michael@0: /*
michael@0: ******************************************************************************
michael@0: *
michael@0: *   Copyright (C) 2001-2013, International Business Machines
michael@0: *   Corporation and others.  All Rights Reserved.
michael@0: *
michael@0: ******************************************************************************
michael@0: *   file name:  utrie2.cpp
michael@0: *   encoding:   US-ASCII
michael@0: *   tab size:   8 (not used)
michael@0: *   indentation:4
michael@0: *
michael@0: *   created on: 2008aug16 (starting from a copy of utrie.c)
michael@0: *   created by: Markus W. Scherer
michael@0: *
michael@0: *   This is a common implementation of a Unicode trie.
michael@0: *   It is a kind of compressed, serializable table of 16- or 32-bit values associated with
michael@0: *   Unicode code points (0..0x10ffff).
michael@0: *   This is the second common version of a Unicode trie (hence the name UTrie2).
michael@0: *   See utrie2.h for a comparison.
michael@0: *
michael@0: *   This file contains only the runtime and enumeration code, for read-only access.
michael@0: *   See utrie2_builder.c for the builder code.
michael@0: */
michael@0: #ifdef UTRIE2_DEBUG
michael@0: #   include <stdio.h>
michael@0: #endif
michael@0: 
michael@0: #include "unicode/utypes.h"
michael@0: #include "unicode/utf.h"
michael@0: #include "unicode/utf8.h"
michael@0: #include "unicode/utf16.h"
michael@0: #include "cmemory.h"
michael@0: #include "utrie2.h"
michael@0: #include "utrie2_impl.h"
michael@0: #include "uassert.h"
michael@0: 
michael@0: /* Public UTrie2 API implementation ----------------------------------------- */
michael@0: 
michael@0: static uint32_t
michael@0: get32(const UNewTrie2 *trie, UChar32 c, UBool fromLSCP) {
michael@0:     int32_t i2, block;
michael@0: 
michael@0:     if(c>=trie->highStart && (!U_IS_LEAD(c) || fromLSCP)) {
michael@0:         return trie->data[trie->dataLength-UTRIE2_DATA_GRANULARITY];
michael@0:     }
michael@0: 
michael@0:     if(U_IS_LEAD(c) && fromLSCP) {
michael@0:         i2=(UTRIE2_LSCP_INDEX_2_OFFSET-(0xd800>>UTRIE2_SHIFT_2))+
michael@0:             (c>>UTRIE2_SHIFT_2);
michael@0:     } else {
michael@0:         i2=trie->index1[c>>UTRIE2_SHIFT_1]+
michael@0:             ((c>>UTRIE2_SHIFT_2)&UTRIE2_INDEX_2_MASK);
michael@0:     }
michael@0:     block=trie->index2[i2];
michael@0:     return trie->data[block+(c&UTRIE2_DATA_MASK)];
michael@0: }
michael@0: 
michael@0: U_CAPI uint32_t U_EXPORT2
michael@0: utrie2_get32(const UTrie2 *trie, UChar32 c) {
michael@0:     if(trie->data16!=NULL) {
michael@0:         return UTRIE2_GET16(trie, c);
michael@0:     } else if(trie->data32!=NULL) {
michael@0:         return UTRIE2_GET32(trie, c);
michael@0:     } else if((uint32_t)c>0x10ffff) {
michael@0:         return trie->errorValue;
michael@0:     } else {
michael@0:         return get32(trie->newTrie, c, TRUE);
michael@0:     }
michael@0: }
michael@0: 
michael@0: U_CAPI uint32_t U_EXPORT2
michael@0: utrie2_get32FromLeadSurrogateCodeUnit(const UTrie2 *trie, UChar32 c) {
michael@0:     if(!U_IS_LEAD(c)) {
michael@0:         return trie->errorValue;
michael@0:     }
michael@0:     if(trie->data16!=NULL) {
michael@0:         return UTRIE2_GET16_FROM_U16_SINGLE_LEAD(trie, c);
michael@0:     } else if(trie->data32!=NULL) {
michael@0:         return UTRIE2_GET32_FROM_U16_SINGLE_LEAD(trie, c);
michael@0:     } else {
michael@0:         return get32(trie->newTrie, c, FALSE);
michael@0:     }
michael@0: }
michael@0: 
michael@0: static inline int32_t
michael@0: u8Index(const UTrie2 *trie, UChar32 c, int32_t i) {
michael@0:     int32_t idx=
michael@0:         _UTRIE2_INDEX_FROM_CP(
michael@0:             trie,
michael@0:             trie->data32==NULL ? trie->indexLength : 0,
michael@0:             c);
michael@0:     return (idx<<3)|i;
michael@0: }
michael@0: 
michael@0: U_CAPI int32_t U_EXPORT2
michael@0: utrie2_internalU8NextIndex(const UTrie2 *trie, UChar32 c,
