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