C++程序
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/*
*******************************************************************************
*
* Copyright (C) 2005-2010, International Business Machines
* Corporation and others. All Rights Reserved.
*
*******************************************************************************
* file name: utext.cpp
* encoding: US-ASCII
* tab size: 8 (not used)
* indentation:4
*
* created on: 2005apr12
* created by: Markus W. Scherer
*/
#include "unicode/utypes.h"
#include "unicode/ustring.h"
#include "unicode/unistr.h"
#include "unicode/chariter.h"
#include "unicode/utext.h"
#include "ustr_imp.h"
#include "cmemory.h"
#include "cstring.h"
#include "uassert.h"
#include "putilimp.h"
U_NAMESPACE_USE
#define I32_FLAG(bitIndex) ((int32_t)1<<(bitIndex))
static UBool
utext_access(UText *ut, int64_t index, UBool forward) {
return ut->pFuncs->access(ut, index, forward);
}
U_CAPI UBool U_EXPORT2
utext_moveIndex32(UText *ut, int32_t delta) {
UChar32 c;
if (delta > 0) {
do {
if(ut->chunkOffset>=ut->chunkLength && !utext_access(ut, ut->chunkNativeLimit, TRUE)) {
return FALSE;
}
c = ut->chunkContents[ut->chunkOffset];
if (U16_IS_SURROGATE(c)) {
c = utext_next32(ut);
if (c == U_SENTINEL) {
return FALSE;
}
} else {
ut->chunkOffset++;
}
} while(--delta>0);
} else if (delta<0) {
do {
if(ut->chunkOffset<=0 && !utext_access(ut, ut->chunkNativeStart, FALSE)) {
return FALSE;
}
c = ut->chunkContents[ut->chunkOffset-1];
if (U16_IS_SURROGATE(c)) {
c = utext_previous32(ut);
if (c == U_SENTINEL) {
return FALSE;
}
} else {
ut->chunkOffset--;
}
} while(++delta<0);
}
return TRUE;
}
U_CAPI int64_t U_EXPORT2
utext_nativeLength(UText *ut) {
return ut->pFuncs->nativeLength(ut);
}
U_CAPI UBool U_EXPORT2
utext_isLengthExpensive(const UText *ut) {
UBool r = (ut->providerProperties & I32_FLAG(UTEXT_PROVIDER_LENGTH_IS_EXPENSIVE)) != 0;
return r;
}
U_CAPI int64_t U_EXPORT2
utext_getNativeIndex(const UText *ut) {
if(ut->chunkOffset <= ut->nativeIndexingLimit) {
return ut->chunkNativeStart+ut->chunkOffset;
} else {
return ut->pFuncs->mapOffsetToNative(ut);
}
}
U_CAPI void U_EXPORT2
utext_setNativeIndex(UText *ut, int64_t index) {
if(index<ut->chunkNativeStart || index>=ut->chunkNativeLimit) {
// The desired position is outside of the current chunk.
// Access the new position. Assume a forward iteration from here,
// which will also be optimimum for a single random access.
// Reverse iterations may suffer slightly.
ut->pFuncs->access(ut, index, TRUE);
} else if((int32_t)(index - ut->chunkNativeStart) <= ut->nativeIndexingLimit) {
// utf-16 indexing.
ut->chunkOffset=(int32_t)(index-ut->chunkNativeStart);
} else {
ut->chunkOffset=ut->pFuncs->mapNativeIndexToUTF16(ut, index);
}
// The convention is that the index must always be on a code point boundary.
// Adjust the index position if it is in the middle of a surrogate pair.
if (ut->chunkOffset<ut->chunkLength) {
UChar c= ut->chunkContents[ut->chunkOffset];
if (UTF16_IS_TRAIL(c)) {
if (ut->chunkOffset==0) {
ut->pFuncs->access(ut, ut->chunkNativeStart, FALSE);
}
if (ut->chunkOffset>0) {
UChar lead = ut->chunkContents[ut->chunkOffset-1];
if (UTF16_IS_LEAD(lead)) {
ut->chunkOffset--;
}
}
}
}
}
U_CAPI int64_t U_EXPORT2
utext_getPreviousNativeIndex(UText *ut) {
//
// Fast-path the common case.
// Common means current position is not at the beginning of a chunk
// and the preceding character is not supplementary.
//
int32_t i = ut->chunkOffset - 1;
int64_t result;
if (i >= 0) {
UChar c = ut->chunkContents[i];
if (U16_IS_TRAIL(c) == FALSE) {
if (i <= ut->nativeIndexingLimit) {
result = ut->chunkNativeStart + i;
} else {
ut->chunkOffset = i;
result = ut->pFuncs->mapOffsetToNative(ut);
ut->chunkOffset++;
}
return result;
}
}
// If at the start of text, simply return 0.
if (ut->chunkOffset==0 && ut->chunkNativeStart==0) {
return 0;
}
// Harder, less common cases. We are at a chunk boundary, or on a surrogate.
// Keep it simple, use other functions to handle the edges.
//
utext_previous32(ut);
result = UTEXT_GETNATIVEINDEX(ut);
utext_next32(ut);
return result;
}
//
// utext_current32. Get the UChar32 at the current position.
// UText iteration position is always on a code point boundary,
// never on the trail half of a surrogate pair.
//
U_CAPI UChar32 U_EXPORT2
utext_current32(UText *ut) {
UChar32 c;
if (ut->chunkOffset==ut->chunkLength) {
// Current position is just off the end of the chunk.
if (ut->pFuncs->access(ut, ut->chunkNativeLimit, TRUE) == FALSE) {
// Off the end of the text.
return U_SENTINEL;
}
}
c = ut->chunkContents[ut->chunkOffset];
if (U16_IS_LEAD(c) == FALSE) {
// Normal, non-supplementary case.
return c;
}
//
// Possible supplementary char.
//
UChar32 trail = 0;
UChar32 supplementaryC = c;
if ((ut->chunkOffset+1) < ut->chunkLength) {
// The trail surrogate is in the same chunk.
trail = ut->chunkContents[ut->chunkOffset+1];
} else {
// The trail surrogate is in a different chunk.
// Because we must maintain the iteration position, we need to switch forward
// into the new chunk, get the trail surrogate, then revert the chunk back to the
// original one.
// An edge case to be careful of: the entire text may end with an unpaired
// leading surrogate. The attempt to access the trail will fail, but
// the original position before the unpaired lead still needs to be restored.
int64_t nativePosition = ut->chunkNativeLimit;
int32_t originalOffset = ut->chunkOffset;
if (ut->pFuncs->access(ut, nativePosition, TRUE)) {
trail = ut->chunkContents[ut->chunkOffset];
}
UBool r = ut->pFuncs->access(ut, nativePosition, FALSE); // reverse iteration flag loads preceding chunk
U_ASSERT(r==TRUE);
ut->chunkOffset = originalOffset;
if(!r) {
return U_SENTINEL;
}
}
if (U16_IS_TRAIL(trail)) {
supplementaryC = U16_GET_SUPPLEMENTARY(c, trail);
}
return supplementaryC;
}
U_CAPI UChar32 U_EXPORT2
utext_char32At(UText *ut, int64_t nativeIndex) {
UChar32 c = U_SENTINEL;
// Fast path the common case.
if (nativeIndex>=ut->chunkNativeStart && nativeIndex < ut->chunkNativeStart + ut->nativeIndexingLimit) {
ut->chunkOffset = (int32_t)(nativeIndex - ut->chunkNativeStart);
c = ut->chunkContents[ut->chunkOffset];
if (U16_IS_SURROGATE(c) == FALSE) {
return c;
}
}
utext_setNativeIndex(ut, nativeIndex);
if (nativeIndex>=ut->chunkNativeStart && ut->chunkOffset<ut->chunkLength) {
c = ut->chunkContents[ut->chunkOffset];
if (U16_IS_SURROGATE(c)) {
// For surrogates, let current32() deal with the complications
// of supplementaries that may span chunk boundaries.
c = utext_current32(ut);
}
}
return c;
}
U_CAPI UChar32 U_EXPORT2
utext_next32(UText *ut) {
UChar32 c;
if (ut->chunkOffset >= ut->chunkLength) {
if (ut->pFuncs->access(ut, ut->chunkNativeLimit, TRUE) == FALSE) {
return U_SENTINEL;
}
}
c = ut->chunkContents[ut->chunkOffset++];
if (U16_IS_LEAD(c) == FALSE) {
// Normal case, not supplementary.
// (A trail surrogate seen here is just returned as is, as a surrogate value.
// It cannot be part of a pair.)
return c;
}
if (ut->chunkOffset >= ut->chunkLength) {
if (ut->pFuncs->access(ut, ut->chunkNativeLimit, TRUE) == FALSE) {
// c is an unpaired lead surrogate at the end of the text.
// return it as it is.
return c;
}
}
UChar32 trail = ut->chunkContents[ut->chunkOffset];
if (U16_IS_TRAIL(trail) == FALSE) {
// c was an unpaired lead surrogate, not at the end of the text.
// return it as it is (unpaired). Iteration position is on the
// following character, possibly in the next chunk, where the
// trail surrogate would have been if it had existed.
return c;
}
UChar32 supplementary = U16_GET_SUPPLEMENTARY(c, trail);
ut->chunkOffset++; // move iteration position over the trail surrogate.
return supplementary;
}
U_CAPI UChar32 U_EXPORT2
utext_previous32(UText *ut) {
UChar32 c;
if (ut->chunkOffset <= 0) {
if (ut->pFuncs->access(ut, ut->chunkNativeStart, FALSE) == FALSE) {
return U_SENTINEL;
}
}
ut->chunkOffset--;
c = ut->chunkContents[ut->chunkOffset];
if (U16_IS_TRAIL(c) == FALSE) {
// Normal case, not supplementary.
// (A lead surrogate seen here is just returned as is, as a surrogate value.
// It cannot be part of a pair.)
return c;
}
if (ut->chunkOffset <= 0) {
if (ut->pFuncs->access(ut, ut->chunkNativeStart, FALSE) == FALSE) {
// c is an unpaired trail surrogate at the start of the text.
// return it as it is.
return c;
}
}
UChar32 lead = ut->chunkContents[ut->chunkOffset-1];
if (U16_IS_LEAD(lead) == FALSE) {
// c was an unpaired trail surrogate, not at the end of the text.
// return it as it is (unpaired). Iteration position is at c
return c;
}
UChar32 supplementary = U16_GET_SUPPLEMENTARY(lead, c);
ut->chunkOffset--; // move iteration position over the lead surrogate.
return supplementary;
}
U_CAPI UChar32 U_EXPORT2
utext_next32From(UText *ut, int64_t index) {
UChar32 c = U_SENTINEL;
if(index<ut->chunkNativeStart || index>=ut->chunkNativeLimit) {
// Desired position is outside of the current chunk.
if(!ut->pFuncs->access(ut, index, TRUE)) {
// no chunk available here
return U_SENTINEL;
}
} else if (index - ut->chunkNativeStart <= (int64_t)ut->nativeIndexingLimit) {
// Desired position is in chunk, with direct 1:1 native to UTF16 indexing
ut->chunkOffset = (int32_t)(index - ut->chunkNativeStart);
} else {
// Desired position is in chunk, with non-UTF16 indexing.
ut->chunkOffset = ut->pFuncs->mapNativeIndexToUTF16(ut, index);
}
c = ut->chunkContents[ut->chunkOffset++];
if (U16_IS_SURROGATE(c)) {
// Surrogates. Many edge cases. Use other functions that already
// deal with the problems.
utext_setNativeIndex(ut, index);
c = utext_next32(ut);
}
return c;
}
U_CAPI UChar32 U_EXPORT2
utext_previous32From(UText *ut, int64_t index) {
//
// Return the character preceding the specified index.
// Leave the iteration position at the start of the character that was returned.
//
UChar32 cPrev; // The character preceding cCurr, which is what we will return.
// Address the chunk containg the position preceding the incoming index
// A tricky edge case:
// We try to test the requested native index against the chunkNativeStart to determine
// whether the character preceding the one at the index is in the current chunk.
// BUT, this test can fail with UTF-8 (or any other multibyte encoding), when the
// requested index is on something other than the first position of the first char.
