"""Macintosh binhex compression/decompression.
easy interface:
binhex(inputfilename, outputfilename)
hexbin(inputfilename, outputfilename)
"""
#
# Jack Jansen, CWI, August 1995.
#
# The module is supposed to be as compatible as possible. Especially the
# easy interface should work "as expected" on any platform.
# XXXX Note: currently, textfiles appear in mac-form on all platforms.
# We seem to lack a simple character-translate in python.
# (we should probably use ISO-Latin-1 on all but the mac platform).
# XXXX The simple routines are too simple: they expect to hold the complete
# files in-core. Should be fixed.
# XXXX It would be nice to handle AppleDouble format on unix
# (for servers serving macs).
# XXXX I don't understand what happens when you get 0x90 times the same byte on
# input. The resulting code (xx 90 90) would appear to be interpreted as an
# escaped *value* of 0x90. All coders I've seen appear to ignore this nicety...
#
import sys
import os
import struct
import binascii
__all__ = ["binhex","hexbin","Error"]
class Error(Exception):
pass
# States (what have we written)
_DID_HEADER = 0
_DID_DATA = 1
# Various constants
REASONABLY_LARGE=32768 # Minimal amount we pass the rle-coder
LINELEN=64
RUNCHAR=chr(0x90) # run-length introducer
#
# This code is no longer byte-order dependent
#
# Workarounds for non-mac machines.
try:
from Carbon.File import FSSpec, FInfo
from MacOS import openrf
def getfileinfo(name):
finfo = FSSpec(name).FSpGetFInfo()
dir, file = os.path.split(name)
# XXX Get resource/data sizes
fp = open(name, 'rb')
fp.seek(0, 2)
dlen = fp.tell()
fp = openrf(name, '*rb')
fp.seek(0, 2)
rlen = fp.tell()
return file, finfo, dlen, rlen
def openrsrc(name, *mode):
if not mode:
mode = '*rb'
else:
mode = '*' + mode[0]
return openrf(name, mode)
except ImportError:
#
# Glue code for non-macintosh usage
#
class FInfo:
def __init__(self):
self.Type = '????'
self.Creator = '????'
self.Flags = 0
def getfileinfo(name):
finfo = FInfo()
# Quick check for textfile
fp = open(name)
data = open(name).read(256)
for c in data:
if not c.isspace() and (c<' ' or ord(c) > 0x7f):
break
else:
finfo.Type = 'TEXT'
fp.seek(0, 2)
dsize = fp.tell()
fp.close()
dir, file = os.path.split(name)
file = file.replace(':', '-', 1)
return file, finfo, dsize, 0
class openrsrc:
def __init__(self, *args):
pass
def read(self, *args):
return ''
def write(self, *args):
pass
def close(self):
pass
class _Hqxcoderengine:
"""Write data to the coder in 3-byte chunks"""
def __init__(self, ofp):
self.ofp = ofp
self.data = ''
self.hqxdata = ''
self.linelen = LINELEN-1
def write(self, data):
self.data = self.data + data
datalen = len(self.data)
todo = (datalen//3)*3
data = self.data[:todo]
self.data = self.data[todo:]
if not data:
return
self.hqxdata = self.hqxdata + binascii.b2a_hqx(data)
self._flush(0)
def _flush(self, force):
first = 0
while first <= len(self.hqxdata)-self.linelen:
last = first + self.linelen
self.ofp.write(self.hqxdata[first:last]+'\n')
self.linelen = LINELEN
first = last
self.hqxdata = self.hqxdata[first:]
if force:
self.ofp.write(self.hqxdata + ':\n')
def close(self):
if self.data:
self.hqxdata = \
self.hqxdata + binascii.b2a_hqx(self.data)
self._flush(1)
self.ofp.close()
del self.ofp
class _Rlecoderengine:
"""Write data to the RLE-coder in suitably large chunks"""
def __init__(self, ofp):
self.ofp = ofp
self.data = ''
def write(self, data):
self.data = self.data + data
if len(self.data) < REASONABLY_LARGE:
return
rledata = binascii.rlecode_hqx(self.data)
self.ofp.write(rledata)
self.data = ''
def close(self):
if self.data:
rledata = binascii.rlecode_hqx(self.data)
self.ofp.write(rledata)
self.ofp.close()
del self.ofp
class BinHex:
def __init__(self, name_finfo_dlen_rlen, ofp):
name, finfo, dlen, rlen = name_finfo_dlen_rlen
if type(ofp) == type(''):
ofname = ofp
ofp = open(ofname, 'w')
ofp.write('(This file must be converted with BinHex 4.0)\n\n:')
hqxer = _Hqxcoderengine(ofp)
self.ofp = _Rlecoderengine(hqxer)
self.crc = 0
if finfo is None:
finfo = FInfo()
self.dlen = dlen
self.rlen = rlen
self._writeinfo(name, finfo)
self.state = _DID_HEADER
def _writeinfo(self, name, finfo):
nl = len(name)
if nl > 63:
raise Error, 'Filename too long'
d = chr(nl) + name + '\0'
d2 = finfo.Type + finfo.Creator
# Force all structs to be packed with big-endian
d3 = struct.pack('>h', finfo.Flags)
d4 = struct.pack('>ii', self.dlen, self.rlen)
info = d + d2 + d3 + d4
self._write(info)
self._writecrc()
def _write(self, data):
self.crc = binascii.crc_hqx(data, self.crc)
self.ofp.write(data)
def _writecrc(self):
