Current File : //lib/calibre/calibre/ebooks/compression/palmdoc.py
#!/usr/bin/env python3
__license__ = 'GPL v3'
__copyright__ = '2008, Kovid Goyal <kovid at kovidgoyal.net>'
import io
from struct import pack
from calibre_extensions import cPalmdoc
def decompress_doc(data):
return cPalmdoc.decompress(data)
def compress_doc(data):
return cPalmdoc.compress(data) if data else b''
def py_compress_doc(data):
out = io.BytesIO()
i = 0
ldata = len(data)
while i < ldata:
if i > 10 and (ldata - i) > 10:
chunk = b''
match = -1
for j in range(10, 2, -1):
chunk = data[i:i+j]
try:
match = data.rindex(chunk, 0, i)
except ValueError:
continue
if (i - match) <= 2047:
break
match = -1
if match >= 0:
n = len(chunk)
m = i - match
code = 0x8000 + ((m << 3) & 0x3ff8) + (n - 3)
out.write(pack('>H', code))
i += n
continue
ch = data[i:i+1]
och = ord(ch)
i += 1
if ch == b' ' and (i + 1) < ldata:
onch = ord(data[i:i+1])
if onch >= 0x40 and onch < 0x80:
out.write(pack('>B', onch ^ 0x80))
i += 1
continue
if och == 0 or (och > 8 and och < 0x80):
out.write(ch)
else:
j = i
binseq = [ch]
while j < ldata and len(binseq) < 8:
ch = data[j:j+1]
och = ord(ch)
if och == 0 or (och > 8 and och < 0x80):
break
binseq.append(ch)
j += 1
out.write(pack('>B', len(binseq)))
out.write(b''.join(binseq))
i += len(binseq) - 1
return out.getvalue()
def find_tests():
import unittest
class Test(unittest.TestCase):
def test_palmdoc_compression(self):
for test in [
b'abc\x03\x04\x05\x06ms', # Test binary writing
b'a b c \xfed ', # Test encoding of spaces
b'0123456789axyz2bxyz2cdfgfo9iuyerh',
b'0123456789asd0123456789asd|yyzzxxffhhjjkk',
(b'ciewacnaq eiu743 r787q 0w% ; sa fd\xef\ffdxosac wocjp acoiecowei '
b'owaic jociowapjcivcjpoivjporeivjpoavca; p9aw8743y6r74%$^$^%8 ')
]:
x = compress_doc(test)
self.assertEqual(py_compress_doc(test), x)
self.assertEqual(decompress_doc(x), test)
return unittest.defaultTestLoader.loadTestsFromTestCase(Test)
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