The Tor Browser / file revision

 /*

 ******************************************************************************

 *

 *   Copyright (C) 2001-2011, International Business Machines

 *   Corporation and others.  All Rights Reserved.

 *

 ******************************************************************************

 *   file name:  utrie.h

 *   encoding:   US-ASCII

 *   tab size:   8 (not used)

 *   indentation:4

 *

 *   created on: 2001nov08

 *   created by: Markus W. Scherer

 */

 #ifndef __UTRIE_H__

 #define __UTRIE_H__

 #include "unicode/utypes.h"

 #include "unicode/utf16.h"

 #include "udataswp.h"

 U_CDECL_BEGIN

 /**

  * \file

  *

  * This is a common implementation of a "folded" trie.

  * It is a kind of compressed, serializable table of 16- or 32-bit values associated with

  * Unicode code points (0..0x10ffff).

  *

  * This implementation is optimized for getting values while walking forward

  * through a UTF-16 string.

  * Therefore, the simplest and fastest access macros are the

  * _FROM_LEAD() and _FROM_OFFSET_TRAIL() macros.

  *

  * The _FROM_BMP() macros are a little more complicated; they get values

  * even for lead surrogate code _points_, while the _FROM_LEAD() macros

  * get special "folded" values for lead surrogate code _units_ if

  * there is relevant data associated with them.

  * From such a folded value, an offset needs to be extracted to supply

  * to the _FROM_OFFSET_TRAIL() macros.

  *

  * Most of the more complex (and more convenient) functions/macros call a callback function

  * to get that offset from the folded value for a lead surrogate unit.

  */

 /**

  * Trie constants, defining shift widths, index array lengths, etc.

  */

 enum {

     /** Shift size for shifting right the input index. 1..9 */

     UTRIE_SHIFT=5,

     /** Number of data values in a stage 2 (data array) block. 2, 4, 8, .., 0x200 */

     UTRIE_DATA_BLOCK_LENGTH=1<<UTRIE_SHIFT,

     /** Mask for getting the lower bits from the input index. */

     UTRIE_MASK=UTRIE_DATA_BLOCK_LENGTH-1,

     /**

      * Lead surrogate code points' index displacement in the index array.

      * 0x10000-0xd800=0x2800

      */

     UTRIE_LEAD_INDEX_DISP=0x2800>>UTRIE_SHIFT,

     /**

      * Shift size for shifting left the index array values.

      * Increases possible data size with 16-bit index values at the cost

      * of compactability.

      * This requires blocks of stage 2 data to be aligned by UTRIE_DATA_GRANULARITY.

      * 0..UTRIE_SHIFT

      */

     UTRIE_INDEX_SHIFT=2,

     /** The alignment size of a stage 2 data block. Also the granularity for compaction. */

     UTRIE_DATA_GRANULARITY=1<<UTRIE_INDEX_SHIFT,

     /** Number of bits of a trail surrogate that are used in index table lookups. */

     UTRIE_SURROGATE_BLOCK_BITS=10-UTRIE_SHIFT,

     /**

      * Number of index (stage 1) entries per lead surrogate.

      * Same as number of index entries for 1024 trail surrogates,

      * ==0x400>>UTRIE_SHIFT

      */

     UTRIE_SURROGATE_BLOCK_COUNT=(1<<UTRIE_SURROGATE_BLOCK_BITS),

     /** Length of the BMP portion of the index (stage 1) array. */

     UTRIE_BMP_INDEX_LENGTH=0x10000>>UTRIE_SHIFT

 };

 /**

  * Length of the index (stage 1) array before folding.

  * Maximum number of Unicode code points (0x110000) shifted right by UTRIE_SHIFT.

  */

 #define UTRIE_MAX_INDEX_LENGTH (0x110000>>UTRIE_SHIFT)

 /**

  * Maximum length of the runtime data (stage 2) array.

  * Limited by 16-bit index values that are left-shifted by UTRIE_INDEX_SHIFT.

  */

 #define UTRIE_MAX_DATA_LENGTH (0x10000<<UTRIE_INDEX_SHIFT)

 /**

  * Maximum length of the build-time data (stage 2) array.

  * The maximum length is 0x110000+UTRIE_DATA_BLOCK_LENGTH+0x400.

  * (Number of Unicode code points + one all-initial-value block +

  *  possible duplicate entries for 1024 lead surrogates.)

