| /* |
| ****************************************************************************** |
| * |
| * Copyright (C) 2003-2013, International Business Machines |
| * Corporation and others. All Rights Reserved. |
| * |
| ****************************************************************************** |
| * file name: ucnv_ext.h |
| * encoding: US-ASCII |
| * tab size: 8 (not used) |
| * indentation:4 |
| * |
| * created on: 2003jun13 |
| * created by: Markus W. Scherer |
| * |
| * Conversion extensions |
| */ |
| |
| #ifndef __UCNV_EXT_H__ |
| #define __UCNV_EXT_H__ |
| |
| #include "unicode/utypes.h" |
| |
| #if !UCONFIG_NO_CONVERSION |
| |
| #include "unicode/ucnv.h" |
| #include "ucnv_cnv.h" |
| |
| /* |
| * See icuhtml/design/conversion/conversion_extensions.html |
| * |
| * Conversion extensions serve three purposes: |
| * 1. They support m:n mappings. |
| * 2. They support extension-only conversion files that are used together |
| * with the regular conversion data in base files. |
| * 3. They support mappings with more complicated meta data, |
| * for example "good one-way" mappings (|4). |
| * |
| * A base file may contain an extension table (explicitly requested or |
| * implicitly generated for m:n mappings), but its extension table is not |
| * used when an extension-only file is used. |
| * |
| * It is an error if a base file contains any regular (not extension) mapping |
| * from the same sequence as a mapping in the extension file |
| * because the base mapping would hide the extension mapping. |
| * |
| * |
| * Data for conversion extensions: |
| * |
| * One set of data structures per conversion direction (to/from Unicode). |
| * The data structures are sorted by input units to allow for binary search. |
| * Input sequences of more than one unit are handled like contraction tables |
| * in collation: |
| * The lookup value of a unit points to another table that is to be searched |
| * for the next unit, recursively. |
| * |
| * For conversion from Unicode, the initial code point is looked up in |
| * a 3-stage trie for speed, |
| * with an additional table of unique results to save space. |
| * |
| * Long output strings are stored in separate arrays, with length and index |
| * in the lookup tables. |
| * Output results also include a flag distinguishing roundtrip from |
| * (reverse) fallback mappings. |
| * |
| * Input Unicode strings must not begin or end with unpaired surrogates |
| * to avoid problems with matches on parts of surrogate pairs. |
| * |
| * Mappings from multiple characters (code points or codepage state |
| * table sequences) must be searched preferring the longest match. |
| * For this to work and be efficient, the variable-width table must contain |
| * all mappings that contain prefixes of the multiple characters. |
| * If an extension table is built on top of a base table in another file |
| * and a base table entry is a prefix of a multi-character mapping, then |
| * this is an error. |
| * |
| * |
| * Implementation note: |
| * |
| * Currently, the parser and several checks in the code limit the number |
| * of UChars or bytes in a mapping to |
| * UCNV_EXT_MAX_UCHARS and UCNV_EXT_MAX_BYTES, respectively, |
| * which are output value limits in the data structure. |
| * |
| * For input, this is not strictly necessary - it is a hard limit only for the |
| * buffers in UConverter that are used to store partial matches. |
| * |
| * Input sequences could otherwise be arbitrarily long if partial matches |
| * need not be stored (i.e., if a sequence does not span several buffers with too |
| * many units before the last buffer), although then results would differ |
| * depending on whether partial matches exceed the limits or not, |
| * which depends on the pattern of buffer sizes. |
| * |
| * |
| * Data structure: |
| * |
| * int32_t indexes[>=32]; |