michael@0:                            const uint8_t *src, const uint8_t *limit) {
michael@0:     int32_t i, length;
michael@0:     i=0;
michael@0:     /* support 64-bit pointers by avoiding cast of arbitrary difference */
michael@0:     if((limit-src)<=7) {
michael@0:         length=(int32_t)(limit-src);
michael@0:     } else {
michael@0:         length=7;
michael@0:     }
michael@0:     c=utf8_nextCharSafeBody(src, &i, length, c, -1);
michael@0:     return u8Index(trie, c, i);
michael@0: }
michael@0: 
michael@0: U_CAPI int32_t U_EXPORT2
michael@0: utrie2_internalU8PrevIndex(const UTrie2 *trie, UChar32 c,
michael@0:                            const uint8_t *start, const uint8_t *src) {
michael@0:     int32_t i, length;
michael@0:     /* support 64-bit pointers by avoiding cast of arbitrary difference */
michael@0:     if((src-start)<=7) {
michael@0:         i=length=(int32_t)(src-start);
michael@0:     } else {
michael@0:         i=length=7;
michael@0:         start=src-7;
michael@0:     }
michael@0:     c=utf8_prevCharSafeBody(start, 0, &i, c, -1);
michael@0:     i=length-i;  /* number of bytes read backward from src */
michael@0:     return u8Index(trie, c, i);
michael@0: }
michael@0: 
michael@0: U_CAPI UTrie2 * U_EXPORT2
michael@0: utrie2_openFromSerialized(UTrie2ValueBits valueBits,
michael@0:                           const void *data, int32_t length, int32_t *pActualLength,
michael@0:                           UErrorCode *pErrorCode) {
michael@0:     const UTrie2Header *header;
michael@0:     const uint16_t *p16;
michael@0:     int32_t actualLength;
michael@0: 
michael@0:     UTrie2 tempTrie;
michael@0:     UTrie2 *trie;
michael@0: 
michael@0:     if(U_FAILURE(*pErrorCode)) {
michael@0:         return 0;
michael@0:     }
michael@0: 
michael@0:     if( length<=0 || (U_POINTER_MASK_LSB(data, 3)!=0) ||
michael@0:         valueBits<0 || UTRIE2_COUNT_VALUE_BITS<=valueBits
michael@0:     ) {
michael@0:         *pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
michael@0:         return 0;
michael@0:     }
michael@0: 
michael@0:     /* enough data for a trie header? */
michael@0:     if(length<(int32_t)sizeof(UTrie2Header)) {
michael@0:         *pErrorCode=U_INVALID_FORMAT_ERROR;
michael@0:         return 0;
michael@0:     }
michael@0: 
michael@0:     /* check the signature */
michael@0:     header=(const UTrie2Header *)data;
michael@0:     if(header->signature!=UTRIE2_SIG) {
michael@0:         *pErrorCode=U_INVALID_FORMAT_ERROR;
michael@0:         return 0;
michael@0:     }
michael@0: 
michael@0:     /* get the options */
michael@0:     if(valueBits!=(UTrie2ValueBits)(header->options&UTRIE2_OPTIONS_VALUE_BITS_MASK)) {
michael@0:         *pErrorCode=U_INVALID_FORMAT_ERROR;
michael@0:         return 0;
michael@0:     }
michael@0: 
michael@0:     /* get the length values and offsets */
michael@0:     uprv_memset(&tempTrie, 0, sizeof(tempTrie));
michael@0:     tempTrie.indexLength=header->indexLength;
michael@0:     tempTrie.dataLength=header->shiftedDataLength<<UTRIE2_INDEX_SHIFT;
michael@0:     tempTrie.index2NullOffset=header->index2NullOffset;
michael@0:     tempTrie.dataNullOffset=header->dataNullOffset;
michael@0: 
michael@0:     tempTrie.highStart=header->shiftedHighStart<<UTRIE2_SHIFT_1;
michael@0:     tempTrie.highValueIndex=tempTrie.dataLength-UTRIE2_DATA_GRANULARITY;
michael@0:     if(valueBits==UTRIE2_16_VALUE_BITS) {
michael@0:         tempTrie.highValueIndex+=tempTrie.indexLength;
michael@0:     }
michael@0: 
michael@0:     /* calculate the actual length */
michael@0:     actualLength=(int32_t)sizeof(UTrie2Header)+tempTrie.indexLength*2;
michael@0:     if(valueBits==UTRIE2_16_VALUE_BITS) {
michael@0:         actualLength+=tempTrie.dataLength*2;
michael@0:     } else {
michael@0:         actualLength+=tempTrie.dataLength*4;
michael@0:     }
michael@0:     if(length<actualLength) {
michael@0:         *pErrorCode=U_INVALID_FORMAT_ERROR;  /* not enough bytes */
michael@0:         return 0;
michael@0:     }
michael@0: 
