# Xlib.protocol.rq -- structure primitives for request, events and errors
#
# Copyright (C) 2000-2002 Peter Liljenberg <petli@ctrl-c.liu.se>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; 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
import string
from array import array
import types
import new
# Xlib modules
from Xlib import X
from Xlib.support import lock
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] = string.upper(c)
try:
struct_to_array_codes[signed_codes[size]] = c
struct_to_array_codes[unsigned_codes[size]] = string.upper(c)
except KeyError:
pass
# print array_unsigned_codes, struct_to_array_codes
class Field:
"""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 %s'
% self)
class Pad(Field):
def __init__(self, size):
self.size = size
self.value = '\0' * size
self.structcode = '%dx' % 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 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
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):
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 type(value) is types.InstanceType:
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 FixedString(ValueField):
structvalues = 1
def __init__(self, name, size):
ValueField.__init__(self, name)
self.structcode = '%ds' % size
class String8(ValueField):
structcode = None
def __init__(self, name, pad = 1):
ValueField.__init__(self, name)
self.pad = pad
def pack_value(self, val):
slen = len(val)
if self.pad:
return val + '\0' * ((4 - slen % 4) % 4), slen, None
else:
return val, slen, None
def parse_binary_value(self, data, display, length, format):
if length is None:
return str(data), ''
if self.pad:
slen = length + ((4 - length % 4) % 4)
else:
slen = length
return str(data[:length]), buffer(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 type(val) is types.StringType:
val = map(lambda c: ord(c), val)
slen = len(val)
if self.pad:
pad = '\0\0' * (slen % 2)
else:
pad = ''
return apply(struct.pack, ('>' + 'H' * slen, ) + tuple(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]), buffer(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 = buffer(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 = buffer(data, pos)
if self.pad:
data = buffer(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:
data = array(struct_to_array_codes[self.type.structcode],
val).tostring()
else:
data = []
for v in val:
data.append(self.type.pack_value(v))
data = string.join(data, '')
if self.pad:
dlen = len(data)
data = data + '\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):
structcode = None
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):
if self.type.structcode is None:
return self.type.parse_binary(data, display)
else:
scode = '=' + self.type.structcode
slen = struct.calcsize(scode)
v = struct.unpack(scode, data[:slen])
if self.type.structvalues == 1:
v = v[0]
if self.type.parse_value is not None:
v = self.type.parse_value(v, display)
return v, buffer(data, slen)
def parse_value(self, val, display):
if self.type.parse_value is None:
return val
else:
return self.type.parse_value(val, display)
def pack_value(self, val):
# Single-char values, we'll assume that mean an integer
if self.type.structcode and len(self.type.structcode) == 1:
return struct.pack('=' + self.type.structcode, val), None, None
else:
return self.type.pack_value(val)
def check_value(self, val):
if self.type.structcode is None:
return val
if type(val) is types.TupleType:
return val
if type(val) is types.DictType:
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:
vals.append(data[f.name])
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, str(data[:length]))
data = buffer(data, length + ((4 - length % 4) % 4))
elif format == 16:
ret = (16, array(array_unsigned_codes[2], str(data[:2 * length])))
data = buffer(data, 2 * (length + length % 2))
elif format == 32:
ret = (32, array(array_unsigned_codes[4], str(data[:4 * length])))
data = buffer(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 %d' % fmt)
if type(val) is types.StringType:
size = fmt / 8
vlen = len(val)
if vlen % size:
vlen = vlen - vlen % size
data = val[:vlen]
else:
data = val
dlen = vlen / size
else:
if type(val) is types.TupleType:
val = list(val)
size = fmt / 8
data = array(array_unsigned_codes[size], val).tostring()
dlen = len(val)
dl = len(data)
data = data + '\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 = '=%s%dx' % (unsigned_codes[mask], pad)
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 = ''
if arg == self.default:
arg = keys
for field, flag in self.fields:
if arg.has_key(field.name):
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 + '\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 = buffer(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 = buffer(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], str(data[:dlen]))
ret = []
for i in range(0, len(a), format):
ret.append(a[i : i + format])
return ret, buffer(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 a.tostring(), len(value), keycodes
class ModifierMapping(ValueField):
structcode = None
def parse_binary_value(self, data, display, length, format):
a = array(array_unsigned_codes[1], str(data[:8 * format]))
ret = []
for i in range(0, 8):
ret.append(a[i * format : (i + 1) * format])
return ret, buffer(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 a.tostring(), 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):
import event
estruct = display.event_classes.get(ord(data[0]) & 0x7f, event.AnyEvent)
return estruct(display = display, binarydata = data[:32]), buffer(data, 32)
#
# Objects usable for List and FixedList fields.
# Struct is also usable.
#
class ScalarObj:
def __init__(self, code):
self.structcode = code
self.structvalues = 1
self.parse_value = None
Card8Obj = ScalarObj('B')
Card16Obj = ScalarObj('H')
Card32Obj = ScalarObj('L')
class ResourceObj:
structcode = 'L'
structvalues = 1
def __init__(self, class_name):
self.class_name = class_name
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:
structcode = None
def pack_value(self, val):
return chr(len(val)) + val
def parse_binary(self, data, display):
slen = ord(data[0]) + 1
return data[1:slen], buffer(data, slen)
Str = StrClass()
class Struct:
"""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.
