1######################## BEGIN LICENSE BLOCK ########################
2# The Original Code is mozilla.org code.
3#
4# The Initial Developer of the Original Code is
5# Netscape Communications Corporation.
6# Portions created by the Initial Developer are Copyright (C) 1998
7# the Initial Developer. All Rights Reserved.
8#
9# Contributor(s):
10#   Mark Pilgrim - port to Python
11#
12# This library is free software; you can redistribute it and/or
13# modify it under the terms of the GNU Lesser General Public
14# License as published by the Free Software Foundation; either
15# version 2.1 of the License, or (at your option) any later version.
16#
17# This library is distributed in the hope that it will be useful,
18# but WITHOUT ANY WARRANTY; without even the implied warranty of
19# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
20# Lesser General Public License for more details.
21#
22# You should have received a copy of the GNU Lesser General Public
23# License along with this library; if not, write to the Free Software
24# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
25# 02110-1301  USA
26######################### END LICENSE BLOCK #########################
27
28import sys
29from . import constants
30from .mbcharsetprober import MultiByteCharSetProber
31from .codingstatemachine import CodingStateMachine
32from .chardistribution import EUCJPDistributionAnalysis
33from .jpcntx import EUCJPContextAnalysis
34from .mbcssm import EUCJPSMModel
35
36
37class EUCJPProber(MultiByteCharSetProber):
38    def __init__(self):
39        MultiByteCharSetProber.__init__(self)
40        self._mCodingSM = CodingStateMachine(EUCJPSMModel)
41        self._mDistributionAnalyzer = EUCJPDistributionAnalysis()
42        self._mContextAnalyzer = EUCJPContextAnalysis()
43        self.reset()
44
45    def reset(self):
46        MultiByteCharSetProber.reset(self)
47        self._mContextAnalyzer.reset()
48
49    def get_charset_name(self):
50        return "EUC-JP"
51
52    def feed(self, aBuf):
53        aLen = len(aBuf)
54        for i in range(0, aLen):
55            # PY3K: aBuf is a byte array, so aBuf[i] is an int, not a byte
56            codingState = self._mCodingSM.next_state(aBuf[i])
57            if codingState == constants.eError:
58                if constants._debug:
59                    sys.stderr.write(self.get_charset_name()
60                                     + ' prober hit error at byte ' + str(i)
61                                     + '\n')
62                self._mState = constants.eNotMe
63                break
64            elif codingState == constants.eItsMe:
65                self._mState = constants.eFoundIt
66                break
67            elif codingState == constants.eStart:
68                charLen = self._mCodingSM.get_current_charlen()
69                if i == 0:
70                    self._mLastChar[1] = aBuf[0]
71                    self._mContextAnalyzer.feed(self._mLastChar, charLen)
72                    self._mDistributionAnalyzer.feed(self._mLastChar, charLen)
73                else:
74                    self._mContextAnalyzer.feed(aBuf[i - 1:i + 1], charLen)
75                    self._mDistributionAnalyzer.feed(aBuf[i - 1:i + 1],
76                                                     charLen)
77
78        self._mLastChar[0] = aBuf[aLen - 1]
79
80        if self.get_state() == constants.eDetecting:
81            if (self._mContextAnalyzer.got_enough_data() and
82               (self.get_confidence() > constants.SHORTCUT_THRESHOLD)):
83                self._mState = constants.eFoundIt
84
85        return self.get_state()
86
87    def get_confidence(self):
88        contxtCf = self._mContextAnalyzer.get_confidence()
89        distribCf = self._mDistributionAnalyzer.get_confidence()
90        return max(contxtCf, distribCf)
91