michael@0:     /* allocate the trie */
michael@0:     trie=(UTrie2 *)uprv_malloc(sizeof(UTrie2));
michael@0:     if(trie==NULL) {
michael@0:         *pErrorCode=U_MEMORY_ALLOCATION_ERROR;
michael@0:         return 0;
michael@0:     }
michael@0:     uprv_memcpy(trie, &tempTrie, sizeof(tempTrie));
michael@0:     trie->memory=(uint32_t *)data;
michael@0:     trie->length=actualLength;
michael@0:     trie->isMemoryOwned=FALSE;
michael@0: 
michael@0:     /* set the pointers to its index and data arrays */
michael@0:     p16=(const uint16_t *)(header+1);
michael@0:     trie->index=p16;
michael@0:     p16+=trie->indexLength;
michael@0: 
michael@0:     /* get the data */
michael@0:     switch(valueBits) {
michael@0:     case UTRIE2_16_VALUE_BITS:
michael@0:         trie->data16=p16;
michael@0:         trie->data32=NULL;
michael@0:         trie->initialValue=trie->index[trie->dataNullOffset];
michael@0:         trie->errorValue=trie->data16[UTRIE2_BAD_UTF8_DATA_OFFSET];
michael@0:         break;
michael@0:     case UTRIE2_32_VALUE_BITS:
michael@0:         trie->data16=NULL;
michael@0:         trie->data32=(const uint32_t *)p16;
michael@0:         trie->initialValue=trie->data32[trie->dataNullOffset];
michael@0:         trie->errorValue=trie->data32[UTRIE2_BAD_UTF8_DATA_OFFSET];
michael@0:         break;
michael@0:     default:
michael@0:         *pErrorCode=U_INVALID_FORMAT_ERROR;
michael@0:         return 0;
michael@0:     }
michael@0: 
michael@0:     if(pActualLength!=NULL) {
michael@0:         *pActualLength=actualLength;
michael@0:     }
michael@0:     return trie;
michael@0: }
michael@0: 
michael@0: U_CAPI UTrie2 * U_EXPORT2
michael@0: utrie2_openDummy(UTrie2ValueBits valueBits,
michael@0:                  uint32_t initialValue, uint32_t errorValue,
michael@0:                  UErrorCode *pErrorCode) {
michael@0:     UTrie2 *trie;
michael@0:     UTrie2Header *header;
michael@0:     uint32_t *p;
michael@0:     uint16_t *dest16;
michael@0:     int32_t indexLength, dataLength, length, i;
michael@0:     int32_t dataMove;  /* >0 if the data is moved to the end of the index array */
michael@0: 
michael@0:     if(U_FAILURE(*pErrorCode)) {
michael@0:         return 0;
michael@0:     }
michael@0: 
michael@0:     if(valueBits<0 || UTRIE2_COUNT_VALUE_BITS<=valueBits) {
michael@0:         *pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
michael@0:         return 0;
michael@0:     }
michael@0: 
michael@0:     /* calculate the total length of the dummy trie data */
michael@0:     indexLength=UTRIE2_INDEX_1_OFFSET;
michael@0:     dataLength=UTRIE2_DATA_START_OFFSET+UTRIE2_DATA_GRANULARITY;
michael@0:     length=(int32_t)sizeof(UTrie2Header)+indexLength*2;
michael@0:     if(valueBits==UTRIE2_16_VALUE_BITS) {
michael@0:         length+=dataLength*2;
michael@0:     } else {
michael@0:         length+=dataLength*4;
michael@0:     }
michael@0: 
michael@0:     /* allocate the trie */
michael@0:     trie=(UTrie2 *)uprv_malloc(sizeof(UTrie2));
michael@0:     if(trie==NULL) {
michael@0:         *pErrorCode=U_MEMORY_ALLOCATION_ERROR;
michael@0:         return 0;
michael@0:     }
michael@0:     uprv_memset(trie, 0, sizeof(UTrie2));
michael@0:     trie->memory=uprv_malloc(length);
michael@0:     if(trie->memory==NULL) {
michael@0:         uprv_free(trie);
michael@0:         *pErrorCode=U_MEMORY_ALLOCATION_ERROR;
michael@0:         return 0;
michael@0:     }
michael@0:     trie->length=length;
michael@0:     trie->isMemoryOwned=TRUE;
michael@0: 
michael@0:     /* set the UTrie2 fields */
michael@0:     if(valueBits==UTRIE2_16_VALUE_BITS) {
michael@0:         dataMove=indexLength;
michael@0:     } else {
michael@0:         dataMove=0;
michael@0:     }
michael@0: 
michael@0:     trie->indexLength=indexLength;
michael@0:     trie->dataLength=dataLength;
michael@0:     trie->index2NullOffset=UTRIE2_INDEX_2_OFFSET;
michael@0:     trie->dataNullOffset=(uint16_t)dataMove;
michael@0:     trie->initialValue=initialValue;
michael@0:     trie->errorValue=errorValue;