  */

 #define UTRIE_MAX_BUILD_TIME_DATA_LENGTH (0x110000+UTRIE_DATA_BLOCK_LENGTH+0x400)

 /**

  * Number of bytes for a dummy trie.

  * A dummy trie is an empty runtime trie, used when a real data trie cannot

  * be loaded.

  * The number of bytes works for Latin-1-linear tries with 32-bit data

  * (worst case).

  *

  * Calculation:

  *   BMP index + 1 index block for lead surrogate code points +

  *   Latin-1-linear array + 1 data block for lead surrogate code points

  *

  * Latin-1: if(UTRIE_SHIFT<=8) { 256 } else { included in first data block }

  *

  * @see utrie_unserializeDummy

  */

 #define UTRIE_DUMMY_SIZE ((UTRIE_BMP_INDEX_LENGTH+UTRIE_SURROGATE_BLOCK_COUNT)*2+(UTRIE_SHIFT<=8?256:UTRIE_DATA_BLOCK_LENGTH)*4+UTRIE_DATA_BLOCK_LENGTH*4)

 /**

  * Runtime UTrie callback function.

  * Extract from a lead surrogate's data the

  * index array offset of the indexes for that lead surrogate.

  *

  * @param data data value for a surrogate from the trie, including the folding offset

  * @return offset>=UTRIE_BMP_INDEX_LENGTH, or 0 if there is no data for the lead surrogate

  */

 typedef int32_t U_CALLCONV

 UTrieGetFoldingOffset(uint32_t data);

 /**

  * Run-time Trie structure.

  *

  * Either the data table is 16 bits wide and accessed via the index

  * pointer, with each index item increased by indexLength;

  * in this case, data32==NULL.

  *

  * Or the data table is 32 bits wide and accessed via the data32 pointer.

  */

 struct UTrie {

     const uint16_t *index;

     const uint32_t *data32; /* NULL if 16b data is used via index */

     /**

      * This function is not used in _FROM_LEAD, _FROM_BMP, and _FROM_OFFSET_TRAIL macros.

      * If convenience macros like _GET16 or _NEXT32 are used, this function must be set.

      *

      * utrie_unserialize() sets a default function which simply returns

      * the lead surrogate's value itself - which is the inverse of the default

      * folding function used by utrie_serialize().

      *

      * @see UTrieGetFoldingOffset

      */

     UTrieGetFoldingOffset *getFoldingOffset;

     int32_t indexLength, dataLength;

     uint32_t initialValue;

     UBool isLatin1Linear;

 };

 #ifndef __UTRIE2_H__

 typedef struct UTrie UTrie;

 #endif

 /** Internal trie getter from an offset (0 if c16 is a BMP/lead units) and a 16-bit unit */

 #define _UTRIE_GET_RAW(trie, data, offset, c16) \

     (trie)->data[ \

         ((int32_t)((trie)->index[(offset)+((c16)>>UTRIE_SHIFT)])<<UTRIE_INDEX_SHIFT)+ \

         ((c16)&UTRIE_MASK) \

     ]

 /** Internal trie getter from a pair of surrogates */

 #define _UTRIE_GET_FROM_PAIR(trie, data, c, c2, result, resultType) { \

     int32_t __offset; \

 \

     /* get data for lead surrogate */ \

     (result)=_UTRIE_GET_RAW((trie), data, 0, (c)); \

     __offset=(trie)->getFoldingOffset(result); \

 \

     /* get the real data from the folded lead/trail units */ \

     if(__offset>0) { \

         (result)=_UTRIE_GET_RAW((trie), data, __offset, (c2)&0x3ff); \

     } else { \

         (result)=(resultType)((trie)->initialValue); \

     } \

 }

 /** Internal trie getter from a BMP code point, treating a lead surrogate as a normal code point */

 #define _UTRIE_GET_FROM_BMP(trie, data, c16) \

     _UTRIE_GET_RAW(trie, data, 0xd800<=(c16) && (c16)<=0xdbff ? UTRIE_LEAD_INDEX_DISP : 0, c16);

 /**

  * Internal trie getter from a code point.