//
if(index<=ut->chunkNativeStart || index>ut->chunkNativeLimit) {
// Requested native index is outside of the current chunk.
if(!ut->pFuncs->access(ut, index, FALSE)) {
// no chunk available here
return U_SENTINEL;
}
} else if(index - ut->chunkNativeStart <= (int64_t)ut->nativeIndexingLimit) {
// Direct UTF-16 indexing.
ut->chunkOffset = (int32_t)(index - ut->chunkNativeStart);
} else {
ut->chunkOffset=ut->pFuncs->mapNativeIndexToUTF16(ut, index);
if (ut->chunkOffset==0 && !ut->pFuncs->access(ut, index, FALSE)) {
// no chunk available here
return U_SENTINEL;
}
}
//
// Simple case with no surrogates.
//
ut->chunkOffset--;
cPrev = ut->chunkContents[ut->chunkOffset];
if (U16_IS_SURROGATE(cPrev)) {
// Possible supplementary. Many edge cases.
// Let other functions do the heavy lifting.
utext_setNativeIndex(ut, index);
cPrev = utext_previous32(ut);
}
return cPrev;
}
U_CAPI int32_t U_EXPORT2
utext_extract(UText *ut,
int64_t start, int64_t limit,
UChar *dest, int32_t destCapacity,
UErrorCode *status) {
return ut->pFuncs->extract(ut, start, limit, dest, destCapacity, status);
}
U_CAPI UBool U_EXPORT2
utext_equals(const UText *a, const UText *b) {
if (a==NULL || b==NULL ||
a->magic != UTEXT_MAGIC ||
b->magic != UTEXT_MAGIC) {
// Null or invalid arguments don't compare equal to anything.
return FALSE;
}
if (a->pFuncs != b->pFuncs) {
// Different types of text providers.
return FALSE;
}
if (a->context != b->context) {
// Different sources (different strings)
return FALSE;
}
if (utext_getNativeIndex(a) != utext_getNativeIndex(b)) {
// Different current position in the string.
return FALSE;
}
return TRUE;
}
U_CAPI int32_t U_EXPORT2
utext_compare(UText *s1, int32_t length1,
UText *s2, int32_t length2) {
UChar32 c1 = 0, c2 = 0;
if(length1<0 && length2<0) {
/* strcmp style, go until end of string */
for(;;) {
c1 = UTEXT_NEXT32(s1);
c2 = UTEXT_NEXT32(s2);
if(c1 != c2) {
break;
} else if(c1 == U_SENTINEL) {
return 0;
}
}
} else {
if(length1 < 0) {
length1 = INT32_MIN;
} else if (length2 < 0) {
length2 = INT32_MIN;
}
/* memcmp/UnicodeString style, both length-specified */
while((length1 > 0 || length1 == INT32_MIN) && (length2 > 0 || length2 == INT32_MIN)) {
c1 = UTEXT_NEXT32(s1);
c2 = UTEXT_NEXT32(s2);
if(c1 != c2) {
break;
} else if(c1 == U_SENTINEL) {
return 0;
}
if (length1 != INT32_MIN) {
length1 -= 1;
}
if (length2 != INT32_MIN) {
length2 -= 1;
}
}
if(length1 <= 0 && length1 != INT32_MIN) {
if(length2 <= 0) {
return 0;
} else {
return -1;
}
} else if(length2 <= 0 && length2 != INT32_MIN) {
if (length1 <= 0) {
return 0;
} else {
return 1;
}
}
}
return (int32_t)c1-(int32_t)c2;
}
U_CAPI int32_t U_EXPORT2
utext_compareNativeLimit(UText *s1, int64_t limit1,
UText *s2, int64_t limit2) {
UChar32 c1, c2;
if(limit1<0 && limit2<0) {
/* strcmp style, go until end of string */
for(;;) {
c1 = UTEXT_NEXT32(s1);
c2 = UTEXT_NEXT32(s2);
if(c1 != c2) {
return (int32_t)c1-(int32_t)c2;
} else if(c1 == U_SENTINEL) {
return 0;
}
}
} else {
/* memcmp/UnicodeString style, both length-specified */
int64_t index1 = (limit1 >= 0 ? UTEXT_GETNATIVEINDEX(s1) : 0);
int64_t index2 = (limit2 >= 0 ? UTEXT_GETNATIVEINDEX(s2) : 0);
while((limit1 < 0 || index1 < limit1) && (limit2 < 0 || index2 < limit2)) {
c1 = UTEXT_NEXT32(s1);
c2 = UTEXT_NEXT32(s2);
if(c1 != c2) {
return (int32_t)c1-(int32_t)c2;
} else if(c1 == U_SENTINEL) {
return 0;
}
if (limit1 >= 0) {
index1 = UTEXT_GETNATIVEINDEX(s1);
}
if (limit2 >= 0) {
index2 = UTEXT_GETNATIVEINDEX(s2);
}
}
if(limit1 >= 0 && index1 >= limit1) {
if(index2 >= limit2) {
return 0;
} else {
return -1;
}
} else {
if(index1 >= limit1) {
return 0;
} else {
return 1;
}
}
}
}
U_CAPI int32_t U_EXPORT2
utext_caseCompare(UText *s1, int32_t length1,
UText *s2, int32_t length2,
uint32_t options, UErrorCode *pErrorCode) {
const UCaseProps *csp;
/* case folding variables */
const UChar *p;
int32_t length;
/* case folding buffers, only use current-level start/limit */
UChar fold1[UCASE_MAX_STRING_LENGTH+1], fold2[UCASE_MAX_STRING_LENGTH+1];
int32_t foldOffset1, foldOffset2, foldLength1, foldLength2;
/* current code points */
UChar32 c1, c2;
uint8_t cLength1, cLength2;
/* argument checking */
if(pErrorCode==0 || U_FAILURE(*pErrorCode)) {
return 0;
}
if(s1==NULL || s2==NULL) {
*pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
return 0;
}
csp=ucase_getSingleton(pErrorCode);
if(U_FAILURE(*pErrorCode)) {
return 0;
}
/* for variable-length strings */
if(length1 < 0) {
length1 = INT32_MIN;
}
if (length2 < 0) {
length2 = INT32_MIN;
}
/* initialize */
foldOffset1 = foldOffset2 = foldLength1 = foldLength2 = 0;
/* comparison loop */
while((foldOffset1 < foldLength1 || length1 > 0 || length1 == INT32_MIN) &&
(foldOffset2 < foldLength2 || length2 > 0 || length2 == INT32_MIN)) {
if(foldOffset1 < foldLength1) {
U16_NEXT_UNSAFE(fold1, foldOffset1, c1);
cLength1 = 0;
} else {
c1 = UTEXT_NEXT32(s1);
if (c1 != U_SENTINEL) {
cLength1 = U16_LENGTH(c1);
length = ucase_toFullFolding(csp, c1, &p, options);
if(length >= 0) {
if(length <= UCASE_MAX_STRING_LENGTH) { // !!!: Does not correctly handle 0-length folded-case strings
u_memcpy(fold1, p, length);
foldOffset1 = 0;
foldLength1 = length;
U16_NEXT_UNSAFE(fold1, foldOffset1, c1);
} else {
c1 = length;
}
}
}
if(length1 != INT32_MIN) {
length1 -= 1;
}
}
if(foldOffset2 < foldLength2) {
U16_NEXT_UNSAFE(fold2, foldOffset2, c2);
cLength2 = 0;
} else {
c2 = UTEXT_NEXT32(s2);
if (c2 != U_SENTINEL) {
cLength2 = U16_LENGTH(c2);
length = ucase_toFullFolding(csp, c2, &p, options);
if(length >= 0) {
if(length <= UCASE_MAX_STRING_LENGTH) { // !!!: Does not correctly handle 0-length folded-case strings
u_memcpy(fold2, p, length);
foldOffset2 = 0;
foldLength2 = length;
U16_NEXT_UNSAFE(fold2, foldOffset2, c2);
} else {
c2 = length;
}
}
} else if(c1 == U_SENTINEL) {
return 0; // end of both strings at once
}
if(length2 != INT32_MIN) {
length2 -= 1;
}
}
if(c1 != c2) {
return (int32_t)c1-(int32_t)c2;
}
}
/* By now at least one of the strings is out of characters */
length1 += foldLength1 - foldOffset1;
length2 += foldLength2 - foldOffset2;
if(length1 <= 0 && length1 != INT32_MIN) {
if(length2 <= 0) {
return 0;
} else {
return -1;
}
} else {
if (length1 <= 0) {
return 0;
} else {
return 1;
}
}
}
U_CAPI int32_t U_EXPORT2
utext_caseCompareNativeLimit(UText *s1, int64_t limit1,
UText *s2, int64_t limit2,
uint32_t options, UErrorCode *pErrorCode) {
const UCaseProps *csp;
/* case folding variables */
const UChar *p;
int32_t length;
/* case folding buffers, only use current-level start/limit */
UChar fold1[UCASE_MAX_STRING_LENGTH+1], fold2[UCASE_MAX_STRING_LENGTH+1];
int32_t foldOffset1, foldOffset2, foldLength1, foldLength2;
/* current code points */
UChar32 c1, c2;
/* native indexes into s1 and s2 */
int64_t index1, index2;
/* argument checking */
if(pErrorCode==0 || U_FAILURE(*pErrorCode)) {
return 0;
}
if(s1==NULL || s2==NULL) {
*pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
return 0;
}
csp=ucase_getSingleton(pErrorCode);
if(U_FAILURE(*pErrorCode)) {
return 0;
}
/* initialize */
index1 = (limit1 >= 0 ? UTEXT_GETNATIVEINDEX(s1) : 0);
index2 = (limit2 >= 0 ? UTEXT_GETNATIVEINDEX(s2) : 0);
foldOffset1 = foldOffset2 = foldLength1 = foldLength2 = 0;
/* comparison loop */
while((foldOffset1 < foldLength1 || limit1 < 0 || index1 < limit1) &&
(foldOffset2 < foldLength2 || limit2 < 0 || index2 < limit2)) {
if(foldOffset1 < foldLength1) {
U16_NEXT_UNSAFE(fold1, foldOffset1, c1);
} else {
c1 = UTEXT_NEXT32(s1);
if (c1 != U_SENTINEL) {
length = ucase_toFullFolding(csp, c1, &p, options);
if(length >= 0) {
if(length <= UCASE_MAX_STRING_LENGTH) { // !!!: Does not correctly handle 0-length folded-case strings
u_memcpy(fold1, p, length);
foldOffset1 = 0;
foldLength1 = length;
U16_NEXT_UNSAFE(fold1, foldOffset1, c1);
} else {
c1 = length;
}
}
}
if (limit1 >= 0) {
index1 = UTEXT_GETNATIVEINDEX(s1);
}
}
if(foldOffset2 < foldLength2) {
U16_NEXT_UNSAFE(fold2, foldOffset2, c2);
} else {
c2 = UTEXT_NEXT32(s2);
if (c2 != U_SENTINEL) {
length = ucase_toFullFolding(csp, c2, &p, options);
if(length >= 0) {
if(length <= UCASE_MAX_STRING_LENGTH) { // !!!: Does not correctly handle 0-length folded-case strings
u_memcpy(fold2, p, length);
foldOffset2 = 0;
foldLength2 = length;
U16_NEXT_UNSAFE(fold2, foldOffset2, c2);
} else {
c2 = length;
}
}
} else if(c1 == U_SENTINEL) {
return 0;
}
if (limit2 >= 0) {
index2 = UTEXT_GETNATIVEINDEX(s2);
}
}
if(c1 != c2) {
return (int32_t)c1-(int32_t)c2;
}
}
/* By now at least one of the strings is out of characters */
index1 -= foldLength1 - foldOffset1;
index2 -= foldLength2 - foldOffset2;
if(limit1 >= 0 && index1 >= limit1) {
if(index2 >= limit2) {
return 0;
} else {
return -1;
}
} else {
if(index1 >= limit1) {
return 0;
} else {
return 1;
}
}
}
U_CAPI UBool U_EXPORT2
utext_isWritable(const UText *ut)
{
UBool b = (ut->providerProperties & I32_FLAG(UTEXT_PROVIDER_WRITABLE)) != 0;
return b;
}
U_CAPI void U_EXPORT2
utext_freeze(UText *ut) {
// Zero out the WRITABLE flag.
ut->providerProperties &= ~(I32_FLAG(UTEXT_PROVIDER_WRITABLE));
}
U_CAPI UBool U_EXPORT2
utext_hasMetaData(const UText *ut)
{
UBool b = (ut->providerProperties & I32_FLAG(UTEXT_PROVIDER_HAS_META_DATA)) != 0;
return b;
}
U_CAPI int32_t U_EXPORT2
utext_replace(UText *ut,
int64_t nativeStart, int64_t nativeLimit,
const UChar *replacementText, int32_t replacementLength,
UErrorCode *status)
{
if (U_FAILURE(*status)) {
return 0;
}
if ((ut->providerProperties & I32_FLAG(UTEXT_PROVIDER_WRITABLE)) == 0) {
*status = U_NO_WRITE_PERMISSION;
return 0;
}
int32_t i = ut->pFuncs->replace(ut, nativeStart, nativeLimit, replacementText, replacementLength, status);
return i;
}
U_CAPI void U_EXPORT2
utext_copy(UText *ut,
int64_t nativeStart, int64_t nativeLimit,
int64_t destIndex,
UBool move,
UErrorCode *status)
{
if (U_FAILURE(*status)) {
return;
}
if ((ut->providerProperties & I32_FLAG(UTEXT_PROVIDER_WRITABLE)) == 0) {
*status = U_NO_WRITE_PERMISSION;
return;
}
ut->pFuncs->copy(ut, nativeStart, nativeLimit, destIndex, move, status);
}
U_CAPI UText * U_EXPORT2
utext_clone(UText *dest, const UText *src, UBool deep, UBool readOnly, UErrorCode *status) {
UText *result;
result = src->pFuncs->clone(dest, src, deep, status);
if (readOnly) {
utext_freeze(result);
}
return result;
}
//------------------------------------------------------------------------------
//
// UText common functions implementation
//
//------------------------------------------------------------------------------
//
// UText.flags bit definitions
//
enum {
UTEXT_HEAP_ALLOCATED = 1, // 1 if ICU has allocated this UText struct on the heap.