| * |
| * Array of indexes and lengths etc. The length of the array is at least 32. |
| * The actual length is stored in indexes[0] to be forward compatible. |
| * |
| * Each index to another array is the number of bytes from indexes[]. |
| * Each length of an array is the number of array base units in that array. |
| * |
| * Some of the structures may not be present, in which case their indexes |
| * and lengths are 0. |
| * |
| * Usage of indexes[i]: |
| * [0] length of indexes[] |
| * |
| * // to Unicode table |
| * [1] index of toUTable[] (array of uint32_t) |
| * [2] length of toUTable[] |
| * [3] index of toUUChars[] (array of UChar) |
| * [4] length of toUUChars[] |
| * |
| * // from Unicode table, not for the initial code point |
| * [5] index of fromUTableUChars[] (array of UChar) |
| * [6] index of fromUTableValues[] (array of uint32_t) |
| * [7] length of fromUTableUChars[] and fromUTableValues[] |
| * [8] index of fromUBytes[] (array of char) |
| * [9] length of fromUBytes[] |
| * |
| * // from Unicode trie for initial-code point lookup |
| * [10] index of fromUStage12[] (combined array of uint16_t for stages 1 & 2) |
| * [11] length of stage 1 portion of fromUStage12[] |
| * [12] length of fromUStage12[] |
| * [13] index of fromUStage3[] (array of uint16_t indexes into fromUStage3b[]) |
| * [14] length of fromUStage3[] |
| * [15] index of fromUStage3b[] (array of uint32_t like fromUTableValues[]) |
| * [16] length of fromUStage3b[] |
| * |
| * [17] Bit field containing numbers of bytes: |
| * 31..24 reserved, 0 |
| * 23..16 maximum input bytes |
| * 15.. 8 maximum output bytes |
| * 7.. 0 maximum bytes per UChar |
| * |
| * [18] Bit field containing numbers of UChars: |
| * 31..24 reserved, 0 |
| * 23..16 maximum input UChars |
| * 15.. 8 maximum output UChars |
| * 7.. 0 maximum UChars per byte |
| * |
| * [19] Bit field containing flags: |
| * (extension table unicodeMask) |
| * 1 UCNV_HAS_SURROGATES flag for the extension table |
| * 0 UCNV_HAS_SUPPLEMENTARY flag for the extension table |
| * |
| * [20]..[30] reserved, 0 |
| * [31] number of bytes for the entire extension structure |
| * [>31] reserved; there are indexes[0] indexes |
| * |
| * |
| * uint32_t toUTable[]; |
| * |
| * Array of byte/value pairs for lookups for toUnicode conversion. |
| * The array is partitioned into sections like collation contraction tables. |
| * Each section contains one word with the number of following words and |
| * a default value for when the lookup in this section yields no match. |
| * |
| * A section is sorted in ascending order of input bytes, |
| * allowing for fast linear or binary searches. |
| * The builder may store entries for a contiguous range of byte values |
| * (compare difference between the first and last one with count), |
| * which then allows for direct array access. |
| * The builder should always do this for the initial table section. |
| * |
| * Entries may have 0 values, see below. |
| * No two entries in a section have the same byte values. |
| * |
| * Each uint32_t contains an input byte value in bits 31..24 and the |
| * corresponding lookup value in bits 23..0. |
| * Interpret the value as follows: |
| * if(value==0) { |
| * no match, see below |
| * } else if(value<0x1f0000) { |
| * partial match - use value as index to the next toUTable section |
| * and match the next unit; (value indexes toUTable[value]) |
| * } else { |
| * if(bit 23 set) { |
| * roundtrip; |
| * } else { |
| * fallback; |
| * } |
| * unset value bit 23; |
| * if(value<=0x2fffff) { |
| * (value-0x1f0000) is a code point; (BMP: value<=0x1fffff) |
| * } else { |
| * bits 17..0 (value&0x3ffff) is an index to |
| * the result UChars in toUUChars[]; (0 indexes toUUChars[0]) |
| * length of the result=((value>>18)-12); (length=0..19) |
| * } |
| * } |
| * |