  * Could be faster(?) but longer with

  *   if((c32)<=0xd7ff) { (result)=_UTRIE_GET_RAW(trie, data, 0, c32); }

  */

 #define _UTRIE_GET(trie, data, c32, result, resultType) \

     if((uint32_t)(c32)<=0xffff) { \

         /* BMP code points */ \

         (result)=_UTRIE_GET_FROM_BMP(trie, data, c32); \

     } else if((uint32_t)(c32)<=0x10ffff) { \

         /* supplementary code point */ \

         UChar __lead16=U16_LEAD(c32); \

         _UTRIE_GET_FROM_PAIR(trie, data, __lead16, c32, result, resultType); \

     } else { \

         /* out of range */ \

         (result)=(resultType)((trie)->initialValue); \

     }

 /** Internal next-post-increment: get the next code point (c, c2) and its data */

 #define _UTRIE_NEXT(trie, data, src, limit, c, c2, result, resultType) { \

     (c)=*(src)++; \

     if(!U16_IS_LEAD(c)) { \

         (c2)=0; \

         (result)=_UTRIE_GET_RAW((trie), data, 0, (c)); \

     } else if((src)!=(limit) && U16_IS_TRAIL((c2)=*(src))) { \

         ++(src); \

         _UTRIE_GET_FROM_PAIR((trie), data, (c), (c2), (result), resultType); \

     } else { \

         /* unpaired lead surrogate code point */ \

         (c2)=0; \

         (result)=_UTRIE_GET_RAW((trie), data, UTRIE_LEAD_INDEX_DISP, (c)); \

     } \

 }

 /** Internal previous: get the previous code point (c, c2) and its data */

 #define _UTRIE_PREVIOUS(trie, data, start, src, c, c2, result, resultType) { \

     (c)=*--(src); \

     if(!U16_IS_SURROGATE(c)) { \

         (c2)=0; \

         (result)=_UTRIE_GET_RAW((trie), data, 0, (c)); \

     } else if(!U16_IS_SURROGATE_LEAD(c)) { \

         /* trail surrogate */ \

         if((start)!=(src) && U16_IS_LEAD((c2)=*((src)-1))) { \

             --(src); \

             (result)=(c); (c)=(c2); (c2)=(UChar)(result); /* swap c, c2 */ \

             _UTRIE_GET_FROM_PAIR((trie), data, (c), (c2), (result), resultType); \

         } else { \

             /* unpaired trail surrogate code point */ \

             (c2)=0; \

             (result)=_UTRIE_GET_RAW((trie), data, 0, (c)); \

         } \

     } else { \

         /* unpaired lead surrogate code point */ \

         (c2)=0; \

         (result)=_UTRIE_GET_RAW((trie), data, UTRIE_LEAD_INDEX_DISP, (c)); \

     } \

 }

 /* Public UTrie API ---------------------------------------------------------*/

 /**

  * Get a pointer to the contiguous part of the data array

  * for the Latin-1 range (U+0000..U+00ff).

  * Must be used only if the Latin-1 range is in fact linear

  * (trie->isLatin1Linear).

  *

  * @param trie (const UTrie *, in) a pointer to the runtime trie structure

  * @return (const uint16_t *) pointer to values for Latin-1 code points

  */

 #define UTRIE_GET16_LATIN1(trie) ((trie)->index+(trie)->indexLength+UTRIE_DATA_BLOCK_LENGTH)

 /**

  * Get a pointer to the contiguous part of the data array

  * for the Latin-1 range (U+0000..U+00ff).

  * Must be used only if the Latin-1 range is in fact linear

  * (trie->isLatin1Linear).

  *

  * @param trie (const UTrie *, in) a pointer to the runtime trie structure

  * @return (const uint32_t *) pointer to values for Latin-1 code points

  */

 #define UTRIE_GET32_LATIN1(trie) ((trie)->data32+UTRIE_DATA_BLOCK_LENGTH)

 /**

  * Get a 16-bit trie value from a BMP code point (UChar, <=U+ffff).

  * c16 may be a lead surrogate, which may have a value including a folding offset.

  *

  * @param trie (const UTrie *, in) a pointer to the runtime trie structure

  * @param c16 (UChar, in) the input BMP code point

  * @return (uint16_t) trie lookup result

  */

 #define UTRIE_GET16_FROM_LEAD(trie, c16) _UTRIE_GET_RAW(trie, index, 0, c16)

 /**

  * Get a 32-bit trie value from a BMP code point (UChar, <=U+ffff).

  * c16 may be a lead surrogate, which may have a value including a folding offset.

