804 lines
28 KiB
C++
804 lines
28 KiB
C++
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// © 2017 and later: Unicode, Inc. and others.
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// License & terms of use: http://www.unicode.org/copyright.html
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// edits.cpp
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// created: 2017feb08 Markus W. Scherer
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#include "unicode/edits.h"
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#include "unicode/unistr.h"
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#include "unicode/utypes.h"
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#include "cmemory.h"
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#include "uassert.h"
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#include "util.h"
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U_NAMESPACE_BEGIN
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namespace {
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// 0000uuuuuuuuuuuu records u+1 unchanged text units.
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const int32_t MAX_UNCHANGED_LENGTH = 0x1000;
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const int32_t MAX_UNCHANGED = MAX_UNCHANGED_LENGTH - 1;
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// 0mmmnnnccccccccc with m=1..6 records ccc+1 replacements of m:n text units.
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const int32_t MAX_SHORT_CHANGE_OLD_LENGTH = 6;
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const int32_t MAX_SHORT_CHANGE_NEW_LENGTH = 7;
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const int32_t SHORT_CHANGE_NUM_MASK = 0x1ff;
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const int32_t MAX_SHORT_CHANGE = 0x6fff;
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// 0111mmmmmmnnnnnn records a replacement of m text units with n.
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// m or n = 61: actual length follows in the next edits array unit.
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// m or n = 62..63: actual length follows in the next two edits array units.
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// Bit 30 of the actual length is in the head unit.
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// Trailing units have bit 15 set.
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const int32_t LENGTH_IN_1TRAIL = 61;
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const int32_t LENGTH_IN_2TRAIL = 62;
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} // namespace
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void Edits::releaseArray() U_NOEXCEPT {
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if (array != stackArray) {
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uprv_free(array);
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}
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}
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Edits &Edits::copyArray(const Edits &other) {
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if (U_FAILURE(errorCode_)) {
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length = delta = numChanges = 0;
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return *this;
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}
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if (length > capacity) {
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uint16_t *newArray = (uint16_t *)uprv_malloc((size_t)length * 2);
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if (newArray == nullptr) {
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length = delta = numChanges = 0;
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errorCode_ = U_MEMORY_ALLOCATION_ERROR;
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return *this;
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}
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releaseArray();
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array = newArray;
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capacity = length;
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}
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if (length > 0) {
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uprv_memcpy(array, other.array, (size_t)length * 2);
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}
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return *this;
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}
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Edits &Edits::moveArray(Edits &src) U_NOEXCEPT {
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if (U_FAILURE(errorCode_)) {
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length = delta = numChanges = 0;
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return *this;
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}
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releaseArray();
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if (length > STACK_CAPACITY) {
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array = src.array;
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capacity = src.capacity;
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src.array = src.stackArray;
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src.capacity = STACK_CAPACITY;
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src.reset();
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return *this;
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}
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array = stackArray;
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capacity = STACK_CAPACITY;
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if (length > 0) {
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uprv_memcpy(array, src.array, (size_t)length * 2);
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}
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return *this;
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}
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Edits &Edits::operator=(const Edits &other) {
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length = other.length;
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delta = other.delta;
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numChanges = other.numChanges;
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errorCode_ = other.errorCode_;
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return copyArray(other);
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}
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Edits &Edits::operator=(Edits &&src) U_NOEXCEPT {
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length = src.length;
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delta = src.delta;
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numChanges = src.numChanges;
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errorCode_ = src.errorCode_;
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return moveArray(src);
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}
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Edits::~Edits() {
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releaseArray();
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}
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void Edits::reset() U_NOEXCEPT {
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length = delta = numChanges = 0;
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errorCode_ = U_ZERO_ERROR;
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}
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void Edits::addUnchanged(int32_t unchangedLength) {
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if(U_FAILURE(errorCode_) || unchangedLength == 0) { return; }
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if(unchangedLength < 0) {
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errorCode_ = U_ILLEGAL_ARGUMENT_ERROR;
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return;
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}
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// Merge into previous unchanged-text record, if any.
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int32_t last = lastUnit();
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if(last < MAX_UNCHANGED) {
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int32_t remaining = MAX_UNCHANGED - last;
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if (remaining >= unchangedLength) {
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setLastUnit(last + unchangedLength);
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return;
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}
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setLastUnit(MAX_UNCHANGED);
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unchangedLength -= remaining;
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}
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// Split large lengths into multiple units.
