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// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
*******************************************************************************
* Copyright (C) 2010-2014, International Business Machines
* Corporation and others. All Rights Reserved.
*******************************************************************************
* utf16collationiterator.cpp
*
* created on: 2010oct27
* created by: Markus W. Scherer
*/
#include "unicode/utypes.h"
#if !UCONFIG_NO_COLLATION
#include "charstr.h"
#include "cmemory.h"
#include "collation.h"
#include "collationdata.h"
#include "collationfcd.h"
#include "collationiterator.h"
#include "normalizer2impl.h"
#include "uassert.h"
#include "utf16collationiterator.h"
U_NAMESPACE_BEGIN
UTF16CollationIterator::UTF16CollationIterator(const UTF16CollationIterator &other,
const UChar *newText)
: CollationIterator(other),
start(newText),
pos(newText + (other.pos - other.start)),
limit(other.limit == NULL ? NULL : newText + (other.limit - other.start)) {
}
UTF16CollationIterator::~UTF16CollationIterator() {}
UBool
UTF16CollationIterator::operator==(const CollationIterator &other) const {
if(!CollationIterator::operator==(other)) { return FALSE; }
const UTF16CollationIterator &o = static_cast<const UTF16CollationIterator &>(other);
// Compare the iterator state but not the text: Assume that the caller does that.
return (pos - start) == (o.pos - o.start);
}
void
UTF16CollationIterator::resetToOffset(int32_t newOffset) {
reset();
pos = start + newOffset;
}
int32_t
UTF16CollationIterator::getOffset() const {
return (int32_t)(pos - start);
}
uint32_t
UTF16CollationIterator::handleNextCE32(UChar32 &c, UErrorCode & /*errorCode*/) {
if(pos == limit) {
c = U_SENTINEL;
return Collation::FALLBACK_CE32;
}
c = *pos++;
return UTRIE2_GET32_FROM_U16_SINGLE_LEAD(trie, c);
}
UChar
UTF16CollationIterator::handleGetTrailSurrogate() {
if(pos == limit) { return 0; }
UChar trail;
if(U16_IS_TRAIL(trail = *pos)) { ++pos; }
return trail;
}
UBool
UTF16CollationIterator::foundNULTerminator() {
if(limit == NULL) {
limit = --pos;
return TRUE;
} else {
return FALSE;
}
}
UChar32
UTF16CollationIterator::nextCodePoint(UErrorCode & /*errorCode*/) {
if(pos == limit) {
return U_SENTINEL;
}
UChar32 c = *pos;
if(c == 0 && limit == NULL) {
limit = pos;
return U_SENTINEL;
}
++pos;
UChar trail;
if(U16_IS_LEAD(c) && pos != limit && U16_IS_TRAIL(trail = *pos)) {
++pos;
return U16_GET_SUPPLEMENTARY(c, trail);
} else {
return c;
}
}
UChar32
UTF16CollationIterator::previousCodePoint(UErrorCode & /*errorCode*/) {
if(pos == start) {
return U_SENTINEL;
}
UChar32 c = *--pos;
UChar lead;
if(U16_IS_TRAIL(c) && pos != start && U16_IS_LEAD(lead = *(pos - 1))) {
--pos;
return U16_GET_SUPPLEMENTARY(lead, c);
} else {
return c;
}
}
void
UTF16CollationIterator::forwardNumCodePoints(int32_t num, UErrorCode & /*errorCode*/) {
while(num > 0 && pos != limit) {
UChar32 c = *pos;
if(c == 0 && limit == NULL) {
limit = pos;
break;
}
++pos;
--num;
if(U16_IS_LEAD(c) && pos != limit && U16_IS_TRAIL(*pos)) {
++pos;
}
}
}
void
UTF16CollationIterator::backwardNumCodePoints(int32_t num, UErrorCode & /*errorCode*/) {
while(num > 0 && pos != start) {
UChar32 c = *--pos;
--num;
if(U16_IS_TRAIL(c) && pos != start && U16_IS_LEAD(*(pos-1))) {
--pos;
}
}
}
// FCDUTF16CollationIterator ----------------------------------------------- ***
FCDUTF16CollationIterator::FCDUTF16CollationIterator(const FCDUTF16CollationIterator &other,
const UChar *newText)
: UTF16CollationIterator(other),
rawStart(newText),
segmentStart(newText + (other.segmentStart - other.rawStart)),
segmentLimit(other.segmentLimit == NULL ? NULL : newText + (other.segmentLimit - other.rawStart)),
rawLimit(other.rawLimit == NULL ? NULL : newText + (other.rawLimit - other.rawStart)),
nfcImpl(other.nfcImpl),
normalized(other.normalized),
checkDir(other.checkDir) {
if(checkDir != 0 || other.start == other.segmentStart) {
start = newText + (other.start - other.rawStart);
pos = newText + (other.pos - other.rawStart);
limit = other.limit == NULL ? NULL : newText + (other.limit - other.rawStart);
} else {
start = normalized.getBuffer();
pos = start + (other.pos - other.start);
limit = start + normalized.length();
}
}
FCDUTF16CollationIterator::~FCDUTF16CollationIterator() {}
UBool
FCDUTF16CollationIterator::operator==(const CollationIterator &other) const {
// Skip the UTF16CollationIterator and call its parent.
