--- /dev/null
+/*
+*******************************************************************************
+* Copyright (C) 2010-2014, International Business Machines
+* Corporation and others. All Rights Reserved.
+*******************************************************************************
+* collationiterator.cpp
+*
+* created on: 2010oct27
+* created by: Markus W. Scherer
+*/
+
+#include "utypeinfo.h" // for 'typeid' to work
+
+#include "unicode/utypes.h"
+
+#if !UCONFIG_NO_COLLATION
+
+#include "unicode/ucharstrie.h"
+#include "unicode/ustringtrie.h"
+#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 "uvectr32.h"
+
+U_NAMESPACE_BEGIN
+
+CollationIterator::CEBuffer::~CEBuffer() {}
+
+UBool
+CollationIterator::CEBuffer::ensureAppendCapacity(int32_t appCap, UErrorCode &errorCode) {
+ int32_t capacity = buffer.getCapacity();
+ if((length + appCap) <= capacity) { return TRUE; }
+ if(U_FAILURE(errorCode)) { return FALSE; }
+ do {
+ if(capacity < 1000) {
+ capacity *= 4;
+ } else {
+ capacity *= 2;
+ }
+ } while(capacity < (length + appCap));
+ int64_t *p = buffer.resize(capacity, length);
+ if(p == NULL) {
+ errorCode = U_MEMORY_ALLOCATION_ERROR;
+ return FALSE;
+ }
+ return TRUE;
+}
+
+// State of combining marks skipped in discontiguous contraction.
+// We create a state object on first use and keep it around deactivated between uses.
+class SkippedState : public UMemory {
+public:
+ // Born active but empty.
+ SkippedState() : pos(0), skipLengthAtMatch(0) {}
+ void clear() {
+ oldBuffer.remove();
+ pos = 0;
+ // The newBuffer is reset by setFirstSkipped().
+ }
+
+ UBool isEmpty() const { return oldBuffer.isEmpty(); }
+
+ UBool hasNext() const { return pos < oldBuffer.length(); }
+
+ // Requires hasNext().
+ UChar32 next() {
+ UChar32 c = oldBuffer.char32At(pos);
+ pos += U16_LENGTH(c);
+ return c;
+ }
+
+ // Accounts for one more input code point read beyond the end of the marks buffer.
+ void incBeyond() {
+ U_ASSERT(!hasNext());
+ ++pos;
+ }
+
+ // Goes backward through the skipped-marks buffer.
+ // Returns the number of code points read beyond the skipped marks
+ // that need to be backtracked through normal input.
+ int32_t backwardNumCodePoints(int32_t n) {
+ int32_t length = oldBuffer.length();
+ int32_t beyond = pos - length;
+ if(beyond > 0) {
+ if(beyond >= n) {
+ // Not back far enough to re-enter the oldBuffer.
+ pos -= n;
+ return n;
+ } else {
+ // Back out all beyond-oldBuffer code points and re-enter the buffer.
+ pos = oldBuffer.moveIndex32(length, beyond - n);
+ return beyond;
+ }
+ } else {
+ // Go backwards from inside the oldBuffer.
+ pos = oldBuffer.moveIndex32(pos, -n);
+ return 0;
+ }
+ }
+
+ void setFirstSkipped(UChar32 c) {
+ skipLengthAtMatch = 0;
+ newBuffer.setTo(c);
+ }
+
+ void skip(UChar32 c) {
+ newBuffer.append(c);
+ }
+
+ void recordMatch() { skipLengthAtMatch = newBuffer.length(); }
+
+ // Replaces the characters we consumed with the newly skipped ones.
+ void replaceMatch() {
+ // Note: UnicodeString.replace() pins pos to at most length().
+ oldBuffer.replace(0, pos, newBuffer, 0, skipLengthAtMatch);
+ pos = 0;
+ }
+
+ void saveTrieState(const UCharsTrie &trie) { trie.saveState(state); }
+ void resetToTrieState(UCharsTrie &trie) const { trie.resetToState(state); }
+
+private:
+ // Combining marks skipped in previous discontiguous-contraction matching.
+ // After that discontiguous contraction was completed, we start reading them from here.
+ UnicodeString oldBuffer;
+ // Combining marks newly skipped in current discontiguous-contraction matching.
+ // These might have been read from the normal text or from the oldBuffer.
+ UnicodeString newBuffer;
+ // Reading index in oldBuffer,
+ // or counter for how many code points have been read beyond oldBuffer (pos-oldBuffer.length()).
+ int32_t pos;
+ // newBuffer.length() at the time of the last matching character.
+ // When a partial match fails, we back out skipped and partial-matching input characters.
+ int32_t skipLengthAtMatch;
+ // We save the trie state before we attempt to match a character,
+ // so that we can skip it and try the next one.