  *

  * @param trie (const UTrie *, in) a pointer to the runtime trie structure

  * @param c16 (UChar, in) the input BMP code point

  * @return (uint32_t) trie lookup result

  */

 #define UTRIE_GET32_FROM_LEAD(trie, c16) _UTRIE_GET_RAW(trie, data32, 0, c16)

 /**

  * Get a 16-bit trie value from a BMP code point (UChar, <=U+ffff).

  * Even lead surrogate code points are treated as normal code points,

  * with unfolded values that may differ from _FROM_LEAD() macro results for them.

  *

  * @param trie (const UTrie *, in) a pointer to the runtime trie structure

  * @param c16 (UChar, in) the input BMP code point

  * @return (uint16_t) trie lookup result

  */

 #define UTRIE_GET16_FROM_BMP(trie, c16) _UTRIE_GET_FROM_BMP(trie, index, c16)

 /**

  * Get a 32-bit trie value from a BMP code point (UChar, <=U+ffff).

  * Even lead surrogate code points are treated as normal code points,

  * with unfolded values that may differ from _FROM_LEAD() macro results for them.

  *

  * @param trie (const UTrie *, in) a pointer to the runtime trie structure

  * @param c16 (UChar, in) the input BMP code point

  * @return (uint32_t) trie lookup result

  */

 #define UTRIE_GET32_FROM_BMP(trie, c16) _UTRIE_GET_FROM_BMP(trie, data32, c16)

 /**

  * Get a 16-bit trie value from a code point.

  * Even lead surrogate code points are treated as normal code points,

  * with unfolded values that may differ from _FROM_LEAD() macro results for them.

  *

  * @param trie (const UTrie *, in) a pointer to the runtime trie structure

  * @param c32 (UChar32, in) the input code point

  * @param result (uint16_t, out) uint16_t variable for the trie lookup result

  */

 #define UTRIE_GET16(trie, c32, result) _UTRIE_GET(trie, index, c32, result, uint16_t)

 /**

  * Get a 32-bit trie value from a code point.

  * Even lead surrogate code points are treated as normal code points,

  * with unfolded values that may differ from _FROM_LEAD() macro results for them.

  *

  * @param trie (const UTrie *, in) a pointer to the runtime trie structure

  * @param c32 (UChar32, in) the input code point

  * @param result (uint32_t, out) uint32_t variable for the trie lookup result

  */

 #define UTRIE_GET32(trie, c32, result) _UTRIE_GET(trie, data32, c32, result, uint32_t)

 /**

  * Get the next code point (c, c2), post-increment src,

  * and get a 16-bit value from the trie.

  *

  * @param trie (const UTrie *, in) a pointer to the runtime trie structure

  * @param src (const UChar *, in/out) the source text pointer

  * @param limit (const UChar *, in) the limit pointer for the text, or NULL

  * @param c (UChar, out) variable for the BMP or lead code unit

  * @param c2 (UChar, out) variable for 0 or the trail code unit

  * @param result (uint16_t, out) uint16_t variable for the trie lookup result

  */

 #define UTRIE_NEXT16(trie, src, limit, c, c2, result) _UTRIE_NEXT(trie, index, src, limit, c, c2, result, uint16_t)

 /**

  * Get the next code point (c, c2), post-increment src,

  * and get a 32-bit value from the trie.

  *

  * @param trie (const UTrie *, in) a pointer to the runtime trie structure

  * @param src (const UChar *, in/out) the source text pointer

  * @param limit (const UChar *, in) the limit pointer for the text, or NULL

  * @param c (UChar, out) variable for the BMP or lead code unit

  * @param c2 (UChar, out) variable for 0 or the trail code unit

  * @param result (uint32_t, out) uint32_t variable for the trie lookup result

  */

 #define UTRIE_NEXT32(trie, src, limit, c, c2, result) _UTRIE_NEXT(trie, data32, src, limit, c, c2, result, uint32_t)

 /**

  * Get the previous code point (c, c2), pre-decrement src,

  * and get a 16-bit value from the trie.

  *

  * @param trie (const UTrie *, in) a pointer to the runtime trie structure

  * @param start (const UChar *, in) the start pointer for the text, or NULL

  * @param src (const UChar *, in/out) the source text pointer

  * @param c (UChar, out) variable for the BMP or lead code unit

  * @param c2 (UChar, out) variable for 0 or the trail code unit

  * @param result (uint16_t, out) uint16_t variable for the trie lookup result

  */

 #define UTRIE_PREVIOUS16(trie, start, src, c, c2, result) _UTRIE_PREVIOUS(trie, index, start, src, c, c2, result, uint16_t)

 /**

  * Get the previous code point (c, c2), pre-decrement src,

  * and get a 32-bit value from the trie.