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while(unchangedLength >= MAX_UNCHANGED_LENGTH) {
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append(MAX_UNCHANGED);
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unchangedLength -= MAX_UNCHANGED_LENGTH;
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}
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// Write a small (remaining) length.
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if(unchangedLength > 0) {
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append(unchangedLength - 1);
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}
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}
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void Edits::addReplace(int32_t oldLength, int32_t newLength) {
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if(U_FAILURE(errorCode_)) { return; }
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if(oldLength < 0 || newLength < 0) {
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errorCode_ = U_ILLEGAL_ARGUMENT_ERROR;
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return;
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}
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if (oldLength == 0 && newLength == 0) {
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return;
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}
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++numChanges;
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int32_t newDelta = newLength - oldLength;
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if (newDelta != 0) {
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if ((newDelta > 0 && delta >= 0 && newDelta > (INT32_MAX - delta)) ||
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(newDelta < 0 && delta < 0 && newDelta < (INT32_MIN - delta))) {
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// Integer overflow or underflow.
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errorCode_ = U_INDEX_OUTOFBOUNDS_ERROR;
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return;
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}
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delta += newDelta;
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}
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if(0 < oldLength && oldLength <= MAX_SHORT_CHANGE_OLD_LENGTH &&
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newLength <= MAX_SHORT_CHANGE_NEW_LENGTH) {
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// Merge into previous same-lengths short-replacement record, if any.
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int32_t u = (oldLength << 12) | (newLength << 9);
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int32_t last = lastUnit();
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if(MAX_UNCHANGED < last && last < MAX_SHORT_CHANGE &&
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(last & ~SHORT_CHANGE_NUM_MASK) == u &&
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(last & SHORT_CHANGE_NUM_MASK) < SHORT_CHANGE_NUM_MASK) {
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setLastUnit(last + 1);
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return;
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}
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append(u);
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return;
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}
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int32_t head = 0x7000;
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if (oldLength < LENGTH_IN_1TRAIL && newLength < LENGTH_IN_1TRAIL) {
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head |= oldLength << 6;
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head |= newLength;
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append(head);
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} else if ((capacity - length) >= 5 || growArray()) {
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int32_t limit = length + 1;
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if(oldLength < LENGTH_IN_1TRAIL) {
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head |= oldLength << 6;
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} else if(oldLength <= 0x7fff) {
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head |= LENGTH_IN_1TRAIL << 6;
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array[limit++] = (uint16_t)(0x8000 | oldLength);
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} else {
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head |= (LENGTH_IN_2TRAIL + (oldLength >> 30)) << 6;
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array[limit++] = (uint16_t)(0x8000 | (oldLength >> 15));
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array[limit++] = (uint16_t)(0x8000 | oldLength);
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}
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if(newLength < LENGTH_IN_1TRAIL) {
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head |= newLength;
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} else if(newLength <= 0x7fff) {
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head |= LENGTH_IN_1TRAIL;
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array[limit++] = (uint16_t)(0x8000 | newLength);
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} else {
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head |= LENGTH_IN_2TRAIL + (newLength >> 30);
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array[limit++] = (uint16_t)(0x8000 | (newLength >> 15));
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array[limit++] = (uint16_t)(0x8000 | newLength);
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}
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array[length] = (uint16_t)head;
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length = limit;
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}
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}
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void Edits::append(int32_t r) {
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if(length < capacity || growArray()) {
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array[length++] = (uint16_t)r;
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}
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}
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UBool Edits::growArray() {
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int32_t newCapacity;
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if (array == stackArray) {
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newCapacity = 2000;
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} else if (capacity == INT32_MAX) {
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// Not U_BUFFER_OVERFLOW_ERROR because that could be confused on a string transform API
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// with a result-string-buffer overflow.
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errorCode_ = U_INDEX_OUTOFBOUNDS_ERROR;
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return FALSE;
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} else if (capacity >= (INT32_MAX / 2)) {
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newCapacity = INT32_MAX;
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} else {
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newCapacity = 2 * capacity;
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}
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// Grow by at least 5 units so that a maximal change record will fit.