if(!CollationIterator::operator==(other)) { return FALSE; }
const FCDUTF16CollationIterator &o = static_cast<const FCDUTF16CollationIterator &>(other);
// Compare the iterator state but not the text: Assume that the caller does that.
if(checkDir != o.checkDir) { return FALSE; }
if(checkDir == 0 && (start == segmentStart) != (o.start == o.segmentStart)) { return FALSE; }
if(checkDir != 0 || start == segmentStart) {
return (pos - rawStart) == (o.pos - o.rawStart);
} else {
return (segmentStart - rawStart) == (o.segmentStart - o.rawStart) &&
(pos - start) == (o.pos - o.start);
}
}
void
FCDUTF16CollationIterator::resetToOffset(int32_t newOffset) {
reset();
start = segmentStart = pos = rawStart + newOffset;
limit = rawLimit;
checkDir = 1;
}
int32_t
FCDUTF16CollationIterator::getOffset() const {
if(checkDir != 0 || start == segmentStart) {
return (int32_t)(pos - rawStart);
} else if(pos == start) {
return (int32_t)(segmentStart - rawStart);
} else {
return (int32_t)(segmentLimit - rawStart);
}
}
uint32_t
FCDUTF16CollationIterator::handleNextCE32(UChar32 &c, UErrorCode &errorCode) {
for(;;) {
if(checkDir > 0) {
if(pos == limit) {
c = U_SENTINEL;
return Collation::FALLBACK_CE32;
}
c = *pos++;
if(CollationFCD::hasTccc(c)) {
if(CollationFCD::maybeTibetanCompositeVowel(c) ||
(pos != limit && CollationFCD::hasLccc(*pos))) {
--pos;
if(!nextSegment(errorCode)) {
c = U_SENTINEL;
return Collation::FALLBACK_CE32;
}
c = *pos++;
}
}
break;
} else if(checkDir == 0 && pos != limit) {
c = *pos++;
break;
} else {
switchToForward();
}
}
return UTRIE2_GET32_FROM_U16_SINGLE_LEAD(trie, c);
}
UBool
FCDUTF16CollationIterator::foundNULTerminator() {
if(limit == NULL) {
limit = rawLimit = --pos;
return TRUE;
} else {
return FALSE;
}
}
UChar32
FCDUTF16CollationIterator::nextCodePoint(UErrorCode &errorCode) {
UChar32 c;
for(;;) {
if(checkDir > 0) {
if(pos == limit) {
return U_SENTINEL;
}
c = *pos++;
if(CollationFCD::hasTccc(c)) {
if(CollationFCD::maybeTibetanCompositeVowel(c) ||
(pos != limit && CollationFCD::hasLccc(*pos))) {
--pos;
if(!nextSegment(errorCode)) {
return U_SENTINEL;
}
c = *pos++;
}
} else if(c == 0 && limit == NULL) {
limit = rawLimit = --pos;
return U_SENTINEL;
}
break;
} else if(checkDir == 0 && pos != limit) {
c = *pos++;
break;
} else {
switchToForward();
}
}
UChar trail;
if(U16_IS_LEAD(c) && pos != limit && U16_IS_TRAIL(trail = *pos)) {
++pos;
return U16_GET_SUPPLEMENTARY(c, trail);
} else {
return c;
}
}
UChar32
FCDUTF16CollationIterator::previousCodePoint(UErrorCode &errorCode) {
UChar32 c;
for(;;) {
if(checkDir < 0) {
if(pos == start) {
return U_SENTINEL;
}
c = *--pos;
if(CollationFCD::hasLccc(c)) {
if(CollationFCD::maybeTibetanCompositeVowel(c) ||
(pos != start && CollationFCD::hasTccc(*(pos - 1)))) {
++pos;
if(!previousSegment(errorCode)) {
return U_SENTINEL;
}
c = *--pos;
}
}
break;
} else if(checkDir == 0 && pos != start) {
c = *--pos;
break;
} else {
switchToBackward();
}
}
UChar lead;
if(U16_IS_TRAIL(c) && pos != start && U16_IS_LEAD(lead = *(pos - 1))) {
--pos;
return U16_GET_SUPPLEMENTARY(lead, c);
} else {
return c;
}
}
void
FCDUTF16CollationIterator::forwardNumCodePoints(int32_t num, UErrorCode &errorCode) {
// Specify the class to avoid a virtual-function indirection.
// In Java, we would declare this class final.
while(num > 0 && FCDUTF16CollationIterator::nextCodePoint(errorCode) >= 0) {
--num;
}
}
void
FCDUTF16CollationIterator::backwardNumCodePoints(int32_t num, UErrorCode &errorCode) {
// Specify the class to avoid a virtual-function indirection.
// In Java, we would declare this class final.
while(num > 0 && FCDUTF16CollationIterator::previousCodePoint(errorCode) >= 0) {
--num;
}
}
void
FCDUTF16CollationIterator::switchToForward() {
U_ASSERT(checkDir < 0 || (checkDir == 0 && pos == limit));
if(checkDir < 0) {
// Turn around from backward checking.
start = segmentStart = pos;
if(pos == segmentLimit) {
limit = rawLimit;
checkDir = 1; // Check forward.