michael@0:     trie->highStart=0;
michael@0:     trie->highValueIndex=dataMove+UTRIE2_DATA_START_OFFSET;
michael@0: 
michael@0:     /* set the header fields */
michael@0:     header=(UTrie2Header *)trie->memory;
michael@0: 
michael@0:     header->signature=UTRIE2_SIG; /* "Tri2" */
michael@0:     header->options=(uint16_t)valueBits;
michael@0: 
michael@0:     header->indexLength=(uint16_t)indexLength;
michael@0:     header->shiftedDataLength=(uint16_t)(dataLength>>UTRIE2_INDEX_SHIFT);
michael@0:     header->index2NullOffset=(uint16_t)UTRIE2_INDEX_2_OFFSET;
michael@0:     header->dataNullOffset=(uint16_t)dataMove;
michael@0:     header->shiftedHighStart=0;
michael@0: 
michael@0:     /* fill the index and data arrays */
michael@0:     dest16=(uint16_t *)(header+1);
michael@0:     trie->index=dest16;
michael@0: 
michael@0:     /* write the index-2 array values shifted right by UTRIE2_INDEX_SHIFT */
michael@0:     for(i=0; i<UTRIE2_INDEX_2_BMP_LENGTH; ++i) {
michael@0:         *dest16++=(uint16_t)(dataMove>>UTRIE2_INDEX_SHIFT);  /* null data block */
michael@0:     }
michael@0: 
michael@0:     /* write UTF-8 2-byte index-2 values, not right-shifted */
michael@0:     for(i=0; i<(0xc2-0xc0); ++i) {                                  /* C0..C1 */
michael@0:         *dest16++=(uint16_t)(dataMove+UTRIE2_BAD_UTF8_DATA_OFFSET);
michael@0:     }
michael@0:     for(; i<(0xe0-0xc0); ++i) {                                     /* C2..DF */
michael@0:         *dest16++=(uint16_t)dataMove;
michael@0:     }
michael@0: 
michael@0:     /* write the 16/32-bit data array */
michael@0:     switch(valueBits) {
michael@0:     case UTRIE2_16_VALUE_BITS:
michael@0:         /* write 16-bit data values */
michael@0:         trie->data16=dest16;
michael@0:         trie->data32=NULL;
michael@0:         for(i=0; i<0x80; ++i) {
michael@0:             *dest16++=(uint16_t)initialValue;
michael@0:         }
michael@0:         for(; i<0xc0; ++i) {
michael@0:             *dest16++=(uint16_t)errorValue;
michael@0:         }
michael@0:         /* highValue and reserved values */
michael@0:         for(i=0; i<UTRIE2_DATA_GRANULARITY; ++i) {
michael@0:             *dest16++=(uint16_t)initialValue;
michael@0:         }
michael@0:         break;
michael@0:     case UTRIE2_32_VALUE_BITS:
michael@0:         /* write 32-bit data values */
michael@0:         p=(uint32_t *)dest16;
michael@0:         trie->data16=NULL;
michael@0:         trie->data32=p;
michael@0:         for(i=0; i<0x80; ++i) {
michael@0:             *p++=initialValue;
michael@0:         }
michael@0:         for(; i<0xc0; ++i) {
michael@0:             *p++=errorValue;
michael@0:         }
michael@0:         /* highValue and reserved values */
michael@0:         for(i=0; i<UTRIE2_DATA_GRANULARITY; ++i) {
michael@0:             *p++=initialValue;
michael@0:         }
michael@0:         break;
michael@0:     default:
michael@0:         *pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
michael@0:         return 0;
michael@0:     }
michael@0: 
michael@0:     return trie;
michael@0: }
michael@0: 
michael@0: U_CAPI void U_EXPORT2
michael@0: utrie2_close(UTrie2 *trie) {
michael@0:     if(trie!=NULL) {
michael@0:         if(trie->isMemoryOwned) {
michael@0:             uprv_free(trie->memory);
michael@0:         }
michael@0:         if(trie->newTrie!=NULL) {
michael@0:             uprv_free(trie->newTrie->data);
michael@0:             uprv_free(trie->newTrie);
michael@0:         }
michael@0:         uprv_free(trie);
michael@0:     }
michael@0: }
michael@0: 
michael@0: U_CAPI int32_t U_EXPORT2
michael@0: utrie2_getVersion(const void *data, int32_t length, UBool anyEndianOk) {
michael@0:     uint32_t signature;
michael@0:     if(length<16 || data==NULL || (U_POINTER_MASK_LSB(data, 3)!=0)) {
michael@0:         return 0;
michael@0:     }
michael@0:     signature=*(const uint32_t *)data;
michael@0:     if(signature==UTRIE2_SIG) {
michael@0:         return 2;
michael@0:     }