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if ((newCapacity - capacity) < 5) {
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errorCode_ = U_INDEX_OUTOFBOUNDS_ERROR;
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return FALSE;
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}
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uint16_t *newArray = (uint16_t *)uprv_malloc((size_t)newCapacity * 2);
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if (newArray == NULL) {
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errorCode_ = U_MEMORY_ALLOCATION_ERROR;
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return FALSE;
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}
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uprv_memcpy(newArray, array, (size_t)length * 2);
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releaseArray();
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array = newArray;
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capacity = newCapacity;
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return TRUE;
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}
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UBool Edits::copyErrorTo(UErrorCode &outErrorCode) const {
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if (U_FAILURE(outErrorCode)) { return TRUE; }
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if (U_SUCCESS(errorCode_)) { return FALSE; }
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outErrorCode = errorCode_;
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return TRUE;
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}
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Edits &Edits::mergeAndAppend(const Edits &ab, const Edits &bc, UErrorCode &errorCode) {
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if (copyErrorTo(errorCode)) { return *this; }
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// Picture string a --(Edits ab)--> string b --(Edits bc)--> string c.
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// Parallel iteration over both Edits.
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Iterator abIter = ab.getFineIterator();
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Iterator bcIter = bc.getFineIterator();
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UBool abHasNext = TRUE, bcHasNext = TRUE;
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// Copy iterator state into local variables, so that we can modify and subdivide spans.
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// ab old & new length, bc old & new length
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int32_t aLength = 0, ab_bLength = 0, bc_bLength = 0, cLength = 0;
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// When we have different-intermediate-length changes, we accumulate a larger change.
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int32_t pending_aLength = 0, pending_cLength = 0;
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for (;;) {
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// At this point, for each of the two iterators:
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// Either we are done with the locally cached current edit,
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// and its intermediate-string length has been reset,
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// or we will continue to work with a truncated remainder of this edit.
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//
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// If the current edit is done, and the iterator has not yet reached the end,
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// then we fetch the next edit. This is true for at least one of the iterators.
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//
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// Normally it does not matter whether we fetch from ab and then bc or vice versa.
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// However, the result is observably different when
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// ab deletions meet bc insertions at the same intermediate-string index.
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// Some users expect the bc insertions to come first, so we fetch from bc first.
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if (bc_bLength == 0) {
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if (bcHasNext && (bcHasNext = bcIter.next(errorCode)) != 0) {
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bc_bLength = bcIter.oldLength();
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cLength = bcIter.newLength();
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if (bc_bLength == 0) {
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// insertion
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if (ab_bLength == 0 || !abIter.hasChange()) {
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addReplace(pending_aLength, pending_cLength + cLength);
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pending_aLength = pending_cLength = 0;
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} else {
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pending_cLength += cLength;
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}
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continue;
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}
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}
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// else see if the other iterator is done, too.
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}
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if (ab_bLength == 0) {
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if (abHasNext && (abHasNext = abIter.next(errorCode)) != 0) {
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aLength = abIter.oldLength();
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ab_bLength = abIter.newLength();
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if (ab_bLength == 0) {
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// deletion
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if (bc_bLength == bcIter.oldLength() || !bcIter.hasChange()) {
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addReplace(pending_aLength + aLength, pending_cLength);
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pending_aLength = pending_cLength = 0;
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} else {
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pending_aLength += aLength;
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}
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continue;
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}
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} else if (bc_bLength == 0) {
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// Both iterators are done at the same time:
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// The intermediate-string lengths match.
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break;
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} else {
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// The ab output string is shorter than the bc input string.
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if (!copyErrorTo(errorCode)) {
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errorCode = U_ILLEGAL_ARGUMENT_ERROR;
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}
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return *this;
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}
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}
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if (bc_bLength == 0) {
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// The bc input string is shorter than the ab output string.
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if (!copyErrorTo(errorCode)) {
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errorCode = U_ILLEGAL_ARGUMENT_ERROR;
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}
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return *this;
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}
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// Done fetching: ab_bLength > 0 && bc_bLength > 0
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// The current state has two parts:
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// - Past: We accumulate a longer ac edit in the "pending" variables.
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// - Current: We have copies of the current ab/bc edits in local variables.
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// At least one side is newly fetched.
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// One side might be a truncated remainder of an edit we fetched earlier.
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if (!abIter.hasChange() && !bcIter.hasChange()) {
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// An unchanged span all the way from string a to string c.
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if (pending_aLength != 0 || pending_cLength != 0) {
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addReplace(pending_aLength, pending_cLength);
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pending_aLength = pending_cLength = 0;
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}
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int32_t unchangedLength = aLength <= cLength ? aLength : cLength;
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addUnchanged(unchangedLength);
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ab_bLength = aLength -= unchangedLength;
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bc_bLength = cLength -= unchangedLength;
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// At least one of the unchanged spans is now empty.
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continue;
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}
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if (!abIter.hasChange() && bcIter.hasChange()) {
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// Unchanged a->b but changed b->c.
