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1"""Macintosh binhex compression/decompression.
2
3easy interface:
4binhex(inputfilename, outputfilename)
5hexbin(inputfilename, outputfilename)
6"""
7
8#
9# Jack Jansen, CWI, August 1995.
10#
11# The module is supposed to be as compatible as possible. Especially the
12# easy interface should work "as expected" on any platform.
13# XXXX Note: currently, textfiles appear in mac-form on all platforms.
14# We seem to lack a simple character-translate in python.
15# (we should probably use ISO-Latin-1 on all but the mac platform).
16# XXXX The simple routines are too simple: they expect to hold the complete
17# files in-core. Should be fixed.
18# XXXX It would be nice to handle AppleDouble format on unix
19# (for servers serving macs).
20# XXXX I don't understand what happens when you get 0x90 times the same byte on
21# input. The resulting code (xx 90 90) would appear to be interpreted as an
22# escaped *value* of 0x90. All coders I've seen appear to ignore this nicety...
23#
24import sys
25import os
26import struct
27import binascii
28
29__all__ = ["binhex","hexbin","Error"]
30
31class Error(Exception):
32    pass
33
34# States (what have we written)
35_DID_HEADER = 0
36_DID_DATA = 1
37
38# Various constants
39REASONABLY_LARGE=32768  # Minimal amount we pass the rle-coder
40LINELEN=64
41RUNCHAR=chr(0x90)   # run-length introducer
42
43#
44# This code is no longer byte-order dependent
45
46#
47# Workarounds for non-mac machines.
48try:
49    from Carbon.File import FSSpec, FInfo
50    from MacOS import openrf
51
52    def getfileinfo(name):
53        finfo = FSSpec(name).FSpGetFInfo()
54        dir, file = os.path.split(name)
55        # XXX Get resource/data sizes
56        fp = open(name, 'rb')
57        fp.seek(0, 2)
58        dlen = fp.tell()
59        fp = openrf(name, '*rb')
60        fp.seek(0, 2)
61        rlen = fp.tell()
62        return file, finfo, dlen, rlen
63
64    def openrsrc(name, *mode):
65        if not mode:
66            mode = '*rb'
67        else:
68            mode = '*' + mode[0]
69        return openrf(name, mode)
70
71except ImportError:
72    #
73    # Glue code for non-macintosh usage
74    #
75
76    class FInfo:
77        def __init__(self):
78            self.Type = '????'
79            self.Creator = '????'
80            self.Flags = 0
81
82    def getfileinfo(name):
83        finfo = FInfo()
84        # Quick check for textfile
85        fp = open(name)
86        data = open(name).read(256)
87        for c in data:
88            if not c.isspace() and (c<' ' or ord(c) > 0x7f):
89                break
90        else:
91            finfo.Type = 'TEXT'
92        fp.seek(0, 2)
93        dsize = fp.tell()
94        fp.close()
95        dir, file = os.path.split(name)
96        file = file.replace(':', '-', 1)
97        return file, finfo, dsize, 0
98
99    class openrsrc:
100        def __init__(self, *args):
101            pass
102
103        def read(self, *args):
104            return ''
105
106        def write(self, *args):
107            pass
108
109        def close(self):
110            pass
111
112class _Hqxcoderengine:
113    """Write data to the coder in 3-byte chunks"""
114
115    def __init__(self, ofp):
116        self.ofp = ofp
117        self.data = ''
118        self.hqxdata = ''
119        self.linelen = LINELEN-1
120
121    def write(self, data):
122        self.data = self.data + data
123        datalen = len(self.data)
124        todo = (datalen//3)*3
125        data = self.data[:todo]
126        self.data = self.data[todo:]
127        if not data:
128            return
129        self.hqxdata = self.hqxdata + binascii.b2a_hqx(data)
130        self._flush(0)
131
132    def _flush(self, force):
133        first = 0
134        while first <= len(self.hqxdata)-self.linelen:
135            last = first + self.linelen
136            self.ofp.write(self.hqxdata[first:last]+'\n')
137            self.linelen = LINELEN
138            first = last
139        self.hqxdata = self.hqxdata[first:]
140        if force:
141            self.ofp.write(self.hqxdata + ':\n')
142
143    def close(self):
144        if self.data:
145            self.hqxdata = \
146                 self.hqxdata + binascii.b2a_hqx(self.data)
147        self._flush(1)
148        self.ofp.close()
149        del self.ofp
150
151class _Rlecoderengine:
152    """Write data to the RLE-coder in suitably large chunks"""