"""
code = ''
total_length = str(self.static_size)
joins = []
args = []
defargs = []
kwarg = 0
# First pack all varfields so their lengths and formats are
# available when we pack their static LengthFields and
# FormatFields
i = 0
for f in self.var_fields:
if f.keyword_args:
kwarg = 1
kw = ', _keyword_args'
else:
kw = ''
# Call pack_value method for each field, storing
# the return values for later use
code = code + (' _%(name)s, _%(name)s_length, _%(name)s_format'
' = self.var_fields[%(fno)d].pack_value(%(name)s%(kw)s)\n'
% { 'name': f.name,
'fno': i,
'kw': kw })
total_length = total_length + ' + len(_%s)' % f.name
joins.append('_%s' % f.name)
i = i + 1
# Construct argument list for struct.pack call, packing all
# static fields. First argument is the structcode, the
# remaining are values.
pack_args = ['"%s"' % self.static_codes]
i = 0
for f in self.static_fields:
if isinstance(f, LengthField):
# If this is a total length field, insert
# the calculated field value here
if isinstance(f, TotalLengthField):
if self.var_fields:
pack_args.append('self.static_fields[%d].calc_length(%s)'
% (i, total_length))
else:
pack_args.append(str(f.calc_length(self.static_size)))
else:
pack_args.append('self.static_fields[%d].calc_length(_%s_length)'
% (i, f.name))
# Format field, just insert the value we got previously
elif isinstance(f, FormatField):
pack_args.append('_%s_format' % f.name)
# A constant field, insert its value directly
elif isinstance(f, ConstantField):
pack_args.append(str(f.value))
# Value fields
else:
if f.structvalues == 1:
# If there's a value check/convert function, call it
if f.check_value is not None:
pack_args.append('self.static_fields[%d].check_value(%s)'
% (i, f.name))
# Else just use the argument as provided
else:
pack_args.append(f.name)
# Multivalue field. Handled like single valuefield,
# but the value are tuple unpacked into seperate arguments
# which are appended to pack_args
else:
a = []
for j in range(f.structvalues):
a.append('_%s_%d' % (f.name, j))
if f.check_value is not None:
code = code + (' %s = self.static_fields[%d].check_value(%s)\n'
% (string.join(a, ', '), i, f.name))
else:
code = code + ' %s = %s\n' % (string.join(a, ', '), f.name)
pack_args = pack_args + a
# Add field to argument list
if f.name:
if f.default is None:
args.append(f.name)
else:
defargs.append('%s = %s' % (f.name, repr(f.default)))
i = i + 1
# Construct call to struct.pack
pack = 'struct.pack(%s)' % string.join(pack_args, ', ')
# If there are any varfields, we append the packed strings to build
# the resulting binary value
if self.var_fields:
code = code + ' return %s + %s\n' % (pack, string.join(joins, ' + '))
# If there's only static fields, return the packed value
else:
code = code + ' return %s\n' % pack
# Add all varsize fields to argument list. We do it here
# to ensure that they appear after the static fields.
for f in self.var_fields:
if f.name:
if f.default is None:
args.append(f.name)
else:
defargs.append('%s = %s' % (f.name, repr(f.default)))
args = args + defargs
if kwarg:
args.append('**_keyword_args')
# Add function header
code = 'def to_binary(self, %s):\n' % string.join(args, ', ') + code
# self._pack_code = code
# print
# print code
# print
# Finally, compile function by evaluating it. This will store
# the function in the local variable to_binary, thanks to the
# def: line. Convert it into a instance metod bound to self,
# and store it in self.
# Unfortunately, this creates a circular reference. However,
# Structs are not really created dynamically so the potential
# memory leak isn't that serious. Besides, Python 2.0 has
# real garbage collect.
exec code
self.to_binary = new.instancemethod(to_binary, self, self.__class__)
# Finally call it manually
return apply(self.to_binary, varargs, keys)
def pack_value(self, value):
""" This function allows Struct objects to be used in List and
Object fields. Each item represents the arguments to pass to
to_binary, either a tuple, a dictionary or a DictWrapper.
