, all
static fields must appear before all dynamic fields.
Fields are represented by various subclasses of the abstract base
class Field. The fields of a structure are given as arguments
when instantiating a Struct object.
Struct objects have two public methods:
to_binary() -- build a binary representation of the structure
with the values given as arguments
parse_binary() -- convert a binary (string) representation into
a Python dictionary or object.
These functions will be generated dynamically for each Struct
object to make conversion as fast as possible. They are
generated the first time the methods are called.
"""
def __init__(self, *fields):
self.fields = fields
# Structures for to_binary, parse_value and parse_binary
self.static_codes = '='
self.static_values = 0
self.static_fields = []
self.static_size = None
self.var_fields = []
for f in self.fields:
# Append structcode if there is one and we haven't
# got any varsize fields yet.
if f.structcode is not None:
assert not self.var_fields
self.static_codes = self.static_codes + f.structcode
# Only store fields with values
if f.structvalues > 0:
self.static_fields.append(f)
self.static_values = self.static_values + f.structvalues
# If we have got one varsize field, all the rest must
# also be varsize fields.
else:
self.var_fields.append(f)
self.static_size = struct.calcsize(self.static_codes)
if self.var_fields:
self.structcode = None
self.structvalues = 0
else:
self.structcode = self.static_codes[1:]
self.structvalues = self.static_values
# These functions get called only once, as they will override
# themselves with dynamically created functions in the Struct
# object
def to_binary(self, *varargs, **keys):
"""data = s.to_binary(...)
Convert Python values into the binary representation. The
arguments will be all value fields with names, in the order
given when the Struct object was instantiated. With one
exception: fields with default arguments will be last.
Returns the binary representation as the string DATA.
"""
# Emulate Python function argument handling with our field names
names = [f.name for f in self.fields \
if isinstance(f, ValueField) and f.name]
field_args = dict(zip(names, varargs))
if set(field_args).intersection(keys):
dupes = ", ".join(set(field_args).intersection(keys))
raise TypeError("{0} arguments were passed both positionally and by keyword".format(dupes))
field_args.update(keys)