  *

  * @param trie (const UTrie *, in) a pointer to the runtime trie structure

  * @param start (const UChar *, in) the start pointer for the text, or NULL

  * @param src (const UChar *, in/out) the source text pointer

  * @param c (UChar, out) variable for the BMP or lead code unit

  * @param c2 (UChar, out) variable for 0 or the trail code unit

  * @param result (uint32_t, out) uint32_t variable for the trie lookup result

  */

 #define UTRIE_PREVIOUS32(trie, start, src, c, c2, result) _UTRIE_PREVIOUS(trie, data32, start, src, c, c2, result, uint32_t)

 /**

  * Get a 16-bit trie value from a pair of surrogates.

  *

  * @param trie (const UTrie *, in) a pointer to the runtime trie structure

  * @param c (UChar, in) a lead surrogate

  * @param c2 (UChar, in) a trail surrogate

  * @param result (uint16_t, out) uint16_t variable for the trie lookup result

  */

 #define UTRIE_GET16_FROM_PAIR(trie, c, c2, result) _UTRIE_GET_FROM_PAIR(trie, index, c, c2, result, uint16_t)

 /**

  * Get a 32-bit trie value from a pair of surrogates.

  *

  * @param trie (const UTrie *, in) a pointer to the runtime trie structure

  * @param c (UChar, in) a lead surrogate

  * @param c2 (UChar, in) a trail surrogate

  * @param result (uint32_t, out) uint32_t variable for the trie lookup result

  */

 #define UTRIE_GET32_FROM_PAIR(trie, c, c2, result) _UTRIE_GET_FROM_PAIR(trie, data32, c, c2, result, uint32_t)

 /**

  * Get a 16-bit trie value from a folding offset (from the value of a lead surrogate)

  * and a trail surrogate.

  *

  * @param trie (const UTrie *, in) a pointer to the runtime trie structure

  * @param offset (int32_t, in) the folding offset from the value of a lead surrogate

  * @param c2 (UChar, in) a trail surrogate (only the 10 low bits are significant)

  * @return (uint16_t) trie lookup result

  */

 #define UTRIE_GET16_FROM_OFFSET_TRAIL(trie, offset, c2) _UTRIE_GET_RAW(trie, index, offset, (c2)&0x3ff)

 /**

  * Get a 32-bit trie value from a folding offset (from the value of a lead surrogate)

  * and a trail surrogate.

  *

  * @param trie (const UTrie *, in) a pointer to the runtime trie structure

  * @param offset (int32_t, in) the folding offset from the value of a lead surrogate

  * @param c2 (UChar, in) a trail surrogate (only the 10 low bits are significant)

  * @return (uint32_t) trie lookup result

  */

 #define UTRIE_GET32_FROM_OFFSET_TRAIL(trie, offset, c2) _UTRIE_GET_RAW(trie, data32, offset, (c2)&0x3ff)

 /* enumeration callback types */

 /**

  * Callback from utrie_enum(), extracts a uint32_t value from a

  * trie value. This value will be passed on to the UTrieEnumRange function.

  *

  * @param context an opaque pointer, as passed into utrie_enum()

  * @param value a value from the trie

  * @return the value that is to be passed on to the UTrieEnumRange function

  */

 typedef uint32_t U_CALLCONV

 UTrieEnumValue(const void *context, uint32_t value);

 /**

  * Callback from utrie_enum(), is called for each contiguous range

  * of code points with the same value as retrieved from the trie and

  * transformed by the UTrieEnumValue function.

  *

  * The callback function can stop the enumeration by returning FALSE.

  *

  * @param context an opaque pointer, as passed into utrie_enum()

  * @param start the first code point in a contiguous range with value

  * @param limit one past the last code point in a contiguous range with value

  * @param value the value that is set for all code points in [start..limit[

  * @return FALSE to stop the enumeration

  */

 typedef UBool U_CALLCONV

 UTrieEnumRange(const void *context, UChar32 start, UChar32 limit, uint32_t value);

 /**

  * Enumerate efficiently all values in a trie.