| * The first word in a section contains the number of following words in the |
| * input byte position (bits 31..24, number=1..0xff). |
| * The value of the initial word is used when the current byte is not found |
| * in this section. |
| * If the value is not 0, then it represents a result as above. |
| * If the value is 0, then the search has to return a shorter match with an |
| * earlier default value as the result, or result in "unmappable" even for the |
| * initial bytes. |
| * If the value is 0 for the initial toUTable entry, then the initial byte |
| * does not start any mapping input. |
| * |
| * |
| * UChar toUUChars[]; |
| * |
| * Contains toUnicode mapping results, stored as sequences of UChars. |
| * Indexes and lengths stored in the toUTable[]. |
| * |
| * |
| * UChar fromUTableUChars[]; |
| * uint32_t fromUTableValues[]; |
| * |
| * The fromUTable is split into two arrays, but works otherwise much like |
| * the toUTable. The array is partitioned into sections like collation |
| * contraction tables and toUTable. |
| * A row in the table consists of same-index entries in fromUTableUChars[] |
| * and fromUTableValues[]. |
| * |
| * Interpret a value as follows: |
| * if(value==0) { |
| * no match, see below |
| * } else if(value<=0xffffff) { (bits 31..24 are 0) |
| * partial match - use value as index to the next fromUTable section |
| * and match the next unit; (value indexes fromUTable[value]) |
| * } else { |
| * if(value==0x80000001) { |
| * return no mapping, but request for <subchar1>; |
| * } |
| * if(bit 31 set) { |
| * roundtrip (|0); |
| * } else if(bit 30 set) { |
| * "good one-way" mapping (|4); -- new in ICU4C 51, _MBCSHeader.version 5.4/4.4 |
| * } else { |
| * normal fallback (|1); |
| * } |
| * // bit 29 reserved, 0 |
| * length=(value>>24)&0x1f; (bits 28..24) |
| * if(length==1..3) { |
| * bits 23..0 contain 1..3 bytes, padded with 00s on the left; |
| * } else { |
| * bits 23..0 (value&0xffffff) is an index to |
| * the result bytes in fromUBytes[]; (0 indexes fromUBytes[0]) |
| * } |
| * } |
| * |
| * The first pair in a section contains the number of following pairs in the |
| * UChar position (16 bits, number=1..0xffff). |
| * The value of the initial pair is used when the current UChar is not found |
| * in this section. |
| * If the value is not 0, then it represents a result as above. |
| * If the value is 0, then the search has to return a shorter match with an |
| * earlier default value as the result, or result in "unmappable" even for the |
| * initial UChars. |
| * |
| * If the from Unicode trie is present, then the from Unicode search tables |
| * are not used for initial code points. |
| * In this case, the first entries (index 0) in the tables are not used |
| * (reserved, set to 0) because a value of 0 is used in trie results |
| * to indicate no mapping. |
| * |
| * |
| * uint16_t fromUStage12[]; |
| * |
| * Stages 1 & 2 of a trie that maps an initial code point. |
| * Indexes in stage 1 are all offset by the length of stage 1 so that the |
| * same array pointer can be used for both stages. |
| * If (c>>10)>=(length of stage 1) then c does not start any mapping. |
| * Same bit distribution as for regular conversion tries. |
| * |
| * |
| * uint16_t fromUStage3[]; |
| * uint32_t fromUStage3b[]; |
| * |
| * Stage 3 of the trie. The first array simply contains indexes to the second, |
| * which contains words in the same format as fromUTableValues[]. |
| * Use a stage 3 granularity of 4, which allows for 256k stage 3 entries, |
| * and 16-bit entries in stage 3 allow for 64k stage 3b entries. |
| * The stage 3 granularity means that the stage 2 entry needs to be left-shifted. |
| * |
| * Two arrays are used because it is expected that more than half of the stage 3 |
| * entries will be zero. The 16-bit index stage 3 array saves space even |