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if (ab_bLength >= bc_bLength) {
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// Split the longer unchanged span into change + remainder.
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addReplace(pending_aLength + bc_bLength, pending_cLength + cLength);
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pending_aLength = pending_cLength = 0;
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|
aLength = ab_bLength -= bc_bLength;
|
||
|
|
bc_bLength = 0;
|
||
|
|
continue;
|
||
|
|
}
|
||
|
|
// Handle the shorter unchanged span below like a change.
|
||
|
|
} else if (abIter.hasChange() && !bcIter.hasChange()) {
|
||
|
|
// Changed a->b and then unchanged b->c.
|
||
|
|
if (ab_bLength <= bc_bLength) {
|
||
|
|
// Split the longer unchanged span into change + remainder.
|
||
|
|
addReplace(pending_aLength + aLength, pending_cLength + ab_bLength);
|
||
|
|
pending_aLength = pending_cLength = 0;
|
||
|
|
cLength = bc_bLength -= ab_bLength;
|
||
|
|
ab_bLength = 0;
|
||
|
|
continue;
|
||
|
|
}
|
||
|
|
// Handle the shorter unchanged span below like a change.
|
||
|
|
} else { // both abIter.hasChange() && bcIter.hasChange()
|
||
|
|
if (ab_bLength == bc_bLength) {
|
||
|
|
// Changes on both sides up to the same position. Emit & reset.
|
||
|
|
addReplace(pending_aLength + aLength, pending_cLength + cLength);
|
||
|
|
pending_aLength = pending_cLength = 0;
|
||
|
|
ab_bLength = bc_bLength = 0;
|
||
|
|
continue;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
// Accumulate the a->c change, reset the shorter side,
|
||
|
|
// keep a remainder of the longer one.
|
||
|
|
pending_aLength += aLength;
|
||
|
|
pending_cLength += cLength;
|
||
|
|
if (ab_bLength < bc_bLength) {
|
||
|
|
bc_bLength -= ab_bLength;
|
||
|
|
cLength = ab_bLength = 0;
|
||
|
|
} else { // ab_bLength > bc_bLength
|
||
|
|
ab_bLength -= bc_bLength;
|
||
|
|
aLength = bc_bLength = 0;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
if (pending_aLength != 0 || pending_cLength != 0) {
|
||
|
|
addReplace(pending_aLength, pending_cLength);
|
||
|
|
}
|
||
|
|
copyErrorTo(errorCode);
|
||
|
|
return *this;
|
||
|
|
}
|
||
|
|
|
||
|
|
Edits::Iterator::Iterator(const uint16_t *a, int32_t len, UBool oc, UBool crs) :
|
||
|
|
array(a), index(0), length(len), remaining(0),
|
||
|
|
onlyChanges_(oc), coarse(crs),
|
||
|
|
dir(0), changed(FALSE), oldLength_(0), newLength_(0),
|
||
|
|
srcIndex(0), replIndex(0), destIndex(0) {}
|
||
|
|
|
||
|
|
int32_t Edits::Iterator::readLength(int32_t head) {
|
||
|
|
if (head < LENGTH_IN_1TRAIL) {
|
||
|
|
return head;
|
||
|
|
} else if (head < LENGTH_IN_2TRAIL) {
|
||
|
|
U_ASSERT(index < length);
|
||
|
|
U_ASSERT(array[index] >= 0x8000);
|
||
|
|
return array[index++] & 0x7fff;
|
||
|
|
} else {
|
||
|
|
U_ASSERT((index + 2) <= length);
|
||
|
|
U_ASSERT(array[index] >= 0x8000);
|
||
|
|
U_ASSERT(array[index + 1] >= 0x8000);
|
||
|
|
int32_t len = ((head & 1) << 30) |
|
||
|
|
((int32_t)(array[index] & 0x7fff) << 15) |
|
||
|
|
(array[index + 1] & 0x7fff);
|
||
|
|
index += 2;
|
||
|
|
return len;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
void Edits::Iterator::updateNextIndexes() {
|
||
|
|
srcIndex += oldLength_;
|
||
|
|
if (changed) {
|
||
|
|
replIndex += newLength_;
|
||
|
|
}
|
||
|
|
destIndex += newLength_;
|
||
|
|
}
|
||
|
|
|
||
|
|
void Edits::Iterator::updatePreviousIndexes() {
|
||
|
|
srcIndex -= oldLength_;
|
||
|
|
if (changed) {
|
||
|
|
replIndex -= newLength_;
|
||
|
|
}
|
||
|
|
destIndex -= newLength_;
|
||
|
|
}
|
||
|
|
|
||
|
|
UBool Edits::Iterator::noNext() {
|
||
|
|
// No change before or beyond the string.