153
154    def __init__(self, ofp):
155        self.ofp = ofp
156        self.data = ''
157
158    def write(self, data):
159        self.data = self.data + data
160        if len(self.data) < REASONABLY_LARGE:
161            return
162        rledata = binascii.rlecode_hqx(self.data)
163        self.ofp.write(rledata)
164        self.data = ''
165
166    def close(self):
167        if self.data:
168            rledata = binascii.rlecode_hqx(self.data)
169            self.ofp.write(rledata)
170        self.ofp.close()
171        del self.ofp
172
173class BinHex:
174    def __init__(self, name_finfo_dlen_rlen, ofp):
175        name, finfo, dlen, rlen = name_finfo_dlen_rlen
176        if type(ofp) == type(''):
177            ofname = ofp
178            ofp = open(ofname, 'w')
179        ofp.write('(This file must be converted with BinHex 4.0)\n\n:')
180        hqxer = _Hqxcoderengine(ofp)
181        self.ofp = _Rlecoderengine(hqxer)
182        self.crc = 0
183        if finfo is None:
184            finfo = FInfo()
185        self.dlen = dlen
186        self.rlen = rlen
187        self._writeinfo(name, finfo)
188        self.state = _DID_HEADER
189
190    def _writeinfo(self, name, finfo):
191        nl = len(name)
192        if nl > 63:
193            raise Error, 'Filename too long'
194        d = chr(nl) + name + '\0'
195        d2 = finfo.Type + finfo.Creator
196
197        # Force all structs to be packed with big-endian
198        d3 = struct.pack('>h', finfo.Flags)
199        d4 = struct.pack('>ii', self.dlen, self.rlen)
200        info = d + d2 + d3 + d4
201        self._write(info)
202        self._writecrc()
203
204    def _write(self, data):
205        self.crc = binascii.crc_hqx(data, self.crc)
206        self.ofp.write(data)
207
208    def _writecrc(self):
209        # XXXX Should this be here??
210        # self.crc = binascii.crc_hqx('\0\0', self.crc)
211        if self.crc < 0:
212            fmt = '>h'
213        else:
214            fmt = '>H'
215        self.ofp.write(struct.pack(fmt, self.crc))
216        self.crc = 0
217
218    def write(self, data):
219        if self.state != _DID_HEADER:
220            raise Error, 'Writing data at the wrong time'
221        self.dlen = self.dlen - len(data)
222        self._write(data)
223
224    def close_data(self):
225        if self.dlen != 0:
226            raise Error, 'Incorrect data size, diff=%r' % (self.rlen,)
227        self._writecrc()
228        self.state = _DID_DATA
229
230    def write_rsrc(self, data):
231        if self.state < _DID_DATA:
232            self.close_data()
233        if self.state != _DID_DATA:
234            raise Error, 'Writing resource data at the wrong time'
235        self.rlen = self.rlen - len(data)
236        self._write(data)
237
238    def close(self):
239        if self.state is None:
240            return
241        try:
242            if self.state < _DID_DATA:
243                self.close_data()
244            if self.state != _DID_DATA:
245                raise Error, 'Close at the wrong time'
246            if self.rlen != 0:
247                raise Error, \
248                    "Incorrect resource-datasize, diff=%r" % (self.rlen,)
249            self._writecrc()
250        finally:
251            self.state = None
252            ofp = self.ofp
253            del self.ofp
254            ofp.close()
255
256def binhex(inp, out):
257    """(infilename, outfilename) - Create binhex-encoded copy of a file"""
258    finfo = getfileinfo(inp)
259    ofp = BinHex(finfo, out)
260
261    ifp = open(inp, 'rb')
262    # XXXX Do textfile translation on non-mac systems
263    while 1:
264        d = ifp.read(128000)
265        if not d: break
266        ofp.write(d)
267    ofp.close_data()
268    ifp.close()
269
270    ifp = openrsrc(inp, 'rb')
271    while 1:
272        d = ifp.read(128000)
273        if not d: break
274        ofp.write_rsrc(d)
275    ofp.close()
276    ifp.close()
277
278class _Hqxdecoderengine:
279    """Read data via the decoder in 4-byte chunks"""
280
281    def __init__(self, ifp):
282        self.ifp = ifp
283        self.eof = 0
284
285    def read(self, totalwtd):
286        """Read at least wtd bytes (or until EOF)"""
287        decdata = ''
288        wtd = totalwtd
289        #
290        # The loop here is convoluted, since we don't really now how
291        # much to decode: there may be newlines in the incoming data.
