text: /*
   * _codecs_cn.c: Codecs collection for Mainland Chinese encodings
   *
   * Written by Hye-Shik Chang <perky@FreeBSD.org>
   */
  
  #include "src/cjkcodecs/cjkcodecs.h"
  #include "src/cjkcodecs/mappings_cn.h"
  
  /**
   * hz is predefined as 100 on AIX. So we undefine it to avoid
   * conflict against hz codec's.
   */
  #ifdef _AIX
  #undef hz
  #endif
  
  /* GBK and GB2312 map differently in few codepoints that are listed below:
   *
   *              gb2312                          gbk
   * A1A4         U+30FB KATAKANA MIDDLE DOT      U+00B7 MIDDLE DOT
   * A1AA         U+2015 HORIZONTAL BAR           U+2014 EM DASH
   * A844         undefined                       U+2015 HORIZONTAL BAR
   */
  
  #define GBK_DECODE(dc1, dc2, assi) \
      if ((dc1) == 0xa1 && (dc2) == 0xaa) (assi) = 0x2014; \
      else if ((dc1) == 0xa8 && (dc2) == 0x44) (assi) = 0x2015; \
      else if ((dc1) == 0xa1 && (dc2) == 0xa4) (assi) = 0x00b7; \
      else TRYMAP_DEC(gb2312, assi, dc1 ^ 0x80, dc2 ^ 0x80); \
      else TRYMAP_DEC(gbkext, assi, dc1, dc2);
  
  #define GBK_ENCODE(code, assi) \
      if ((code) == 0x2014) (assi) = 0xa1aa; \
      else if ((code) == 0x2015) (assi) = 0xa844; \
      else if ((code) == 0x00b7) (assi) = 0xa1a4; \
      else if ((code) != 0x30fb && TRYMAP_ENC_COND(gbcommon, assi, code));
  
  /*
   * GB2312 codec
   */
  
  ENCODER(gb2312)
  {
      while (inleft > 0) {
          Py_UNICODE c = IN1;
          DBCHAR code;
  
          if (c < 0x80) {
              WRITE1((unsigned char)c)
              NEXT(1, 1)
              continue;
          }
          UCS4INVALID(c)
  
          REQUIRE_OUTBUF(2)
          TRYMAP_ENC(gbcommon, code, c);
          else return 1;
  
          if (code & 0x8000) /* MSB set: GBK */
              return 1;
  
          OUT1((code >> 8) | 0x80)
          OUT2((code & 0xFF) | 0x80)
          NEXT(1, 2)
      }
  
      return 0;
  }
  
  DECODER(gb2312)
  {
      while (inleft > 0) {
          unsigned char c = **inbuf;
  
          REQUIRE_OUTBUF(1)
  
          if (c < 0x80) {
              OUT1(c)
              NEXT(1, 1)
              continue;
          }
  
          REQUIRE_INBUF(2)
          TRYMAP_DEC(gb2312, **outbuf, c ^ 0x80, IN2 ^ 0x80) {
              NEXT(2, 1)
          }
          else return 2;
      }
  
      return 0;
  }
  
  
  /*
   * GBK codec
   */
  
  ENCODER(gbk)
  {
      while (inleft > 0) {
          Py_UNICODE c = IN1;
          DBCHAR code;
  
          if (c < 0x80) {
              WRITE1((unsigned char)c)
              NEXT(1, 1)
              continue;
          }
          UCS4INVALID(c)
  
          REQUIRE_OUTBUF(2)
  
          GBK_ENCODE(c, code)
          else return 1;
  
          OUT1((code >> 8) | 0x80)
          if (code & 0x8000)
              OUT2((code & 0xFF)) /* MSB set: GBK */
          else
              OUT2((code & 0xFF) | 0x80) /* MSB unset: GB2312 */
          NEXT(1, 2)
      }
  
      return 0;
  }
  
  DECODER(gbk)
  {
      while (inleft > 0) {
          unsigned char c = IN1;
  
          REQUIRE_OUTBUF(1)
  
          if (c < 0x80) {
              OUT1(c)
              NEXT(1, 1)
              continue;
          }
  