// 0 if caller provided storage for the UText.
UTEXT_EXTRA_HEAP_ALLOCATED = 2, // 1 if ICU has allocated extra storage as a separate
// heap block.
// 0 if there is no separate allocation. Either no extra
// storage was requested, or it is appended to the end
// of the main UText storage.
UTEXT_OPEN = 4 // 1 if this UText is currently open
// 0 if this UText is not open.
};
//
// Extended form of a UText. The purpose is to aid in computing the total size required
// when a provider asks for a UText to be allocated with extra storage.
struct ExtendedUText {
UText ut;
UAlignedMemory extension;
};
static const UText emptyText = UTEXT_INITIALIZER;
U_CAPI UText * U_EXPORT2
utext_setup(UText *ut, int32_t extraSpace, UErrorCode *status) {
if (U_FAILURE(*status)) {
return ut;
}
if (ut == NULL) {
// We need to heap-allocate storage for the new UText
int32_t spaceRequired = sizeof(UText);
if (extraSpace > 0) {
spaceRequired = sizeof(ExtendedUText) + extraSpace - sizeof(UAlignedMemory);
}
ut = (UText *)uprv_malloc(spaceRequired);
if (ut == NULL) {
*status = U_MEMORY_ALLOCATION_ERROR;
return NULL;
} else {
*ut = emptyText;
ut->flags |= UTEXT_HEAP_ALLOCATED;
if (spaceRequired>0) {
ut->extraSize = extraSpace;
ut->pExtra = &((ExtendedUText *)ut)->extension;
}
}
} else {
// We have been supplied with an already existing UText.
// Verify that it really appears to be a UText.
if (ut->magic != UTEXT_MAGIC) {
*status = U_ILLEGAL_ARGUMENT_ERROR;
return ut;
}
// If the ut is already open and there's a provider supplied close
// function, call it.
if ((ut->flags & UTEXT_OPEN) && ut->pFuncs->close != NULL) {
ut->pFuncs->close(ut);
}
ut->flags &= ~UTEXT_OPEN;
// If extra space was requested by our caller, check whether
// sufficient already exists, and allocate new if needed.
if (extraSpace > ut->extraSize) {
// Need more space. If there is existing separately allocated space,
// delete it first, then allocate new space.
if (ut->flags & UTEXT_EXTRA_HEAP_ALLOCATED) {
uprv_free(ut->pExtra);
ut->extraSize = 0;
}
ut->pExtra = uprv_malloc(extraSpace);
if (ut->pExtra == NULL) {
*status = U_MEMORY_ALLOCATION_ERROR;
} else {
ut->extraSize = extraSpace;
ut->flags |= UTEXT_EXTRA_HEAP_ALLOCATED;
}
}
}
if (U_SUCCESS(*status)) {
ut->flags |= UTEXT_OPEN;
// Initialize all remaining fields of the UText.
//
ut->context = NULL;
ut->chunkContents = NULL;
ut->p = NULL;
ut->q = NULL;
ut->r = NULL;
ut->a = 0;
ut->b = 0;
ut->c = 0;
ut->chunkOffset = 0;
ut->chunkLength = 0;
ut->chunkNativeStart = 0;
ut->chunkNativeLimit = 0;
ut->nativeIndexingLimit = 0;
ut->providerProperties = 0;
ut->privA = 0;
ut->privB = 0;
ut->privC = 0;
ut->privP = NULL;
if (ut->pExtra!=NULL && ut->extraSize>0)
uprv_memset(ut->pExtra, 0, ut->extraSize);
}
return ut;
}
U_CAPI UText * U_EXPORT2
utext_close(UText *ut) {
if (ut==NULL ||
ut->magic != UTEXT_MAGIC ||
(ut->flags & UTEXT_OPEN) == 0)
{
// The supplied ut is not an open UText.
// Do nothing.
return ut;
}
// If the provider gave us a close function, call it now.
// This will clean up anything allocated specifically by the provider.
if (ut->pFuncs->close != NULL) {
ut->pFuncs->close(ut);
}
ut->flags &= ~UTEXT_OPEN;
// If we (the framework) allocated the UText or subsidiary storage,
// delete it.
if (ut->flags & UTEXT_EXTRA_HEAP_ALLOCATED) {
uprv_free(ut->pExtra);
ut->pExtra = NULL;
ut->flags &= ~UTEXT_EXTRA_HEAP_ALLOCATED;
ut->extraSize = 0;
}
// Zero out function table of the closed UText. This is a defensive move,
// inteded to cause applications that inadvertantly use a closed
// utext to crash with null pointer errors.
ut->pFuncs = NULL;
if (ut->flags & UTEXT_HEAP_ALLOCATED) {
// This UText was allocated by UText setup. We need to free it.
// Clear magic, so we can detect if the user messes up and immediately
// tries to reopen another UText using the deleted storage.
ut->magic = 0;
uprv_free(ut);
ut = NULL;
}
return ut;
}
//
// invalidateChunk Reset a chunk to have no contents, so that the next call
// to access will cause new data to load.
// This is needed when copy/move/replace operate directly on the
// backing text, potentially putting it out of sync with the
// contents in the chunk.
//
static void
invalidateChunk(UText *ut) {
ut->chunkLength = 0;
ut->chunkNativeLimit = 0;
ut->chunkNativeStart = 0;
ut->chunkOffset = 0;
ut->nativeIndexingLimit = 0;
}
//
// pinIndex Do range pinning on a native index parameter.
// 64 bit pinning is done in place.
// 32 bit truncated result is returned as a convenience for
// use in providers that don't need 64 bits.
static int32_t
pinIndex(int64_t &index, int64_t limit) {
if (index<0) {
index = 0;
} else if (index > limit) {
index = limit;
}
return (int32_t)index;
}
U_CDECL_BEGIN
//
// Pointer relocation function,
// a utility used by shallow clone.
// Adjust a pointer that refers to something within one UText (the source)
// to refer to the same relative offset within a another UText (the target)
//
static void adjustPointer(UText *dest, const void **destPtr, const UText *src) {
// convert all pointers to (char *) so that byte address arithmetic will work.
char *dptr = (char *)*destPtr;
char *dUText = (char *)dest;
char *sUText = (char *)src;
if (dptr >= (char *)src->pExtra && dptr < ((char*)src->pExtra)+src->extraSize) {
// target ptr was to something within the src UText's pExtra storage.
// relocate it into the target UText's pExtra region.
*destPtr = ((char *)dest->pExtra) + (dptr - (char *)src->pExtra);
} else if (dptr>=sUText && dptr < sUText+src->sizeOfStruct) {
// target ptr was pointing to somewhere within the source UText itself.
// Move it to the same offset within the target UText.
*destPtr = dUText + (dptr-sUText);
}
}
//
// Clone. This is a generic copy-the-utext-by-value clone function that can be
// used as-is with some utext types, and as a helper by other clones.
//
static UText * U_CALLCONV
shallowTextClone(UText * dest, const UText * src, UErrorCode * status) {
if (U_FAILURE(*status)) {
return NULL;
}
int32_t srcExtraSize = src->extraSize;
//
// Use the generic text_setup to allocate storage if required.
//
dest = utext_setup(dest, srcExtraSize, status);
if (U_FAILURE(*status)) {
return dest;
}
//
// flags (how the UText was allocated) and the pointer to the
// extra storage must retain the values in the cloned utext that
// were set up by utext_setup. Save them separately before
// copying the whole struct.
//
void *destExtra = dest->pExtra;
int32_t flags = dest->flags;
//
// Copy the whole UText struct by value.
// Any "Extra" storage is copied also.
//
int sizeToCopy = src->sizeOfStruct;
if (sizeToCopy > dest->sizeOfStruct) {
sizeToCopy = dest->sizeOfStruct;
}
uprv_memcpy(dest, src, sizeToCopy);
dest->pExtra = destExtra;
dest->flags = flags;
if (srcExtraSize > 0) {
uprv_memcpy(dest->pExtra, src->pExtra, srcExtraSize);
}
//
// Relocate any pointers in the target that refer to the UText itself
// to point to the cloned copy rather than the original source.
//
adjustPointer(dest, &dest->context, src);
adjustPointer(dest, &dest->p, src);
adjustPointer(dest, &dest->q, src);
adjustPointer(dest, &dest->r, src);
adjustPointer(dest, (const void **)&dest->chunkContents, src);
return dest;
}
U_CDECL_END
//------------------------------------------------------------------------------
//
// UText implementation for UTF-8 char * strings (read-only)
// Limitation: string length must be <= 0x7fffffff in length.
// (length must for in an int32_t variable)
//
// Use of UText data members:
// context pointer to UTF-8 string
// utext.b is the input string length (bytes).
// utext.c Length scanned so far in string
// (for optimizing finding length of zero terminated strings.)
// utext.p pointer to the current buffer
// utext.q pointer to the other buffer.
//
//------------------------------------------------------------------------------
// Chunk size.
// Must be less than 85, because of byte mapping from UChar indexes to native indexes.
// Worst case is three native bytes to one UChar. (Supplemenaries are 4 native bytes
// to two UChars.)
//
enum { UTF8_TEXT_CHUNK_SIZE=32 };
//
// UTF8Buf Two of these structs will be set up in the UText's extra allocated space.
// Each contains the UChar chunk buffer, the to and from native maps, and
// header info.
//
// because backwards iteration fills the buffers starting at the end and
// working towards the front, the filled part of the buffers may not begin
// at the start of the available storage for the buffers.
//
// Buffer size is one bigger than the specified UTF8_TEXT_CHUNK_SIZE to allow for
// the last character added being a supplementary, and thus requiring a surrogate
// pair. Doing this is simpler than checking for the edge case.
//
struct UTF8Buf {
int32_t bufNativeStart; // Native index of first char in UChar buf
int32_t bufNativeLimit; // Native index following last char in buf.
int32_t bufStartIdx; // First filled position in buf.
int32_t bufLimitIdx; // Limit of filled range in buf.
int32_t bufNILimit; // Limit of native indexing part of buf
int32_t toUCharsMapStart; // Native index corresponding to
// mapToUChars[0].
// Set to bufNativeStart when filling forwards.
// Set to computed value when filling backwards.
UChar buf[UTF8_TEXT_CHUNK_SIZE+4]; // The UChar buffer. Requires one extra position beyond the
// the chunk size, to allow for surrogate at the end.
// Length must be identical to mapToNative array, below,
// because of the way indexing works when the array is
// filled backwards during a reverse iteration. Thus,
// the additional extra size.
uint8_t mapToNative[UTF8_TEXT_CHUNK_SIZE+4]; // map UChar index in buf to
// native offset from bufNativeStart.
// Requires two extra slots,
// one for a supplementary starting in the last normal position,
// and one for an entry for the buffer limit position.
uint8_t mapToUChars[UTF8_TEXT_CHUNK_SIZE*3+6]; // Map native offset from bufNativeStart to
// correspoding offset in filled part of buf.
int32_t align;
};
U_CDECL_BEGIN
//
// utf8TextLength
//
// Get the length of the string. If we don't already know it,
// we'll need to scan for the trailing nul.
//
static int64_t U_CALLCONV
utf8TextLength(UText *ut) {
if (ut->b < 0) {
// Zero terminated string, and we haven't scanned to the end yet.
