1 // Copyright (c) 1994 James Clark
2 // See the file COPYING for copying permission.
3 #pragma ident	"%Z%%M%	%I%	%E% SMI"
4 
5 #include "splib.h"
6 
7 #ifdef SP_MULTI_BYTE
8 
9 #include "EUCJPCodingSystem.h"
10 
11 #ifdef SP_NAMESPACE
12 namespace SP_NAMESPACE {
13 #endif
14 
15 class EUCJPDecoder : public Decoder {
16 public:
EUCJPDecoder()17   EUCJPDecoder() { }
18   size_t decode(Char *, const char *, size_t, const char **);
19 private:
20 };
21 
22 class EUCJPEncoder : public Encoder {
23 public:
EUCJPEncoder()24   EUCJPEncoder() { }
25   void output(const Char *, size_t, OutputByteStream *);
output(Char * tmp_char,size_t tmp_size_t,OutputByteStream * tmp_obs)26   void output(Char *tmp_char, size_t tmp_size_t, OutputByteStream *tmp_obs) {
27         output((const Char *)tmp_char, (size_t) tmp_size_t, (OutputByteStream *)tmp_obs);
28   }
29 
30 };
31 
makeDecoder() const32 Decoder *EUCJPCodingSystem::makeDecoder() const
33 {
34   return new EUCJPDecoder;
35 }
36 
makeEncoder() const37 Encoder *EUCJPCodingSystem::makeEncoder() const
38 {
39   return new EUCJPEncoder;
40 }
41 
decode(Char * to,const char * s,size_t slen,const char ** rest)42 size_t EUCJPDecoder::decode(Char *to, const char *s,
43 			    size_t slen, const char **rest)
44 {
45   Char *start = to;
46   const unsigned char *us = (const unsigned char *)s;
47   while (slen > 0) {
48     if (!(*us & 0x80)) {
49       // G0
50       *to++ = *us++;
51       slen--;
52     }
53     else if (*us == 0x8e) {
54       // G2
55       if (slen < 2)
56 	break;
57       slen -= 2;
58       ++us;
59       *to++ = *us++ | 0x80;
60     }
61     else if (*us == 0x8f) {
62       // G3
63       if (slen < 3)
64 	break;
65       slen -= 3;
66       ++us;
67       unsigned short n = (*us++ | 0x80) << 8;
68       n |= (*us++ & ~0x80);
69       *to++ = n;
70     }
71     else {
72       // G1
73       if (slen < 2)
74 	break;
75       slen -= 2;
76       unsigned short n = *us++ << 8;
77       n |= (*us++ | 0x80);
78       *to++ = n;
79     }
80   }
81   *rest = (const char *)us;
82   return to - start;
83 }
84 
85 
output(const Char * s,size_t n,OutputByteStream * sb)86 void EUCJPEncoder::output(const Char *s, size_t n, OutputByteStream *sb)
87 {
88   for (; n > 0; s++, n--) {
89     Char c = *s;
90     unsigned short mask = (unsigned short)(c & 0x8080);
91     if (mask == 0)
92       sb->sputc((unsigned char)(c & 0xff));
93     else if (mask == 0x8080) {
94       sb->sputc((unsigned char)((c >> 8) & 0xff));
95       sb->sputc((unsigned char)(c & 0xff));
96     }
97     else if (mask == 0x0080) {
98       sb->sputc((unsigned char)0x8e);
99       sb->sputc((unsigned char)(c & 0xff));
100     }
101     else {
102       // mask == 0x8000
103       sb->sputc((unsigned char)0x8f);
104       sb->sputc((unsigned char)((c >> 8) & 0xff));
105       sb->sputc((unsigned char)(c & 0x7f));
106     }
107   }
108 }
109 
110 #ifdef SP_NAMESPACE
111 }
112 #endif
113 
114 #else /* not SP_MULTI_BYTE */
115 
116 #ifndef __GNUG__
117 static char non_empty_translation_unit;	// sigh
118 #endif
119 
120 #endif /* not SP_MULTI_BYTE */
121