+ UCharsTrie::State state;
+};
+
+CollationIterator::CollationIterator(const CollationIterator &other)
+ : UObject(other),
+ trie(other.trie),
+ data(other.data),
+ cesIndex(other.cesIndex),
+ skipped(NULL),
+ numCpFwd(other.numCpFwd),
+ isNumeric(other.isNumeric) {
+ UErrorCode errorCode = U_ZERO_ERROR;
+ int32_t length = other.ceBuffer.length;
+ if(length > 0 && ceBuffer.ensureAppendCapacity(length, errorCode)) {
+ for(int32_t i = 0; i < length; ++i) {
+ ceBuffer.set(i, other.ceBuffer.get(i));
+ }
+ ceBuffer.length = length;
+ } else {
+ cesIndex = 0;
+ }
+}
+
+CollationIterator::~CollationIterator() {
+ delete skipped;
+}
+
+UBool
+CollationIterator::operator==(const CollationIterator &other) const {
+ // Subclasses: Call this method and then add more specific checks.
+ // Compare the iterator state but not the collation data (trie & data fields):
+ // Assume that the caller compares the data.
+ // Ignore skipped since that should be unused between calls to nextCE().
+ // (It only stays around to avoid another memory allocation.)
+ if(!(typeid(*this) == typeid(other) &&
+ ceBuffer.length == other.ceBuffer.length &&
+ cesIndex == other.cesIndex &&
+ numCpFwd == other.numCpFwd &&
+ isNumeric == other.isNumeric)) {
+ return FALSE;
+ }
+ for(int32_t i = 0; i < ceBuffer.length; ++i) {
+ if(ceBuffer.get(i) != other.ceBuffer.get(i)) { return FALSE; }
+ }
+ return TRUE;
+}
+
+void
+CollationIterator::reset() {
+ cesIndex = ceBuffer.length = 0;
+ if(skipped != NULL) { skipped->clear(); }
+}
+
+int32_t
+CollationIterator::fetchCEs(UErrorCode &errorCode) {
+ while(U_SUCCESS(errorCode) && nextCE(errorCode) != Collation::NO_CE) {
+ // No need to loop for each expansion CE.
+ cesIndex = ceBuffer.length;
+ }
+ return ceBuffer.length;
+}
+
+uint32_t
+CollationIterator::handleNextCE32(UChar32 &c, UErrorCode &errorCode) {
+ c = nextCodePoint(errorCode);
+ return (c < 0) ? Collation::FALLBACK_CE32 : data->getCE32(c);
+}
+
+UChar
+CollationIterator::handleGetTrailSurrogate() {
+ return 0;
+}
+
+UBool
+CollationIterator::foundNULTerminator() {
+ return FALSE;
+}
+
+UBool
+CollationIterator::forbidSurrogateCodePoints() const {
+ return FALSE;
+}
+
+uint32_t
+CollationIterator::getDataCE32(UChar32 c) const {
+ return data->getCE32(c);
+}
+
+uint32_t
+CollationIterator::getCE32FromBuilderData(uint32_t /*ce32*/, UErrorCode &errorCode) {
+ if(U_SUCCESS(errorCode)) { errorCode = U_INTERNAL_PROGRAM_ERROR; }
+ return 0;
+}
+
+int64_t
+CollationIterator::nextCEFromCE32(const CollationData *d, UChar32 c, uint32_t ce32,
+ UErrorCode &errorCode) {
+ --ceBuffer.length; // Undo ceBuffer.incLength().
+ appendCEsFromCE32(d, c, ce32, TRUE, errorCode);
+ if(U_SUCCESS(errorCode)) {
+ return ceBuffer.get(cesIndex++);
+ } else {
+ return Collation::NO_CE_PRIMARY;
+ }
+}
+
+void
+CollationIterator::appendCEsFromCE32(const CollationData *d, UChar32 c, uint32_t ce32,
+ UBool forward, UErrorCode &errorCode) {
+ while(Collation::isSpecialCE32(ce32)) {
+ switch(Collation::tagFromCE32(ce32)) {
+ case Collation::FALLBACK_TAG:
+ case Collation::RESERVED_TAG_3:
+ if(U_SUCCESS(errorCode)) { errorCode = U_INTERNAL_PROGRAM_ERROR; }
+ return;
+ case Collation::LONG_PRIMARY_TAG:
+ ceBuffer.append(Collation::ceFromLongPrimaryCE32(ce32), errorCode);
+ return;
+ case Collation::LONG_SECONDARY_TAG:
+ ceBuffer.append(Collation::ceFromLongSecondaryCE32(ce32), errorCode);
+ return;
+ case Collation::LATIN_EXPANSION_TAG:
+ if(ceBuffer.ensureAppendCapacity(2, errorCode)) {
+ ceBuffer.set(ceBuffer.length, Collation::latinCE0FromCE32(ce32));
+ ceBuffer.set(ceBuffer.length + 1, Collation::latinCE1FromCE32(ce32));
+ ceBuffer.length += 2;
+ }
+ return;
+ case Collation::EXPANSION32_TAG: {
+ const uint32_t *ce32s = d->ce32s + Collation::indexFromCE32(ce32);
+ int32_t length = Collation::lengthFromCE32(ce32);
+ if(ceBuffer.ensureAppendCapacity(length, errorCode)) {
+ do {
+ ceBuffer.appendUnsafe(Collation::ceFromCE32(*ce32s++));
+ } while(--length > 0);
+ }
+ return;
+ }
+ case Collation::EXPANSION_TAG: {
+ const int64_t *ces = d->ces + Collation::indexFromCE32(ce32);
+ int32_t length = Collation::lengthFromCE32(ce32);
+ if(ceBuffer.ensureAppendCapacity(length, errorCode)) {
+ do {
+ ceBuffer.appendUnsafe(*ces++);
+ } while(--length > 0);
+ }
+ return;
+ }
+ case Collation::BUILDER_DATA_TAG:
+ ce32 = getCE32FromBuilderData(ce32, errorCode);
+ if(U_FAILURE(errorCode)) { return; }
+ if(ce32 == Collation::FALLBACK_CE32) {
+ d = data->base;
+ ce32 = d->getCE32(c);
+ }
+ break;
+ case Collation::PREFIX_TAG:
+ if(forward) { backwardNumCodePoints(1, errorCode); }
+ ce32 = getCE32FromPrefix(d, ce32, errorCode);
+ if(forward) { forwardNumCodePoints(1, errorCode); }
+ break;
+ case Collation::CONTRACTION_TAG: {
+ const UChar *p = d->contexts + Collation::indexFromCE32(ce32);
+ uint32_t defaultCE32 = CollationData::readCE32(p); // Default if no suffix match.
