_codecs_cn.c - This C code implements a set of character en…

/Modules/cjkcodecs/_codecs_cn.c

http://unladen-swallow.googlecode.com/ · C · 444 lines · 332 code · 84 blank · 28 comment · 107 complexity · 61b64ea46b65615ff2bc5368f433dcdc MD5 · raw file


/*
 * _codecs_cn.c: Codecs collection for Mainland Chinese encodings
 *
 * Written by Hye-Shik Chang <perky@FreeBSD.org>
 */

#include "cjkcodecs.h"
#include "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 || c3 < 0x81 || 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 == 0) {
				WRITE1((unsigned char)c)
				NEXT(1, 1)
			}
			else {
				WRITE3('~', '}', (unsigned char)c)
				NEXT(1, 3)
				state->i = 0;
			}
			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 == '~') {
				WRITE1('~')
				NEXT(2, 1)
				continue;
			}
			else if (c2 == '{' && state->i == 0)
				state->i = 1; /* set GB */
			else if (c2 == '}' && state->i == 1)
				state->i = 0; /* set ASCII */
			else if (c2 == '\n')
				; /* line-continuation */
			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)

Summary ✨

This C code implements a set of character encodings and decodings for various Chinese characters, including GBK, GB2312, and HZ. It provides functions for encoding and decoding text into these formats, as well as handling special cases such as line continuations and ASCII mode. The code is designed to be used in a larger system that requires support for different character encodings.

Alerts (5)

Complexity hotspot; lines 27 to 31 (total complexity: 16)
27 28 29 30 31