| // © 2017 and later: Unicode, Inc. and others. |
| // License & terms of use: http://www.unicode.org/copyright.html |
| |
| // edits.cpp |
| // created: 2017feb08 Markus W. Scherer |
| |
| #include "unicode/edits.h" |
| #include "unicode/unistr.h" |
| #include "unicode/utypes.h" |
| #include "cmemory.h" |
| #include "uassert.h" |
| #include "util.h" |
| |
| U_NAMESPACE_BEGIN |
| |
| namespace { |
| |
| // 0000uuuuuuuuuuuu records u+1 unchanged text units. |
| const int32_t MAX_UNCHANGED_LENGTH = 0x1000; |
| const int32_t MAX_UNCHANGED = MAX_UNCHANGED_LENGTH - 1; |
| |
| // 0mmmnnnccccccccc with m=1..6 records ccc+1 replacements of m:n text units. |
| const int32_t MAX_SHORT_CHANGE_OLD_LENGTH = 6; |
| const int32_t MAX_SHORT_CHANGE_NEW_LENGTH = 7; |
| const int32_t SHORT_CHANGE_NUM_MASK = 0x1ff; |
| const int32_t MAX_SHORT_CHANGE = 0x6fff; |
| |
| // 0111mmmmmmnnnnnn records a replacement of m text units with n. |
| // m or n = 61: actual length follows in the next edits array unit. |
| // m or n = 62..63: actual length follows in the next two edits array units. |
| // Bit 30 of the actual length is in the head unit. |
| // Trailing units have bit 15 set. |
| const int32_t LENGTH_IN_1TRAIL = 61; |
| const int32_t LENGTH_IN_2TRAIL = 62; |
| |
| } // namespace |
| |
| void Edits::releaseArray() U_NOEXCEPT { |
| if (array != stackArray) { |
| uprv_free(array); |
| } |
| } |
| |
| Edits &Edits::copyArray(const Edits &other) { |
| if (U_FAILURE(errorCode_)) { |
| length = delta = numChanges = 0; |
| return *this; |
| } |
| if (length > capacity) { |
| uint16_t *newArray = (uint16_t *)uprv_malloc((size_t)length * 2); |
| if (newArray == nullptr) { |
| length = delta = numChanges = 0; |
| errorCode_ = U_MEMORY_ALLOCATION_ERROR; |
| return *this; |
| } |
| releaseArray(); |
| array = newArray; |
| capacity = length; |
| } |
| if (length > 0) { |
| uprv_memcpy(array, other.array, (size_t)length * 2); |
| } |
| return *this; |
| } |
| |
| Edits &Edits::moveArray(Edits &src) U_NOEXCEPT { |
| if (U_FAILURE(errorCode_)) { |
| length = delta = numChanges = 0; |
| return *this; |
| } |
| releaseArray(); |
| if (length > STACK_CAPACITY) { |
| array = src.array; |
| capacity = src.capacity; |
| src.array = src.stackArray; |
| src.capacity = STACK_CAPACITY; |
| src.reset(); |
| return *this; |
| } |
| array = stackArray; |
| capacity = STACK_CAPACITY; |
| if (length > 0) { |
| uprv_memcpy(array, src.array, (size_t)length * 2); |
| } |
| return *this; |
| } |
| |
| Edits &Edits::operator=(const Edits &other) { |
| length = other.length; |
| delta = other.delta; |
| numChanges = other.numChanges; |
| errorCode_ = other.errorCode_; |
| return copyArray(other); |
| } |
| |
| Edits &Edits::operator=(Edits &&src) U_NOEXCEPT { |
| length = src.length; |
| delta = src.delta; |
| numChanges = src.numChanges; |
| errorCode_ = src.errorCode_; |
| return moveArray(src); |
| } |
| |
| Edits::~Edits() { |
| releaseArray(); |
| } |
| |
| void Edits::reset() U_NOEXCEPT { |
| length = delta = numChanges = 0; |
| errorCode_ = U_ZERO_ERROR; |
| } |
| |
| void Edits::addUnchanged(int32_t unchangedLength) { |
| if(U_FAILURE(errorCode_) || unchangedLength == 0) { return; } |
| if(unchangedLength < 0) { |
| errorCode_ = U_ILLEGAL_ARGUMENT_ERROR; |
| return; |
| } |
| // Merge into previous unchanged-text record, if any. |
| int32_t last = lastUnit(); |