          REQUIRE_INBUF(2)
  
          GBK_DECODE(c, IN2, **outbuf)
          else return 2;
  
          NEXT(2, 1)
      }
  
      return 0;
  }
  
  
  /*
   * GB18030 codec
   */
  
  ENCODER(gb18030)
  {
      while (inleft > 0) {
          ucs4_t c = IN1;
          DBCHAR code;
  
          if (c < 0x80) {
              WRITE1(c)
              NEXT(1, 1)
              continue;
          }
  
          DECODE_SURROGATE(c)
          if (c > 0x10FFFF)
  #if Py_UNICODE_SIZE == 2
              return 2; /* surrogates pair */
  #else
              return 1;
  #endif
          else if (c >= 0x10000) {
              ucs4_t tc = c - 0x10000;
  
              REQUIRE_OUTBUF(4)
  
              OUT4((unsigned char)(tc % 10) + 0x30)
              tc /= 10;
              OUT3((unsigned char)(tc % 126) + 0x81)
              tc /= 126;
              OUT2((unsigned char)(tc % 10) + 0x30)
              tc /= 10;
              OUT1((unsigned char)(tc + 0x90))
  
  #if Py_UNICODE_SIZE == 2
              NEXT(2, 4) /* surrogates pair */
  #else
              NEXT(1, 4)
  #endif
              continue;
          }
  
          REQUIRE_OUTBUF(2)
  
          GBK_ENCODE(c, code)
          else TRYMAP_ENC(gb18030ext, code, c);
          else {
              const struct _gb18030_to_unibmp_ranges *utrrange;
  
              REQUIRE_OUTBUF(4)
  
              for (utrrange = gb18030_to_unibmp_ranges;
                   utrrange->first != 0;
                   utrrange++)
                  if (utrrange->first <= c &&
                      c <= utrrange->last) {
                      Py_UNICODE tc;
  
                      tc = c - utrrange->first +
                           utrrange->base;
  
                      OUT4((unsigned char)(tc % 10) + 0x30)
                      tc /= 10;
                      OUT3((unsigned char)(tc % 126) + 0x81)
                      tc /= 126;
                      OUT2((unsigned char)(tc % 10) + 0x30)
                      tc /= 10;
                      OUT1((unsigned char)tc + 0x81)
  
                      NEXT(1, 4)
                      break;
                  }
  
              if (utrrange->first == 0)
                  return 1;
              continue;
          }
  
          OUT1((code >> 8) | 0x80)
          if (code & 0x8000)
              OUT2((code & 0xFF)) /* MSB set: GBK or GB18030ext */
          else
              OUT2((code & 0xFF) | 0x80) /* MSB unset: GB2312 */
  
          NEXT(1, 2)
      }
  
      return 0;
  }
  
  DECODER(gb18030)
  {
      while (inleft > 0) {
          unsigned char c = IN1, c2;
  
          REQUIRE_OUTBUF(1)
  
          if (c < 0x80) {
              OUT1(c)
              NEXT(1, 1)
              continue;
          }
  
          REQUIRE_INBUF(2)
  
          c2 = IN2;
          if (c2 >= 0x30 && c2 <= 0x39) { /* 4 bytes seq */
              const struct _gb18030_to_unibmp_ranges *utr;
              unsigned char c3, c4;
              ucs4_t lseq;
  
              REQUIRE_INBUF(4)
              c3 = IN3;
              c4 = IN4;
              if (c  < 0x81 || c  > 0xFE ||
                  c3 < 0x81 || c3 > 0xFE ||
                  c4 < 0x30 || c4 > 0x39)
                  return 4;
              c -= 0x81;  c2 -= 0x30;
              c3 -= 0x81; c4 -= 0x30;
  
              if (c < 4) { /* U+0080 - U+FFFF */
                  lseq = ((ucs4_t)c * 10 + c2) * 1260 +
                      (ucs4_t)c3 * 10 + c4;
                  if (lseq < 39420) {
                      for (utr = gb18030_to_unibmp_ranges;
                           lseq >= (utr + 1)->base;
                           utr++) ;
                      OUT1(utr->first - utr->base + lseq)
                      NEXT(4, 1)
                      continue;
                  }
              }
              else if (c >= 15) { /* U+10000 - U+10FFFF */
                  lseq = 0x10000 + (((ucs4_t)c-15) * 10 + c2)
                      * 1260 + (ucs4_t)c3 * 10 + c4;
                  if (lseq <= 0x10FFFF) {
                      WRITEUCS4(lseq);
                      NEXT_IN(4)
                      continue;
                  }
              }
              return 4;
          }
  
