The Tor Browser: intl/icu/source/common/unormimp.h@fc2d59ddac77 (annotated)

intl/icu/source/common/unormimp.h@fc2d59ddac77 (annotated)

intl/icu/source/common/unormimp.h

Wed, 31 Dec 2014 07:22:50 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 07:22:50 +0100
branch: TOR_BUG_3246
changeset 4: fc2d59ddac77
permissions: -rw-r--r--

Correct previous dual key logic pending first delivery installment.

 /*
 *******************************************************************************
 *
 *   Copyright (C) 2001-2011, International Business Machines
 *   Corporation and others.  All Rights Reserved.
 *
 *******************************************************************************
 *   file name:  unormimp.h
 *   encoding:   US-ASCII
 *   tab size:   8 (not used)
 *   indentation:4
 *
 *   created on: 2001may25
 *   created by: Markus W. Scherer
 */
 #ifndef __UNORMIMP_H__
 #define __UNORMIMP_H__
 #include "unicode/utypes.h"
 #if !UCONFIG_NO_NORMALIZATION
 #include "udataswp.h"
 /*
  * The 2001-2010 implementation of the normalization code loads its data from
  * unorm.icu, which is generated with the gennorm tool.
  * The format of that file is described at the end of this file.
  */
 /* norm32 value constants */
 enum {
     /* quick check flags 0..3 set mean "no" for their forms */
     _NORM_QC_NFC=0x11,          /* no|maybe */
     _NORM_QC_NFKC=0x22,         /* no|maybe */
     _NORM_QC_NFD=4,             /* no */
     _NORM_QC_NFKD=8,            /* no */
     _NORM_QC_ANY_NO=0xf,
     /* quick check flags 4..5 mean "maybe" for their forms; test flags>=_NORM_QC_MAYBE */
     _NORM_QC_MAYBE=0x10,
     _NORM_QC_ANY_MAYBE=0x30,
     _NORM_QC_MASK=0x3f,
     _NORM_COMBINES_FWD=0x40,
     _NORM_COMBINES_BACK=0x80,
     _NORM_COMBINES_ANY=0xc0,
     _NORM_CC_SHIFT=8,           /* UnicodeData.txt combining class in bits 15..8 */
     _NORM_CC_MASK=0xff00,
     _NORM_EXTRA_SHIFT=16,               /* 16 bits for the index to UChars and other extra data */
     _NORM_EXTRA_INDEX_TOP=0xfc00,       /* start of surrogate specials after shift */
     _NORM_EXTRA_SURROGATE_MASK=0x3ff,
     _NORM_EXTRA_SURROGATE_TOP=0x3f0,    /* hangul etc. */
     _NORM_EXTRA_HANGUL=_NORM_EXTRA_SURROGATE_TOP,
     _NORM_EXTRA_JAMO_L,
     _NORM_EXTRA_JAMO_V,
     _NORM_EXTRA_JAMO_T
 };
 /* norm32 value constants using >16 bits */
 #define _NORM_MIN_SPECIAL       0xfc000000
 #define _NORM_SURROGATES_TOP    0xfff00000
 #define _NORM_MIN_HANGUL        0xfff00000
 #define _NORM_MIN_JAMO_V        0xfff20000
 #define _NORM_JAMO_V_TOP        0xfff30000
 /* value constants for auxTrie */
 enum {
     _NORM_AUX_COMP_EX_SHIFT=10,
     _NORM_AUX_UNSAFE_SHIFT=11,
     _NORM_AUX_NFC_SKIPPABLE_F_SHIFT=12
 };
 #define _NORM_AUX_MAX_FNC           ((int32_t)1<<_NORM_AUX_COMP_EX_SHIFT)
 #define _NORM_AUX_FNC_MASK          (uint32_t)(_NORM_AUX_MAX_FNC-1)
 #define _NORM_AUX_COMP_EX_MASK      ((uint32_t)1<<_NORM_AUX_COMP_EX_SHIFT)
 #define _NORM_AUX_UNSAFE_MASK       ((uint32_t)1<<_NORM_AUX_UNSAFE_SHIFT)
 #define _NORM_AUX_NFC_SKIP_F_MASK   ((uint32_t)1<<_NORM_AUX_NFC_SKIPPABLE_F_SHIFT)
 /* canonStartSets[0..31] contains indexes for what is in the array */