# XXXX Should this be here??
# self.crc = binascii.crc_hqx('\0\0', self.crc)
if self.crc < 0:
fmt = '>h'
else:
fmt = '>H'
self.ofp.write(struct.pack(fmt, self.crc))
self.crc = 0
def write(self, data):
if self.state != _DID_HEADER:
raise Error, 'Writing data at the wrong time'
self.dlen = self.dlen - len(data)
self._write(data)
def close_data(self):
if self.dlen != 0:
raise Error, 'Incorrect data size, diff=%r' % (self.rlen,)
self._writecrc()
self.state = _DID_DATA
def write_rsrc(self, data):
if self.state < _DID_DATA:
self.close_data()
if self.state != _DID_DATA:
raise Error, 'Writing resource data at the wrong time'
self.rlen = self.rlen - len(data)
self._write(data)
def close(self):
if self.state is None:
return
try:
if self.state < _DID_DATA:
self.close_data()
if self.state != _DID_DATA:
raise Error, 'Close at the wrong time'
if self.rlen != 0:
raise Error, \
"Incorrect resource-datasize, diff=%r" % (self.rlen,)
self._writecrc()
finally:
self.state = None
ofp = self.ofp
del self.ofp
ofp.close()
def binhex(inp, out):
"""(infilename, outfilename) - Create binhex-encoded copy of a file"""
finfo = getfileinfo(inp)
ofp = BinHex(finfo, out)
ifp = open(inp, 'rb')
# XXXX Do textfile translation on non-mac systems
while 1:
d = ifp.read(128000)
if not d: break
ofp.write(d)
ofp.close_data()
ifp.close()
ifp = openrsrc(inp, 'rb')
while 1:
d = ifp.read(128000)
if not d: break
ofp.write_rsrc(d)
ofp.close()
ifp.close()
class _Hqxdecoderengine:
"""Read data via the decoder in 4-byte chunks"""
def __init__(self, ifp):
self.ifp = ifp
self.eof = 0
def read(self, totalwtd):
"""Read at least wtd bytes (or until EOF)"""
decdata = ''
wtd = totalwtd
#
# The loop here is convoluted, since we don't really now how
# much to decode: there may be newlines in the incoming data.
while wtd > 0:
if self.eof: return decdata
wtd = ((wtd+2)//3)*4
data = self.ifp.read(wtd)
#
# Next problem: there may not be a complete number of
# bytes in what we pass to a2b. Solve by yet another
# loop.
#
while 1:
try:
decdatacur, self.eof = \
binascii.a2b_hqx(data)
break
except binascii.Incomplete:
pass
newdata = self.ifp.read(1)
if not newdata:
raise Error, \
'Premature EOF on binhex file'
data = data + newdata
decdata = decdata + decdatacur
wtd = totalwtd - len(decdata)
if not decdata and not self.eof:
raise Error, 'Premature EOF on binhex file'
return decdata
def close(self):
self.ifp.close()
class _Rledecoderengine:
"""Read data via the RLE-coder"""
def __init__(self, ifp):
self.ifp = ifp
self.pre_buffer = ''
self.post_buffer = ''
self.eof = 0
def read(self, wtd):
if wtd > len(self.post_buffer):
self._fill(wtd-len(self.post_buffer))
rv = self.post_buffer[:wtd]
self.post_buffer = self.post_buffer[wtd:]
return rv
def _fill(self, wtd):
self.pre_buffer = self.pre_buffer + self.ifp.read(wtd+4)
if self.ifp.eof:
self.post_buffer = self.post_buffer + \
binascii.rledecode_hqx(self.pre_buffer)
self.pre_buffer = ''