292        while wtd > 0:
293            if self.eof: return decdata
294            wtd = ((wtd+2)//3)*4
295            data = self.ifp.read(wtd)
296            #
297            # Next problem: there may not be a complete number of
298            # bytes in what we pass to a2b. Solve by yet another
299            # loop.
300            #
301            while 1:
302                try:
303                    decdatacur, self.eof = \
304                            binascii.a2b_hqx(data)
305                    break
306                except binascii.Incomplete:
307                    pass
308                newdata = self.ifp.read(1)
309                if not newdata:
310                    raise Error, \
311                          'Premature EOF on binhex file'
312                data = data + newdata
313            decdata = decdata + decdatacur
314            wtd = totalwtd - len(decdata)
315            if not decdata and not self.eof:
316                raise Error, 'Premature EOF on binhex file'
317        return decdata
318
319    def close(self):
320        self.ifp.close()
321
322class _Rledecoderengine:
323    """Read data via the RLE-coder"""
324
325    def __init__(self, ifp):
326        self.ifp = ifp
327        self.pre_buffer = ''
328        self.post_buffer = ''
329        self.eof = 0
330
331    def read(self, wtd):
332        if wtd > len(self.post_buffer):
333            self._fill(wtd-len(self.post_buffer))
334        rv = self.post_buffer[:wtd]
335        self.post_buffer = self.post_buffer[wtd:]
336        return rv
337
338    def _fill(self, wtd):
339        self.pre_buffer = self.pre_buffer + self.ifp.read(wtd+4)
340        if self.ifp.eof:
341            self.post_buffer = self.post_buffer + \
342                binascii.rledecode_hqx(self.pre_buffer)
343            self.pre_buffer = ''
344            return
345
346        #
347        # Obfuscated code ahead. We have to take care that we don't
348        # end up with an orphaned RUNCHAR later on. So, we keep a couple
349        # of bytes in the buffer, depending on what the end of
350        # the buffer looks like:
351        # '\220\0\220' - Keep 3 bytes: repeated \220 (escaped as \220\0)
352        # '?\220' - Keep 2 bytes: repeated something-else
353        # '\220\0' - Escaped \220: Keep 2 bytes.
354        # '?\220?' - Complete repeat sequence: decode all
355        # otherwise: keep 1 byte.
356        #
357        mark = len(self.pre_buffer)
358        if self.pre_buffer[-3:] == RUNCHAR + '\0' + RUNCHAR:
359            mark = mark - 3
360        elif self.pre_buffer[-1] == RUNCHAR:
361            mark = mark - 2
362        elif self.pre_buffer[-2:] == RUNCHAR + '\0':
363            mark = mark - 2
364        elif self.pre_buffer[-2] == RUNCHAR:
365            pass # Decode all
366        else:
367            mark = mark - 1
368
369        self.post_buffer = self.post_buffer + \
370            binascii.rledecode_hqx(self.pre_buffer[:mark])
371        self.pre_buffer = self.pre_buffer[mark:]
372
373    def close(self):
374        self.ifp.close()
375
376class HexBin:
377    def __init__(self, ifp):
378        if type(ifp) == type(''):
379            ifp = open(ifp)
380        #
381        # Find initial colon.