// Scan it now.
const char *r = (const char *)ut->context + ut->c;
while (*r != 0) {
r++;
}
if ((r - (const char *)ut->context) < 0x7fffffff) {
ut->b = (int32_t)(r - (const char *)ut->context);
} else {
// Actual string was bigger (more than 2 gig) than we
// can handle. Clip it to 2 GB.
ut->b = 0x7fffffff;
}
ut->providerProperties &= ~I32_FLAG(UTEXT_PROVIDER_LENGTH_IS_EXPENSIVE);
}
return ut->b;
}
static UBool U_CALLCONV
utf8TextAccess(UText *ut, int64_t index, UBool forward) {
//
// Apologies to those who are allergic to goto statements.
// Consider each goto to a labelled block to be the equivalent of
// call the named block as if it were a function();
// return;
//
const uint8_t *s8=(const uint8_t *)ut->context;
UTF8Buf *u8b = NULL;
int32_t length = ut->b; // Length of original utf-8
int32_t ix= (int32_t)index; // Requested index, trimmed to 32 bits.
int32_t mapIndex = 0;
if (index<0) {
ix=0;
} else if (index > 0x7fffffff) {
// Strings with 64 bit lengths not supported by this UTF-8 provider.
ix = 0x7fffffff;
}
// Pin requested index to the string length.
if (ix>length) {
if (length>=0) {
ix=length;
} else if (ix>=ut->c) {
// Zero terminated string, and requested index is beyond
// the region that has already been scanned.
// Scan up to either the end of the string or to the
// requested position, whichever comes first.
while (ut->c<ix && s8[ut->c]!=0) {
ut->c++;
}
// TODO: support for null terminated string length > 32 bits.
if (s8[ut->c] == 0) {
// We just found the actual length of the string.
// Trim the requested index back to that.
ix = ut->c;
ut->b = ut->c;
length = ut->c;
ut->providerProperties &= ~I32_FLAG(UTEXT_PROVIDER_LENGTH_IS_EXPENSIVE);
}
}
}
//
// Dispatch to the appropriate action for a forward iteration request.
//
if (forward) {
if (ix==ut->chunkNativeLimit) {
// Check for normal sequential iteration cases first.
if (ix==length) {
// Just reached end of string
// Don't swap buffers, but do set the
// current buffer position.
ut->chunkOffset = ut->chunkLength;
return FALSE;
} else {
// End of current buffer.
// check whether other buffer already has what we need.
UTF8Buf *altB = (UTF8Buf *)ut->q;
if (ix>=altB->bufNativeStart && ix<altB->bufNativeLimit) {
goto swapBuffers;
}
}
}
// A random access. Desired index could be in either or niether buf.
// For optimizing the order of testing, first check for the index
// being in the other buffer. This will be the case for uses that
// move back and forth over a fairly limited range
{
u8b = (UTF8Buf *)ut->q; // the alternate buffer
if (ix>=u8b->bufNativeStart && ix<u8b->bufNativeLimit) {
// Requested index is in the other buffer.
goto swapBuffers;
}
if (ix == length) {
// Requested index is end-of-string.
// (this is the case of randomly seeking to the end.
// The case of iterating off the end is handled earlier.)
if (ix == ut->chunkNativeLimit) {
// Current buffer extends up to the end of the string.
// Leave it as the current buffer.
ut->chunkOffset = ut->chunkLength;
return FALSE;
}
if (ix == u8b->bufNativeLimit) {
// Alternate buffer extends to the end of string.
// Swap it in as the current buffer.
goto swapBuffersAndFail;
}
// Neither existing buffer extends to the end of the string.
goto makeStubBuffer;
}
if (ix<ut->chunkNativeStart || ix>=ut->chunkNativeLimit) {
// Requested index is in neither buffer.
goto fillForward;
}
// Requested index is in this buffer.
u8b = (UTF8Buf *)ut->p; // the current buffer
mapIndex = ix - u8b->toUCharsMapStart;
ut->chunkOffset = u8b->mapToUChars[mapIndex] - u8b->bufStartIdx;
return TRUE;
}
}
//
// Dispatch to the appropriate action for a
// Backwards Diretion iteration request.
//
if (ix==ut->chunkNativeStart) {
// Check for normal sequential iteration cases first.
if (ix==0) {
// Just reached the start of string
// Don't swap buffers, but do set the
// current buffer position.
ut->chunkOffset = 0;
return FALSE;
} else {
// Start of current buffer.
// check whether other buffer already has what we need.
UTF8Buf *altB = (UTF8Buf *)ut->q;
if (ix>altB->bufNativeStart && ix<=altB->bufNativeLimit) {
goto swapBuffers;
}
}
}
// A random access. Desired index could be in either or niether buf.
// For optimizing the order of testing,
// Most likely case: in the other buffer.
// Second most likely: in neither buffer.
// Unlikely, but must work: in the current buffer.
u8b = (UTF8Buf *)ut->q; // the alternate buffer
if (ix>u8b->bufNativeStart && ix<=u8b->bufNativeLimit) {
// Requested index is in the other buffer.
goto swapBuffers;
}
// Requested index is start-of-string.
// (this is the case of randomly seeking to the start.
// The case of iterating off the start is handled earlier.)
if (ix==0) {
if (u8b->bufNativeStart==0) {
// Alternate buffer contains the data for the start string.
// Make it be the current buffer.
goto swapBuffersAndFail;
} else {
// Request for data before the start of string,
// neither buffer is usable.
// set up a zero-length buffer.
goto makeStubBuffer;
}
}
if (ix<=ut->chunkNativeStart || ix>ut->chunkNativeLimit) {
// Requested index is in neither buffer.
goto fillReverse;
}
// Requested index is in this buffer.
// Set the utf16 buffer index.
u8b = (UTF8Buf *)ut->p;
mapIndex = ix - u8b->toUCharsMapStart;
ut->chunkOffset = u8b->mapToUChars[mapIndex] - u8b->bufStartIdx;
if (ut->chunkOffset==0) {
// This occurs when the first character in the text is
// a multi-byte UTF-8 char, and the requested index is to
// one of the trailing bytes. Because there is no preceding ,
// character, this access fails. We can't pick up on the
// situation sooner because the requested index is not zero.
return FALSE;
} else {
return TRUE;
}
swapBuffers:
// The alternate buffer (ut->q) has the string data that was requested.
// Swap the primary and alternate buffers, and set the
// chunk index into the new primary buffer.
{
u8b = (UTF8Buf *)ut->q;
ut->q = ut->p;
ut->p = u8b;
ut->chunkContents = &u8b->buf[u8b->bufStartIdx];
ut->chunkLength = u8b->bufLimitIdx - u8b->bufStartIdx;
ut->chunkNativeStart = u8b->bufNativeStart;
ut->chunkNativeLimit = u8b->bufNativeLimit;
ut->nativeIndexingLimit = u8b->bufNILimit;
// Index into the (now current) chunk
// Use the map to set the chunk index. It's more trouble than it's worth
// to check whether native indexing can be used.
U_ASSERT(ix>=u8b->bufNativeStart);
U_ASSERT(ix<=u8b->bufNativeLimit);
mapIndex = ix - u8b->toUCharsMapStart;
U_ASSERT(mapIndex>=0);
U_ASSERT(mapIndex<(int32_t)sizeof(u8b->mapToUChars));
ut->chunkOffset = u8b->mapToUChars[mapIndex] - u8b->bufStartIdx;
return TRUE;
}
swapBuffersAndFail:
// We got a request for either the start or end of the string,
// with iteration continuing in the out-of-bounds direction.
// The alternate buffer already contains the data up to the
// start/end.
// Swap the buffers, then return failure, indicating that we couldn't
// make things correct for continuing the iteration in the requested
// direction. The position & buffer are correct should the
// user decide to iterate in the opposite direction.
u8b = (UTF8Buf *)ut->q;
ut->q = ut->p;
ut->p = u8b;
ut->chunkContents = &u8b->buf[u8b->bufStartIdx];
ut->chunkLength = u8b->bufLimitIdx - u8b->bufStartIdx;
ut->chunkNativeStart = u8b->bufNativeStart;
ut->chunkNativeLimit = u8b->bufNativeLimit;
ut->nativeIndexingLimit = u8b->bufNILimit;
// Index into the (now current) chunk
// For this function (swapBuffersAndFail), the requested index
// will always be at either the start or end of the chunk.
if (ix==u8b->bufNativeLimit) {
ut->chunkOffset = ut->chunkLength;
} else {
ut->chunkOffset = 0;
U_ASSERT(ix == u8b->bufNativeStart);
}
return FALSE;
makeStubBuffer:
// The user has done a seek/access past the start or end
// of the string. Rather than loading data that is likely
// to never be used, just set up a zero-length buffer at
// the position.
u8b = (UTF8Buf *)ut->q;
u8b->bufNativeStart = ix;
u8b->bufNativeLimit = ix;
u8b->bufStartIdx = 0;
u8b->bufLimitIdx = 0;
u8b->bufNILimit = 0;
u8b->toUCharsMapStart = ix;
u8b->mapToNative[0] = 0;
u8b->mapToUChars[0] = 0;
goto swapBuffersAndFail;
fillForward:
{
// Move the incoming index to a code point boundary.
U8_SET_CP_START(s8, 0, ix);
// Swap the UText buffers.
// We want to fill what was previously the alternate buffer,
// and make what was the current buffer be the new alternate.
UTF8Buf *u8b = (UTF8Buf *)ut->q;
ut->q = ut->p;
ut->p = u8b;
int32_t strLen = ut->b;
UBool nulTerminated = FALSE;
if (strLen < 0) {
strLen = 0x7fffffff;
nulTerminated = TRUE;
}
UChar *buf = u8b->buf;
uint8_t *mapToNative = u8b->mapToNative;
uint8_t *mapToUChars = u8b->mapToUChars;
int32_t destIx = 0;
int32_t srcIx = ix;
UBool seenNonAscii = FALSE;
UChar32 c = 0;
// Fill the chunk buffer and mapping arrays.
while (destIx<UTF8_TEXT_CHUNK_SIZE) {
c = s8[srcIx];
if (c>0 && c<0x80) {
// Special case ASCII range for speed.
// zero is excluded to simplify bounds checking.
buf[destIx] = (UChar)c;
mapToNative[destIx] = (uint8_t)(srcIx - ix);
mapToUChars[srcIx-ix] = (uint8_t)destIx;
srcIx++;
destIx++;
} else {
// General case, handle everything.
if (seenNonAscii == FALSE) {
seenNonAscii = TRUE;
u8b->bufNILimit = destIx;
}
int32_t cIx = srcIx;
int32_t dIx = destIx;
int32_t dIxSaved = destIx;
U8_NEXT(s8, srcIx, strLen, c);
if (c==0 && nulTerminated) {
srcIx--;
break;
}
if (c<0) {
// Illegal UTF-8. Replace with sub character.
c = 0x0fffd;
}
U16_APPEND_UNSAFE(buf, destIx, c);
do {
mapToNative[dIx++] = (uint8_t)(cIx - ix);
} while (dIx < destIx);
do {
mapToUChars[cIx++ - ix] = (uint8_t)dIxSaved;
} while (cIx < srcIx);
}
if (srcIx>=strLen) {
break;
}
}
// store Native <--> Chunk Map entries for the end of the buffer.
// There is no actual character here, but the index position is valid.
mapToNative[destIx] = (uint8_t)(srcIx - ix);
mapToUChars[srcIx - ix] = (uint8_t)destIx;
// fill in Buffer descriptor
u8b->bufNativeStart = ix;
u8b->bufNativeLimit = srcIx;
u8b->bufStartIdx = 0;
u8b->bufLimitIdx = destIx;
if (seenNonAscii == FALSE) {
u8b->bufNILimit = destIx;
}
u8b->toUCharsMapStart = u8b->bufNativeStart;
// Set UText chunk to refer to this buffer.
ut->chunkContents = buf;
ut->chunkOffset = 0;
ut->chunkLength = u8b->bufLimitIdx;
ut->chunkNativeStart = u8b->bufNativeStart;
ut->chunkNativeLimit = u8b->bufNativeLimit;
ut->nativeIndexingLimit = u8b->bufNILimit;
// For zero terminated strings, keep track of the maximum point
// scanned so far.
if (nulTerminated && srcIx>ut->c) {
ut->c = srcIx;
if (c==0) {
// We scanned to the end.
// Remember the actual length.
ut->b = srcIx;
ut->providerProperties &= ~I32_FLAG(UTEXT_PROVIDER_LENGTH_IS_EXPENSIVE);
}
}
return TRUE;
}
fillReverse:
{
// Move the incoming index to a code point boundary.
