diff options
Diffstat (limited to 'ext/json/ext/generator/unicode.c')
| -rw-r--r-- | ext/json/ext/generator/unicode.c | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/ext/json/ext/generator/unicode.c b/ext/json/ext/generator/unicode.c new file mode 100644 index 0000000000..947e2d6bda --- /dev/null +++ b/ext/json/ext/generator/unicode.c @@ -0,0 +1,180 @@ +#include "unicode.h" + +#define unicode_escape(buffer, character) \ + snprintf(buf, 7, "\\u%04x", (unsigned int) (character)); \ + rb_str_buf_cat(buffer, buf, 6); + +/* + * Copyright 2001-2004 Unicode, Inc. + * + * Disclaimer + * + * This source code is provided as is by Unicode, Inc. No claims are + * made as to fitness for any particular purpose. No warranties of any + * kind are expressed or implied. The recipient agrees to determine + * applicability of information provided. If this file has been + * purchased on magnetic or optical media from Unicode, Inc., the + * sole remedy for any claim will be exchange of defective media + * within 90 days of receipt. + * + * Limitations on Rights to Redistribute This Code + * + * Unicode, Inc. hereby grants the right to freely use the information + * supplied in this file in the creation of products supporting the + * Unicode Standard, and to make copies of this file in any form + * for internal or external distribution as long as this notice + * remains attached. + */ + +/* + * Index into the table below with the first byte of a UTF-8 sequence to + * get the number of trailing bytes that are supposed to follow it. + * Note that *legal* UTF-8 values can't have 4 or 5-bytes. The table is + * left as-is for anyone who may want to do such conversion, which was + * allowed in earlier algorithms. + */ +static const char trailingBytesForUTF8[256] = { + 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, + 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, + 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, + 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, + 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, + 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, + 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, + 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, 3,3,3,3,3,3,3,3,4,4,4,4,5,5,5,5 +}; + +/* + * Magic values subtracted from a buffer value during UTF8 conversion. + * This table contains as many values as there might be trailing bytes + * in a UTF-8 sequence. + */ +static const UTF32 offsetsFromUTF8[6] = { 0x00000000UL, 0x00003080UL, 0x000E2080UL, + 0x03C82080UL, 0xFA082080UL, 0x82082080UL }; + +/* + * Once the bits are split out into bytes of UTF-8, this is a mask OR-ed + * into the first byte, depending on how many bytes follow. There are + * as many entries in this table as there are UTF-8 sequence types. + * (I.e., one byte sequence, two byte... etc.). Remember that sequencs + * for *legal* UTF-8 will be 4 or fewer bytes total. + */ +static const UTF8 firstByteMark[7] = { 0x00, 0x00, 0xC0, 0xE0, 0xF0, 0xF8, 0xFC }; + +/* + * Utility routine to tell whether a sequence of bytes is legal UTF-8. + * This must be called with the length pre-determined by the first byte. + * If not calling this from ConvertUTF8to*, then the length can be set by: + * length = trailingBytesForUTF8[*source]+1; + * and the sequence is illegal right away if there aren't that many bytes + * available. + * If presented with a length > 4, this returns 0. The Unicode + * definition of UTF-8 goes up to 4-byte sequences. + */ + +inline static unsigned char isLegalUTF8(const UTF8 *source, int length) +{ + UTF8 a; + const UTF8 *srcptr = source+length; + switch (length) { + default: return 0; + /* Everything else falls through when "1"... */ + case 4: if ((a = (*--srcptr)) < 0x80 || a > 0xBF) return 0; + case 3: if ((a = (*--srcptr)) < 0x80 || a > 0xBF) return 0; + case 2: if ((a = (*--srcptr)) > 0xBF) return 0; + + switch (*source) { + /* no fall-through in this inner switch */ + case 0xE0: if (a < 0xA0) return 0; break; + case 0xED: if (a > 0x9F) return 0; break; + case 0xF0: if (a < 0x90) return 0; break; + case 0xF4: if (a > 0x8F) return 0; break; + default: if (a < 0x80) return 0; + } + + case 1: if (*source >= 0x80 && *source < 0xC2) return 0; + } + if (*source > 0xF4) return 0; + return 1; +} + +void JSON_convert_UTF8_to_JSON(VALUE buffer, VALUE string, ConversionFlags flags) +{ + char buf[7]; + const UTF8* source = (UTF8 *) RSTRING_PTR(string); + const UTF8* sourceEnd = source + RSTRING_LEN(string); + + while (source < sourceEnd) { + UTF32 ch = 0; + unsigned short extraBytesToRead = trailingBytesForUTF8[*source]; + if (source + extraBytesToRead >= sourceEnd) { + rb_raise(rb_path2class("JSON::GeneratorError"), + "partial character in source, but hit end"); + } + if (!isLegalUTF8(source, extraBytesToRead+1)) { + rb_raise(rb_path2class("JSON::GeneratorError"), + "source sequence is illegal/malformed"); + } + /* + * The cases all fall through. See "Note A" below. + */ + switch (extraBytesToRead) { + case 5: ch += *source++; ch <<= 6; /* remember, illegal UTF-8 */ + case 4: ch += *source++; ch <<= 6; /* remember, illegal UTF-8 */ + case 3: ch += *source++; ch <<= 6; + case 2: ch += *source++; ch <<= 6; + case 1: ch += *source++; ch <<= 6; + case 0: ch += *source++; + } + ch -= offsetsFromUTF8[extraBytesToRead]; + + if (ch <= UNI_MAX_BMP) { /* Target is a character <= 0xFFFF */ + /* UTF-16 surrogate values are illegal in UTF-32 */ + if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_LOW_END) { + if (flags == strictConversion) { + source -= (extraBytesToRead+1); /* return to the illegal value itself */ + rb_raise(rb_path2class("JSON::GeneratorError"), + "source sequence is illegal/malformed"); + } else { + unicode_escape(buffer, UNI_REPLACEMENT_CHAR); + } + } else { + /* normal case */ + if (ch == '"') { + rb_str_buf_cat2(buffer, "\\\""); + } else if (ch == '\\') { + rb_str_buf_cat2(buffer, "\\\\"); + } else if (ch >= 0x20 && ch <= 0x7f) { + rb_str_buf_cat(buffer, (char *) source - 1, 1); + } else if (ch == '\n') { + rb_str_buf_cat2(buffer, "\\n"); + } else if (ch == '\r') { + rb_str_buf_cat2(buffer, "\\r"); + } else if (ch == '\t') { + rb_str_buf_cat2(buffer, "\\t"); + } else if (ch == '\f') { + rb_str_buf_cat2(buffer, "\\f"); + } else if (ch == '\b') { + rb_str_buf_cat2(buffer, "\\b"); + } else if (ch < 0x20) { + unicode_escape(buffer, (UTF16) ch); + } else { + unicode_escape(buffer, (UTF16) ch); + } + } + } else if (ch > UNI_MAX_UTF16) { + if (flags == strictConversion) { + source -= (extraBytesToRead+1); /* return to the start */ + rb_raise(rb_path2class("JSON::GeneratorError"), + "source sequence is illegal/malformed"); + } else { + unicode_escape(buffer, UNI_REPLACEMENT_CHAR); + } + } else { + /* target is a character in range 0xFFFF - 0x10FFFF. */ + ch -= halfBase; + unicode_escape(buffer, (UTF16)((ch >> halfShift) + UNI_SUR_HIGH_START)); + unicode_escape(buffer, (UTF16)((ch & halfMask) + UNI_SUR_LOW_START)); + } + } +} |