michael@0:     if(anyEndianOk && signature==UTRIE2_OE_SIG) {
michael@0:         return 2;
michael@0:     }
michael@0:     if(signature==UTRIE_SIG) {
michael@0:         return 1;
michael@0:     }
michael@0:     if(anyEndianOk && signature==UTRIE_OE_SIG) {
michael@0:         return 1;
michael@0:     }
michael@0:     return 0;
michael@0: }
michael@0: 
michael@0: U_CAPI int32_t U_EXPORT2
michael@0: utrie2_swap(const UDataSwapper *ds,
michael@0:             const void *inData, int32_t length, void *outData,
michael@0:             UErrorCode *pErrorCode) {
michael@0:     const UTrie2Header *inTrie;
michael@0:     UTrie2Header trie;
michael@0:     int32_t dataLength, size;
michael@0:     UTrie2ValueBits valueBits;
michael@0: 
michael@0:     if(U_FAILURE(*pErrorCode)) {
michael@0:         return 0;
michael@0:     }
michael@0:     if(ds==NULL || inData==NULL || (length>=0 && outData==NULL)) {
michael@0:         *pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
michael@0:         return 0;
michael@0:     }
michael@0: 
michael@0:     /* setup and swapping */
michael@0:     if(length>=0 && length<(int32_t)sizeof(UTrie2Header)) {
michael@0:         *pErrorCode=U_INDEX_OUTOFBOUNDS_ERROR;
michael@0:         return 0;
michael@0:     }
michael@0: 
michael@0:     inTrie=(const UTrie2Header *)inData;
michael@0:     trie.signature=ds->readUInt32(inTrie->signature);
michael@0:     trie.options=ds->readUInt16(inTrie->options);
michael@0:     trie.indexLength=ds->readUInt16(inTrie->indexLength);
michael@0:     trie.shiftedDataLength=ds->readUInt16(inTrie->shiftedDataLength);
michael@0: 
michael@0:     valueBits=(UTrie2ValueBits)(trie.options&UTRIE2_OPTIONS_VALUE_BITS_MASK);
michael@0:     dataLength=(int32_t)trie.shiftedDataLength<<UTRIE2_INDEX_SHIFT;
michael@0: 
michael@0:     if( trie.signature!=UTRIE2_SIG ||
michael@0:         valueBits<0 || UTRIE2_COUNT_VALUE_BITS<=valueBits ||
michael@0:         trie.indexLength<UTRIE2_INDEX_1_OFFSET ||
michael@0:         dataLength<UTRIE2_DATA_START_OFFSET
michael@0:     ) {
michael@0:         *pErrorCode=U_INVALID_FORMAT_ERROR; /* not a UTrie */
michael@0:         return 0;
michael@0:     }
michael@0: 
michael@0:     size=sizeof(UTrie2Header)+trie.indexLength*2;
michael@0:     switch(valueBits) {
michael@0:     case UTRIE2_16_VALUE_BITS:
michael@0:         size+=dataLength*2;
michael@0:         break;
michael@0:     case UTRIE2_32_VALUE_BITS:
michael@0:         size+=dataLength*4;
michael@0:         break;
michael@0:     default:
michael@0:         *pErrorCode=U_INVALID_FORMAT_ERROR;
michael@0:         return 0;
michael@0:     }
michael@0: 
michael@0:     if(length>=0) {
michael@0:         UTrie2Header *outTrie;
michael@0: 
michael@0:         if(length<size) {
michael@0:             *pErrorCode=U_INDEX_OUTOFBOUNDS_ERROR;
michael@0:             return 0;
michael@0:         }
michael@0: 
michael@0:         outTrie=(UTrie2Header *)outData;
michael@0: 
michael@0:         /* swap the header */
michael@0:         ds->swapArray32(ds, &inTrie->signature, 4, &outTrie->signature, pErrorCode);
michael@0:         ds->swapArray16(ds, &inTrie->options, 12, &outTrie->options, pErrorCode);
michael@0: 
michael@0:         /* swap the index and the data */
michael@0:         switch(valueBits) {
michael@0:         case UTRIE2_16_VALUE_BITS:
michael@0:             ds->swapArray16(ds, inTrie+1, (trie.indexLength+dataLength)*2, outTrie+1, pErrorCode);
michael@0:             break;
michael@0:         case UTRIE2_32_VALUE_BITS:
michael@0:             ds->swapArray16(ds, inTrie+1, trie.indexLength*2, outTrie+1, pErrorCode);
michael@0:             ds->swapArray32(ds, (const uint16_t *)(inTrie+1)+trie.indexLength, dataLength*4,
michael@0:                                      (uint16_t *)(outTrie+1)+trie.indexLength, pErrorCode);
michael@0:             break;
michael@0:         default:
michael@0:             *pErrorCode=U_INVALID_FORMAT_ERROR;
michael@0:             return 0;
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     return size;