// Can only do this if the incoming index is somewhere in the interior of the string.
// If index is at the end, there is no character there to look at.
if (ix != ut->b) {
U8_SET_CP_START(s8, 0, ix);
}
// Swap the UText buffers.
// We want to fill what was previously the alternate buffer,
// and make what was the current buffer be the new alternate.
UTF8Buf *u8b = (UTF8Buf *)ut->q;
ut->q = ut->p;
ut->p = u8b;
UChar *buf = u8b->buf;
uint8_t *mapToNative = u8b->mapToNative;
uint8_t *mapToUChars = u8b->mapToUChars;
int32_t toUCharsMapStart = ix - (UTF8_TEXT_CHUNK_SIZE*3 + 1);
int32_t destIx = UTF8_TEXT_CHUNK_SIZE+2; // Start in the overflow region
// at end of buffer to leave room
// for a surrogate pair at the
// buffer start.
int32_t srcIx = ix;
int32_t bufNILimit = destIx;
UChar32 c;
// Map to/from Native Indexes, fill in for the position at the end of
// the buffer.
//
mapToNative[destIx] = (uint8_t)(srcIx - toUCharsMapStart);
mapToUChars[srcIx - toUCharsMapStart] = (uint8_t)destIx;
// Fill the chunk buffer
// Work backwards, filling from the end of the buffer towards the front.
//
while (destIx>2 && (srcIx - toUCharsMapStart > 5) && (srcIx > 0)) {
srcIx--;
destIx--;
// Get last byte of the UTF-8 character
c = s8[srcIx];
if (c<0x80) {
// Special case ASCII range for speed.
buf[destIx] = (UChar)c;
mapToUChars[srcIx - toUCharsMapStart] = (uint8_t)destIx;
mapToNative[destIx] = (uint8_t)(srcIx - toUCharsMapStart);
} else {
// General case, handle everything non-ASCII.
int32_t sIx = srcIx; // ix of last byte of multi-byte u8 char
// Get the full character from the UTF8 string.
// use code derived from tbe macros in utf.8
// Leaves srcIx pointing at the first byte of the UTF-8 char.
//
if (c<=0xbf) {
c=utf8_prevCharSafeBody(s8, 0, &srcIx, c, -1);
// leaves srcIx at first byte of the multi-byte char.
} else {
c=0x0fffd;
}
// Store the character in UTF-16 buffer.
if (c<0x10000) {
buf[destIx] = (UChar)c;
mapToNative[destIx] = (uint8_t)(srcIx - toUCharsMapStart);
} else {
buf[destIx] = U16_TRAIL(c);
mapToNative[destIx] = (uint8_t)(srcIx - toUCharsMapStart);
buf[--destIx] = U16_LEAD(c);
mapToNative[destIx] = (uint8_t)(srcIx - toUCharsMapStart);
}
// Fill in the map from native indexes to UChars buf index.
do {
mapToUChars[sIx-- - toUCharsMapStart] = (uint8_t)destIx;
} while (sIx >= srcIx);
// Set native indexing limit to be the current position.
// We are processing a non-ascii, non-native-indexing char now;
// the limit will be here if the rest of the chars to be
// added to this buffer are ascii.
bufNILimit = destIx;
}
}
u8b->bufNativeStart = srcIx;
u8b->bufNativeLimit = ix;
u8b->bufStartIdx = destIx;
u8b->bufLimitIdx = UTF8_TEXT_CHUNK_SIZE+2;
u8b->bufNILimit = bufNILimit - u8b->bufStartIdx;
u8b->toUCharsMapStart = toUCharsMapStart;
ut->chunkContents = &buf[u8b->bufStartIdx];
ut->chunkLength = u8b->bufLimitIdx - u8b->bufStartIdx;
ut->chunkOffset = ut->chunkLength;
ut->chunkNativeStart = u8b->bufNativeStart;
ut->chunkNativeLimit = u8b->bufNativeLimit;
ut->nativeIndexingLimit = u8b->bufNILimit;
return TRUE;
}
}
//
// This is a slightly modified copy of u_strFromUTF8,
// Inserts a Replacement Char rather than failing on invalid UTF-8
// Removes unnecessary features.
//
static UChar*
utext_strFromUTF8(UChar *dest,
int32_t destCapacity,
int32_t *pDestLength,
const char* src,
int32_t srcLength, // required. NUL terminated not supported.
UErrorCode *pErrorCode
)
{
UChar *pDest = dest;
UChar *pDestLimit = dest+destCapacity;
UChar32 ch=0;
int32_t index = 0;
int32_t reqLength = 0;
uint8_t* pSrc = (uint8_t*) src;
while((index < srcLength)&&(pDest<pDestLimit)){
ch = pSrc[index++];
if(ch <=0x7f){
*pDest++=(UChar)ch;
}else{
ch=utf8_nextCharSafeBody(pSrc, &index, srcLength, ch, -1);
if(ch<0){
ch = 0xfffd;
}
if(U_IS_BMP(ch)){
*(pDest++)=(UChar)ch;
}else{
*(pDest++)=UTF16_LEAD(ch);
if(pDest<pDestLimit){
*(pDest++)=UTF16_TRAIL(ch);
}else{
reqLength++;
break;
}
}
}
}
/* donot fill the dest buffer just count the UChars needed */
while(index < srcLength){
ch = pSrc[index++];
if(ch <= 0x7f){
reqLength++;
}else{
ch=utf8_nextCharSafeBody(pSrc, &index, srcLength, ch, -1);
if(ch<0){
ch = 0xfffd;
}
reqLength+=U16_LENGTH(ch);
}
}
reqLength+=(int32_t)(pDest - dest);
if(pDestLength){
*pDestLength = reqLength;
}
/* Terminate the buffer */
u_terminateUChars(dest,destCapacity,reqLength,pErrorCode);
return dest;
}
static int32_t U_CALLCONV
utf8TextExtract(UText *ut,
int64_t start, int64_t limit,
UChar *dest, int32_t destCapacity,
UErrorCode *pErrorCode) {
if(U_FAILURE(*pErrorCode)) {
return 0;
}
if(destCapacity<0 || (dest==NULL && destCapacity>0)) {
*pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
return 0;
}
int32_t length = ut->b;
int32_t start32 = pinIndex(start, length);
int32_t limit32 = pinIndex(limit, length);
if(start32>limit32) {
*pErrorCode=U_INDEX_OUTOFBOUNDS_ERROR;
return 0;
}
// adjust the incoming indexes to land on code point boundaries if needed.
// adjust by no more than three, because that is the largest number of trail bytes
// in a well formed UTF8 character.
const uint8_t *buf = (const uint8_t *)ut->context;
int i;
if (start32 < ut->chunkNativeLimit) {
for (i=0; i<3; i++) {
if (U8_IS_SINGLE(buf[start32]) || U8_IS_LEAD(buf[start32]) || start32==0) {
break;
}
start32--;
}
}
if (limit32 < ut->chunkNativeLimit) {
for (i=0; i<3; i++) {
if (U8_IS_SINGLE(buf[limit32]) || U8_IS_LEAD(buf[limit32]) || limit32==0) {
break;
}
limit32--;
}
}
// Do the actual extract.
int32_t destLength=0;
utext_strFromUTF8(dest, destCapacity, &destLength,
(const char *)ut->context+start32, limit32-start32,
pErrorCode);
utf8TextAccess(ut, limit32, TRUE);
return destLength;
}
//
// utf8TextMapOffsetToNative
//
// Map a chunk (UTF-16) offset to a native index.
static int64_t U_CALLCONV
utf8TextMapOffsetToNative(const UText *ut) {
//
UTF8Buf *u8b = (UTF8Buf *)ut->p;
U_ASSERT(ut->chunkOffset>ut->nativeIndexingLimit && ut->chunkOffset<=ut->chunkLength);
int32_t nativeOffset = u8b->mapToNative[ut->chunkOffset + u8b->bufStartIdx] + u8b->toUCharsMapStart;
U_ASSERT(nativeOffset >= ut->chunkNativeStart && nativeOffset <= ut->chunkNativeLimit);
return nativeOffset;
}
//
// Map a native index to the corrsponding chunk offset
//
static int32_t U_CALLCONV
utf8TextMapIndexToUTF16(const UText *ut, int64_t index64) {
U_ASSERT(index64 <= 0x7fffffff);
int32_t index = (int32_t)index64;
UTF8Buf *u8b = (UTF8Buf *)ut->p;
U_ASSERT(index>=ut->chunkNativeStart+ut->nativeIndexingLimit);
U_ASSERT(index<=ut->chunkNativeLimit);
int32_t mapIndex = index - u8b->toUCharsMapStart;
int32_t offset = u8b->mapToUChars[mapIndex] - u8b->bufStartIdx;
U_ASSERT(offset>=0 && offset<=ut->chunkLength);
return offset;
}
static UText * U_CALLCONV
utf8TextClone(UText *dest, const UText *src, UBool deep, UErrorCode *status)
{
// First do a generic shallow clone. Does everything needed for the UText struct itself.
dest = shallowTextClone(dest, src, status);
// For deep clones, make a copy of the string.
// The copied storage is owned by the newly created clone.
//
// TODO: There is an isssue with using utext_nativeLength().
// That function is non-const in cases where the input was NUL terminated
// and the length has not yet been determined.
// This function (clone()) is const.
// There potentially a thread safety issue lurking here.
//
if (deep && U_SUCCESS(*status)) {
int32_t len = (int32_t)utext_nativeLength((UText *)src);
char *copyStr = (char *)uprv_malloc(len+1);
if (copyStr == NULL) {
*status = U_MEMORY_ALLOCATION_ERROR;
} else {
uprv_memcpy(copyStr, src->context, len+1);
dest->context = copyStr;
dest->providerProperties |= I32_FLAG(UTEXT_PROVIDER_OWNS_TEXT);
}
}
return dest;
}
static void U_CALLCONV
utf8TextClose(UText *ut) {
// Most of the work of close is done by the generic UText framework close.
// All that needs to be done here is to delete the UTF8 string if the UText
// owns it. This occurs if the UText was created by cloning.
if (ut->providerProperties & I32_FLAG(UTEXT_PROVIDER_OWNS_TEXT)) {
char *s = (char *)ut->context;
uprv_free(s);
ut->context = NULL;
}
}
U_CDECL_END
static const struct UTextFuncs utf8Funcs =
{
sizeof(UTextFuncs),
0, 0, 0, // Reserved alignment padding
utf8TextClone,
utf8TextLength,
utf8TextAccess,
utf8TextExtract,
NULL, /* replace*/
NULL, /* copy */
utf8TextMapOffsetToNative,
utf8TextMapIndexToUTF16,
utf8TextClose,
NULL, // spare 1
NULL, // spare 2
NULL // spare 3
};
static const char gEmptyString[] = {0};
U_CAPI UText * U_EXPORT2
utext_openUTF8(UText *ut, const char *s, int64_t length, UErrorCode *status) {
if(U_FAILURE(*status)) {
return NULL;
}
if(s==NULL && length==0) {
s = gEmptyString;
}
if(s==NULL || length<-1 || length>INT32_MAX) {
*status=U_ILLEGAL_ARGUMENT_ERROR;
return NULL;
}
ut = utext_setup(ut, sizeof(UTF8Buf) * 2, status);
if (U_FAILURE(*status)) {
return ut;
}
ut->pFuncs = &utf8Funcs;
ut->context = s;
ut->b = (int32_t)length;
ut->c = (int32_t)length;
if (ut->c < 0) {
ut->c = 0;
ut->providerProperties |= I32_FLAG(UTEXT_PROVIDER_LENGTH_IS_EXPENSIVE);
}
ut->p = ut->pExtra;
ut->q = (char *)ut->pExtra + sizeof(UTF8Buf);
return ut;
}
//------------------------------------------------------------------------------
//
// UText implementation wrapper for Replaceable (read/write)
//
// Use of UText data members:
// context pointer to Replaceable.
// p pointer to Replaceable if it is owned by the UText.
//
//------------------------------------------------------------------------------
// minimum chunk size for this implementation: 3
// to allow for possible trimming for code point boundaries
enum { REP_TEXT_CHUNK_SIZE=10 };
struct ReplExtra {
/*
* Chunk UChars.
* +1 to simplify filling with surrogate pair at the end.