 enum {
     _NORM_SET_INDEX_CANON_SETS_LENGTH,      /* number of uint16_t in canonical starter sets */
     _NORM_SET_INDEX_CANON_BMP_TABLE_LENGTH, /* number of uint16_t in the BMP search table (contains pairs) */
     _NORM_SET_INDEX_CANON_SUPP_TABLE_LENGTH,/* number of uint16_t in the supplementary search table (contains triplets) */
     /* from formatVersion 2.3: */
     _NORM_SET_INDEX_NX_CJK_COMPAT_OFFSET,   /* uint16_t offset from canonStartSets[0] to the
                                                exclusion set for CJK compatibility characters */
     _NORM_SET_INDEX_NX_UNICODE32_OFFSET,    /* uint16_t offset from canonStartSets[0] to the
                                                exclusion set for Unicode 3.2 characters */
     _NORM_SET_INDEX_NX_RESERVED_OFFSET,     /* uint16_t offset from canonStartSets[0] to the
                                                end of the previous exclusion set */
     _NORM_SET_INDEX_TOP=32                  /* changing this requires a new formatVersion */
 };
 /* more constants for canonical starter sets */
 /* 14 bit indexes to canonical USerializedSets */
 #define _NORM_MAX_CANON_SETS            0x4000
 /* single-code point BMP sets are encoded directly in the search table except if result=0x4000..0x7fff */
 #define _NORM_CANON_SET_BMP_MASK        0xc000
 #define _NORM_CANON_SET_BMP_IS_INDEX    0x4000
 /* indexes[] value names */
 enum {
     _NORM_INDEX_TRIE_SIZE,              /* number of bytes in normalization trie */
     _NORM_INDEX_UCHAR_COUNT,            /* number of UChars in extra data */
     _NORM_INDEX_COMBINE_DATA_COUNT,     /* number of uint16_t words for combining data */
     _NORM_INDEX_COMBINE_FWD_COUNT,      /* number of code points that combine forward */
     _NORM_INDEX_COMBINE_BOTH_COUNT,     /* number of code points that combine forward and backward */
     _NORM_INDEX_COMBINE_BACK_COUNT,     /* number of code points that combine backward */
     _NORM_INDEX_MIN_NFC_NO_MAYBE,       /* first code point with quick check NFC NO/MAYBE */
     _NORM_INDEX_MIN_NFKC_NO_MAYBE,      /* first code point with quick check NFKC NO/MAYBE */
     _NORM_INDEX_MIN_NFD_NO_MAYBE,       /* first code point with quick check NFD NO/MAYBE */
     _NORM_INDEX_MIN_NFKD_NO_MAYBE,      /* first code point with quick check NFKD NO/MAYBE */
     _NORM_INDEX_FCD_TRIE_SIZE,          /* number of bytes in FCD trie */
     _NORM_INDEX_AUX_TRIE_SIZE,          /* number of bytes in the auxiliary trie */
     _NORM_INDEX_CANON_SET_COUNT,        /* number of uint16_t in the array of serialized USet */
     _NORM_INDEX_TOP=32                  /* changing this requires a new formatVersion */
 };
 enum {
     /* FCD check: everything below this code point is known to have a 0 lead combining class */
     _NORM_MIN_WITH_LEAD_CC=0x300
 };
 enum {
     /**
      * Bit 7 of the length byte for a decomposition string in extra data is
      * a flag indicating whether the decomposition string is
      * preceded by a 16-bit word with the leading and trailing cc
      * of the decomposition (like for A-umlaut);
      * if not, then both cc's are zero (like for compatibility ideographs).