+ if(!forward) {
+ // Backward contractions are handled by previousCEUnsafe().
+ // c has contractions but they were not found.
+ ce32 = defaultCE32;
+ break;
+ }
+ UChar32 nextCp;
+ if(skipped == NULL && numCpFwd < 0) {
+ // Some portion of nextCE32FromContraction() pulled out here as an ASCII fast path,
+ // avoiding the function call and the nextSkippedCodePoint() overhead.
+ nextCp = nextCodePoint(errorCode);
+ if(nextCp < 0) {
+ // No more text.
+ ce32 = defaultCE32;
+ break;
+ } else if((ce32 & Collation::CONTRACT_NEXT_CCC) != 0 &&
+ !CollationFCD::mayHaveLccc(nextCp)) {
+ // All contraction suffixes start with characters with lccc!=0
+ // but the next code point has lccc==0.
+ backwardNumCodePoints(1, errorCode);
+ ce32 = defaultCE32;
+ break;
+ }
+ } else {
+ nextCp = nextSkippedCodePoint(errorCode);
+ if(nextCp < 0) {
+ // No more text.
+ ce32 = defaultCE32;
+ break;
+ } else if((ce32 & Collation::CONTRACT_NEXT_CCC) != 0 &&
+ !CollationFCD::mayHaveLccc(nextCp)) {
+ // All contraction suffixes start with characters with lccc!=0
+ // but the next code point has lccc==0.
+ backwardNumSkipped(1, errorCode);
+ ce32 = defaultCE32;
+ break;
+ }
+ }
+ ce32 = nextCE32FromContraction(d, ce32, p + 2, defaultCE32, nextCp, errorCode);
+ if(ce32 == Collation::NO_CE32) {
+ // CEs from a discontiguous contraction plus the skipped combining marks
+ // have been appended already.
+ return;
+ }
+ break;
+ }
+ case Collation::DIGIT_TAG:
+ if(isNumeric) {
+ appendNumericCEs(ce32, forward, errorCode);
+ return;
+ } else {
+ // Fetch the non-numeric-collation CE32 and continue.
+ ce32 = d->ce32s[Collation::indexFromCE32(ce32)];
+ break;
+ }
+ case Collation::U0000_TAG:
+ U_ASSERT(c == 0);
+ if(forward && foundNULTerminator()) {
+ // Handle NUL-termination. (Not needed in Java.)
+ ceBuffer.append(Collation::NO_CE, errorCode);
+ return;
+ } else {
+ // Fetch the normal ce32 for U+0000 and continue.
+ ce32 = d->ce32s[0];
+ break;
+ }
+ case Collation::HANGUL_TAG: {
+ const uint32_t *jamoCE32s = d->jamoCE32s;
+ c -= Hangul::HANGUL_BASE;
+ UChar32 t = c % Hangul::JAMO_T_COUNT;
+ c /= Hangul::JAMO_T_COUNT;
+ UChar32 v = c % Hangul::JAMO_V_COUNT;
+ c /= Hangul::JAMO_V_COUNT;
+ if((ce32 & Collation::HANGUL_NO_SPECIAL_JAMO) != 0) {
+ // None of the Jamo CE32s are isSpecialCE32().
+ // Avoid recursive function calls and per-Jamo tests.
+ if(ceBuffer.ensureAppendCapacity(t == 0 ? 2 : 3, errorCode)) {
+ ceBuffer.set(ceBuffer.length, Collation::ceFromCE32(jamoCE32s[c]));
+ ceBuffer.set(ceBuffer.length + 1, Collation::ceFromCE32(jamoCE32s[19 + v]));
+ ceBuffer.length += 2;
+ if(t != 0) {
+ ceBuffer.appendUnsafe(Collation::ceFromCE32(jamoCE32s[39 + t]));
+ }
+ }
+ return;
+ } else {
+ // We should not need to compute each Jamo code point.