*/
UChar s[REP_TEXT_CHUNK_SIZE+1];
};
U_CDECL_BEGIN
static UText * U_CALLCONV
repTextClone(UText *dest, const UText *src, UBool deep, UErrorCode *status) {
// First do a generic shallow clone. Does everything needed for the UText struct itself.
dest = shallowTextClone(dest, src, status);
// For deep clones, make a copy of the Replaceable.
// The copied Replaceable storage is owned by the newly created UText clone.
// A non-NULL pointer in UText.p is the signal to the close() function to delete
// it.
//
if (deep && U_SUCCESS(*status)) {
const Replaceable *replSrc = (const Replaceable *)src->context;
dest->context = replSrc->clone();
dest->providerProperties |= I32_FLAG(UTEXT_PROVIDER_OWNS_TEXT);
// with deep clone, the copy is writable, even when the source is not.
dest->providerProperties |= I32_FLAG(UTEXT_PROVIDER_WRITABLE);
}
return dest;
}
static void U_CALLCONV
repTextClose(UText *ut) {
// Most of the work of close is done by the generic UText framework close.
// All that needs to be done here is delete the Replaceable if the UText
// owns it. This occurs if the UText was created by cloning.
if (ut->providerProperties & I32_FLAG(UTEXT_PROVIDER_OWNS_TEXT)) {
Replaceable *rep = (Replaceable *)ut->context;
delete rep;
ut->context = NULL;
}
}
static int64_t U_CALLCONV
repTextLength(UText *ut) {
const Replaceable *replSrc = (const Replaceable *)ut->context;
int32_t len = replSrc->length();
return len;
}
static UBool U_CALLCONV
repTextAccess(UText *ut, int64_t index, UBool forward) {
const Replaceable *rep=(const Replaceable *)ut->context;
int32_t length=rep->length(); // Full length of the input text (bigger than a chunk)
// clip the requested index to the limits of the text.
int32_t index32 = pinIndex(index, length);
U_ASSERT(index<=INT32_MAX);
/*
* Compute start/limit boundaries around index, for a segment of text
* to be extracted.
* To allow for the possibility that our user gave an index to the trailing
* half of a surrogate pair, we must request one extra preceding UChar when
* going in the forward direction. This will ensure that the buffer has the
* entire code point at the specified index.
*/
if(forward) {
if (index32>=ut->chunkNativeStart && index32<ut->chunkNativeLimit) {
// Buffer already contains the requested position.
ut->chunkOffset = (int32_t)(index - ut->chunkNativeStart);
return TRUE;
}
if (index32>=length && ut->chunkNativeLimit==length) {
// Request for end of string, and buffer already extends up to it.
// Can't get the data, but don't change the buffer.
ut->chunkOffset = length - (int32_t)ut->chunkNativeStart;
return FALSE;
}
ut->chunkNativeLimit = index + REP_TEXT_CHUNK_SIZE - 1;
// Going forward, so we want to have the buffer with stuff at and beyond
// the requested index. The -1 gets us one code point before the
// requested index also, to handle the case of the index being on
// a trail surrogate of a surrogate pair.
if(ut->chunkNativeLimit > length) {
ut->chunkNativeLimit = length;
}
// unless buffer ran off end, start is index-1.
ut->chunkNativeStart = ut->chunkNativeLimit - REP_TEXT_CHUNK_SIZE;
if(ut->chunkNativeStart < 0) {
ut->chunkNativeStart = 0;
}
} else {
// Reverse iteration. Fill buffer with data preceding the requested index.
if (index32>ut->chunkNativeStart && index32<=ut->chunkNativeLimit) {
// Requested position already in buffer.
ut->chunkOffset = index32 - (int32_t)ut->chunkNativeStart;
return TRUE;
}
if (index32==0 && ut->chunkNativeStart==0) {
// Request for start, buffer already begins at start.
// No data, but keep the buffer as is.
ut->chunkOffset = 0;
return FALSE;
}
// Figure out the bounds of the chunk to extract for reverse iteration.
// Need to worry about chunk not splitting surrogate pairs, and while still
// containing the data we need.
// Fix by requesting a chunk that includes an extra UChar at the end.
// If this turns out to be a lead surrogate, we can lop it off and still have
// the data we wanted.
ut->chunkNativeStart = index32 + 1 - REP_TEXT_CHUNK_SIZE;
if (ut->chunkNativeStart < 0) {
ut->chunkNativeStart = 0;
}
ut->chunkNativeLimit = index32 + 1;
if (ut->chunkNativeLimit > length) {
ut->chunkNativeLimit = length;
}
}
// Extract the new chunk of text from the Replaceable source.
ReplExtra *ex = (ReplExtra *)ut->pExtra;
// UnicodeString with its buffer a writable alias to the chunk buffer
UnicodeString buffer(ex->s, 0 /*buffer length*/, REP_TEXT_CHUNK_SIZE /*buffer capacity*/);
rep->extractBetween((int32_t)ut->chunkNativeStart, (int32_t)ut->chunkNativeLimit, buffer);
ut->chunkContents = ex->s;
ut->chunkLength = (int32_t)(ut->chunkNativeLimit - ut->chunkNativeStart);
ut->chunkOffset = (int32_t)(index32 - ut->chunkNativeStart);
// Surrogate pairs from the input text must not span chunk boundaries.
// If end of chunk could be the start of a surrogate, trim it off.
if (ut->chunkNativeLimit < length &&
U16_IS_LEAD(ex->s[ut->chunkLength-1])) {
ut->chunkLength--;
ut->chunkNativeLimit--;
if (ut->chunkOffset > ut->chunkLength) {
ut->chunkOffset = ut->chunkLength;
}
}
// if the first UChar in the chunk could be the trailing half of a surrogate pair,
// trim it off.
if(ut->chunkNativeStart>0 && U16_IS_TRAIL(ex->s[0])) {
++(ut->chunkContents);
++(ut->chunkNativeStart);
--(ut->chunkLength);
--(ut->chunkOffset);
}
// adjust the index/chunkOffset to a code point boundary
U16_SET_CP_START(ut->chunkContents, 0, ut->chunkOffset);
// Use fast indexing for get/setNativeIndex()
ut->nativeIndexingLimit = ut->chunkLength;
return TRUE;
}
static int32_t U_CALLCONV
repTextExtract(UText *ut,
int64_t start, int64_t limit,
UChar *dest, int32_t destCapacity,
UErrorCode *status) {
const Replaceable *rep=(const Replaceable *)ut->context;
int32_t length=rep->length();
if(U_FAILURE(*status)) {
return 0;
}
if(destCapacity<0 || (dest==NULL && destCapacity>0)) {
*status=U_ILLEGAL_ARGUMENT_ERROR;
}
if(start>limit) {
*status=U_INDEX_OUTOFBOUNDS_ERROR;
return 0;
}
int32_t start32 = pinIndex(start, length);
int32_t limit32 = pinIndex(limit, length);
// adjust start, limit if they point to trail half of surrogates
if (start32<length && U16_IS_TRAIL(rep->charAt(start32)) &&
U_IS_SUPPLEMENTARY(rep->char32At(start32))){
start32--;
}
if (limit32<length && U16_IS_TRAIL(rep->charAt(limit32)) &&
U_IS_SUPPLEMENTARY(rep->char32At(limit32))){
limit32--;
}
length=limit32-start32;
if(length>destCapacity) {
limit32 = start32 + destCapacity;
}
UnicodeString buffer(dest, 0, destCapacity); // writable alias
rep->extractBetween(start32, limit32, buffer);
repTextAccess(ut, limit32, TRUE);
return u_terminateUChars(dest, destCapacity, length, status);
}
static int32_t U_CALLCONV
repTextReplace(UText *ut,
int64_t start, int64_t limit,
const UChar *src, int32_t length,
UErrorCode *status) {
Replaceable *rep=(Replaceable *)ut->context;
int32_t oldLength;
if(U_FAILURE(*status)) {
return 0;
}
if(src==NULL && length!=0) {
*status=U_ILLEGAL_ARGUMENT_ERROR;
return 0;
}
oldLength=rep->length(); // will subtract from new length
if(start>limit ) {
*status=U_INDEX_OUTOFBOUNDS_ERROR;
return 0;
}
int32_t start32 = pinIndex(start, oldLength);
int32_t limit32 = pinIndex(limit, oldLength);
// Snap start & limit to code point boundaries.
if (start32<oldLength && U16_IS_TRAIL(rep->charAt(start32)) &&
start32>0 && U16_IS_LEAD(rep->charAt(start32-1)))
{
start32--;
}
if (limit32<oldLength && U16_IS_LEAD(rep->charAt(limit32-1)) &&
U16_IS_TRAIL(rep->charAt(limit32)))
{
limit32++;
}
// Do the actual replace operation using methods of the Replaceable class
UnicodeString replStr((UBool)(length<0), src, length); // read-only alias
rep->handleReplaceBetween(start32, limit32, replStr);
int32_t newLength = rep->length();
int32_t lengthDelta = newLength - oldLength;
// Is the UText chunk buffer OK?
if (ut->chunkNativeLimit > start32) {
// this replace operation may have impacted the current chunk.
// invalidate it, which will force a reload on the next access.
invalidateChunk(ut);
}
// set the iteration position to the end of the newly inserted replacement text.
int32_t newIndexPos = limit32 + lengthDelta;
repTextAccess(ut, newIndexPos, TRUE);
return lengthDelta;
}
static void U_CALLCONV
repTextCopy(UText *ut,
int64_t start, int64_t limit,
int64_t destIndex,
UBool move,
UErrorCode *status)
{
Replaceable *rep=(Replaceable *)ut->context;
int32_t length=rep->length();
if(U_FAILURE(*status)) {
return;
}
if (start>limit || (start<destIndex && destIndex<limit))
{
*status=U_INDEX_OUTOFBOUNDS_ERROR;
return;
}
int32_t start32 = pinIndex(start, length);
int32_t limit32 = pinIndex(limit, length);
int32_t destIndex32 = pinIndex(destIndex, length);
// TODO: snap input parameters to code point boundaries.
if(move) {
// move: copy to destIndex, then replace original with nothing
int32_t segLength=limit32-start32;
rep->copy(start32, limit32, destIndex32);
if(destIndex32<start32) {
start32+=segLength;
limit32+=segLength;
}
rep->handleReplaceBetween(start32, limit32, UnicodeString());
} else {
// copy
rep->copy(start32, limit32, destIndex32);
}
// If the change to the text touched the region in the chunk buffer,
// invalidate the buffer.
int32_t firstAffectedIndex = destIndex32;
if (move && start32<firstAffectedIndex) {
firstAffectedIndex = start32;
}
if (firstAffectedIndex < ut->chunkNativeLimit) {
// changes may have affected range covered by the chunk
invalidateChunk(ut);
}
// Put iteration position at the newly inserted (moved) block,
int32_t nativeIterIndex = destIndex32 + limit32 - start32;
if (move && destIndex32>start32) {
// moved a block of text towards the end of the string.
nativeIterIndex = destIndex32;
}
// Set position, reload chunk if needed.
repTextAccess(ut, nativeIterIndex, TRUE);
}
static const struct UTextFuncs repFuncs =
{
sizeof(UTextFuncs),
0, 0, 0, // Reserved alignment padding
repTextClone,
repTextLength,
repTextAccess,
repTextExtract,
repTextReplace,
repTextCopy,
NULL, // MapOffsetToNative,
NULL, // MapIndexToUTF16,
repTextClose,
NULL, // spare 1
NULL, // spare 2
NULL // spare 3
};
U_CAPI UText * U_EXPORT2
utext_openReplaceable(UText *ut, Replaceable *rep, UErrorCode *status)
{
if(U_FAILURE(*status)) {
return NULL;
}
if(rep==NULL) {
*status=U_ILLEGAL_ARGUMENT_ERROR;
return NULL;
}
ut = utext_setup(ut, sizeof(ReplExtra), status);
ut->providerProperties = I32_FLAG(UTEXT_PROVIDER_WRITABLE);
if(rep->hasMetaData()) {
ut->providerProperties |=I32_FLAG(UTEXT_PROVIDER_HAS_META_DATA);
}
ut->pFuncs = &repFuncs;
ut->context = rep;
return ut;
}
U_CDECL_END
//------------------------------------------------------------------------------
//
// UText implementation for UnicodeString (read/write) and
// for const UnicodeString (read only)
// (same implementation, only the flags are different)
//
// Use of UText data members:
// context pointer to UnicodeString
// p pointer to UnicodeString IF this UText owns the string
// and it must be deleted on close(). NULL otherwise.