return
#
# Obfuscated code ahead. We have to take care that we don't
# end up with an orphaned RUNCHAR later on. So, we keep a couple
# of bytes in the buffer, depending on what the end of
# the buffer looks like:
# '\220\0\220' - Keep 3 bytes: repeated \220 (escaped as \220\0)
# '?\220' - Keep 2 bytes: repeated something-else
# '\220\0' - Escaped \220: Keep 2 bytes.
# '?\220?' - Complete repeat sequence: decode all
# otherwise: keep 1 byte.
#
mark = len(self.pre_buffer)
if self.pre_buffer[-3:] == RUNCHAR + '\0' + RUNCHAR:
mark = mark - 3
elif self.pre_buffer[-1] == RUNCHAR:
mark = mark - 2
elif self.pre_buffer[-2:] == RUNCHAR + '\0':
mark = mark - 2
elif self.pre_buffer[-2] == RUNCHAR:
pass # Decode all
else:
mark = mark - 1
self.post_buffer = self.post_buffer + \
binascii.rledecode_hqx(self.pre_buffer[:mark])
self.pre_buffer = self.pre_buffer[mark:]
def close(self):
self.ifp.close()
class HexBin:
def __init__(self, ifp):
if type(ifp) == type(''):
ifp = open(ifp)
#
# Find initial colon.
#
while 1:
ch = ifp.read(1)
if not ch:
raise Error, "No binhex data found"
# Cater for \r\n terminated lines (which show up as \n\r, hence
# all lines start with \r)
if ch == '\r':
continue
if ch == ':':
break
if ch != '\n':
dummy = ifp.readline()
hqxifp = _Hqxdecoderengine(ifp)
self.ifp = _Rledecoderengine(hqxifp)
self.crc = 0
self._readheader()
def _read(self, len):
data = self.ifp.read(len)
self.crc = binascii.crc_hqx(data, self.crc)
return data
def _checkcrc(self):
filecrc = struct.unpack('>h', self.ifp.read(2))[0] & 0xffff
#self.crc = binascii.crc_hqx('\0\0', self.crc)
# XXXX Is this needed??
self.crc = self.crc & 0xffff
if filecrc != self.crc:
raise Error, 'CRC error, computed %x, read %x' \
%(self.crc, filecrc)
self.crc = 0
def _readheader(self):
len = self._read(1)
fname = self._read(ord(len))
rest = self._read(1+4+4+2+4+4)
self._checkcrc()
type = rest[1:5]
creator = rest[5:9]
flags = struct.unpack('>h', rest[9:11])[0]
self.dlen = struct.unpack('>l', rest[11:15])[0]
self.rlen = struct.unpack('>l', rest[15:19])[0]
self.FName = fname
self.FInfo = FInfo()
self.FInfo.Creator = creator
self.FInfo.Type = type
self.FInfo.Flags = flags
self.state = _DID_HEADER
def read(self, *n):
if self.state != _DID_HEADER:
raise Error, 'Read data at wrong time'
if n:
n = n[0]
n = min(n, self.dlen)
else:
n = self.dlen
rv = ''
while len(rv) < n:
rv = rv + self._read(n-len(rv))
self.dlen = self.dlen - n
return rv
def close_data(self):
if self.state != _DID_HEADER:
raise Error, 'close_data at wrong time'
if self.dlen:
dummy = self._read(self.dlen)
self._checkcrc()
self.state = _DID_DATA
def read_rsrc(self, *n):
if self.state == _DID_HEADER:
self.close_data()
if self.state != _DID_DATA:
raise Error, 'Read resource data at wrong time'
if n:
n = n[0]
n = min(n, self.rlen)
else:
n = self.rlen
self.rlen = self.rlen - n
return self._read(n)
def close(self):
if self.state is None:
return
try:
if self.rlen:
dummy = self.read_rsrc(self.rlen)
self._checkcrc()
finally:
self.state = None
self.ifp.close()
def hexbin(inp, out):
"""(infilename, outfilename) - Decode binhexed file"""
ifp = HexBin(inp)
finfo = ifp.FInfo
if not out:
out = ifp.FName
ofp = open(out, 'wb')
# XXXX Do translation on non-mac systems
while 1:
d = ifp.read(128000)
if not d: break
ofp.write(d)
ofp.close()
ifp.close_data()
d = ifp.read_rsrc(128000)
if d:
ofp = openrsrc(out, 'wb')
ofp.write(d)
while 1:
d = ifp.read_rsrc(128000)
if not d: break
ofp.write(d)
ofp.close()
ifp.close()
def _test():
fname = sys.argv[1]
binhex(fname, fname+'.hqx')
hexbin(fname+'.hqx', fname+'.viahqx')
#hexbin(fname, fname+'.unpacked')
sys.exit(1)
if __name__ == '__main__':
_test()