          GBK_DECODE(c, c2, **outbuf)
          else TRYMAP_DEC(gb18030ext, **outbuf, c, c2);
          else return 2;
  
          NEXT(2, 1)
      }
  
      return 0;
  }
  
  
  /*
   * HZ codec
   */
  
  ENCODER_INIT(hz)
  {
      state->i = 0;
      return 0;
  }
  
  ENCODER_RESET(hz)
  {
      if (state->i != 0) {
          WRITE2('~', '}')
          state->i = 0;
          NEXT_OUT(2)
      }
      return 0;
  }
  
  ENCODER(hz)
  {
      while (inleft > 0) {
          Py_UNICODE c = IN1;
          DBCHAR code;
  
          if (c < 0x80) {
              if (state->i) {
                  WRITE2('~', '}');
                  NEXT_OUT(2);
                  state->i = 0;
              }
              WRITE1((unsigned char)c);
              NEXT(1, 1);
              if (c == '~') {
                  WRITE1('~');
                  NEXT_OUT(1);
              }
              continue;
          }
  
          UCS4INVALID(c)
  
          TRYMAP_ENC(gbcommon, code, c);
          else return 1;
  
          if (code & 0x8000) /* MSB set: GBK */
              return 1;
  
          if (state->i == 0) {
              WRITE4('~', '{', code >> 8, code & 0xff)
              NEXT(1, 4)
              state->i = 1;
          }
          else {
              WRITE2(code >> 8, code & 0xff)
              NEXT(1, 2)
          }
      }
  
      return 0;
  }
  
  DECODER_INIT(hz)
  {
      state->i = 0;
      return 0;
  }
  
  DECODER_RESET(hz)
  {
      state->i = 0;
      return 0;
  }
  
  DECODER(hz)
  {
      while (inleft > 0) {
          unsigned char c = IN1;
  
          if (c == '~') {
              unsigned char c2 = IN2;
  
              REQUIRE_INBUF(2)
              if (c2 == '~' && state->i == 0) {
                  WRITE1('~')
              }
              else if (c2 == '{' && state->i == 0)
                  state->i = 1; /* set GB */
              else if (c2 == '\n' && state->i == 0)
                  ; /* line-continuation */
              else if (c2 == '}' && state->i == 1)
                  state->i = 0; /* set ASCII */
              else
                  return 2;
              NEXT(2, 0);
              continue;
          }
  
          if (c & 0x80)
              return 1;
  
          if (state->i == 0) { /* ASCII mode */
              WRITE1(c)
              NEXT(1, 1)
          }
          else { /* GB mode */
              REQUIRE_INBUF(2)
              REQUIRE_OUTBUF(1)
              TRYMAP_DEC(gb2312, **outbuf, c, IN2) {
                  NEXT(2, 1)
              }
              else
                  return 2;
          }
      }
  
      return 0;
  }
  
  
  BEGIN_MAPPINGS_LIST
    MAPPING_DECONLY(gb2312)
    MAPPING_DECONLY(gbkext)
    MAPPING_ENCONLY(gbcommon)
    MAPPING_ENCDEC(gb18030ext)
  END_MAPPINGS_LIST
  
  BEGIN_CODECS_LIST
    CODEC_STATELESS(gb2312)
    CODEC_STATELESS(gbk)
    CODEC_STATELESS(gb18030)
    CODEC_STATEFUL(hz)
  END_CODECS_LIST
  
  I_AM_A_MODULE_FOR(cn)
  