//
//------------------------------------------------------------------------------
U_CDECL_BEGIN
static UText * U_CALLCONV
unistrTextClone(UText *dest, const UText *src, UBool deep, UErrorCode *status) {
// First do a generic shallow clone. Does everything needed for the UText struct itself.
dest = shallowTextClone(dest, src, status);
// For deep clones, make a copy of the UnicodeSring.
// The copied UnicodeString storage is owned by the newly created UText clone.
// A non-NULL pointer in UText.p is the signal to the close() function to delete
// the UText.
//
if (deep && U_SUCCESS(*status)) {
const UnicodeString *srcString = (const UnicodeString *)src->context;
dest->context = new UnicodeString(*srcString);
dest->providerProperties |= I32_FLAG(UTEXT_PROVIDER_OWNS_TEXT);
// with deep clone, the copy is writable, even when the source is not.
dest->providerProperties |= I32_FLAG(UTEXT_PROVIDER_WRITABLE);
}
return dest;
}
static void U_CALLCONV
unistrTextClose(UText *ut) {
// Most of the work of close is done by the generic UText framework close.
// All that needs to be done here is delete the UnicodeString if the UText
// owns it. This occurs if the UText was created by cloning.
if (ut->providerProperties & I32_FLAG(UTEXT_PROVIDER_OWNS_TEXT)) {
UnicodeString *str = (UnicodeString *)ut->context;
delete str;
ut->context = NULL;
}
}
static int64_t U_CALLCONV
unistrTextLength(UText *t) {
return ((const UnicodeString *)t->context)->length();
}
static UBool U_CALLCONV
unistrTextAccess(UText *ut, int64_t index, UBool forward) {
int32_t length = ut->chunkLength;
ut->chunkOffset = pinIndex(index, length);
// Check whether request is at the start or end
UBool retVal = (forward && index<length) || (!forward && index>0);
return retVal;
}
static int32_t U_CALLCONV
unistrTextExtract(UText *t,
int64_t start, int64_t limit,
UChar *dest, int32_t destCapacity,
UErrorCode *pErrorCode) {
const UnicodeString *us=(const UnicodeString *)t->context;
int32_t length=us->length();
if(U_FAILURE(*pErrorCode)) {
return 0;
}
if(destCapacity<0 || (dest==NULL && destCapacity>0)) {
*pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
}
if(start<0 || start>limit) {
*pErrorCode=U_INDEX_OUTOFBOUNDS_ERROR;
return 0;
}
int32_t start32 = start<length ? us->getChar32Start((int32_t)start) : length;
int32_t limit32 = limit<length ? us->getChar32Start((int32_t)limit) : length;
length=limit32-start32;
if (destCapacity>0 && dest!=NULL) {
int32_t trimmedLength = length;
if(trimmedLength>destCapacity) {
trimmedLength=destCapacity;
}
us->extract(start32, trimmedLength, dest);
t->chunkOffset = start32+trimmedLength;
} else {
t->chunkOffset = start32;
}
u_terminateUChars(dest, destCapacity, length, pErrorCode);
return length;
}
static int32_t U_CALLCONV
unistrTextReplace(UText *ut,
int64_t start, int64_t limit,
const UChar *src, int32_t length,
UErrorCode *pErrorCode) {
UnicodeString *us=(UnicodeString *)ut->context;
int32_t oldLength;
if(U_FAILURE(*pErrorCode)) {
return 0;
}
if(src==NULL && length!=0) {
*pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
}
if(start>limit) {
*pErrorCode=U_INDEX_OUTOFBOUNDS_ERROR;
return 0;
}
oldLength=us->length();
int32_t start32 = pinIndex(start, oldLength);
int32_t limit32 = pinIndex(limit, oldLength);
if (start32 < oldLength) {
start32 = us->getChar32Start(start32);
}
if (limit32 < oldLength) {
limit32 = us->getChar32Start(limit32);
}
// replace
us->replace(start32, limit32-start32, src, length);
int32_t newLength = us->length();
// Update the chunk description.
ut->chunkContents = us->getBuffer();
ut->chunkLength = newLength;
ut->chunkNativeLimit = newLength;
ut->nativeIndexingLimit = newLength;
// Set iteration position to the point just following the newly inserted text.
int32_t lengthDelta = newLength - oldLength;
ut->chunkOffset = limit32 + lengthDelta;
return lengthDelta;
}
static void U_CALLCONV
unistrTextCopy(UText *ut,
int64_t start, int64_t limit,
int64_t destIndex,
UBool move,
UErrorCode *pErrorCode) {
UnicodeString *us=(UnicodeString *)ut->context;
int32_t length=us->length();
if(U_FAILURE(*pErrorCode)) {
return;
}
int32_t start32 = pinIndex(start, length);
int32_t limit32 = pinIndex(limit, length);
int32_t destIndex32 = pinIndex(destIndex, length);
if( start32>limit32 || (start32<destIndex32 && destIndex32<limit32)) {
*pErrorCode=U_INDEX_OUTOFBOUNDS_ERROR;
return;
}
if(move) {
// move: copy to destIndex, then replace original with nothing
int32_t segLength=limit32-start32;
us->copy(start32, limit32, destIndex32);
if(destIndex32<start32) {
start32+=segLength;
}
us->replace(start32, segLength, NULL, 0);
} else {
// copy
us->copy(start32, limit32, destIndex32);
}
// update chunk description, set iteration position.
ut->chunkContents = us->getBuffer();
if (move==FALSE) {
// copy operation, string length grows
ut->chunkLength += limit32-start32;
ut->chunkNativeLimit = ut->chunkLength;
ut->nativeIndexingLimit = ut->chunkLength;
}
// Iteration position to end of the newly inserted text.
ut->chunkOffset = destIndex32+limit32-start32;
if (move && destIndex32>start32) {
ut->chunkOffset = destIndex32;
}
}
static const struct UTextFuncs unistrFuncs =
{
sizeof(UTextFuncs),
0, 0, 0, // Reserved alignment padding
unistrTextClone,
unistrTextLength,
unistrTextAccess,
unistrTextExtract,
unistrTextReplace,
unistrTextCopy,
NULL, // MapOffsetToNative,
NULL, // MapIndexToUTF16,
unistrTextClose,
NULL, // spare 1
NULL, // spare 2
NULL // spare 3
};
U_CDECL_END
U_CAPI UText * U_EXPORT2
utext_openUnicodeString(UText *ut, UnicodeString *s, UErrorCode *status) {
// TODO: use openConstUnicodeString, then add in the differences.
//
ut = utext_setup(ut, 0, status);
if (U_SUCCESS(*status)) {
ut->pFuncs = &unistrFuncs;
ut->context = s;
ut->providerProperties = I32_FLAG(UTEXT_PROVIDER_STABLE_CHUNKS)|
I32_FLAG(UTEXT_PROVIDER_WRITABLE);
ut->chunkContents = s->getBuffer();
ut->chunkLength = s->length();
ut->chunkNativeStart = 0;
ut->chunkNativeLimit = ut->chunkLength;
ut->nativeIndexingLimit = ut->chunkLength;
}
return ut;
}
U_CAPI UText * U_EXPORT2
utext_openConstUnicodeString(UText *ut, const UnicodeString *s, UErrorCode *status) {
ut = utext_setup(ut, 0, status);
// note: use the standard (writable) function table for UnicodeString.
// The flag settings disable writing, so having the functions in
// the table is harmless.
if (U_SUCCESS(*status)) {
ut->pFuncs = &unistrFuncs;
ut->context = s;
ut->providerProperties = I32_FLAG(UTEXT_PROVIDER_STABLE_CHUNKS);
ut->chunkContents = s->getBuffer();
ut->chunkLength = s->length();
ut->chunkNativeStart = 0;
ut->chunkNativeLimit = ut->chunkLength;
ut->nativeIndexingLimit = ut->chunkLength;
}
return ut;
}
//------------------------------------------------------------------------------
//
// UText implementation for const UChar * strings
//
// Use of UText data members:
// context pointer to UnicodeString
// a length. -1 if not yet known.
//
// TODO: support 64 bit lengths.
//
//------------------------------------------------------------------------------
U_CDECL_BEGIN
static UText * U_CALLCONV
ucstrTextClone(UText *dest, const UText * src, UBool deep, UErrorCode * status) {
// First do a generic shallow clone.
dest = shallowTextClone(dest, src, status);
// For deep clones, make a copy of the string.
// The copied storage is owned by the newly created clone.
// A non-NULL pointer in UText.p is the signal to the close() function to delete
// it.
//
if (deep && U_SUCCESS(*status)) {
U_ASSERT(utext_nativeLength(dest) < INT32_MAX);
int32_t len = (int32_t)utext_nativeLength(dest);
// The cloned string IS going to be NUL terminated, whether or not the original was.
const UChar *srcStr = (const UChar *)src->context;
UChar *copyStr = (UChar *)uprv_malloc((len+1) * sizeof(UChar));
if (copyStr == NULL) {
*status = U_MEMORY_ALLOCATION_ERROR;
} else {
int64_t i;
for (i=0; i<len; i++) {
copyStr[i] = srcStr[i];
}
copyStr[len] = 0;
dest->context = copyStr;
dest->providerProperties |= I32_FLAG(UTEXT_PROVIDER_OWNS_TEXT);
}
}
return dest;
}
static void U_CALLCONV
ucstrTextClose(UText *ut) {
// Most of the work of close is done by the generic UText framework close.
// All that needs to be done here is delete the string if the UText
// owns it. This occurs if the UText was created by cloning.
if (ut->providerProperties & I32_FLAG(UTEXT_PROVIDER_OWNS_TEXT)) {
UChar *s = (UChar *)ut->context;
uprv_free(s);
ut->context = NULL;
}
}
static int64_t U_CALLCONV
ucstrTextLength(UText *ut) {
if (ut->a < 0) {
// null terminated, we don't yet know the length. Scan for it.
// Access is not convenient for doing this
// because the current interation postion can't be changed.
const UChar *str = (const UChar *)ut->context;
for (;;) {
if (str[ut->chunkNativeLimit] == 0) {
break;
}
ut->chunkNativeLimit++;
}
ut->a = ut->chunkNativeLimit;
ut->chunkLength = (int32_t)ut->chunkNativeLimit;
ut->nativeIndexingLimit = ut->chunkLength;
ut->providerProperties &= ~I32_FLAG(UTEXT_PROVIDER_LENGTH_IS_EXPENSIVE);
}
return ut->a;
}
static UBool U_CALLCONV
ucstrTextAccess(UText *ut, int64_t index, UBool forward) {
const UChar *str = (const UChar *)ut->context;
// pin the requested index to the bounds of the string,
// and set current iteration position.
if (index<0) {
index = 0;
} else if (index < ut->chunkNativeLimit) {
// The request data is within the chunk as it is known so far.
// Put index on a code point boundary.
U16_SET_CP_START(str, 0, index);
} else if (ut->a >= 0) {
// We know the length of this string, and the user is requesting something
// at or beyond the length. Pin the requested index to the length.
index = ut->a;
} else {
// Null terminated string, length not yet known, and the requested index
// is beyond where we have scanned so far.
// Scan to 32 UChars beyond the requested index. The strategy here is
// to avoid fully scanning a long string when the caller only wants to
// see a few characters at its beginning.
int32_t scanLimit = (int32_t)index + 32;
if ((index + 32)>INT32_MAX || (index + 32)<0 ) { // note: int64 expression
scanLimit = INT32_MAX;
}
int32_t chunkLimit = (int32_t)ut->chunkNativeLimit;
for (; chunkLimit<scanLimit; chunkLimit++) {
if (str[chunkLimit] == 0) {
// We found the end of the string. Remember it, pin the requested index to it,
// and bail out of here.
ut->a = chunkLimit;
ut->chunkLength = chunkLimit;
ut->nativeIndexingLimit = chunkLimit;
if (index >= chunkLimit) {
index = chunkLimit;
} else {
U16_SET_CP_START(str, 0, index);
}
ut->chunkNativeLimit = chunkLimit;
ut->providerProperties &= ~I32_FLAG(UTEXT_PROVIDER_LENGTH_IS_EXPENSIVE);
goto breakout;
}
}
// We scanned through the next batch of UChars without finding the end.
U16_SET_CP_START(str, 0, index);
if (chunkLimit == INT32_MAX) {
// Scanned to the limit of a 32 bit length.
// Forceably trim the overlength string back so length fits in int32
// TODO: add support for 64 bit strings.
ut->a = chunkLimit;
ut->chunkLength = chunkLimit;
ut->nativeIndexingLimit = chunkLimit;
if (index > chunkLimit) {
index = chunkLimit;
}
ut->chunkNativeLimit = chunkLimit;
ut->providerProperties &= ~I32_FLAG(UTEXT_PROVIDER_LENGTH_IS_EXPENSIVE);
} else {
// The endpoint of a chunk must not be left in the middle of a surrogate pair.