"""
if type(value) is types.TupleType:
return apply(self.to_binary, value, {})
elif type(value) is types.DictionaryType:
return apply(self.to_binary, (), value)
elif isinstance(value, DictWrapper):
return apply(self.to_binary, (), value._data)
else:
raise BadDataError('%s is not a tuple or a list' % (value))
def parse_value(self, val, display, rawdict = 0):
"""This function is used by List and Object fields to convert
Struct objects with no var_fields into Python values.
"""
code = ('def parse_value(self, val, display, rawdict = 0):\n'
' ret = {}\n')
vno = 0
fno = 0
for f in self.static_fields:
# Fields without names should be ignored, and there should
# not be any length or format fields if this function
# ever gets called. (If there were such fields, there should
# be a matching field in var_fields and then parse_binary
# would have been called instead.
if not f.name:
pass
elif isinstance(f, LengthField):
pass
elif isinstance(f, FormatField):
pass
# Value fields
else:
# Get the index or range in val representing this field.
if f.structvalues == 1:
vrange = str(vno)
else:
vrange = '%d:%d' % (vno, vno + f.structvalues)
# If this field has a parse_value method, call it, otherwise
# use the unpacked value as is.
if f.parse_value is None:
code = code + ' ret["%s"] = val[%s]\n' % (f.name, vrange)
else:
code = code + (' ret["%s"] = self.static_fields[%d].'
'parse_value(val[%s], display)\n'
% (f.name, fno, vrange))
fno = fno + 1
vno = vno + f.structvalues
code = code + ' if not rawdict: return DictWrapper(ret)\n'
code = code + ' return ret\n'
# print
# print code
# print
# Finally, compile function as for to_binary.
exec code
self.parse_value = new.instancemethod(parse_value, self, self.__class__)
# Call it manually
return self.parse_value(val, display, rawdict)
def parse_binary(self, data, display, rawdict = 0):
"""values, remdata = s.parse_binary(data, display, rawdict = 0)
Convert a binary representation of the structure into Python values.
DATA is a string or a buffer containing the binary data.
DISPLAY should be a Xlib.protocol.display.Display object if
there are any Resource fields or Lists with ResourceObjs.
The Python values are returned as VALUES. If RAWDICT is true,
a Python dictionary is returned, where the keys are field
names and the values are the corresponding Python value. If
RAWDICT is false, a DictWrapper will be returned where all
fields are available as attributes.
REMDATA are the remaining binary data, unused by the Struct object.
"""
code = ('def parse_binary(self, data, display, rawdict = 0):\n'
' ret = {}\n'
' val = struct.unpack("%s", data[:%d])\n'
% (self.static_codes, self.static_size))
lengths = {}
formats = {}
vno = 0
fno = 0
for f in self.static_fields:
# Fields without name should be ignored. This is typically
# pad and constant fields
if not f.name:
pass
# Store index in val for Length and Format fields, to be used
# when treating varfields.
elif isinstance(f, LengthField):
if f.parse_value is None:
lengths[f.name] = 'val[%d]' % vno
else:
lengths[f.name] = ('self.static_fields[%d].'
'parse_value(val[%d], display)'
% (fno, vno))
elif isinstance(f, FormatField):
formats[f.name] = 'val[%d]' % vno
# Treat value fields the same was as in parse_value.
else:
if f.structvalues == 1:
vrange = str(vno)
else:
vrange = '%d:%d' % (vno, vno + f.structvalues)
if f.parse_value is None:
code = code + ' ret["%s"] = val[%s]\n' % (f.name, vrange)
else:
code = code + (' ret["%s"] = self.static_fields[%d].'
'parse_value(val[%s], display)\n'
% (f.name, fno, vrange))
fno = fno + 1
vno = vno + f.structvalues
code = code + ' data = buffer(data, %d)\n' % self.static_size
# Call parse_binary_value for each var_field, passing the
# length and format values from the unpacked val.
fno = 0
for f in self.var_fields:
code = code + (' ret["%s"], data = '
'self.var_fields[%d].parse_binary_value'
'(data, display, %s, %s)\n'
% (f.name, fno,
lengths.get(f.name, 'None'),
formats.get(f.name, 'None')))
fno = fno + 1
code = code + ' if not rawdict: ret = DictWrapper(ret)\n'
code = code + ' return ret, data\n'