+ // In particular, there should be no offset or implicit ce32.
+ appendCEsFromCE32(d, U_SENTINEL, jamoCE32s[c], forward, errorCode);
+ appendCEsFromCE32(d, U_SENTINEL, jamoCE32s[19 + v], forward, errorCode);
+ if(t == 0) { return; }
+ // offset 39 = 19 + 21 - 1:
+ // 19 = JAMO_L_COUNT
+ // 21 = JAMO_T_COUNT
+ // -1 = omit t==0
+ ce32 = jamoCE32s[39 + t];
+ c = U_SENTINEL;
+ break;
+ }
+ }
+ case Collation::LEAD_SURROGATE_TAG: {
+ U_ASSERT(forward); // Backward iteration should never see lead surrogate code _unit_ data.
+ U_ASSERT(U16_IS_LEAD(c));
+ UChar trail;
+ if(U16_IS_TRAIL(trail = handleGetTrailSurrogate())) {
+ c = U16_GET_SUPPLEMENTARY(c, trail);
+ ce32 &= Collation::LEAD_TYPE_MASK;
+ if(ce32 == Collation::LEAD_ALL_UNASSIGNED) {
+ ce32 = Collation::UNASSIGNED_CE32; // unassigned-implicit
+ } else if(ce32 == Collation::LEAD_ALL_FALLBACK ||
+ (ce32 = d->getCE32FromSupplementary(c)) == Collation::FALLBACK_CE32) {
+ // fall back to the base data
+ d = d->base;
+ ce32 = d->getCE32FromSupplementary(c);
+ }
+ } else {
+ // c is an unpaired surrogate.
+ ce32 = Collation::UNASSIGNED_CE32;
+ }
+ break;
+ }
+ case Collation::OFFSET_TAG:
+ U_ASSERT(c >= 0);
+ ceBuffer.append(d->getCEFromOffsetCE32(c, ce32), errorCode);
+ return;
+ case Collation::IMPLICIT_TAG:
+ U_ASSERT(c >= 0);
+ if(U_IS_SURROGATE(c) && forbidSurrogateCodePoints()) {
+ ce32 = Collation::FFFD_CE32;
+ break;
+ } else {
+ ceBuffer.append(Collation::unassignedCEFromCodePoint(c), errorCode);
+ return;
+ }
+ }
+ }
+ ceBuffer.append(Collation::ceFromSimpleCE32(ce32), errorCode);
+}
+
+uint32_t
+CollationIterator::getCE32FromPrefix(const CollationData *d, uint32_t ce32,
+ UErrorCode &errorCode) {
+ const UChar *p = d->contexts + Collation::indexFromCE32(ce32);
+ ce32 = CollationData::readCE32(p); // Default if no prefix match.
+ p += 2;
+ // Number of code points read before the original code point.
+ int32_t lookBehind = 0;
+ UCharsTrie prefixes(p);
+ for(;;) {
+ UChar32 c = previousCodePoint(errorCode);
+ if(c < 0) { break; }
+ ++lookBehind;
+ UStringTrieResult match = prefixes.nextForCodePoint(c);
+ if(USTRINGTRIE_HAS_VALUE(match)) {
+ ce32 = (uint32_t)prefixes.getValue();
+ }
+ if(!USTRINGTRIE_HAS_NEXT(match)) { break; }
+ }
+ forwardNumCodePoints(lookBehind, errorCode);
+ return ce32;
+}
+
+UChar32
+CollationIterator::nextSkippedCodePoint(UErrorCode &errorCode) {
+ if(skipped != NULL && skipped->hasNext()) { return skipped->next(); }
+ if(numCpFwd == 0) { return U_SENTINEL; }
+ UChar32 c = nextCodePoint(errorCode);
+ if(skipped != NULL && !skipped->isEmpty() && c >= 0) { skipped->incBeyond(); }
+ if(numCpFwd > 0 && c >= 0) { --numCpFwd; }
+ return c;
+}
+
+void
+CollationIterator::backwardNumSkipped(int32_t n, UErrorCode &errorCode) {
+ if(skipped != NULL && !skipped->isEmpty()) {
+ n = skipped->backwardNumCodePoints(n);
+ }
+ backwardNumCodePoints(n, errorCode);
+ if(numCpFwd >= 0) { numCpFwd += n; }
+}
+
+uint32_t
+CollationIterator::nextCE32FromContraction(const CollationData *d, uint32_t contractionCE32,
+ const UChar *p, uint32_t ce32, UChar32 c,
+ UErrorCode &errorCode) {
+ // c: next code point after the original one
+
+ // Number of code points read beyond the original code point.
+ // Needed for discontiguous contraction matching.
+ int32_t lookAhead = 1;
+ // Number of code points read since the last match (initially only c).
