Edit
kc3-lang/libxml2/encoding.c
Daniel Veillard
- encoding.c
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/* * encoding.c : implements the encoding conversion functions needed for XML * * Related specs: * rfc2044 (UTF-8 and UTF-16) F. Yergeau Alis Technologies * [ISO-10646] UTF-8 and UTF-16 in Annexes * [ISO-8859-1] ISO Latin-1 characters codes. * [UNICODE] The Unicode Consortium, "The Unicode Standard -- * Worldwide Character Encoding -- Version 1.0", Addison- * Wesley, Volume 1, 1991, Volume 2, 1992. UTF-8 is * described in Unicode Technical Report #4. * [US-ASCII] Coded Character Set--7-bit American Standard Code for * Information Interchange, ANSI X3.4-1986. * * Original code from "Martin J. Duerst" <duerst@w3.org> * * See Copyright for the status of this software. * * $Id$ * * Daniel.Veillard@w3.org */ #include "encoding.h" /** * isolat1ToUTF8: * @out: a pointer ot an array of bytes to store the result * @outlen: the lenght of @out * @in: a pointer ot an array of ISO Latin 1 chars * @inlen: the lenght of @in * * Take a block of ISO Latin 1 chars in and try to convert it to an UTF-8 * block of chars out. * return values: number of byte written, or -1 by lack of space. */ int isolat1ToUTF8(unsigned char* out, int outlen, unsigned char* in, int inlen) { unsigned char* outstart= out; unsigned char* outend= out+outlen; unsigned char* inend= in+inlen; unsigned char c; while (in < inend) { c= *in++; if (c < 0x80) { if (out >= outend) return -1; *out++ = c; } else { if (out >= outend) return -1; *out++ = 0xC0 | (c >> 6); if (out >= outend) return -1; *out++ = 0x80 | (0x3F & c); } } return out-outstart; } /** * UTF8Toisolat1: * @out: a pointer ot an array of bytes to store the result * @outlen: the lenght of @out * @in: a pointer ot an array of UTF-8 chars * @inlen: the lenght of @in * * Take a block of UTF-8 chars in and try to convert it to an ISO Latin 1 * block of chars out. * TODO: need a fallback mechanism ... * return values: the number of byte written, or -1 by lack of space, or -2 * if the transcoding failed. */ int UTF8Toisolat1(unsigned char* out, int outlen, unsigned char* in, int inlen) { unsigned char* outstart= out; unsigned char* outend= out+outlen; unsigned char* inend= in+inlen; unsigned char c; while (in < inend) { c= *in++; if (c < 0x80) { if (out >= outend) return -1; *out++= c; } else if (((c & 0xFE) == 0xC2) && in<inend) { if (out >= outend) return -1; *out++= ((c & 0x03) << 6) | (*in++ & 0x3F); } else return -2; } return out-outstart; } /** * UTF16ToUTF8: * @out: a pointer ot an array of bytes to store the result * @outlen: the lenght of @out * @in: a pointer ot an array of UTF-16 chars (array of unsigned shorts) * @inlen: the lenght of @in * * Take a block of UTF-16 ushorts in and try to convert it to an UTF-8 * block of chars out. * return values: number of byte written, or -1 by lack of space. */ int UTF16ToUTF8(unsigned char* out, int outlen, unsigned short* in, int inlen) { unsigned char* outstart= out; unsigned char* outend= out+outlen; unsigned short* inend= in+inlen; unsigned int c, d; int bits; while (in < inend) { c= *in++; if ((c & 0xFC00) == 0xD800) { /* surrogates */ if ((in<inend) && (((d=*in++) & 0xFC00) == 0xDC00)) { c &= 0x03FF; c <<= 10; c |= d & 0x03FF; c += 0x10000; } else return -1; } /* assertion: c is a single UTF-4 value */ if (out >= outend) return -1; if (c < 0x80) { *out++= c; bits= -6; } else if (c < 0x800) { *out++= (c >> 6) | 0xC0; bits= 0; } else if (c < 0x10000) { *out++= (c >> 12) | 0xE0; bits= 6; } else { *out++= (c >> 18) | 0xF0; bits= 12; } for ( ; bits < 0; bits-= 6) { if (out >= outend) return -1; *out++= (c >> bits) & 0x3F; } } return out-outstart; } /** * UTF8ToUTF16: * @out: a pointer ot an array of shorts to store the result * @outlen: the lenght of @out (number of shorts) * @in: a pointer ot an array of UTF-8 chars * @inlen: the lenght of @in * * Take a block of UTF-8 chars in and try to convert it to an UTF-16 * block of chars out. * TODO: need a fallback mechanism ... * return values: the number of byte written, or -1 by lack of space, or -2 * if the transcoding failed. */ int UTF8ToUTF16(unsigned short* out, int outlen, unsigned char* in, int inlen) { unsigned short* outstart= out; unsigned short* outend= out+outlen; unsigned char* inend= in+inlen; unsigned int c, d, trailing; while (in < inend) { d= *in++; if (d < 0x80) { c= d; trailing= 0; } else if (d < 0xC0) return -2; /* trailing byte in leading position */ else if (d < 0xE0) { c= d & 0x1F; trailing= 1; } else if (d < 0xF0) { c= d & 0x0F; trailing= 2; } else if (d < 0xF8) { c= d & 0x07; trailing= 3; } else return -2; /* no chance for this in UTF-16 */ for ( ; trailing; trailing--) { if ((in >= inend) || (((d= *in++) & 0xC0) != 0x80)) return -1; c <<= 6; c |= d & 0x3F; } /* assertion: c is a single UTF-4 value */ if (c < 0x10000) { if (out >= outend) return -1; *out++ = c; } else if (c < 0x110000) { if (out+1 >= outend) return -1; c -= 0x10000; *out++ = 0xD800 | (c >> 10); *out++ = 0xDC00 | (c & 0x03FF); } else return -1; } return out-outstart; }