      */
     _NORM_DECOMP_FLAG_LENGTH_HAS_CC=0x80,
     /**
      * Bits 6..0 of the length byte contain the actual length.
      */
     _NORM_DECOMP_LENGTH_MASK=0x7f
 };
 /** Constants for options flags for normalization. */
 enum {
     /** Options bit 0, do not decompose Hangul syllables. */
     UNORM_NX_HANGUL=1,
     /** Options bit 1, do not decompose CJK compatibility characters. */
     UNORM_NX_CJK_COMPAT=2
 };
 /**
  * Description of the format of unorm.icu version 2.3.
  *
  * Main change from version 1 to version 2:
  * Use of new, common UTrie instead of normalization-specific tries.
  * Change to version 2.1: add third/auxiliary trie with associated data.
  * Change to version 2.2: add skippable (f) flag data (_NORM_AUX_NFC_SKIP_F_MASK).
  * Change to version 2.3: add serialized sets for normalization exclusions
  *                        stored inside canonStartSets[]
  *
  * For more details of how to use the data structures see the code
  * in unorm.cpp (runtime normalization code) and
  * in gennorm.c and gennorm/store.c (build-time data generation).
  *
  * For the serialized format of UTrie see utrie.c/UTrieHeader.
  *
  * - Overall partition
  *
  * unorm.dat customarily begins with a UDataInfo structure, see udata.h and .c.
  * After that there are the following structures:
  *
  * int32_t indexes[_NORM_INDEX_TOP];            -- _NORM_INDEX_TOP=32, see enum in this file
  *
  * UTrie normTrie;                              -- size in bytes=indexes[_NORM_INDEX_TRIE_SIZE]
  *
  * uint16_t extraData[extraDataTop];            -- extraDataTop=indexes[_NORM_INDEX_UCHAR_COUNT]
  *                                                 extraData[0] contains the number of units for
  *                                                 FC_NFKC_Closure (formatVersion>=2.1)
  *
  * uint16_t combiningTable[combiningTableTop];  -- combiningTableTop=indexes[_NORM_INDEX_COMBINE_DATA_COUNT]
  *                                                 combiningTableTop may include one 16-bit padding unit
  *                                                 to make sure that fcdTrie is 32-bit-aligned
  *
  * UTrie fcdTrie;                               -- size in bytes=indexes[_NORM_INDEX_FCD_TRIE_SIZE]
  *
  * UTrie auxTrie;                               -- size in bytes=indexes[_NORM_INDEX_AUX_TRIE_SIZE]
  *
  * uint16_t canonStartSets[canonStartSetsTop]   -- canonStartSetsTop=indexes[_NORM_INDEX_CANON_SET_COUNT]
  *                                                 serialized USets and binary search tables, see below
  *
  *
  * The indexes array contains lengths and sizes of the following arrays and structures
  * as well as the following values:
  *  indexes[_NORM_INDEX_COMBINE_FWD_COUNT]=combineFwdTop
  *      -- one more than the highest combining index computed for forward-only-combining characters
  *  indexes[_NORM_INDEX_COMBINE_BOTH_COUNT]=combineBothTop-combineFwdTop
  *      -- number of combining indexes computed for both-ways-combining characters
  *  indexes[_NORM_INDEX_COMBINE_BACK_COUNT]=combineBackTop-combineBothTop
  *      -- number of combining indexes computed for backward-only-combining characters
  *
  *  indexes[_NORM_INDEX_MIN_NF*_NO_MAYBE] (where *={ C, D, KC, KD })
  *      -- first code point with a quick check NF* value of NO/MAYBE
  *
  *
  * - Tries
  *
  * The main structures are two UTrie tables ("compact arrays"),
  * each with one index array and one data array.
  * See utrie.h and utrie.c.
  *
  *
  * - Tries in unorm.dat
  *
  * The first trie (normTrie above)
  * provides data for the NF* quick checks and normalization.