+ int32_t sinceMatch = 1;
+ // Normally we only need a contiguous match,
+ // and therefore need not remember the suffixes state from before a mismatch for retrying.
+ // If we are already processing skipped combining marks, then we do track the state.
+ UCharsTrie suffixes(p);
+ if(skipped != NULL && !skipped->isEmpty()) { skipped->saveTrieState(suffixes); }
+ UStringTrieResult match = suffixes.firstForCodePoint(c);
+ for(;;) {
+ UChar32 nextCp;
+ if(USTRINGTRIE_HAS_VALUE(match)) {
+ ce32 = (uint32_t)suffixes.getValue();
+ if(!USTRINGTRIE_HAS_NEXT(match) || (c = nextSkippedCodePoint(errorCode)) < 0) {
+ return ce32;
+ }
+ if(skipped != NULL && !skipped->isEmpty()) { skipped->saveTrieState(suffixes); }
+ sinceMatch = 1;
+ } else if(match == USTRINGTRIE_NO_MATCH || (nextCp = nextSkippedCodePoint(errorCode)) < 0) {
+ // No match for c, or partial match (USTRINGTRIE_NO_VALUE) and no further text.
+ // Back up if necessary, and try a discontiguous contraction.
+ if((contractionCE32 & Collation::CONTRACT_TRAILING_CCC) != 0 &&
+ // Discontiguous contraction matching extends an existing match.
+ // If there is no match yet, then there is nothing to do.
+ ((contractionCE32 & Collation::CONTRACT_SINGLE_CP_NO_MATCH) == 0 ||
+ sinceMatch < lookAhead)) {
+ // The last character of at least one suffix has lccc!=0,
+ // allowing for discontiguous contractions.
+ // UCA S2.1.1 only processes non-starters immediately following
+ // "a match in the table" (sinceMatch=1).
+ if(sinceMatch > 1) {
+ // Return to the state after the last match.
+ // (Return to sinceMatch=0 and re-fetch the first partially-matched character.)
+ backwardNumSkipped(sinceMatch, errorCode);
+ c = nextSkippedCodePoint(errorCode);
+ lookAhead -= sinceMatch - 1;
+ sinceMatch = 1;
+ }
+ if(d->getFCD16(c) > 0xff) {
+ return nextCE32FromDiscontiguousContraction(
+ d, suffixes, ce32, lookAhead, c, errorCode);
+ }
+ }
+ break;
+ } else {
+ // Continue after partial match (USTRINGTRIE_NO_VALUE) for c.
+ // It does not have a result value, therefore it is not itself "a match in the table".
+ // If a partially-matched c has ccc!=0 then
+ // it might be skipped in discontiguous contraction.
+ c = nextCp;
+ ++sinceMatch;
+ }
+ ++lookAhead;
+ match = suffixes.nextForCodePoint(c);
+ }
+ backwardNumSkipped(sinceMatch, errorCode);
+ return ce32;
+}
+
+uint32_t
+CollationIterator::nextCE32FromDiscontiguousContraction(
+ const CollationData *d, UCharsTrie &suffixes, uint32_t ce32,
+ int32_t lookAhead, UChar32 c,
+ UErrorCode &errorCode) {
+ if(U_FAILURE(errorCode)) { return 0; }
+
+ // UCA section 3.3.2 Contractions:
+ // Contractions that end with non-starter characters
+ // are known as discontiguous contractions.
+ // ... discontiguous contractions must be detected in input text
+ // whenever the final sequence of non-starter characters could be rearranged
+ // so as to make a contiguous matching sequence that is canonically equivalent.
+
+ // UCA: http://www.unicode.org/reports/tr10/#S2.1
+ // S2.1 Find the longest initial substring S at each point that has a match in the table.
+ // S2.1.1 If there are any non-starters following S, process each non-starter C.
+ // S2.1.2 If C is not blocked from S, find if S + C has a match in the table.
+ // Note: A non-starter in a string is called blocked
+ // if there is another non-starter of the same canonical combining class or zero
+ // between it and the last character of canonical combining class 0.
+ // S2.1.3 If there is a match, replace S by S + C, and remove C.
+
+ // First: Is a discontiguous contraction even possible?
+ uint16_t fcd16 = d->getFCD16(c);
+ U_ASSERT(fcd16 > 0xff); // The caller checked this already, as a shortcut.
+ UChar32 nextCp = nextSkippedCodePoint(errorCode);
+ if(nextCp < 0) {
+ // No further text.
+ backwardNumSkipped(1, errorCode);
+ return ce32;
+ }
+ ++lookAhead;
+ uint8_t prevCC = (uint8_t)fcd16;
+ fcd16 = d->getFCD16(nextCp);
+ if(fcd16 <= 0xff) {
+ // The next code point after c is a starter (S2.1.1 "process each non-starter").
+ backwardNumSkipped(2, errorCode);
+ return ce32;
+ }
+
+ // We have read and matched (lookAhead-2) code points,
+ // read non-matching c and peeked ahead at nextCp.
+ // Return to the state before the mismatch and continue matching with nextCp.