|
||
|
|
dir = 0;
|
||
|
|
changed = FALSE;
|
||
|
|
oldLength_ = newLength_ = 0;
|
||
|
|
return FALSE;
|
||
|
|
}
|
||
|
|
|
||
|
|
UBool Edits::Iterator::next(UBool onlyChanges, UErrorCode &errorCode) {
|
||
|
|
// Forward iteration: Update the string indexes to the limit of the current span,
|
||
|
|
// and post-increment-read array units to assemble a new span.
|
||
|
|
// Leaves the array index one after the last unit of that span.
|
||
|
|
if (U_FAILURE(errorCode)) { return FALSE; }
|
||
|
|
// We have an errorCode in case we need to start guarding against integer overflows.
|
||
|
|
// It is also convenient for caller loops if we bail out when an error was set elsewhere.
|
||
|
|
if (dir > 0) {
|
||
|
|
updateNextIndexes();
|
||
|
|
} else {
|
||
|
|
if (dir < 0) {
|
||
|
|
// Turn around from previous() to next().
|
||
|
|
// Post-increment-read the same span again.
|
||
|
|
if (remaining > 0) {
|
||
|
|
// Fine-grained iterator:
|
||
|
|
// Stay on the current one of a sequence of compressed changes.
|
||
|
|
++index; // next() rests on the index after the sequence unit.
|
||
|
|
dir = 1;
|
||
|
|
return TRUE;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
dir = 1;
|
||
|
|
}
|
||
|
|
if (remaining >= 1) {
|
||
|
|
// Fine-grained iterator: Continue a sequence of compressed changes.
|
||
|
|
if (remaining > 1) {
|
||
|
|
--remaining;
|
||
|
|
return TRUE;
|
||
|
|
}
|
||
|
|
remaining = 0;
|
||
|
|
}
|
||
|
|
if (index >= length) {
|
||
|
|
return noNext();
|
||
|
|
}
|
||
|
|
int32_t u = array[index++];
|
||
|
|
if (u <= MAX_UNCHANGED) {
|
||
|
|
// Combine adjacent unchanged ranges.
|
||
|
|
changed = FALSE;
|
||
|
|
oldLength_ = u + 1;
|
||
|
|
while (index < length && (u = array[index]) <= MAX_UNCHANGED) {
|
||
|
|
++index;
|
||
|
|
oldLength_ += u + 1;
|
||
|
|
}
|
||
|
|
newLength_ = oldLength_;
|
||
|
|
if (onlyChanges) {
|
||
|
|
updateNextIndexes();
|
||
|
|
if (index >= length) {
|
||
|
|
return noNext();
|
||
|
|
}
|
||
|
|
// already fetched u > MAX_UNCHANGED at index
|
||
|
|
++index;
|
||
|
|
} else {
|
||
|
|
return TRUE;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
changed = TRUE;
|
||
|
|
if (u <= MAX_SHORT_CHANGE) {
|
||
|
|
int32_t oldLen = u >> 12;
|
||
|
|
int32_t newLen = (u >> 9) & MAX_SHORT_CHANGE_NEW_LENGTH;
|
||
|
|
int32_t num = (u & SHORT_CHANGE_NUM_MASK) + 1;
|
||
|
|
if (coarse) {
|
||
|
|
oldLength_ = num * oldLen;
|
||
|
|
newLength_ = num * newLen;
|
||
|
|
} else {
|
||
|
|
// Split a sequence of changes that was compressed into one unit.
|
||
|
|
oldLength_ = oldLen;
|
||
|
|
newLength_ = newLen;
|
||
|
|
if (num > 1) {
|
||
|
|
remaining = num; // This is the first of two or more changes.
|
||
|
|
}
|
||
|
|
return TRUE;
|
||
|
|
}
|
||
|
|
} else {
|
||
|
|
U_ASSERT(u <= 0x7fff);
|
||
|
|
oldLength_ = readLength((u >> 6) & 0x3f);
|
||
|
|
newLength_ = readLength(u & 0x3f);
|
||
|
|
if (!coarse) {
|
||
|
|
return TRUE;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
// Combine adjacent changes.