  * For each entry in the trie, the value to be delivered is passed through

  * the UTrieEnumValue function.

  * The value is unchanged if that function pointer is NULL.

  *

  * For each contiguous range of code points with a given value,

  * the UTrieEnumRange function is called.

  *

  * @param trie a pointer to the runtime trie structure

  * @param enumValue a pointer to a function that may transform the trie entry value,

  *                  or NULL if the values from the trie are to be used directly

  * @param enumRange a pointer to a function that is called for each contiguous range

  *                  of code points with the same value

  * @param context an opaque pointer that is passed on to the callback functions

  */

 U_CAPI void U_EXPORT2

 utrie_enum(const UTrie *trie,

            UTrieEnumValue *enumValue, UTrieEnumRange *enumRange, const void *context);

 /**

  * Unserialize a trie from 32-bit-aligned memory.

  * Inverse of utrie_serialize().

  * Fills the UTrie runtime trie structure with the settings for the trie data.

  *

  * @param trie a pointer to the runtime trie structure

  * @param data a pointer to 32-bit-aligned memory containing trie data

  * @param length the number of bytes available at data

  * @param pErrorCode an in/out ICU UErrorCode

  * @return the number of bytes at data taken up by the trie data

  */

 U_CAPI int32_t U_EXPORT2

 utrie_unserialize(UTrie *trie, const void *data, int32_t length, UErrorCode *pErrorCode);

 /**

  * "Unserialize" a dummy trie.

  * A dummy trie is an empty runtime trie, used when a real data trie cannot

  * be loaded.

  *

  * The input memory is filled so that the trie always returns the initialValue,

  * or the leadUnitValue for lead surrogate code points.

  * The Latin-1 part is always set up to be linear.

  *

  * @param trie a pointer to the runtime trie structure

  * @param data a pointer to 32-bit-aligned memory to be filled with the dummy trie data

  * @param length the number of bytes available at data (recommended to use UTRIE_DUMMY_SIZE)

  * @param initialValue the initial value that is set for all code points

  * @param leadUnitValue the value for lead surrogate code _units_ that do not

  *                      have associated supplementary data

  * @param pErrorCode an in/out ICU UErrorCode

  *

  * @see UTRIE_DUMMY_SIZE

  * @see utrie_open

  */

 U_CAPI int32_t U_EXPORT2

 utrie_unserializeDummy(UTrie *trie,

                        void *data, int32_t length,

                        uint32_t initialValue, uint32_t leadUnitValue,

                        UBool make16BitTrie,

                        UErrorCode *pErrorCode);

 /**

  * Default implementation for UTrie.getFoldingOffset, set automatically by

  * utrie_unserialize().

  * Simply returns the lead surrogate's value itself - which is the inverse

  * of the default folding function used by utrie_serialize().

  * Exported for static const UTrie structures.

  *

  * @see UTrieGetFoldingOffset

  */

 U_CAPI int32_t U_EXPORT2

 utrie_defaultGetFoldingOffset(uint32_t data);

 /* Building a trie ----------------------------------------------------------*/

 /**

  * Build-time trie structure.

  * Opaque definition, here only to make fillIn parameters possible

  * for utrie_open() and utrie_clone().

  */

 struct UNewTrie {

     /**

      * Index values at build-time are 32 bits wide for easier processing.

      * Bit 31 is set if the data block is used by multiple index values (from utrie_setRange()).

      */

     int32_t index[UTRIE_MAX_INDEX_LENGTH];

     uint32_t *data;

     uint32_t leadUnitValue;

     int32_t indexLength, dataCapacity, dataLength;

     UBool isAllocated, isDataAllocated;

     UBool isLatin1Linear, isCompacted;

     /**

      * Map of adjusted indexes, used in utrie_compact().

      * Maps from original indexes to new ones.

      */

     int32_t map[UTRIE_MAX_BUILD_TIME_DATA_LENGTH>>UTRIE_SHIFT];

 };

 typedef struct UNewTrie UNewTrie;

 /**

  * Build-time trie callback function, used with utrie_serialize().

  * This function calculates a lead surrogate's value including a folding offset

  * from the 1024 supplementary code points [start..start+1024[ .

  * It is U+10000 <= start <= U+10fc00 and (start&0x3ff)==0.

  *

  * The folding offset is provided by the caller.