+ if(skipped == NULL || skipped->isEmpty()) {
+ if(skipped == NULL) {
+ skipped = new SkippedState();
+ if(skipped == NULL) {
+ errorCode = U_MEMORY_ALLOCATION_ERROR;
+ return 0;
+ }
+ }
+ suffixes.reset();
+ if(lookAhead > 2) {
+ // Replay the partial match so far.
+ backwardNumCodePoints(lookAhead, errorCode);
+ suffixes.firstForCodePoint(nextCodePoint(errorCode));
+ for(int32_t i = 3; i < lookAhead; ++i) {
+ suffixes.nextForCodePoint(nextCodePoint(errorCode));
+ }
+ // Skip c (which did not match) and nextCp (which we will try now).
+ forwardNumCodePoints(2, errorCode);
+ }
+ skipped->saveTrieState(suffixes);
+ } else {
+ // Reset to the trie state before the failed match of c.
+ skipped->resetToTrieState(suffixes);
+ }
+
+ skipped->setFirstSkipped(c);
+ // Number of code points read since the last match (at this point: c and nextCp).
+ int32_t sinceMatch = 2;
+ c = nextCp;
+ for(;;) {
+ UStringTrieResult match;
+ // "If C is not blocked from S, find if S + C has a match in the table." (S2.1.2)
+ if(prevCC < (fcd16 >> 8) && USTRINGTRIE_HAS_VALUE(match = suffixes.nextForCodePoint(c))) {
+ // "If there is a match, replace S by S + C, and remove C." (S2.1.3)
+ // Keep prevCC unchanged.
+ ce32 = (uint32_t)suffixes.getValue();
+ sinceMatch = 0;
+ skipped->recordMatch();
+ if(!USTRINGTRIE_HAS_NEXT(match)) { break; }
+ skipped->saveTrieState(suffixes);
+ } else {
+ // No match for "S + C", skip C.
+ skipped->skip(c);
+ skipped->resetToTrieState(suffixes);
+ prevCC = (uint8_t)fcd16;
+ }
+ if((c = nextSkippedCodePoint(errorCode)) < 0) { break; }
+ ++sinceMatch;
+ fcd16 = d->getFCD16(c);
+ if(fcd16 <= 0xff) {
+ // The next code point after c is a starter (S2.1.1 "process each non-starter").
+ break;
+ }
+ }
+ backwardNumSkipped(sinceMatch, errorCode);
+ UBool isTopDiscontiguous = skipped->isEmpty();
+ skipped->replaceMatch();
+ if(isTopDiscontiguous && !skipped->isEmpty()) {
+ // We did get a match after skipping one or more combining marks,
+ // and we are not in a recursive discontiguous contraction.
+ // Append CEs from the contraction ce32
+ // and then from the combining marks that we skipped before the match.
+ c = U_SENTINEL;
+ for(;;) {
+ appendCEsFromCE32(d, c, ce32, TRUE, errorCode);
+ // Fetch CE32s for skipped combining marks from the normal data, with fallback,
+ // rather than from the CollationData where we found the contraction.
+ if(!skipped->hasNext()) { break; }
+ c = skipped->next();
+ ce32 = getDataCE32(c);
+ if(ce32 == Collation::FALLBACK_CE32) {
+ d = data->base;
+ ce32 = d->getCE32(c);
+ } else {
+ d = data;
+ }
+ // Note: A nested discontiguous-contraction match
+ // replaces consumed combining marks with newly skipped ones
+ // and resets the reading position to the beginning.
+ }
+ skipped->clear();
+ ce32 = Collation::NO_CE32; // Signal to the caller that the result is in the ceBuffer.
+ }
+ return ce32;
+}
+
+void
+CollationIterator::appendNumericCEs(uint32_t ce32, UBool forward, UErrorCode &errorCode) {
+ // Collect digits.
+ CharString digits;
+ if(forward) {
+ for(;;) {
+ char digit = Collation::digitFromCE32(ce32);
+ digits.append(digit, errorCode);
+ if(numCpFwd == 0) { break; }
+ UChar32 c = nextCodePoint(errorCode);
+ if(c < 0) { break; }
+ ce32 = data->getCE32(c);
+ if(ce32 == Collation::FALLBACK_CE32) {
+ ce32 = data->base->getCE32(c);
+ }
+ if(!Collation::hasCE32Tag(ce32, Collation::DIGIT_TAG)) {
+ backwardNumCodePoints(1, errorCode);
+ break;
+ }
+ if(numCpFwd > 0) { --numCpFwd; }
+ }
+ } else {
+ for(;;) {
+ char digit = Collation::digitFromCE32(ce32);
+ digits.append(digit, errorCode);
+ UChar32 c = previousCodePoint(errorCode);
+ if(c < 0) { break; }
+ ce32 = data->getCE32(c);
+ if(ce32 == Collation::FALLBACK_CE32) {
+ ce32 = data->base->getCE32(c);
+ }
+ if(!Collation::hasCE32Tag(ce32, Collation::DIGIT_TAG)) {
+ forwardNumCodePoints(1, errorCode);
+ break;
+ }
+ }
+ // Reverse the digit string.