|
||
|
|
while (index < length && (u = array[index]) > MAX_UNCHANGED) {
|
||
|
|
++index;
|
||
|
|
if (u <= MAX_SHORT_CHANGE) {
|
||
|
|
int32_t num = (u & SHORT_CHANGE_NUM_MASK) + 1;
|
||
|
|
oldLength_ += (u >> 12) * num;
|
||
|
|
newLength_ += ((u >> 9) & MAX_SHORT_CHANGE_NEW_LENGTH) * num;
|
||
|
|
} else {
|
||
|
|
U_ASSERT(u <= 0x7fff);
|
||
|
|
oldLength_ += readLength((u >> 6) & 0x3f);
|
||
|
|
newLength_ += readLength(u & 0x3f);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return TRUE;
|
||
|
|
}
|
||
|
|
|
||
|
|
UBool Edits::Iterator::previous(UErrorCode &errorCode) {
|
||
|
|
// Backward iteration: Pre-decrement-read array units to assemble a new span,
|
||
|
|
// then update the string indexes to the start of that span.
|
||
|
|
// Leaves the array index on the head unit of that span.
|
||
|
|
if (U_FAILURE(errorCode)) { return FALSE; }
|
||
|
|
// We have an errorCode in case we need to start guarding against integer overflows.
|
||
|
|
// It is also convenient for caller loops if we bail out when an error was set elsewhere.
|
||
|
|
if (dir >= 0) {
|
||
|
|
if (dir > 0) {
|
||
|
|
// Turn around from next() to previous().
|
||
|
|
// Set the string indexes to the span limit and
|
||
|
|
// pre-decrement-read the same span again.
|
||
|
|
if (remaining > 0) {
|
||
|
|
// Fine-grained iterator:
|
||
|
|
// Stay on the current one of a sequence of compressed changes.
|
||
|
|
--index; // previous() rests on the sequence unit.
|
||
|
|
dir = -1;
|
||
|
|
return TRUE;
|
||
|
|
}
|
||
|
|
updateNextIndexes();
|
||
|
|
}
|
||
|
|
dir = -1;
|
||
|
|
}
|
||
|
|
if (remaining > 0) {
|
||
|
|
// Fine-grained iterator: Continue a sequence of compressed changes.
|
||
|
|
int32_t u = array[index];
|
||
|
|
U_ASSERT(MAX_UNCHANGED < u && u <= MAX_SHORT_CHANGE);
|
||
|
|
if (remaining <= (u & SHORT_CHANGE_NUM_MASK)) {
|
||
|
|
++remaining;
|
||
|
|
updatePreviousIndexes();
|
||
|
|
return TRUE;
|
||
|
|
}
|
||
|
|
remaining = 0;
|
||
|
|
}
|
||
|
|
if (index <= 0) {
|
||
|
|
return noNext();
|
||
|
|
}
|
||
|
|
int32_t u = array[--index];
|
||
|
|
if (u <= MAX_UNCHANGED) {
|
||
|
|
// Combine adjacent unchanged ranges.
|
||
|
|
changed = FALSE;
|
||
|
|
oldLength_ = u + 1;
|
||
|
|
while (index > 0 && (u = array[index - 1]) <= MAX_UNCHANGED) {
|
||
|
|
--index;
|
||
|
|
oldLength_ += u + 1;
|
||
|
|
}
|
||
|
|
newLength_ = oldLength_;
|
||
|
|
// No need to handle onlyChanges as long as previous() is called only from findIndex().
|
||
|
|
updatePreviousIndexes();
|
||
|
|
return TRUE;
|
||
|
|
}
|
||
|
|
changed = TRUE;
|
||
|
|
if (u <= MAX_SHORT_CHANGE) {
|
||
|
|
int32_t oldLen = u >> 12;
|
||
|
|
int32_t newLen = (u >> 9) & MAX_SHORT_CHANGE_NEW_LENGTH;
|
||
|
|
int32_t num = (u & SHORT_CHANGE_NUM_MASK) + 1;
|
||
|
|
if (coarse) {
|
||
|
|
oldLength_ = num * oldLen;
|
||
|
|
newLength_ = num * newLen;
|
||
|
|
} else {
|
||
|
|
// Split a sequence of changes that was compressed into one unit.
|
||
|
|
oldLength_ = oldLen;
|
||
|
|
newLength_ = newLen;
|
||
|
|
if (num > 1) {
|
||
|
|
remaining = 1; // This is the last of two or more changes.
|
||
|
|
}
|
||
|
|
updatePreviousIndexes();
|
||
|
|
return TRUE;
|
||
|
|
}
|
||
|
|
} else {
|
||
|
|
if (u <= 0x7fff) {
|
||
|
|
// The change is encoded in u alone.
