| /* |
| * 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. |
| * |
| * Daniel.Veillard@w3.org |
| */ |
| |
| #include "encoding.h" |
| |
| /* |
| * From rfc2044: encoding of the Unicode values on UTF-8: |
| * |
| * UCS-4 range (hex.) UTF-8 octet sequence (binary) |
| * 0000 0000-0000 007F 0xxxxxxx |
| * 0000 0080-0000 07FF 110xxxxx 10xxxxxx |
| * 0000 0800-0000 FFFF 1110xxxx 10xxxxxx 10xxxxxx |
| * |
| * I hope we won't use values > 0xFFFF anytime soon ! |
| */ |
| |
| /** |
| * 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. |
| * Returns the 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 ... |
| * Returns 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. |
| * Returns the 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 ... |
| * Returns 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; |
| } |
| |
| |