michael@0: }
michael@0: 
michael@0: // utrie2_swapAnyVersion() should be defined here but lives in utrie2_builder.c
michael@0: // to avoid a dependency from utrie2.cpp on utrie.c.
michael@0: 
michael@0: /* enumeration -------------------------------------------------------------- */
michael@0: 
michael@0: #define MIN_VALUE(a, b) ((a)<(b) ? (a) : (b))
michael@0: 
michael@0: /* default UTrie2EnumValue() returns the input value itself */
michael@0: static uint32_t U_CALLCONV
michael@0: enumSameValue(const void * /*context*/, uint32_t value) {
michael@0:     return value;
michael@0: }
michael@0: 
michael@0: /**
michael@0:  * Enumerate all ranges of code points with the same relevant values.
michael@0:  * The values are transformed from the raw trie entries by the enumValue function.
michael@0:  *
michael@0:  * Currently requires start<limit and both start and limit must be multiples
michael@0:  * of UTRIE2_DATA_BLOCK_LENGTH.
michael@0:  *
michael@0:  * Optimizations:
michael@0:  * - Skip a whole block if we know that it is filled with a single value,
michael@0:  *   and it is the same as we visited just before.
michael@0:  * - Handle the null block specially because we know a priori that it is filled
michael@0:  *   with a single value.
michael@0:  */
michael@0: static void
michael@0: enumEitherTrie(const UTrie2 *trie,
michael@0:                UChar32 start, UChar32 limit,
michael@0:                UTrie2EnumValue *enumValue, UTrie2EnumRange *enumRange, const void *context) {
michael@0:     const uint32_t *data32;
michael@0:     const uint16_t *idx;
michael@0: 
michael@0:     uint32_t value, prevValue, initialValue;
michael@0:     UChar32 c, prev, highStart;
michael@0:     int32_t j, i2Block, prevI2Block, index2NullOffset, block, prevBlock, nullBlock;
michael@0: 
michael@0:     if(enumRange==NULL) {
michael@0:         return;
michael@0:     }
michael@0:     if(enumValue==NULL) {
michael@0:         enumValue=enumSameValue;
michael@0:     }
michael@0: 
michael@0:     if(trie->newTrie==NULL) {
michael@0:         /* frozen trie */
michael@0:         idx=trie->index;
michael@0:         U_ASSERT(idx!=NULL); /* the following code assumes trie->newTrie is not NULL when idx is NULL */
michael@0:         data32=trie->data32;
michael@0: 
michael@0:         index2NullOffset=trie->index2NullOffset;
michael@0:         nullBlock=trie->dataNullOffset;
michael@0:     } else {
michael@0:         /* unfrozen, mutable trie */
michael@0:         idx=NULL;
michael@0:         data32=trie->newTrie->data;
michael@0:         U_ASSERT(data32!=NULL); /* the following code assumes idx is not NULL when data32 is NULL */
michael@0: 
michael@0:         index2NullOffset=trie->newTrie->index2NullOffset;
michael@0:         nullBlock=trie->newTrie->dataNullOffset;
michael@0:     }
michael@0: 
michael@0:     highStart=trie->highStart;
michael@0: 
michael@0:     /* get the enumeration value that corresponds to an initial-value trie data entry */
michael@0:     initialValue=enumValue(context, trie->initialValue);
michael@0: 
michael@0:     /* set variables for previous range */
michael@0:     prevI2Block=-1;
michael@0:     prevBlock=-1;
michael@0:     prev=start;
michael@0:     prevValue=0;
michael@0: 
michael@0:     /* enumerate index-2 blocks */
michael@0:     for(c=start; c<limit && c<highStart;) {
michael@0:         /* Code point limit for iterating inside this i2Block. */
michael@0:         UChar32 tempLimit=c+UTRIE2_CP_PER_INDEX_1_ENTRY;
michael@0:         if(limit<tempLimit) {
michael@0:             tempLimit=limit;
michael@0:         }
michael@0:         if(c<=0xffff) {
michael@0:             if(!U_IS_SURROGATE(c)) {
michael@0:                 i2Block=c>>UTRIE2_SHIFT_2;
michael@0:             } else if(U_IS_SURROGATE_LEAD(c)) {
michael@0:                 /*
michael@0:                  * Enumerate values for lead surrogate code points, not code units:
michael@0:                  * This special block has half the normal length.