| if(last < MAX_UNCHANGED) { |
| int32_t remaining = MAX_UNCHANGED - last; |
| if (remaining >= unchangedLength) { |
| setLastUnit(last + unchangedLength); |
| return; |
| } |
| setLastUnit(MAX_UNCHANGED); |
| unchangedLength -= remaining; |
| } |
| // Split large lengths into multiple units. |
| while(unchangedLength >= MAX_UNCHANGED_LENGTH) { |
| append(MAX_UNCHANGED); |
| unchangedLength -= MAX_UNCHANGED_LENGTH; |
| } |
| // Write a small (remaining) length. |
| if(unchangedLength > 0) { |
| append(unchangedLength - 1); |
| } |
| } |
| |
| void Edits::addReplace(int32_t oldLength, int32_t newLength) { |
| if(U_FAILURE(errorCode_)) { return; } |
| if(oldLength < 0 || newLength < 0) { |
| errorCode_ = U_ILLEGAL_ARGUMENT_ERROR; |
| return; |
| } |
| if (oldLength == 0 && newLength == 0) { |
| return; |
| } |
| ++numChanges; |
| int32_t newDelta = newLength - oldLength; |
| if (newDelta != 0) { |
| if ((newDelta > 0 && delta >= 0 && newDelta > (INT32_MAX - delta)) || |
| (newDelta < 0 && delta < 0 && newDelta < (INT32_MIN - delta))) { |
| // Integer overflow or underflow. |
| errorCode_ = U_INDEX_OUTOFBOUNDS_ERROR; |
| return; |
| } |
| delta += newDelta; |
| } |
| |
| if(0 < oldLength && oldLength <= MAX_SHORT_CHANGE_OLD_LENGTH && |
| newLength <= MAX_SHORT_CHANGE_NEW_LENGTH) { |
| // Merge into previous same-lengths short-replacement record, if any. |
| int32_t u = (oldLength << 12) | (newLength << 9); |
| int32_t last = lastUnit(); |
| if(MAX_UNCHANGED < last && last < MAX_SHORT_CHANGE && |
| (last & ~SHORT_CHANGE_NUM_MASK) == u && |
| (last & SHORT_CHANGE_NUM_MASK) < SHORT_CHANGE_NUM_MASK) { |
| setLastUnit(last + 1); |
| return; |
| } |
| append(u); |
| return; |
| } |
| |
| int32_t head = 0x7000; |
| if (oldLength < LENGTH_IN_1TRAIL && newLength < LENGTH_IN_1TRAIL) { |
| head |= oldLength << 6; |
| head |= newLength; |
| append(head); |
| } else if ((capacity - length) >= 5 || growArray()) { |
| int32_t limit = length + 1; |
| if(oldLength < LENGTH_IN_1TRAIL) { |
| head |= oldLength << 6; |
| } else if(oldLength <= 0x7fff) { |
| head |= LENGTH_IN_1TRAIL << 6; |
| array[limit++] = (uint16_t)(0x8000 | oldLength); |
| } else { |
| head |= (LENGTH_IN_2TRAIL + (oldLength >> 30)) << 6; |
| array[limit++] = (uint16_t)(0x8000 | (oldLength >> 15)); |
| array[limit++] = (uint16_t)(0x8000 | oldLength); |
| } |
| if(newLength < LENGTH_IN_1TRAIL) { |
| head |= newLength; |
| } else if(newLength <= 0x7fff) { |
| head |= LENGTH_IN_1TRAIL; |
| array[limit++] = (uint16_t)(0x8000 | newLength); |
| } else { |
| head |= LENGTH_IN_2TRAIL + (newLength >> 30); |
| array[limit++] = (uint16_t)(0x8000 | (newLength >> 15)); |
| array[limit++] = (uint16_t)(0x8000 | newLength); |
| } |
| array[length] = (uint16_t)head; |
| length = limit; |
| } |
| } |
| |
| void Edits::append(int32_t r) { |
| if(length < capacity || growArray()) { |
| array[length++] = (uint16_t)r; |
| } |
| } |
| |
| UBool Edits::growArray() { |
| int32_t newCapacity; |
| if (array == stackArray) { |
| newCapacity = 2000; |
| } else if (capacity == INT32_MAX) { |
| // Not U_BUFFER_OVERFLOW_ERROR because that could be confused on a string transform API |
| // with a result-string-buffer overflow. |
| errorCode_ = U_INDEX_OUTOFBOUNDS_ERROR; |
| return FALSE; |
| } else if (capacity >= (INT32_MAX / 2)) { |
| newCapacity = INT32_MAX; |
| } else { |
| newCapacity = 2 * capacity; |
