def encode_7b_cbs(txt):
"""translates the unicode string `txt' into a tuple of page(s)
containing GSM 7 bit characters, ready for broadcast
a page is a 2-tuple: 82-bytes buffer, message length (<= 82)
"""
pages, page, cnt = [], [], 0
# check the number of 7 bit characters required for txt
for c in txt:
if c in _GSM7bLUTInv:
c_cnt = 1
elif c in _GSM7bExtLUTInv:
c_cnt = 2
else:
raise (PycrateErr('invalid GSM 7 bit char: %r' % c))
if cnt + c_cnt < 94:
page.append(c)
cnt += c_cnt
else:
# encode the current page to pages
enc = encode_7b(''.join(page))[0]
enc_len = len(enc)
if enc_len < 82:
enc += (82 - enc_len) * b'\0'
pages.append((enc, enc_len))
# restart filling current page
page, cnt = [c], c_cnt
# pad and append last page
if page:
last = encode_7b(''.join(page))[0]
last_len = len(last)
last += (82 - last_len) * b'\0'
pages.append((last, last_len))
# return the tuple of pages
return tuple(pages)
def encode_7b(txt):
"""translates the unicode string `txt' to a GSM 7 bit characters buffer
"""
arr, cnt = [], 0
for c in reversed(txt):
try:
arr.append((TYPE_UINT, _GSM7bLUTInv[c], 7))
except KeyError:
try:
arr.append((TYPE_UINT, _GSM7bExtLUTInv[c], 7))
except KeyError:
raise (PycrateErr('invalid GSM 7 bit char: %r' % c))
else:
# add an escape char
arr.append((TYPE_UINT, 27, 7))
cnt += 2
else:
cnt += 1
# check the length in bits and add padding bits
pad = (8 - (7 * len(arr)) % 8) % 8
arr.insert(0, (TYPE_UINT, 0, pad))
if python_version < 3:
return ''.join(reversed(pack_val(*arr)[0])), cnt
else:
return bytes(reversed(pack_val(*arr)[0])), cnt
def encode_7b(txt, off=0):
"""translates the unicode string `txt' to a GSM 7 bit characters buffer
Args:
txt (utf8 str): text string to encode
off (uint): bit offset
Returns:
encoded buffer and septet count (bytes, uint)
"""
arr, cnt = [], 0
for c in reversed(txt):
try:
arr.append( (TYPE_UINT, _GSM7bLUTInv[c], 7) )
except KeyError:
try:
arr.append( (TYPE_UINT, _GSM7bExtLUTInv[c], 7) )
except KeyError:
raise(PycrateErr('invalid GSM 7 bit char: %r' % c))
else:
# add an escape char
arr.append( (TYPE_UINT, 27, 7) )
cnt += 2
else:
cnt += 1
# check the length in bits and add padding bits
pad = ((8-(7*len(arr)+off)%8)%8)
arr.insert(0, (TYPE_UINT, 0, pad))
if python_version < 3:
return ''.join(reversed(pack_val(*arr)[0])), cnt
else:
return bytes(reversed(pack_val(*arr)[0])), cnt
def __init__(self, *args, **kw):
if 'IE' in kw:
if isinstance(kw['IE'], (Element, CSN1Obj)):
self._IE = kw['IE'].clone()
elif self._SAFE_STAT:
raise(PycrateErr('IE [__init__]: IE type is {0}, expecting Element'\
.format(type(kw['IE']).__name__)))
Envelope.__init__(self, *args, **kw)
def _from_char(self, char):
if self.get_trans():
return
self[0]._from_char(char)
if self[0]():
# long format
self[1]._name = 'Len'
self[1]._from_char(char)
self.append(Uint('Val', bl=self[1]() << 3))
self[2]._from_char(char)
val = self[2]()
if val > self.MAXLEN:
raise (PycrateErr('Length too long, %i' % self[2]()))
elif val == 0:
raise (PycrateErr('Undefinite length'))
else:
# short format
self[1]._from_char(char)
def set_val(self, val):
if 0 <= val < 0x80:
self[0].set_val(val)
elif 0x80 <= val < 0x100:
self[0].set_val(0x81)
self[1].set_bl(8)
self[1].set_val(val)
elif 0x100 <= val < 0x10000:
self[0].set_val(0x82)
self[1].set_bl(16)
self[1].set_val(val)
elif 0x10000 <= val < 0x1000000:
self[0].set_val(0x83)
self[1].set_bl(24)
self[1].set_val(val)
else:
raise (PycrateErr('invalid length'))