diff options
Diffstat (limited to 'couchjs/c_src/utf8.c')
| -rw-r--r-- | couchjs/c_src/utf8.c | 293 |
1 files changed, 293 insertions, 0 deletions
diff --git a/couchjs/c_src/utf8.c b/couchjs/c_src/utf8.c new file mode 100644 index 00000000..57928ba9 --- /dev/null +++ b/couchjs/c_src/utf8.c @@ -0,0 +1,293 @@ +// Licensed under the Apache License, Version 2.0 (the "License"); you may not +// use this file except in compliance with the License. You may obtain a copy of +// the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT +// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the +// License for the specific language governing permissions and limitations under +// the License. + +#include "config.h" +#ifdef HAVE_JS_JSAPI_H +#include <js/jsapi.h> +#elif HAVE_MOZJS_JSAPI_H +#include <mozjs/jsapi.h> +#else +#include <jsapi.h> +#endif + +static int +enc_char(uint8 *utf8Buffer, uint32 ucs4Char) +{ + int utf8Length = 1; + + if (ucs4Char < 0x80) + { + *utf8Buffer = (uint8)ucs4Char; + } + else + { + int i; + uint32 a = ucs4Char >> 11; + utf8Length = 2; + while(a) + { + a >>= 5; + utf8Length++; + } + i = utf8Length; + while(--i) + { + utf8Buffer[i] = (uint8)((ucs4Char & 0x3F) | 0x80); + ucs4Char >>= 6; + } + *utf8Buffer = (uint8)(0x100 - (1 << (8-utf8Length)) + ucs4Char); + } + + return utf8Length; +} + +static JSBool +enc_charbuf(const jschar* src, size_t srclen, char* dst, size_t* dstlenp) +{ + size_t i; + size_t utf8Len; + size_t dstlen = *dstlenp; + size_t origDstlen = dstlen; + jschar c; + jschar c2; + uint32 v; + uint8 utf8buf[6]; + + if(!dst) + { + dstlen = origDstlen = (size_t) -1; + } + + while(srclen) + { + c = *src++; + srclen--; + + if((c >= 0xDC00) && (c <= 0xDFFF)) goto bad_surrogate; + + if(c < 0xD800 || c > 0xDBFF) + { + v = c; + } + else + { + if(srclen < 1) goto buffer_too_small; + c2 = *src++; + srclen--; + if ((c2 < 0xDC00) || (c2 > 0xDFFF)) + { + c = c2; + goto bad_surrogate; + } + v = ((c - 0xD800) << 10) + (c2 - 0xDC00) + 0x10000; + } + if(v < 0x0080) + { + /* no encoding necessary - performance hack */ + if(!dstlen) goto buffer_too_small; + if(dst) *dst++ = (char) v; + utf8Len = 1; + } + else + { + utf8Len = enc_char(utf8buf, v); + if(utf8Len > dstlen) goto buffer_too_small; + if(dst) + { + for (i = 0; i < utf8Len; i++) + { + *dst++ = (char) utf8buf[i]; + } + } + } + dstlen -= utf8Len; + } + + *dstlenp = (origDstlen - dstlen); + return JS_TRUE; + +bad_surrogate: + *dstlenp = (origDstlen - dstlen); + return JS_FALSE; + +buffer_too_small: + *dstlenp = (origDstlen - dstlen); + return JS_FALSE; +} + +char* +enc_string(JSContext* cx, jsval arg, size_t* buflen) +{ + JSString* str = NULL; + jschar* src = NULL; + char* bytes = NULL; + size_t srclen = 0; + size_t byteslen = 0; + + str = JS_ValueToString(cx, arg); + if(!str) goto error; + + src = JS_GetStringChars(str); + srclen = JS_GetStringLength(str); + + if(!enc_charbuf(src, srclen, NULL, &byteslen)) goto error; + + bytes = JS_malloc(cx, (byteslen) + 1); + bytes[byteslen] = 0; + + if(!enc_charbuf(src, srclen, bytes, &byteslen)) goto error; + + if(buflen) *buflen = byteslen; + goto success; + +error: + if(bytes != NULL) JS_free(cx, bytes); + bytes = NULL; + +success: + return bytes; +} + +static uint32 +dec_char(const uint8 *utf8Buffer, int utf8Length) +{ + uint32 ucs4Char; + uint32 minucs4Char; + + /* from Unicode 3.1, non-shortest form is illegal */ + static const uint32 minucs4Table[] = { + 0x00000080, 0x00000800, 0x0001000, 0x0020000, 0x0400000 + }; + + if (utf8Length == 1) + { + ucs4Char = *utf8Buffer; + } + else + { + ucs4Char = *utf8Buffer++ & ((1<<(7-utf8Length))-1); + minucs4Char = minucs4Table[utf8Length-2]; + while(--utf8Length) + { + ucs4Char = ucs4Char<<6 | (*utf8Buffer++ & 0x3F); + } + if(ucs4Char < minucs4Char || ucs4Char == 0xFFFE || ucs4Char == 0xFFFF) + { + ucs4Char = 0xFFFD; + } + } + + return ucs4Char; +} + +static JSBool +dec_charbuf(const char *src, size_t srclen, jschar *dst, size_t *dstlenp) +{ + uint32 v; + size_t offset = 0; + size_t j; + size_t n; + size_t dstlen = *dstlenp; + size_t origDstlen = dstlen; + + if(!dst) dstlen = origDstlen = (size_t) -1; + + while(srclen) + { + v = (uint8) *src; + n = 1; + + if(v & 0x80) + { + while(v & (0x80 >> n)) + { + n++; + } + + if(n > srclen) goto buffer_too_small; + if(n == 1 || n > 6) goto bad_character; + + for(j = 1; j < n; j++) + { + if((src[j] & 0xC0) != 0x80) goto bad_character; + } + + v = dec_char((const uint8 *) src, n); + if(v >= 0x10000) + { + v -= 0x10000; + + if(v > 0xFFFFF || dstlen < 2) + { + *dstlenp = (origDstlen - dstlen); + return JS_FALSE; + } + + if(dstlen < 2) goto buffer_too_small; + + if(dst) + { + *dst++ = (jschar)((v >> 10) + 0xD800); + v = (jschar)((v & 0x3FF) + 0xDC00); + } + dstlen--; + } + } + + if(!dstlen) goto buffer_too_small; + if(dst) *dst++ = (jschar) v; + + dstlen--; + offset += n; + src += n; + srclen -= n; + } + + *dstlenp = (origDstlen - dstlen); + return JS_TRUE; + +bad_character: + *dstlenp = (origDstlen - dstlen); + return JS_FALSE; + +buffer_too_small: + *dstlenp = (origDstlen - dstlen); + return JS_FALSE; +} + +JSString* +dec_string(JSContext* cx, const char* bytes, size_t byteslen) +{ + JSString* str = NULL; + jschar* chars = NULL; + size_t charslen; + + if(!dec_charbuf(bytes, byteslen, NULL, &charslen)) goto error; + + chars = JS_malloc(cx, (charslen + 1) * sizeof(jschar)); + if(!chars) return NULL; + chars[charslen] = 0; + + if(!dec_charbuf(bytes, byteslen, chars, &charslen)) goto error; + + str = JS_NewUCString(cx, chars, charslen - 1); + if(!str) goto error; + + goto success; + +error: + if(chars != NULL) JS_free(cx, chars); + str = NULL; + +success: + return str; +} |