  * It is offset=UTRIE_BMP_INDEX_LENGTH+n*UTRIE_SURROGATE_BLOCK_COUNT with n=0..1023.

  * Instead of the offset itself, n can be stored in 10 bits -

  * or fewer if it can be assumed that few lead surrogates have associated data.

  *

  * The returned value must be

  * - not zero if and only if there is relevant data

  *   for the corresponding 1024 supplementary code points

  * - such that UTrie.getFoldingOffset(UNewTrieGetFoldedValue(..., offset))==offset

  *

  * @return a folded value, or 0 if there is no relevant data for the lead surrogate.

  */

 typedef uint32_t U_CALLCONV

 UNewTrieGetFoldedValue(UNewTrie *trie, UChar32 start, int32_t offset);

 /**

  * Open a build-time trie structure.

  * The size of the build-time data array is specified to avoid allocating a large

  * array in all cases. The array itself can also be passed in.

  *

  * Although the trie is never fully expanded to a linear array, especially when

  * utrie_setRange32() is used, the data array could be large during build time.

  * The maximum length is

  * UTRIE_MAX_BUILD_TIME_DATA_LENGTH=0x110000+UTRIE_DATA_BLOCK_LENGTH+0x400.

  * (Number of Unicode code points + one all-initial-value block +

  *  possible duplicate entries for 1024 lead surrogates.)

  * (UTRIE_DATA_BLOCK_LENGTH<=0x200 in all cases.)

  *

  * @param fillIn a pointer to a UNewTrie structure to be initialized (will not be released), or

  *               NULL if one is to be allocated

  * @param aliasData a pointer to a data array to be used (will not be released), or

  *                  NULL if one is to be allocated

  * @param maxDataLength the capacity of aliasData (if not NULL) or

  *                      the length of the data array to be allocated

  * @param initialValue the initial value that is set for all code points

  * @param leadUnitValue the value for lead surrogate code _units_ that do not

  *                      have associated supplementary data

  * @param latin1Linear a flag indicating whether the Latin-1 range is to be allocated and

  *                     kept in a linear, contiguous part of the data array

  * @return a pointer to the initialized fillIn or the allocated and initialized new UNewTrie

  */

 U_CAPI UNewTrie * U_EXPORT2

 utrie_open(UNewTrie *fillIn,

            uint32_t *aliasData, int32_t maxDataLength,

            uint32_t initialValue, uint32_t leadUnitValue,

            UBool latin1Linear);

 /**

  * Clone a build-time trie structure with all entries.

  *

  * @param fillIn like in utrie_open()

  * @param other the build-time trie structure to clone

  * @param aliasData like in utrie_open(),

  *                  used if aliasDataLength>=(capacity of other's data array)

  * @param aliasDataLength the length of aliasData

  * @return a pointer to the initialized fillIn or the allocated and initialized new UNewTrie

  */

 U_CAPI UNewTrie * U_EXPORT2

 utrie_clone(UNewTrie *fillIn, const UNewTrie *other, uint32_t *aliasData, int32_t aliasDataLength);

 /**

  * Close a build-time trie structure, and release memory

  * that was allocated by utrie_open() or utrie_clone().

  *

  * @param trie the build-time trie

  */

 U_CAPI void U_EXPORT2

 utrie_close(UNewTrie *trie);

 /**

  * Get the data array of a build-time trie.

  * The data may be modified, but entries that are equal before

  * must still be equal after modification.

  *

  * @param trie the build-time trie

  * @param pLength (out) a pointer to a variable that receives the number

  *                of entries in the data array

  * @return the data array

  */

 U_CAPI uint32_t * U_EXPORT2

 utrie_getData(UNewTrie *trie, int32_t *pLength);

 /**

  * Set a value for a code point.

  *

  * @param trie the build-time trie

  * @param c the code point

  * @param value the value

  * @return FALSE if a failure occurred (illegal argument or data array overrun)

  */

 U_CAPI UBool U_EXPORT2

 utrie_set32(UNewTrie *trie, UChar32 c, uint32_t value);

 /**

  * Get a value from a code point as stored in the build-time trie.

  *

  * @param trie the build-time trie

  * @param c the code point

  * @param pInBlockZero if not NULL, then *pInBlockZero is set to TRUE

  *                     iff the value is retrieved from block 0;

  *                     block 0 is the all-initial-value initial block

  * @return the value

  */

 U_CAPI uint32_t U_EXPORT2

 utrie_get32(UNewTrie *trie, UChar32 c, UBool *pInBlockZero);

 /**

  * Set a value in a range of code points [start..limit[.