+ char *p = digits.data();
+ char *q = p + digits.length() - 1;
+ while(p < q) {
+ char digit = *p;
+ *p++ = *q;
+ *q-- = digit;
+ }
+ }
+ if(U_FAILURE(errorCode)) { return; }
+ int32_t pos = 0;
+ do {
+ // Skip leading zeros.
+ while(pos < (digits.length() - 1) && digits[pos] == 0) { ++pos; }
+ // Write a sequence of CEs for at most 254 digits at a time.
+ int32_t segmentLength = digits.length() - pos;
+ if(segmentLength > 254) { segmentLength = 254; }
+ appendNumericSegmentCEs(digits.data() + pos, segmentLength, errorCode);
+ pos += segmentLength;
+ } while(U_SUCCESS(errorCode) && pos < digits.length());
+}
+
+void
+CollationIterator::appendNumericSegmentCEs(const char *digits, int32_t length, UErrorCode &errorCode) {
+ U_ASSERT(1 <= length && length <= 254);
+ U_ASSERT(length == 1 || digits[0] != 0);
+ uint32_t numericPrimary = data->numericPrimary;
+ // Note: We use primary byte values 2..255: digits are not compressible.
+ if(length <= 7) {
+ // Very dense encoding for small numbers.
+ int32_t value = digits[0];
+ for(int32_t i = 1; i < length; ++i) {
+ value = value * 10 + digits[i];
+ }
+ // Primary weight second byte values:
+ // 74 byte values 2.. 75 for small numbers in two-byte primary weights.
+ // 40 byte values 76..115 for medium numbers in three-byte primary weights.
+ // 16 byte values 116..131 for large numbers in four-byte primary weights.
+ // 124 byte values 132..255 for very large numbers with 4..127 digit pairs.
+ int32_t firstByte = 2;
+ int32_t numBytes = 74;
+ if(value < numBytes) {
+ // Two-byte primary for 0..73, good for day & month numbers etc.
+ uint32_t primary = numericPrimary | ((firstByte + value) << 16);
+ ceBuffer.append(Collation::makeCE(primary), errorCode);
+ return;
+ }
+ value -= numBytes;
+ firstByte += numBytes;
+ numBytes = 40;
+ if(value < numBytes * 254) {
+ // Three-byte primary for 74..10233=74+40*254-1, good for year numbers and more.
+ uint32_t primary = numericPrimary |
+ ((firstByte + value / 254) << 16) | ((2 + value % 254) << 8);
+ ceBuffer.append(Collation::makeCE(primary), errorCode);
+ return;
+ }
+ value -= numBytes * 254;
+ firstByte += numBytes;
+ numBytes = 16;
+ if(value < numBytes * 254 * 254) {
+ // Four-byte primary for 10234..1042489=10234+16*254*254-1.
+ uint32_t primary = numericPrimary | (2 + value % 254);
+ value /= 254;
+ primary |= (2 + value % 254) << 8;
+ value /= 254;
+ primary |= (firstByte + value % 254) << 16;
+ ceBuffer.append(Collation::makeCE(primary), errorCode);
+ return;
+ }
+ // original value > 1042489
+ }
+ U_ASSERT(length >= 7);
+
+ // The second primary byte value 132..255 indicates the number of digit pairs (4..127),
+ // then we generate primary bytes with those pairs.
+ // Omit trailing 00 pairs.
+ // Decrement the value for the last pair.
+
+ // Set the exponent. 4 pairs->132, 5 pairs->133, ..., 127 pairs->255.
+ int32_t numPairs = (length + 1) / 2;
+ uint32_t primary = numericPrimary | ((132 - 4 + numPairs) << 16);
+ // Find the length without trailing 00 pairs.
+ while(digits[length - 1] == 0 && digits[length - 2] == 0) {
+ length -= 2;
+ }
+ // Read the first pair.
+ uint32_t pair;
+ int32_t pos;
+ if(length & 1) {
+ // Only "half a pair" if we have an odd number of digits.
+ pair = digits[0];
+ pos = 1;
+ } else {
+ pair = digits[0] * 10 + digits[1];
+ pos = 2;
+ }
+ pair = 11 + 2 * pair;
+ // Add the pairs of digits between pos and length.
+ int32_t shift = 8;
+ while(pos < length) {
+ if(shift == 0) {
+ // Every three pairs/bytes we need to store a 4-byte-primary CE
+ // and start with a new CE with the '0' primary lead byte.
+ primary |= pair;
+ ceBuffer.append(Collation::makeCE(primary), errorCode);
+ primary = numericPrimary;
+ shift = 16;
+ } else {
+ primary |= pair << shift;
+ shift -= 8;
+ }
+ pair = 11 + 2 * (digits[pos] * 10 + digits[pos + 1]);
+ pos += 2;
+ }
+ primary |= (pair - 1) << shift;
+ ceBuffer.append(Collation::makeCE(primary), errorCode);
+}
+
+int64_t
+CollationIterator::previousCE(UVector32 &offsets, UErrorCode &errorCode) {
+ if(ceBuffer.length > 0) {
+ // Return the previous buffered CE.