382        #
383        while 1:
384            ch = ifp.read(1)
385            if not ch:
386                raise Error, "No binhex data found"
387            # Cater for \r\n terminated lines (which show up as \n\r, hence
388            # all lines start with \r)
389            if ch == '\r':
390                continue
391            if ch == ':':
392                break
393            if ch != '\n':
394                dummy = ifp.readline()
395
396        hqxifp = _Hqxdecoderengine(ifp)
397        self.ifp = _Rledecoderengine(hqxifp)
398        self.crc = 0
399        self._readheader()
400
401    def _read(self, len):
402        data = self.ifp.read(len)
403        self.crc = binascii.crc_hqx(data, self.crc)
404        return data
405
406    def _checkcrc(self):
407        filecrc = struct.unpack('>h', self.ifp.read(2))[0] & 0xffff
408        #self.crc = binascii.crc_hqx('\0\0', self.crc)
409        # XXXX Is this needed??
410        self.crc = self.crc & 0xffff
411        if filecrc != self.crc:
412            raise Error, 'CRC error, computed %x, read %x' \
413                  %(self.crc, filecrc)
414        self.crc = 0
415
416    def _readheader(self):
417        len = self._read(1)
418        fname = self._read(ord(len))
419        rest = self._read(1+4+4+2+4+4)
420        self._checkcrc()
421
422        type = rest[1:5]
423        creator = rest[5:9]
424        flags = struct.unpack('>h', rest[9:11])[0]
425        self.dlen = struct.unpack('>l', rest[11:15])[0]
426        self.rlen = struct.unpack('>l', rest[15:19])[0]
427
428        self.FName = fname
429        self.FInfo = FInfo()
430        self.FInfo.Creator = creator
431        self.FInfo.Type = type
432        self.FInfo.Flags = flags
433
434        self.state = _DID_HEADER
435
436    def read(self, *n):
437        if self.state != _DID_HEADER:
438            raise Error, 'Read data at wrong time'
439        if n:
440            n = n[0]
441            n = min(n, self.dlen)
442        else:
443            n = self.dlen
444        rv = ''
445        while len(rv) < n:
446            rv = rv + self._read(n-len(rv))
447        self.dlen = self.dlen - n
448        return rv
449
450    def close_data(self):
451        if self.state != _DID_HEADER:
452            raise Error, 'close_data at wrong time'
453        if self.dlen:
454            dummy = self._read(self.dlen)
455        self._checkcrc()
456        self.state = _DID_DATA
457
458    def read_rsrc(self, *n):
459        if self.state == _DID_HEADER:
460            self.close_data()
461        if self.state != _DID_DATA:
462            raise Error, 'Read resource data at wrong time'
463        if n:
464            n = n[0]
465            n = min(n, self.rlen)
466        else:
467            n = self.rlen
468        self.rlen = self.rlen - n
469        return self._read(n)
470
471    def close(self):
472        if self.state is None:
473            return
474        try:
475            if self.rlen:
476                dummy = self.read_rsrc(self.rlen)
477            self._checkcrc()
478        finally:
479            self.state = None
480            self.ifp.close()
481
482def hexbin(inp, out):
483    """(infilename, outfilename) - Decode binhexed file"""
484    ifp = HexBin(inp)
485    finfo = ifp.FInfo
486    if not out:
487        out = ifp.FName
488
489    ofp = open(out, 'wb')
490    # XXXX Do translation on non-mac systems
491    while 1:
492        d = ifp.read(128000)
493        if not d: break
494        ofp.write(d)
495    ofp.close()
496    ifp.close_data()
497
498    d = ifp.read_rsrc(128000)
499    if d:
500        ofp = openrsrc(out, 'wb')
501        ofp.write(d)
502        while 1:
503            d = ifp.read_rsrc(128000)
504            if not d: break
505            ofp.write(d)
506        ofp.close()
507
508    ifp.close()
509
510def _test():
511    fname = sys.argv[1]
512    binhex(fname, fname+'.hqx')
513    hexbin(fname+'.hqx', fname+'.viahqx')
514    #hexbin(fname, fname+'.unpacked')
515    sys.exit(1)
516
517if __name__ == '__main__':
518    _test()
519