|
||
|
|
oldLength_ = readLength((u >> 6) & 0x3f);
|
||
|
|
newLength_ = readLength(u & 0x3f);
|
||
|
|
} else {
|
||
|
|
// Back up to the head of the change, read the lengths,
|
||
|
|
// and reset the index to the head again.
|
||
|
|
U_ASSERT(index > 0);
|
||
|
|
while ((u = array[--index]) > 0x7fff) {}
|
||
|
|
U_ASSERT(u > MAX_SHORT_CHANGE);
|
||
|
|
int32_t headIndex = index++;
|
||
|
|
oldLength_ = readLength((u >> 6) & 0x3f);
|
||
|
|
newLength_ = readLength(u & 0x3f);
|
||
|
|
index = headIndex;
|
||
|
|
}
|
||
|
|
if (!coarse) {
|
||
|
|
updatePreviousIndexes();
|
||
|
|
return TRUE;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
// Combine adjacent changes.
|
||
|
|
while (index > 0 && (u = array[index - 1]) > MAX_UNCHANGED) {
|
||
|
|
--index;
|
||
|
|
if (u <= MAX_SHORT_CHANGE) {
|
||
|
|
int32_t num = (u & SHORT_CHANGE_NUM_MASK) + 1;
|
||
|
|
oldLength_ += (u >> 12) * num;
|
||
|
|
newLength_ += ((u >> 9) & MAX_SHORT_CHANGE_NEW_LENGTH) * num;
|
||
|
|
} else if (u <= 0x7fff) {
|
||
|
|
// Read the lengths, and reset the index to the head again.
|
||
|
|
int32_t headIndex = index++;
|
||
|
|
oldLength_ += readLength((u >> 6) & 0x3f);
|
||
|
|
newLength_ += readLength(u & 0x3f);
|
||
|
|
index = headIndex;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
updatePreviousIndexes();
|
||
|
|
return TRUE;
|
||
|
|
}
|
||
|
|
|
||
|
|
int32_t Edits::Iterator::findIndex(int32_t i, UBool findSource, UErrorCode &errorCode) {
|
||
|
|
if (U_FAILURE(errorCode) || i < 0) { return -1; }
|
||
|
|
int32_t spanStart, spanLength;
|
||
|
|
if (findSource) { // find source index
|
||
|
|
spanStart = srcIndex;
|
||
|
|
spanLength = oldLength_;
|
||
|
|
} else { // find destination index
|
||
|
|
spanStart = destIndex;
|
||
|
|
spanLength = newLength_;
|
||
|
|
}
|
||
|
|
if (i < spanStart) {
|
||
|
|
if (i >= (spanStart / 2)) {
|
||
|
|
// Search backwards.
|
||
|
|
for (;;) {
|
||
|
|
UBool hasPrevious = previous(errorCode);
|
||
|
|
U_ASSERT(hasPrevious); // because i>=0 and the first span starts at 0
|
||
|
|
(void)hasPrevious; // avoid unused-variable warning
|
||
|
|
spanStart = findSource ? srcIndex : destIndex;
|
||
|
|
if (i >= spanStart) {
|
||
|
|
// The index is in the current span.
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
if (remaining > 0) {
|
||
|
|
// Is the index in one of the remaining compressed edits?
|
||
|
|
// spanStart is the start of the current span, first of the remaining ones.
|
||
|
|
spanLength = findSource ? oldLength_ : newLength_;
|
||
|
|
int32_t u = array[index];
|
||
|
|
U_ASSERT(MAX_UNCHANGED < u && u <= MAX_SHORT_CHANGE);
|
||
|
|
int32_t num = (u & SHORT_CHANGE_NUM_MASK) + 1 - remaining;
|
||
|
|
int32_t len = num * spanLength;
|
||
|
|
if (i >= (spanStart - len)) {
|
||
|
|
int32_t n = ((spanStart - i - 1) / spanLength) + 1;
|
||
|
|
// 1 <= n <= num
|
||
|
|
srcIndex -= n * oldLength_;
|
||
|
|
replIndex -= n * newLength_;
|
||
|
|
destIndex -= n * newLength_;
|
||
|
|
remaining += n;
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
// Skip all of these edits at once.
|
||
|
|
srcIndex -= num * oldLength_;
|
||
|
|
replIndex -= num * newLength_;
|
||
|
|
destIndex -= num * newLength_;
|
||
|
|
remaining = 0;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
// Reset the iterator to the start.
|
||
|
|
dir = 0;
|
||
|
|
index = remaining = oldLength_ = newLength_ = srcIndex = replIndex = destIndex = 0;
|
||
|
|
} else if (i < (spanStart + spanLength)) {
|
||
|
|
// The index is in the current span.