| * considering storing a total of 6 bytes per non-zero entry in both arrays |
| * together. |
| * Using a stage 3 granularity of >1 diminishes the compactability in that stage |
| * but provides a larger effective addressing space in stage 2. |
| * All but the final result stage use 16-bit entries to save space. |
| * |
| * fromUStage3b[] contains a zero for "no mapping" at its index 0, |
| * and may contain UCNV_EXT_FROM_U_SUBCHAR1 at index 1 for "<subchar1> SUB mapping" |
| * (i.e., "no mapping" with preference for <subchar1> rather than <subchar>), |
| * and all other items are unique non-zero results. |
| * |
| * The default value of a fromUTableValues[] section that is referenced |
| * _directly_ from a fromUStage3b[] item may also be UCNV_EXT_FROM_U_SUBCHAR1, |
| * but this value must not occur anywhere else in fromUTableValues[] |
| * because "no mapping" is always a property of a single code point, |
| * never of multiple. |
| * |
| * |
| * char fromUBytes[]; |
| * |
| * Contains fromUnicode mapping results, stored as sequences of chars. |
| * Indexes and lengths stored in the fromUTableValues[]. |
| */ |
| enum { |
| UCNV_EXT_INDEXES_LENGTH, /* 0 */ |
| |
| UCNV_EXT_TO_U_INDEX, /* 1 */ |
| UCNV_EXT_TO_U_LENGTH, |
| UCNV_EXT_TO_U_UCHARS_INDEX, |
| UCNV_EXT_TO_U_UCHARS_LENGTH, |
| |
| UCNV_EXT_FROM_U_UCHARS_INDEX, /* 5 */ |
| UCNV_EXT_FROM_U_VALUES_INDEX, |
| UCNV_EXT_FROM_U_LENGTH, |
| UCNV_EXT_FROM_U_BYTES_INDEX, |
| UCNV_EXT_FROM_U_BYTES_LENGTH, |
| |
| UCNV_EXT_FROM_U_STAGE_12_INDEX, /* 10 */ |
| UCNV_EXT_FROM_U_STAGE_1_LENGTH, |
| UCNV_EXT_FROM_U_STAGE_12_LENGTH, |
| UCNV_EXT_FROM_U_STAGE_3_INDEX, |
| UCNV_EXT_FROM_U_STAGE_3_LENGTH, |
| UCNV_EXT_FROM_U_STAGE_3B_INDEX, |
| UCNV_EXT_FROM_U_STAGE_3B_LENGTH, |
| |
| UCNV_EXT_COUNT_BYTES, /* 17 */ |
| UCNV_EXT_COUNT_UCHARS, |
| UCNV_EXT_FLAGS, |
| |
| UCNV_EXT_RESERVED_INDEX, /* 20, moves with additional indexes */ |
| |
| UCNV_EXT_SIZE=31, |
| UCNV_EXT_INDEXES_MIN_LENGTH=32 |
| }; |
| |
| /* get the pointer to an extension array from indexes[index] */ |
| #define UCNV_EXT_ARRAY(indexes, index, itemType) \ |
| ((const itemType *)((const char *)(indexes)+(indexes)[index])) |
| |
| #define UCNV_GET_MAX_BYTES_PER_UCHAR(indexes) \ |
| ((indexes)[UCNV_EXT_COUNT_BYTES]&0xff) |
| |
| /* internal API ------------------------------------------------------------- */ |
| |
| U_CFUNC UBool |
| ucnv_extInitialMatchToU(UConverter *cnv, const int32_t *cx, |
| int32_t firstLength, |
| const char **src, const char *srcLimit, |
| UChar **target, const UChar *targetLimit, |
| int32_t **offsets, int32_t srcIndex, |
| UBool flush, |
| UErrorCode *pErrorCode); |
| |
| U_CFUNC UChar32 |
| ucnv_extSimpleMatchToU(const int32_t *cx, |
| const char *source, int32_t length, |
| UBool useFallback); |
| |
| U_CFUNC void |
| ucnv_extContinueMatchToU(UConverter *cnv, |
| UConverterToUnicodeArgs *pArgs, int32_t srcIndex, |
| UErrorCode *pErrorCode); |
| |
| |
| U_CFUNC UBool |
| ucnv_extInitialMatchFromU(UConverter *cnv, const int32_t *cx, |
| UChar32 cp, |
| const UChar **src, const UChar *srcLimit, |
| char **target, const char *targetLimit, |
| int32_t **offsets, int32_t srcIndex, |
| UBool flush, |
| UErrorCode *pErrorCode); |
| |
| U_CFUNC int32_t |
| ucnv_extSimpleMatchFromU(const int32_t *cx, |
| UChar32 cp, uint32_t *pValue, |
| UBool useFallback); |
| |
| U_CFUNC void |
| ucnv_extContinueMatchFromU(UConverter *cnv, |
| UConverterFromUnicodeArgs *pArgs, int32_t srcIndex, |
| UErrorCode *pErrorCode); |
| |
| /* |
| * Add code points and strings to the set according to the extension mappings. |
| * Limitation on the UConverterSetFilter: |
| * The filters currently assume that they are used with 1:1 mappings. |
| * They only apply to single input code points, and then they pass through |
| * only mappings with single-charset-code results. |