  * All code points c with start<=c<limit will get the value if

  * overwrite is TRUE or if the old value is 0.

  *

  * @param trie the build-time trie

  * @param start the first code point to get the value

  * @param limit one past the last code point to get the value

  * @param value the value

  * @param overwrite flag for whether old non-initial values are to be overwritten

  * @return FALSE if a failure occurred (illegal argument or data array overrun)

  */

 U_CAPI UBool U_EXPORT2

 utrie_setRange32(UNewTrie *trie, UChar32 start, UChar32 limit, uint32_t value, UBool overwrite);

 /**

  * Compact the build-time trie after all values are set, and then

  * serialize it into 32-bit aligned memory.

  *

  * After this, the trie can only be serizalized again and/or closed;

  * no further values can be added.

  *

  * @see utrie_unserialize()

  *

  * @param trie the build-time trie

  * @param data a pointer to 32-bit-aligned memory for the trie data

  * @param capacity the number of bytes available at data

  * @param getFoldedValue a callback function that calculates the value for

  *                       a lead surrogate from all of its supplementary code points

  *                       and the folding offset;

  *                       if NULL, then a default function is used which returns just

  *                       the input offset when there are any non-initial-value entries

  * @param reduceTo16Bits flag for whether the values are to be reduced to a

  *                       width of 16 bits for serialization and runtime

  * @param pErrorCode a UErrorCode argument; among other possible error codes:

  * - U_BUFFER_OVERFLOW_ERROR if the data storage block is too small for serialization

  * - U_MEMORY_ALLOCATION_ERROR if the trie data array is too small

  * - U_INDEX_OUTOFBOUNDS_ERROR if the index or data arrays are too long after compaction for serialization

  *

  * @return the number of bytes written for the trie

  */

 U_CAPI int32_t U_EXPORT2

 utrie_serialize(UNewTrie *trie, void *data, int32_t capacity,

                 UNewTrieGetFoldedValue *getFoldedValue,

                 UBool reduceTo16Bits,

                 UErrorCode *pErrorCode);

 /**

  * Swap a serialized UTrie.

  * @internal

  */

 U_CAPI int32_t U_EXPORT2

 utrie_swap(const UDataSwapper *ds,

            const void *inData, int32_t length, void *outData,

            UErrorCode *pErrorCode);

 /* serialization ------------------------------------------------------------ */

 /**

  * Trie data structure in serialized form:

  *

  * UTrieHeader header;

  * uint16_t index[header.indexLength];

  * uint16_t data[header.dataLength];

  * @internal

  */

 typedef struct UTrieHeader {

     /** "Trie" in big-endian US-ASCII (0x54726965) */

     uint32_t signature;

     /**

      * options bit field:

      *     9    1=Latin-1 data is stored linearly at data+UTRIE_DATA_BLOCK_LENGTH

      *     8    0=16-bit data, 1=32-bit data

      *  7..4    UTRIE_INDEX_SHIFT   // 0..UTRIE_SHIFT

      *  3..0    UTRIE_SHIFT         // 1..9

      */

     uint32_t options;

     /** indexLength is a multiple of UTRIE_SURROGATE_BLOCK_COUNT */

     int32_t indexLength;

     /** dataLength>=UTRIE_DATA_BLOCK_LENGTH */

     int32_t dataLength;

 } UTrieHeader;

 /**

  * Constants for use with UTrieHeader.options.

  * @internal

  */

 enum {

     /** Mask to get the UTRIE_SHIFT value from options. */

     UTRIE_OPTIONS_SHIFT_MASK=0xf,

     /** Shift options right this much to get the UTRIE_INDEX_SHIFT value. */

     UTRIE_OPTIONS_INDEX_SHIFT=4,

     /** If set, then the data (stage 2) array is 32 bits wide. */

     UTRIE_OPTIONS_DATA_IS_32_BIT=0x100,

     /**

      * If set, then Latin-1 data (for U+0000..U+00ff) is stored in the data (stage 2) array

      * as a simple, linear array at data+UTRIE_DATA_BLOCK_LENGTH.

      */

     UTRIE_OPTIONS_LATIN1_IS_LINEAR=0x200

 };

 U_CDECL_END

 #endif