} else { // pos < segmentLimit
checkDir = 0; // Stay in FCD segment.
}
} else {
// Reached the end of the FCD segment.
if(start == segmentStart) {
// The input text segment is FCD, extend it forward.
} else {
// The input text segment needed to be normalized.
// Switch to checking forward from it.
pos = start = segmentStart = segmentLimit;
// Note: If this segment is at the end of the input text,
// then it might help to return FALSE to indicate that, so that
// we do not have to re-check and normalize when we turn around and go backwards.
// However, that would complicate the call sites for an optimization of an unusual case.
}
limit = rawLimit;
checkDir = 1;
}
}
UBool
FCDUTF16CollationIterator::nextSegment(UErrorCode &errorCode) {
if(U_FAILURE(errorCode)) { return FALSE; }
U_ASSERT(checkDir > 0 && pos != limit);
// The input text [segmentStart..pos[ passes the FCD check.
const UChar *p = pos;
uint8_t prevCC = 0;
for(;;) {
// Fetch the next character's fcd16 value.
const UChar *q = p;
uint16_t fcd16 = nfcImpl.nextFCD16(p, rawLimit);
uint8_t leadCC = (uint8_t)(fcd16 >> 8);
if(leadCC == 0 && q != pos) {
// FCD boundary before the [q, p[ character.
limit = segmentLimit = q;
break;
}
if(leadCC != 0 && (prevCC > leadCC || CollationFCD::isFCD16OfTibetanCompositeVowel(fcd16))) {
// Fails FCD check. Find the next FCD boundary and normalize.
do {
q = p;
} while(p != rawLimit && nfcImpl.nextFCD16(p, rawLimit) > 0xff);
if(!normalize(pos, q, errorCode)) { return FALSE; }
pos = start;
break;
}
prevCC = (uint8_t)fcd16;
if(p == rawLimit || prevCC == 0) {
// FCD boundary after the last character.
limit = segmentLimit = p;
break;
}
}
U_ASSERT(pos != limit);
checkDir = 0;
return TRUE;
}
void
FCDUTF16CollationIterator::switchToBackward() {
U_ASSERT(checkDir > 0 || (checkDir == 0 && pos == start));
if(checkDir > 0) {
// Turn around from forward checking.
limit = segmentLimit = pos;
if(pos == segmentStart) {
start = rawStart;
checkDir = -1; // Check backward.
} else { // pos > segmentStart
checkDir = 0; // Stay in FCD segment.
}
} else {
// Reached the start of the FCD segment.
if(start == segmentStart) {
// The input text segment is FCD, extend it backward.
} else {
// The input text segment needed to be normalized.
// Switch to checking backward from it.
pos = limit = segmentLimit = segmentStart;
}
start = rawStart;
checkDir = -1;
}
}
UBool
FCDUTF16CollationIterator::previousSegment(UErrorCode &errorCode) {
if(U_FAILURE(errorCode)) { return FALSE; }
U_ASSERT(checkDir < 0 && pos != start);
// The input text [pos..segmentLimit[ passes the FCD check.
const UChar *p = pos;
uint8_t nextCC = 0;
for(;;) {
// Fetch the previous character's fcd16 value.
const UChar *q = p;
uint16_t fcd16 = nfcImpl.previousFCD16(rawStart, p);
uint8_t trailCC = (uint8_t)fcd16;
if(trailCC == 0 && q != pos) {
// FCD boundary after the [p, q[ character.
start = segmentStart = q;
break;
}
if(trailCC != 0 && ((nextCC != 0 && trailCC > nextCC) ||
CollationFCD::isFCD16OfTibetanCompositeVowel(fcd16))) {
// Fails FCD check. Find the previous FCD boundary and normalize.
do {
q = p;
} while(fcd16 > 0xff && p != rawStart &&
(fcd16 = nfcImpl.previousFCD16(rawStart, p)) != 0);
if(!normalize(q, pos, errorCode)) { return FALSE; }
pos = limit;
break;
}
nextCC = (uint8_t)(fcd16 >> 8);
if(p == rawStart || nextCC == 0) {
// FCD boundary before the following character.
start = segmentStart = p;
break;
}
}
U_ASSERT(pos != start);
checkDir = 0;
return TRUE;
}
UBool
FCDUTF16CollationIterator::normalize(const UChar *from, const UChar *to, UErrorCode &errorCode) {
// NFD without argument checking.
U_ASSERT(U_SUCCESS(errorCode));
nfcImpl.decompose(from, to, normalized, (int32_t)(to - from), errorCode);
if(U_FAILURE(errorCode)) { return FALSE; }
// Switch collation processing into the FCD buffer
// with the result of normalizing [segmentStart, segmentLimit[.
segmentStart = from;
segmentLimit = to;
start = normalized.getBuffer();
limit = start + normalized.length();
return TRUE;
}
U_NAMESPACE_END
#endif // !UCONFIG_NO_COLLATION