| * For example, the Shift-JIS filter only works for 2-byte results and tests |
| * that those 2 bytes are in the JIS X 0208 range of Shift-JIS. |
| */ |
| U_CFUNC void |
| ucnv_extGetUnicodeSet(const UConverterSharedData *sharedData, |
| const USetAdder *sa, |
| UConverterUnicodeSet which, |
| UConverterSetFilter filter, |
| UErrorCode *pErrorCode); |
| |
| /* toUnicode helpers -------------------------------------------------------- */ |
| |
| #define UCNV_EXT_TO_U_BYTE_SHIFT 24 |
| #define UCNV_EXT_TO_U_VALUE_MASK 0xffffff |
| #define UCNV_EXT_TO_U_MIN_CODE_POINT 0x1f0000 |
| #define UCNV_EXT_TO_U_MAX_CODE_POINT 0x2fffff |
| #define UCNV_EXT_TO_U_ROUNDTRIP_FLAG ((uint32_t)1<<23) |
| #define UCNV_EXT_TO_U_INDEX_MASK 0x3ffff |
| #define UCNV_EXT_TO_U_LENGTH_SHIFT 18 |
| #define UCNV_EXT_TO_U_LENGTH_OFFSET 12 |
| |
| /* maximum number of indexed UChars */ |
| #define UCNV_EXT_MAX_UCHARS 19 |
| |
| #define UCNV_EXT_TO_U_MAKE_WORD(byte, value) (((uint32_t)(byte)<<UCNV_EXT_TO_U_BYTE_SHIFT)|(value)) |
| |
| #define UCNV_EXT_TO_U_GET_BYTE(word) ((word)>>UCNV_EXT_TO_U_BYTE_SHIFT) |
| #define UCNV_EXT_TO_U_GET_VALUE(word) ((word)&UCNV_EXT_TO_U_VALUE_MASK) |
| |
| #define UCNV_EXT_TO_U_IS_PARTIAL(value) ((value)<UCNV_EXT_TO_U_MIN_CODE_POINT) |
| #define UCNV_EXT_TO_U_GET_PARTIAL_INDEX(value) (value) |
| |
| #define UCNV_EXT_TO_U_IS_ROUNDTRIP(value) (((value)&UCNV_EXT_TO_U_ROUNDTRIP_FLAG)!=0) |
| #define UCNV_EXT_TO_U_MASK_ROUNDTRIP(value) ((value)&~UCNV_EXT_TO_U_ROUNDTRIP_FLAG) |
| |
| /* use after masking off the roundtrip flag */ |
| #define UCNV_EXT_TO_U_IS_CODE_POINT(value) ((value)<=UCNV_EXT_TO_U_MAX_CODE_POINT) |
| #define UCNV_EXT_TO_U_GET_CODE_POINT(value) ((value)-UCNV_EXT_TO_U_MIN_CODE_POINT) |
| |
| #define UCNV_EXT_TO_U_GET_INDEX(value) ((value)&UCNV_EXT_TO_U_INDEX_MASK) |
| #define UCNV_EXT_TO_U_GET_LENGTH(value) (((value)>>UCNV_EXT_TO_U_LENGTH_SHIFT)-UCNV_EXT_TO_U_LENGTH_OFFSET) |
| |
| /* fromUnicode helpers ------------------------------------------------------ */ |
| |
| /* most trie constants are shared with ucnvmbcs.h */ |
| |
| /* see similar utrie.h UTRIE_INDEX_SHIFT and UTRIE_DATA_GRANULARITY */ |
| #define UCNV_EXT_STAGE_2_LEFT_SHIFT 2 |
| #define UCNV_EXT_STAGE_3_GRANULARITY 4 |
| |
| /* trie access, returns the stage 3 value=index to stage 3b; s1Index=c>>10 */ |
| #define UCNV_EXT_FROM_U(stage12, stage3, s1Index, c) \ |
| (stage3)[ ((int32_t)(stage12)[ (stage12)[s1Index] +(((c)>>4)&0x3f) ]<<UCNV_EXT_STAGE_2_LEFT_SHIFT) +((c)&0xf) ] |
| |
| #define UCNV_EXT_FROM_U_LENGTH_SHIFT 24 |
| #define UCNV_EXT_FROM_U_ROUNDTRIP_FLAG ((uint32_t)1<<31) |
| #define UCNV_EXT_FROM_U_GOOD_ONE_WAY_FLAG 0x40000000 |
| #define UCNV_EXT_FROM_U_STATUS_MASK 0xc0000000 |
| #define UCNV_EXT_FROM_U_RESERVED_MASK 0x20000000 |
| #define UCNV_EXT_FROM_U_DATA_MASK 0xffffff |
| |
| /* special value for "no mapping" to <subchar1> (impossible roundtrip to 0 bytes, value 01) */ |
| #define UCNV_EXT_FROM_U_SUBCHAR1 0x80000001 |
| |
| /* at most 3 bytes in the lower part of the value */ |
| #define UCNV_EXT_FROM_U_MAX_DIRECT_LENGTH 3 |
| |
| /* maximum number of indexed bytes */ |
| #define UCNV_EXT_MAX_BYTES 0x1f |
| |
| #define UCNV_EXT_FROM_U_IS_PARTIAL(value) (((value)>>UCNV_EXT_FROM_U_LENGTH_SHIFT)==0) |
| #define UCNV_EXT_FROM_U_GET_PARTIAL_INDEX(value) (value) |
| |
| #define UCNV_EXT_FROM_U_IS_ROUNDTRIP(value) (((value)&UCNV_EXT_FROM_U_ROUNDTRIP_FLAG)!=0) |
| #define UCNV_EXT_FROM_U_MASK_ROUNDTRIP(value) ((value)&~UCNV_EXT_FROM_U_ROUNDTRIP_FLAG) |
| |
| /* get length; masks away all other bits */ |
| #define UCNV_EXT_FROM_U_GET_LENGTH(value) (int32_t)(((value)>>UCNV_EXT_FROM_U_LENGTH_SHIFT)&UCNV_EXT_MAX_BYTES) |
| |
| /* get bytes or bytes index */ |
| #define UCNV_EXT_FROM_U_GET_DATA(value) ((value)&UCNV_EXT_FROM_U_DATA_MASK) |
| |
| #endif |
| |
| #endif |