  * The second trie (fcdTrie above) provides data just for FCD checks.
  *
  *
  * - norm32 data words from the first trie
  *
  * The norm32Table contains one 32-bit word "norm32" per code point.
  * It contains the following bit fields:
  * 31..16   extra data index, _NORM_EXTRA_SHIFT is used to shift this field down
  *          if this index is <_NORM_EXTRA_INDEX_TOP then it is an index into
  *              extraData[] where variable-length normalization data for this
  *              code point is found
  *          if this index is <_NORM_EXTRA_INDEX_TOP+_NORM_EXTRA_SURROGATE_TOP
  *              then this is a norm32 for a leading surrogate, and the index
  *              value is used together with the following trailing surrogate
  *              code unit in the second trie access
  *          if this index is >=_NORM_EXTRA_INDEX_TOP+_NORM_EXTRA_SURROGATE_TOP
  *              then this is a norm32 for a "special" character,
  *              i.e., the character is a Hangul syllable or a Jamo
  *              see _NORM_EXTRA_HANGUL etc.
  *          generally, instead of extracting this index from the norm32 and
  *              comparing it with the above constants,
  *              the normalization code compares the entire norm32 value
  *              with _NORM_MIN_SPECIAL, _NORM_SURROGATES_TOP, _NORM_MIN_HANGUL etc.
  *
  * 15..8    combining class (cc) according to UnicodeData.txt
  *
  *  7..6    _NORM_COMBINES_ANY flags, used in composition to see if a character
  *              combines with any following or preceding character(s)
  *              at all
  *     7    _NORM_COMBINES_BACK
  *     6    _NORM_COMBINES_FWD
  *
  *  5..0    quick check flags, set for "no" or "maybe", with separate flags for
  *              each normalization form
  *              the higher bits are "maybe" flags; for NF*D there are no such flags
  *              the lower bits are "no" flags for all forms, in the same order
  *              as the "maybe" flags,
  *              which is (MSB to LSB): NFKD NFD NFKC NFC
  *  5..4    _NORM_QC_ANY_MAYBE
  *  3..0    _NORM_QC_ANY_NO
  *              see further related constants
  *
  *
  * - Extra data per code point
  *
  * "Extra data" is referenced by the index in norm32.
  * It is variable-length data. It is only present, and only those parts
  * of it are, as needed for a given character.
  * The norm32 extra data index is added to the beginning of extraData[]
  * to get to a vector of 16-bit words with data at the following offsets:
  *
  * [-1]     Combining index for composition.
  *              Stored only if norm32&_NORM_COMBINES_ANY .
  * [0]      Lengths of the canonical and compatibility decomposition strings.
  *              Stored only if there are decompositions, i.e.,
  *              if norm32&(_NORM_QC_NFD|_NORM_QC_NFKD)
  *          High byte: length of NFKD, or 0 if none
  *          Low byte: length of NFD, or 0 if none
  *          Each length byte also has another flag:
  *              Bit 7 of a length byte is set if there are non-zero
  *              combining classes (cc's) associated with the respective
  *              decomposition. If this flag is set, then the decomposition
  *              is preceded by a 16-bit word that contains the
  *              leading and trailing cc's.
  *              Bits 6..0 of a length byte are the length of the
  *              decomposition string, not counting the cc word.
  * [1..n]   NFD
  * [n+1..]  NFKD
  *
  * Each of the two decompositions consists of up to two parts:
  * - The 16-bit words with the leading and trailing cc's.
  *   This is only stored if bit 7 of the corresponding length byte
  *   is set. In this case, at least one of the cc's is not zero.
  *   High byte: leading cc==cc of the first code point in the decomposition string
  *   Low byte: trailing cc==cc of the last code point in the decomposition string
  * - The decomposition string in UTF-16, with length code units.
  *
  *
  * - Combining indexes and combiningTable[]
  *
  * Combining indexes are stored at the [-1] offset of the extra data
  * if the character combines forward or backward with any other characters.