# print
# print code
# print
# Finally, compile function as for to_binary.
exec code
self.parse_binary = new.instancemethod(parse_binary, self, self.__class__)
# Call it manually
return self.parse_binary(data, display, rawdict)
class TextElements8(ValueField):
string_textitem = Struct( LengthOf('string', 1),
Int8('delta'),
String8('string', pad = 0) )
def pack_value(self, value):
data = ''
args = {}
for v in value:
# Let values be simple strings, meaning a delta of 0
if type(v) is types.StringType:
v = (0, v)
# A tuple, it should be (delta, string)
# Encode it as one or more textitems
if type(v) in (types.TupleType, types.DictType) or \
isinstance(v, DictWrapper):
if type(v) is types.TupleType:
delta, str = v
else:
delta = v['delta']
str = v['string']
while delta or str:
args['delta'] = delta
args['string'] = str[:254]
data = data + apply(self.string_textitem.to_binary, (), args)
delta = 0
str = str[254:]
# Else an integer, i.e. a font change
else:
# Use fontable cast function if instance
if type(v) is types.InstanceType:
v = v.__fontable__()
data = data + struct.pack('>BL', 255, v)
# Pad out to four byte length
dlen = len(data)
return data + '\0' * ((4 - dlen % 4) % 4), None, None
def parse_binary_value(self, data, display, length, format):
values = []
while 1:
if len(data) < 2:
break
# font change
if ord(data[0]) == 255:
values.append(struct.unpack('>L', str(data[1:5]))[0])
data = buffer(data, 5)
# skip null strings
elif ord(data[0]) == 0 and ord(data[1]) == 0:
data = buffer(data, 2)
# string with delta
else:
v, data = self.string_textitem.parse_binary(data, display)
values.append(v)
return values, ''
class TextElements16(TextElements8):
string_textitem = Struct( LengthOf('string', 1),
Int8('delta'),
String16('string', pad = 0) )
class GetAttrData:
def __getattr__(self, attr):
try:
if self._data:
return self._data[attr]
else:
raise AttributeError(attr)
except KeyError:
raise AttributeError(attr)
class DictWrapper(GetAttrData):
def __init__(self, dict):
self.__dict__['_data'] = dict
def __getitem__(self, key):
return self._data[key]
def __setitem__(self, key, value):
self._data[key] = value
def __delitem__(self, key):
del self._data[key]
def __setattr__(self, key, value):
self._data[key] = value
def __delattr__(self, key):
del self._data[key]
def __str__(self):
return str(self._data)
def __repr__(self):
return '%s(%s)' % (self.__class__, repr(self._data))
def __cmp__(self, other):
if isinstance(other, DictWrapper):
return cmp(self._data, other._data)
else:
return cmp(self._data, other)
class Request:
def __init__(self, display, onerror = None, *args, **keys):
self._errorhandler = onerror
self._binary = apply(self._request.to_binary, args, keys)
self._serial = None
display.send_request(self, onerror is not None)
def _set_error(self, error):
if self._errorhandler is not None:
return call_error_handler(self._errorhandler, error, self)
else:
return 0
class ReplyRequest(GetAttrData):
def __init__(self, display, defer = 0, *args, **keys):
self._display = display
self._binary = apply(self._request.to_binary, args, keys)
self._serial = None
self._data = None
self._error = None
self._response_lock = lock.allocate_lock()
self._display.send_request(self, 1)
if not defer:
self.reply()
def reply(self):
# Send request and wait for reply if we hasn't
# already got one. This means that reply() can safely
# be called more than one time.
self._response_lock.acquire()
while self._data is None and self._error is None:
self._display.send_recv_lock.acquire()
self._response_lock.release()
self._display.send_and_recv(request = self._serial)
self._response_lock.acquire()
self._response_lock.release()
self._display = None
# If error has been set, raise it
if self._error:
raise self._error
def _parse_response(self, data):
self._response_lock.acquire()
self._data, d = self._reply.parse_binary(data, self._display, rawdict = 1)
self._response_lock.release()
def _set_error(self, error):
self._response_lock.acquire()
self._error = error
self._response_lock.release()
return 1
def __repr__(self):
return '<%s serial = %s, data = %s, error = %s>' % (self.__class__, self._serial, self._data, self._error)
class Event(GetAttrData):
def __init__(self, binarydata = None, display = None,
**keys):
if binarydata:
self._binary = binarydata
self._data, data = self._fields.parse_binary(binarydata, display,
rawdict = 1)
# split event type into type and send_event bit
self._data['send_event'] = not not self._data['type'] & 0x80
self._data['type'] = self._data['type'] & 0x7f
else:
if self._code:
keys['type'] = self._code
keys['sequence_number'] = 0
self._binary = apply(self._fields.to_binary, (), keys)
keys['send_event'] = 0
self._data = keys
def __repr__(self):
kwlist = []
for kw, val in self._data.items():
if kw == 'send_event':
continue
if kw == 'type' and self._data['send_event']:
val = val | 0x80
kwlist.append('%s = %s' % (kw, repr(val)))
kws = string.join(kwlist, ', ')
return '%s(%s)' % (self.__class__, kws)
def __cmp__(self, other):
if isinstance(other, Event):
return cmp(self._data, other._data)
else:
return cmp(self._data, other)
def call_error_handler(handler, error, request):
try:
return handler(error, request)
except:
sys.stderr.write('Exception raised by error handler.\n')
traceback.print_exc()
return 0
|