michael@0:                  */
michael@0:                 i2Block=UTRIE2_LSCP_INDEX_2_OFFSET;
michael@0:                 tempLimit=MIN_VALUE(0xdc00, limit);
michael@0:             } else {
michael@0:                 /*
michael@0:                  * Switch back to the normal part of the index-2 table.
michael@0:                  * Enumerate the second half of the surrogates block.
michael@0:                  */
michael@0:                 i2Block=0xd800>>UTRIE2_SHIFT_2;
michael@0:                 tempLimit=MIN_VALUE(0xe000, limit);
michael@0:             }
michael@0:         } else {
michael@0:             /* supplementary code points */
michael@0:             if(idx!=NULL) {
michael@0:                 i2Block=idx[(UTRIE2_INDEX_1_OFFSET-UTRIE2_OMITTED_BMP_INDEX_1_LENGTH)+
michael@0:                               (c>>UTRIE2_SHIFT_1)];
michael@0:             } else {
michael@0:                 i2Block=trie->newTrie->index1[c>>UTRIE2_SHIFT_1];
michael@0:             }
michael@0:             if(i2Block==prevI2Block && (c-prev)>=UTRIE2_CP_PER_INDEX_1_ENTRY) {
michael@0:                 /*
michael@0:                  * The index-2 block is the same as the previous one, and filled with prevValue.
michael@0:                  * Only possible for supplementary code points because the linear-BMP index-2
michael@0:                  * table creates unique i2Block values.
michael@0:                  */
michael@0:                 c+=UTRIE2_CP_PER_INDEX_1_ENTRY;
michael@0:                 continue;
michael@0:             }
michael@0:         }
michael@0:         prevI2Block=i2Block;
michael@0:         if(i2Block==index2NullOffset) {
michael@0:             /* this is the null index-2 block */
michael@0:             if(prevValue!=initialValue) {
michael@0:                 if(prev<c && !enumRange(context, prev, c-1, prevValue)) {
michael@0:                     return;
michael@0:                 }
michael@0:                 prevBlock=nullBlock;
michael@0:                 prev=c;
michael@0:                 prevValue=initialValue;
michael@0:             }
michael@0:             c+=UTRIE2_CP_PER_INDEX_1_ENTRY;
michael@0:         } else {
michael@0:             /* enumerate data blocks for one index-2 block */
michael@0:             int32_t i2, i2Limit;
michael@0:             i2=(c>>UTRIE2_SHIFT_2)&UTRIE2_INDEX_2_MASK;
michael@0:             if((c>>UTRIE2_SHIFT_1)==(tempLimit>>UTRIE2_SHIFT_1)) {
michael@0:                 i2Limit=(tempLimit>>UTRIE2_SHIFT_2)&UTRIE2_INDEX_2_MASK;
michael@0:             } else {
michael@0:                 i2Limit=UTRIE2_INDEX_2_BLOCK_LENGTH;
michael@0:             }
michael@0:             for(; i2<i2Limit; ++i2) {
michael@0:                 if(idx!=NULL) {
michael@0:                     block=(int32_t)idx[i2Block+i2]<<UTRIE2_INDEX_SHIFT;
michael@0:                 } else {
michael@0:                     block=trie->newTrie->index2[i2Block+i2];
michael@0:                 }
michael@0:                 if(block==prevBlock && (c-prev)>=UTRIE2_DATA_BLOCK_LENGTH) {
michael@0:                     /* the block is the same as the previous one, and filled with prevValue */
michael@0:                     c+=UTRIE2_DATA_BLOCK_LENGTH;
michael@0:                     continue;
michael@0:                 }
michael@0:                 prevBlock=block;
michael@0:                 if(block==nullBlock) {
michael@0:                     /* this is the null data block */
michael@0:                     if(prevValue!=initialValue) {
michael@0:                         if(prev<c && !enumRange(context, prev, c-1, prevValue)) {
michael@0:                             return;
michael@0:                         }
michael@0:                         prev=c;
michael@0:                         prevValue=initialValue;