  * They are used for (re)composition in NF*C.
  * Values of combining indexes are arranged according to whether a character
  * combines forward, backward, or both ways:
  *    forward-only < both ways < backward-only
  *
  * The index values for forward-only and both-ways combining characters
  * are indexes into the combiningTable[].
  * The index values for backward-only combining characters are simply
  * incremented from the preceding index values to be unique.
  *
  * In the combiningTable[], a variable-length list
  * of variable-length (back-index, code point) pair entries is stored
  * for each forward-combining character.
  *
  * These back-indexes are the combining indexes of both-ways or backward-only
  * combining characters that the forward-combining character combines with.
  *
  * Each list is sorted in ascending order of back-indexes.
  * Each list is terminated with the last back-index having bit 15 set.
  *
  * Each pair (back-index, code point) takes up either 2 or 3
  * 16-bit words.
  * The first word of a list entry is the back-index, with its bit 15 set if
  * this is the last pair in the list.
  *
  * The second word contains flags in bits 15..13 that determine
  * if there is a third word and how the combined character is encoded:
  * 15   set if there is a third word in this list entry
  * 14   set if the result is a supplementary character
  * 13   set if the result itself combines forward
  *
  * According to these bits 15..14 of the second word,
  * the result character is encoded as follows:
  * 00 or 01 The result is <=0x1fff and stored in bits 12..0 of
  *          the second word.
  * 10       The result is 0x2000..0xffff and stored in the third word.
  *          Bits 12..0 of the second word are not used.
  * 11       The result is a supplementary character.
  *          Bits 9..0 of the leading surrogate are in bits 9..0 of
  *          the second word.
  *          Add 0xd800 to these bits to get the complete surrogate.
  *          Bits 12..10 of the second word are not used.
  *          The trailing surrogate is stored in the third word.
  *
  *
  * - FCD trie
  *
  * The FCD trie is very simple.
  * It is a folded trie with 16-bit data words.
  * In each word, the high byte contains the leading cc of the character,
  * and the low byte contains the trailing cc of the character.
  * These cc's are the cc's of the first and last code points in the
  * canonical decomposition of the character.
  *
  * Since all 16 bits are used for cc's, lead surrogates must be tested
  * by checking the code unit instead of the trie data.
  * This is done only if the 16-bit data word is not zero.
  * If the code unit is a leading surrogate and the data word is not zero,
  * then instead of cc's it contains the offset for the second trie lookup.
  *
  *
  * - Auxiliary trie and data
  *
  * The auxiliary 16-bit trie contains data for additional properties.
  * Bits
  * 15..13   reserved
  *     12   not NFC_Skippable (f) (formatVersion>=2.2)
  *     11   flag: not a safe starter for canonical closure
  *     10   composition exclusion
  *  9.. 0   index into extraData[] to FC_NFKC_Closure string
  *          (not for lead surrogate),
  *          or lead surrogate offset (for lead surrogate, if 9..0 not zero)
  *
  * - FC_NFKC_Closure strings in extraData[]
  *
  * Strings are either stored as a single code unit or as the length
  * followed by that many units.
  *   const UChar *s=extraData+(index from auxTrie data bits 9..0);
  *   int32_t length;
  *   if(*s<0xff00) {
  *     // s points to the single-unit string
  *     length=1;
  *   } else {
  *     length=*s&0xff;
  *     ++s;
  *   }
  *
  * Conditions for "NF* Skippable" from Mark Davis' com.ibm.text.UCD.NFSkippable:
  * (used in NormalizerTransliterator)
  *
  * A skippable character is
  * a) unassigned, or ALL of the following:
  * b) of combining class 0.
  * c) not decomposed by this normalization form.
  * AND if NFC or NFKC,
  * d) can never compose with a previous character.
  * e) can never compose with a following character.
  * f) can never change if another character is added.