// If the current end is on a lead surrogate, back the end up by one.
// It doesn't matter if the end char happens to be an unpaired surrogate,
// and it's simpler not to worry about it.
if (U16_IS_LEAD(str[chunkLimit-1])) {
--chunkLimit;
}
// Null-terminated chunk with end still unknown.
// Update the chunk length to reflect what has been scanned thus far.
// That the full length is still unknown is (still) flagged by
// ut->a being < 0.
ut->chunkNativeLimit = chunkLimit;
ut->nativeIndexingLimit = chunkLimit;
ut->chunkLength = chunkLimit;
}
}
breakout:
U_ASSERT(index<=INT32_MAX);
ut->chunkOffset = (int32_t)index;
// Check whether request is at the start or end
UBool retVal = (forward && index<ut->chunkNativeLimit) || (!forward && index>0);
return retVal;
}
static int32_t U_CALLCONV
ucstrTextExtract(UText *ut,
int64_t start, int64_t limit,
UChar *dest, int32_t destCapacity,
UErrorCode *pErrorCode)
{
if(U_FAILURE(*pErrorCode)) {
return 0;
}
if(destCapacity<0 || (dest==NULL && destCapacity>0) || start>limit) {
*pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
return 0;
}
const UChar *s=(const UChar *)ut->context;
int32_t si, di;
int32_t start32;
int32_t limit32;
// Access the start. Does two things we need:
// Pins 'start' to the length of the string, if it came in out-of-bounds.
// Snaps 'start' to the beginning of a code point.
ucstrTextAccess(ut, start, TRUE);
U_ASSERT(start <= INT32_MAX);
start32 = (int32_t)start;
int32_t strLength=(int32_t)ut->a;
if (strLength >= 0) {
limit32 = pinIndex(limit, strLength);
} else {
limit32 = pinIndex(limit, INT32_MAX);
}
di = 0;
for (si=start32; si<limit32; si++) {
if (strLength<0 && s[si]==0) {
// Just hit the end of a null-terminated string.
ut->a = si; // set string length for this UText
ut->chunkNativeLimit = si;
ut->chunkLength = si;
ut->nativeIndexingLimit = si;
strLength = si;
break;
}
if (di<destCapacity) {
// only store if there is space.
dest[di] = s[si];
} else {
if (strLength>=0) {
// We have filled the destination buffer, and the string length is known.
// Cut the loop short. There is no need to scan string termination.
di = limit32 - start32;
si = limit32;
break;
}
}
di++;
}
// If the limit index points to a lead surrogate of a pair,
// add the corresponding trail surrogate to the destination.
if (si>0 && U16_IS_LEAD(s[si-1]) &&
((si<strLength || strLength<0) && U16_IS_TRAIL(s[si])))
{
if (di<destCapacity) {
// store only if there is space in the output buffer.
dest[di++] = s[si++];
}
}
// Put iteration position at the point just following the extracted text
ut->chunkOffset = uprv_min(strLength, start32 + destCapacity);
// Add a terminating NUL if space in the buffer permits,
// and set the error status as required.
u_terminateUChars(dest, destCapacity, di, pErrorCode);
return di;
}
static const struct UTextFuncs ucstrFuncs =
{
sizeof(UTextFuncs),
0, 0, 0, // Reserved alignment padding
ucstrTextClone,
ucstrTextLength,
ucstrTextAccess,
ucstrTextExtract,
NULL, // Replace
NULL, // Copy
NULL, // MapOffsetToNative,
NULL, // MapIndexToUTF16,
ucstrTextClose,
NULL, // spare 1
NULL, // spare 2
NULL, // spare 3
};
U_CDECL_END
static const UChar gEmptyUString[] = {0};
U_CAPI UText * U_EXPORT2
utext_openUChars(UText *ut, const UChar *s, int64_t length, UErrorCode *status) {
if (U_FAILURE(*status)) {
return NULL;
}
if(s==NULL && length==0) {
s = gEmptyUString;
}
if (s==NULL || length < -1 || length>INT32_MAX) {
*status = U_ILLEGAL_ARGUMENT_ERROR;
return NULL;
}
ut = utext_setup(ut, 0, status);
if (U_SUCCESS(*status)) {
ut->pFuncs = &ucstrFuncs;
ut->context = s;
ut->providerProperties = I32_FLAG(UTEXT_PROVIDER_STABLE_CHUNKS);
if (length==-1) {
ut->providerProperties |= I32_FLAG(UTEXT_PROVIDER_LENGTH_IS_EXPENSIVE);
}
ut->a = length;
ut->chunkContents = s;
ut->chunkNativeStart = 0;
ut->chunkNativeLimit = length>=0? length : 0;
ut->chunkLength = (int32_t)ut->chunkNativeLimit;
ut->chunkOffset = 0;
ut->nativeIndexingLimit = ut->chunkLength;
}
return ut;
}
//------------------------------------------------------------------------------
//
// UText implementation for text from ICU CharacterIterators
//
// Use of UText data members:
// context pointer to the CharacterIterator
// a length of the full text.
// p pointer to buffer 1
// b start index of local buffer 1 contents
// q pointer to buffer 2
// c start index of local buffer 2 contents
// r pointer to the character iterator if the UText owns it.
// Null otherwise.
//
//------------------------------------------------------------------------------
#define CIBufSize 16
U_CDECL_BEGIN
static void U_CALLCONV
charIterTextClose(UText *ut) {
// Most of the work of close is done by the generic UText framework close.
// All that needs to be done here is delete the CharacterIterator if the UText
// owns it. This occurs if the UText was created by cloning.
CharacterIterator *ci = (CharacterIterator *)ut->r;
delete ci;
ut->r = NULL;
}
static int64_t U_CALLCONV
charIterTextLength(UText *ut) {
return (int32_t)ut->a;
}
static UBool U_CALLCONV
charIterTextAccess(UText *ut, int64_t index, UBool forward) {
CharacterIterator *ci = (CharacterIterator *)ut->context;
int32_t clippedIndex = (int32_t)index;
if (clippedIndex<0) {
clippedIndex=0;
} else if (clippedIndex>=ut->a) {
clippedIndex=(int32_t)ut->a;
}
int32_t neededIndex = clippedIndex;
if (!forward && neededIndex>0) {
// reverse iteration, want the position just before what was asked for.
neededIndex--;
} else if (forward && neededIndex==ut->a && neededIndex>0) {
// Forward iteration, don't ask for something past the end of the text.
neededIndex--;
}
// Find the native index of the start of the buffer containing what we want.
neededIndex -= neededIndex % CIBufSize;
UChar *buf = NULL;
UBool needChunkSetup = TRUE;
int i;
if (ut->chunkNativeStart == neededIndex) {
// The buffer we want is already the current chunk.
needChunkSetup = FALSE;
} else if (ut->b == neededIndex) {
// The first buffer (buffer p) has what we need.
buf = (UChar *)ut->p;
} else if (ut->c == neededIndex) {
// The second buffer (buffer q) has what we need.
buf = (UChar *)ut->q;
} else {
// Neither buffer already has what we need.
// Load new data from the character iterator.
// Use the buf that is not the current buffer.
buf = (UChar *)ut->p;
if (ut->p == ut->chunkContents) {
buf = (UChar *)ut->q;
}
ci->setIndex(neededIndex);
for (i=0; i<CIBufSize; i++) {
buf[i] = ci->nextPostInc();
if (i+neededIndex > ut->a) {
break;
}
}
}
// We have a buffer with the data we need.
// Set it up as the current chunk, if it wasn't already.
if (needChunkSetup) {
ut->chunkContents = buf;
ut->chunkLength = CIBufSize;
ut->chunkNativeStart = neededIndex;
ut->chunkNativeLimit = neededIndex + CIBufSize;
if (ut->chunkNativeLimit > ut->a) {
ut->chunkNativeLimit = ut->a;
ut->chunkLength = (int32_t)(ut->chunkNativeLimit)-(int32_t)(ut->chunkNativeStart);
}
ut->nativeIndexingLimit = ut->chunkLength;
U_ASSERT(ut->chunkOffset>=0 && ut->chunkOffset<=CIBufSize);
}
ut->chunkOffset = clippedIndex - (int32_t)ut->chunkNativeStart;
UBool success = (forward? ut->chunkOffset<ut->chunkLength : ut->chunkOffset>0);
return success;
}
static UText * U_CALLCONV
charIterTextClone(UText *dest, const UText *src, UBool deep, UErrorCode * status) {
if (U_FAILURE(*status)) {
return NULL;
}
if (deep) {
// There is no CharacterIterator API for cloning the underlying text storage.
*status = U_UNSUPPORTED_ERROR;
return NULL;
} else {
CharacterIterator *srcCI =(CharacterIterator *)src->context;
srcCI = srcCI->clone();
dest = utext_openCharacterIterator(dest, srcCI, status);
// cast off const on getNativeIndex.
// For CharacterIterator based UTexts, this is safe, the operation is const.
int64_t ix = utext_getNativeIndex((UText *)src);
utext_setNativeIndex(dest, ix);
dest->r = srcCI; // flags that this UText owns the CharacterIterator
}
return dest;
}
static int32_t U_CALLCONV
charIterTextExtract(UText *ut,
int64_t start, int64_t limit,
UChar *dest, int32_t destCapacity,
UErrorCode *status)
{
if(U_FAILURE(*status)) {
return 0;
}
if(destCapacity<0 || (dest==NULL && destCapacity>0) || start>limit) {
*status=U_ILLEGAL_ARGUMENT_ERROR;
return 0;
}
int32_t length = (int32_t)ut->a;
int32_t start32 = pinIndex(start, length);
int32_t limit32 = pinIndex(limit, length);
int32_t desti = 0;
int32_t srci;
int32_t copyLimit;
CharacterIterator *ci = (CharacterIterator *)ut->context;
ci->setIndex32(start32); // Moves ix to lead of surrogate pair, if needed.
srci = ci->getIndex();
copyLimit = srci;
while (srci<limit32) {
UChar32 c = ci->next32PostInc();
int32_t len = U16_LENGTH(c);
if (desti+len <= destCapacity) {
U16_APPEND_UNSAFE(dest, desti, c);
copyLimit = srci+len;
} else {
desti += len;
*status = U_BUFFER_OVERFLOW_ERROR;
}
srci += len;
}
charIterTextAccess(ut, copyLimit, TRUE);
u_terminateUChars(dest, destCapacity, desti, status);
return desti;
}
static const struct UTextFuncs charIterFuncs =
{
sizeof(UTextFuncs),
0, 0, 0, // Reserved alignment padding
charIterTextClone,
charIterTextLength,
charIterTextAccess,
charIterTextExtract,
NULL, // Replace
NULL, // Copy
NULL, // MapOffsetToNative,
NULL, // MapIndexToUTF16,
charIterTextClose,
NULL, // spare 1
NULL, // spare 2
NULL // spare 3
};
U_CDECL_END
U_CAPI UText * U_EXPORT2
utext_openCharacterIterator(UText *ut, CharacterIterator *ci, UErrorCode *status) {
if (U_FAILURE(*status)) {
return NULL;
}
if (ci->startIndex() > 0) {
// No support for CharacterIterators that do not start indexing from zero.
*status = U_UNSUPPORTED_ERROR;
return NULL;
}
// Extra space in UText for 2 buffers of CIBufSize UChars each.
int32_t extraSpace = 2 * CIBufSize * sizeof(UChar);
ut = utext_setup(ut, extraSpace, status);
if (U_SUCCESS(*status)) {
ut->pFuncs = &charIterFuncs;
ut->context = ci;
ut->providerProperties = 0;
ut->a = ci->endIndex(); // Length of text
ut->p = ut->pExtra; // First buffer
ut->b = -1; // Native index of first buffer contents
ut->q = (UChar*)ut->pExtra+CIBufSize; // Second buffer
ut->c = -1; // Native index of second buffer contents
// Initialize current chunk contents to be empty.
// First access will fault something in.
// Note: The initial nativeStart and chunkOffset must sum to zero
// so that getNativeIndex() will correctly compute to zero
// if no call to Access() has ever been made. They can't be both
// zero without Access() thinking that the chunk is valid.
ut->chunkContents = (UChar *)ut->p;
ut->chunkNativeStart = -1;
ut->chunkOffset = 1;
ut->chunkNativeLimit = 0;
ut->chunkLength = 0;
ut->nativeIndexingLimit = ut->chunkOffset; // enables native indexing
}
return ut;
}