michael@0:                     }
michael@0:                     c+=UTRIE2_DATA_BLOCK_LENGTH;
michael@0:                 } else {
michael@0:                     for(j=0; j<UTRIE2_DATA_BLOCK_LENGTH; ++j) {
michael@0:                         value=enumValue(context, data32!=NULL ? data32[block+j] : idx[block+j]);
michael@0:                         if(value!=prevValue) {
michael@0:                             if(prev<c && !enumRange(context, prev, c-1, prevValue)) {
michael@0:                                 return;
michael@0:                             }
michael@0:                             prev=c;
michael@0:                             prevValue=value;
michael@0:                         }
michael@0:                         ++c;
michael@0:                     }
michael@0:                 }
michael@0:             }
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     if(c>limit) {
michael@0:         c=limit;  /* could be higher if in the index2NullOffset */
michael@0:     } else if(c<limit) {
michael@0:         /* c==highStart<limit */
michael@0:         uint32_t highValue;
michael@0:         if(idx!=NULL) {
michael@0:             highValue=
michael@0:                 data32!=NULL ?
michael@0:                     data32[trie->highValueIndex] :
michael@0:                     idx[trie->highValueIndex];
michael@0:         } else {
michael@0:             highValue=trie->newTrie->data[trie->newTrie->dataLength-UTRIE2_DATA_GRANULARITY];
michael@0:         }
michael@0:         value=enumValue(context, highValue);
michael@0:         if(value!=prevValue) {
michael@0:             if(prev<c && !enumRange(context, prev, c-1, prevValue)) {
michael@0:                 return;
michael@0:             }
michael@0:             prev=c;
michael@0:             prevValue=value;
michael@0:         }
michael@0:         c=limit;
michael@0:     }
michael@0: 
michael@0:     /* deliver last range */
michael@0:     enumRange(context, prev, c-1, prevValue);
michael@0: }
michael@0: 
michael@0: U_CAPI void U_EXPORT2
michael@0: utrie2_enum(const UTrie2 *trie,
michael@0:             UTrie2EnumValue *enumValue, UTrie2EnumRange *enumRange, const void *context) {
michael@0:     enumEitherTrie(trie, 0, 0x110000, enumValue, enumRange, context);
michael@0: }
michael@0: 
michael@0: U_CAPI void U_EXPORT2
michael@0: utrie2_enumForLeadSurrogate(const UTrie2 *trie, UChar32 lead,
michael@0:                             UTrie2EnumValue *enumValue, UTrie2EnumRange *enumRange,
michael@0:                             const void *context) {
michael@0:     if(!U16_IS_LEAD(lead)) {
michael@0:         return;
michael@0:     }
michael@0:     lead=(lead-0xd7c0)<<10;   /* start code point */
michael@0:     enumEitherTrie(trie, lead, lead+0x400, enumValue, enumRange, context);
michael@0: }
michael@0: 
michael@0: /* C++ convenience wrappers ------------------------------------------------- */
michael@0: 
michael@0: U_NAMESPACE_BEGIN
michael@0: 
michael@0: uint16_t BackwardUTrie2StringIterator::previous16() {
michael@0:     codePointLimit=codePointStart;
michael@0:     if(start>=codePointStart) {
michael@0:         codePoint=U_SENTINEL;
michael@0:         return 0;
michael@0:     }
michael@0:     uint16_t result;
michael@0:     UTRIE2_U16_PREV16(trie, start, codePointStart, codePoint, result);
michael@0:     return result;
michael@0: }
michael@0: 
michael@0: uint16_t ForwardUTrie2StringIterator::next16() {
michael@0:     codePointStart=codePointLimit;
michael@0:     if(codePointLimit==limit) {
michael@0:         codePoint=U_SENTINEL;
michael@0:         return 0;
michael@0:     }
michael@0:     uint16_t result;
michael@0:     UTRIE2_U16_NEXT16(trie, codePointLimit, limit, codePoint, result);
michael@0:     return result;
michael@0: }
michael@0: 
michael@0: U_NAMESPACE_END