  *    Example: a-breve might satisfy all but f, but if you
  *    add an ogonek it changes to a-ogonek + breve
  *
  * a)..e) must be tested from norm32.
  * Since f) is more complicated, the (not-)NFC_Skippable flag (f) is built
  * into the auxiliary trie.
  * The same bit is used for NFC and NFKC; (c) differs for them.
  * As usual, we build the "not skippable" flags so that unassigned
  * code points get a 0 bit.
  * This bit is only valid after (a)..(e) test FALSE; test NFD_NO before (f) as well.
  * Test Hangul LV syllables entirely in code.
  *
  *
  * - structure inside canonStartSets[]
  *
  * This array maps from code points c to sets of code points (USerializedSet).
  * The result sets are the code points whose canonical decompositions start
  * with c.
  *
  * canonStartSets[] contains the following sub-arrays:
  *
  * indexes[_NORM_SET_INDEX_TOP]
  *   - contains lengths of sub-arrays etc.
  *
  * startSets[indexes[_NORM_SET_INDEX_CANON_SETS_LENGTH]-_NORM_SET_INDEX_TOP]
  *   - contains serialized sets (USerializedSet) of canonical starters for
  *     enumerating canonically equivalent strings
  *     indexes[_NORM_SET_INDEX_CANON_SETS_LENGTH] includes _NORM_SET_INDEX_TOP
  *     for details about the structure see uset.c
  *
  * bmpTable[indexes[_NORM_SET_INDEX_CANON_BMP_TABLE_LENGTH]]
  *   - a sorted search table for BMP code points whose results are
  *     either indexes to USerializedSets or single code points for
  *     single-code point sets;
  *     each entry is a pair of { code point, result } with result=(binary) yy xxxxxx xxxxxxxx
  *     if yy==01 then there is a USerializedSet at canonStartSets+x
  *     else build a USerializedSet with result as the single code point
  *
  * suppTable[indexes[_NORM_SET_INDEX_CANON_SUPP_TABLE_LENGTH]]
  *   - a sorted search table for supplementary code points whose results are
  *     either indexes to USerializedSets or single code points for
  *     single-code point sets;
  *     each entry is a triplet of { high16(cp), low16(cp), result }
  *     each code point's high-word may contain extra data in bits 15..5:
  *     if the high word has bit 15 set, then build a set with a single code point
  *     which is (((high16(cp)&0x1f00)<<8)|result;
  *     else there is a USerializedSet at canonStartSets+result
  *
  * FormatVersion 2.3 adds 2 serialized sets for normalization exclusions.
  * They are stored in the data file so that the runtime normalization code need
  * not depend on other properties and their data and implementation files.
  * The _NORM_SET_INDEX_NX_..._OFFSET offsets in the canonStartSets index table
  * give the location for each set.
  * There is no set stored for UNORM_NX_HANGUL because it's trivial to create
  * without using properties.
  *
  * Set contents:
  *
  * _NORM_SET_INDEX_NX_CJK_COMPAT_OFFSET (for UNORM_NX_CJK_COMPAT)
  *     [[:Ideographic:]&[:NFD_QC=No:]]
  *     =[CJK Ideographs]&[has canonical decomposition]
  *
  * _NORM_SET_INDEX_NX_UNICODE32_OFFSET (for UNORM_UNICODE_3_2)
  *     [:^Age=3.2:]
  *     =set with all code points that were not designated by the specified Unicode version
  *
  * _NORM_SET_INDEX_NX_RESERVED_OFFSET
  *     This is an offset that points to where the next, future set would start.
  *     Currently it indicates where the previous set ends, and thus its length.
  *     The name for this enum constant may in the future be applied to different
  *     index slots. In order to get the limit of a set, use its index slot and
  *     the immediately following one regardless of that one's enum name.
  */
 #endif /* #if !UCONFIG_NO_NORMALIZATION */
 #endif

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intl/icu/source/common/unormimp.h@fc2d59ddac77 (annotated)

intl/icu/source/common/unormimp.h