+ return ceBuffer.get(--ceBuffer.length);
+ }
+ offsets.removeAllElements();
+ int32_t limitOffset = getOffset();
+ UChar32 c = previousCodePoint(errorCode);
+ if(c < 0) { return Collation::NO_CE; }
+ if(data->isUnsafeBackward(c, isNumeric)) {
+ return previousCEUnsafe(c, offsets, errorCode);
+ }
+ // Simple, safe-backwards iteration:
+ // Get a CE going backwards, handle prefixes but no contractions.
+ uint32_t ce32 = data->getCE32(c);
+ const CollationData *d;
+ if(ce32 == Collation::FALLBACK_CE32) {
+ d = data->base;
+ ce32 = d->getCE32(c);
+ } else {
+ d = data;
+ }
+ if(Collation::isSimpleOrLongCE32(ce32)) {
+ return Collation::ceFromCE32(ce32);
+ }
+ appendCEsFromCE32(d, c, ce32, FALSE, errorCode);
+ if(U_SUCCESS(errorCode)) {
+ if(ceBuffer.length > 1) {
+ offsets.addElement(getOffset(), errorCode);
+ // For an expansion, the offset of each non-initial CE is the limit offset,
+ // consistent with forward iteration.
+ while(offsets.size() <= ceBuffer.length) {
+ offsets.addElement(limitOffset, errorCode);
+ };
+ }
+ return ceBuffer.get(--ceBuffer.length);
+ } else {
+ return Collation::NO_CE_PRIMARY;
+ }
+}
+
+int64_t
+CollationIterator::previousCEUnsafe(UChar32 c, UVector32 &offsets, UErrorCode &errorCode) {
+ // We just move through the input counting safe and unsafe code points
+ // without collecting the unsafe-backward substring into a buffer and
+ // switching to it.
+ // This is to keep the logic simple. Otherwise we would have to handle
+ // prefix matching going before the backward buffer, switching
+ // to iteration and back, etc.
+ // In the most important case of iterating over a normal string,
+ // reading from the string itself is already maximally fast.
+ // The only drawback there is that after getting the CEs we always
+ // skip backward to the safe character rather than switching out
+ // of a backwardBuffer.
+ // But this should not be the common case for previousCE(),
+ // and correctness and maintainability are more important than
+ // complex optimizations.
+ // Find the first safe character before c.
+ int32_t numBackward = 1;
+ while((c = previousCodePoint(errorCode)) >= 0) {
+ ++numBackward;
+ if(!data->isUnsafeBackward(c, isNumeric)) {
+ break;
+ }
+ }
+ // Set the forward iteration limit.
+ // Note: This counts code points.
+ // We cannot enforce a limit in the middle of a surrogate pair or similar.
+ numCpFwd = numBackward;
+ // Reset the forward iterator.
+ cesIndex = 0;
+ U_ASSERT(ceBuffer.length == 0);
+ // Go forward and collect the CEs.
+ int32_t offset = getOffset();
+ while(numCpFwd > 0) {
+ // nextCE() normally reads one code point.
+ // Contraction matching and digit specials read more and check numCpFwd.
+ --numCpFwd;
+ // Append one or more CEs to the ceBuffer.
+ (void)nextCE(errorCode);
+ U_ASSERT(U_FAILURE(errorCode) || ceBuffer.get(ceBuffer.length - 1) != Collation::NO_CE);
+ // No need to loop for getting each expansion CE from nextCE().
+ cesIndex = ceBuffer.length;
+ // However, we need to write an offset for each CE.
+ // This is for CollationElementIterator::getOffset() to return
+ // intermediate offsets from the unsafe-backwards segment.
+ U_ASSERT(offsets.size() < ceBuffer.length);
+ offsets.addElement(offset, errorCode);
+ // For an expansion, the offset of each non-initial CE is the limit offset,
+ // consistent with forward iteration.
+ offset = getOffset();
+ while(offsets.size() < ceBuffer.length) {
+ offsets.addElement(offset, errorCode);
+ };
+ }
+ U_ASSERT(offsets.size() == ceBuffer.length);
+ // End offset corresponding to just after the unsafe-backwards segment.
+ offsets.addElement(offset, errorCode);
+ // Reset the forward iteration limit
+ // and move backward to before the segment for which we fetched CEs.
+ numCpFwd = -1;
+ backwardNumCodePoints(numBackward, errorCode);
+ // Use the collected CEs and return the last one.
+ cesIndex = 0; // Avoid cesIndex > ceBuffer.length when that gets decremented.
+ if(U_SUCCESS(errorCode)) {
+ return ceBuffer.get(--ceBuffer.length);
+ } else {
+ return Collation::NO_CE_PRIMARY;
+ }
+}
+
+U_NAMESPACE_END
+
+#endif // !UCONFIG_NO_COLLATION
projects / apple / icu.git / blobdiff