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
while (next(FALSE, errorCode)) {
|
||
|
|
if (findSource) {
|
||
|
|
spanStart = srcIndex;
|
||
|
|
spanLength = oldLength_;
|
||
|
|
} else {
|
||
|
|
spanStart = destIndex;
|
||
|
|
spanLength = newLength_;
|
||
|
|
}
|
||
|
|
if (i < (spanStart + spanLength)) {
|
||
|
|
// The index is in the current span.
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
if (remaining > 1) {
|
||
|
|
// Is the index in one of the remaining compressed edits?
|
||
|
|
// spanStart is the start of the current span, first of the remaining ones.
|
||
|
|
int32_t len = remaining * spanLength;
|
||
|
|
if (i < (spanStart + len)) {
|
||
|
|
int32_t n = (i - spanStart) / spanLength; // 1 <= n <= remaining - 1
|
||
|
|
srcIndex += n * oldLength_;
|
||
|
|
replIndex += n * newLength_;
|
||
|
|
destIndex += n * newLength_;
|
||
|
|
remaining -= n;
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
// Make next() skip all of these edits at once.
|
||
|
|
oldLength_ *= remaining;
|
||
|
|
newLength_ *= remaining;
|
||
|
|
remaining = 0;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
int32_t Edits::Iterator::destinationIndexFromSourceIndex(int32_t i, UErrorCode &errorCode) {
|
||
|
|
int32_t where = findIndex(i, TRUE, errorCode);
|
||
|
|
if (where < 0) {
|
||
|
|
// Error or before the string.
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
if (where > 0 || i == srcIndex) {
|
||
|
|
// At or after string length, or at start of the found span.
|
||
|
|
return destIndex;
|
||
|
|
}
|
||
|
|
if (changed) {
|
||
|
|
// In a change span, map to its end.
|
||
|
|
return destIndex + newLength_;
|
||
|
|
} else {
|
||
|
|
// In an unchanged span, offset 1:1 within it.
|
||
|
|
return destIndex + (i - srcIndex);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
int32_t Edits::Iterator::sourceIndexFromDestinationIndex(int32_t i, UErrorCode &errorCode) {
|
||
|
|
int32_t where = findIndex(i, FALSE, errorCode);
|
||
|
|
if (where < 0) {
|
||
|
|
// Error or before the string.
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
if (where > 0 || i == destIndex) {
|
||
|
|
// At or after string length, or at start of the found span.
|
||
|
|
return srcIndex;
|
||
|
|
}
|
||
|
|
if (changed) {
|
||
|
|
// In a change span, map to its end.
|
||
|
|
return srcIndex + oldLength_;
|
||
|
|
} else {
|
||
|
|
// In an unchanged span, offset within it.
|
||
|
|
return srcIndex + (i - destIndex);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
UnicodeString& Edits::Iterator::toString(UnicodeString& sb) const {
|
||
|
|
sb.append(u"{ src[", -1);
|
||
|
|
ICU_Utility::appendNumber(sb, srcIndex);
|
||
|
|
sb.append(u"..", -1);
|
||
|
|
ICU_Utility::appendNumber(sb, srcIndex + oldLength_);
|
||
|
|
if (changed) {
|
||
|
|
sb.append(u"] ⇝ dest[", -1);
|
||
|
|
} else {
|
||
|
|
sb.append(u"] ≡ dest[", -1);
|
||
|
|
}
|
||
|
|
ICU_Utility::appendNumber(sb, destIndex);
|
||
|
|
sb.append(u"..", -1);
|
||
|
|
ICU_Utility::appendNumber(sb, destIndex + newLength_);
|
||
|
|
if (changed) {
|
||
|
|
sb.append(u"], repl[", -1);
|
||
|
|
ICU_Utility::appendNumber(sb, replIndex);
|
||
|
|
sb.append(u"..", -1);
|
||
|
|
ICU_Utility::appendNumber(sb, replIndex + newLength_);
|
||
|
|
sb.append(u"] }", -1);
|
||
|
|
} else {
|
||
|
|
sb.append(u"] (no-change) }", -1);
|
||
|
|
}
|
||
|
|
return sb;
|
||
|
|
}
|
||
|
|
|
||
|
|
U_NAMESPACE_END
|