| } |
| // Grow by at least 5 units so that a maximal change record will fit. |
| if ((newCapacity - capacity) < 5) { |
| errorCode_ = U_INDEX_OUTOFBOUNDS_ERROR; |
| return FALSE; |
| } |
| uint16_t *newArray = (uint16_t *)uprv_malloc((size_t)newCapacity * 2); |
| if (newArray == NULL) { |
| errorCode_ = U_MEMORY_ALLOCATION_ERROR; |
| return FALSE; |
| } |
| uprv_memcpy(newArray, array, (size_t)length * 2); |
| releaseArray(); |
| array = newArray; |
| capacity = newCapacity; |
| return TRUE; |
| } |
| |
| UBool Edits::copyErrorTo(UErrorCode &outErrorCode) const { |
| if (U_FAILURE(outErrorCode)) { return TRUE; } |
| if (U_SUCCESS(errorCode_)) { return FALSE; } |
| outErrorCode = errorCode_; |
| return TRUE; |
| } |
| |
| Edits &Edits::mergeAndAppend(const Edits &ab, const Edits &bc, UErrorCode &errorCode) { |
| if (copyErrorTo(errorCode)) { return *this; } |
| // Picture string a --(Edits ab)--> string b --(Edits bc)--> string c. |
| // Parallel iteration over both Edits. |
| Iterator abIter = ab.getFineIterator(); |
| Iterator bcIter = bc.getFineIterator(); |
| UBool abHasNext = TRUE, bcHasNext = TRUE; |
| // Copy iterator state into local variables, so that we can modify and subdivide spans. |
| // ab old & new length, bc old & new length |
| int32_t aLength = 0, ab_bLength = 0, bc_bLength = 0, cLength = 0; |
| // When we have different-intermediate-length changes, we accumulate a larger change. |
| int32_t pending_aLength = 0, pending_cLength = 0; |
| for (;;) { |
| // At this point, for each of the two iterators: |
| // Either we are done with the locally cached current edit, |
| // and its intermediate-string length has been reset, |
| // or we will continue to work with a truncated remainder of this edit. |
| // |
| // If the current edit is done, and the iterator has not yet reached the end, |
| // then we fetch the next edit. This is true for at least one of the iterators. |
| // |
| // Normally it does not matter whether we fetch from ab and then bc or vice versa. |
| // However, the result is observably different when |
| // ab deletions meet bc insertions at the same intermediate-string index. |
| // Some users expect the bc insertions to come first, so we fetch from bc first. |
| if (bc_bLength == 0) { |
| if (bcHasNext && (bcHasNext = bcIter.next(errorCode)) != 0) { |
| bc_bLength = bcIter.oldLength(); |
| cLength = bcIter.newLength(); |
| if (bc_bLength == 0) { |
| // insertion |
| if (ab_bLength == 0 || !abIter.hasChange()) { |
| addReplace(pending_aLength, pending_cLength + cLength); |
| pending_aLength = pending_cLength = 0; |
| } else { |
| pending_cLength += cLength; |
| } |
| continue; |
| } |
| } |
| // else see if the other iterator is done, too. |
| } |
| if (ab_bLength == 0) { |
| if (abHasNext && (abHasNext = abIter.next(errorCode)) != 0) { |
| aLength = abIter.oldLength(); |
| ab_bLength = abIter.newLength(); |
| if (ab_bLength == 0) { |
| // deletion |
| if (bc_bLength == bcIter.oldLength() || !bcIter.hasChange()) { |
| addReplace(pending_aLength + aLength, pending_cLength); |
| pending_aLength = pending_cLength = 0; |
| } else { |
| pending_aLength += aLength; |
| } |
| continue; |
| } |
| } else if (bc_bLength == 0) { |
| // Both iterators are done at the same time: |
| // The intermediate-string lengths match. |
| break; |
| } else { |
| // The ab output string is shorter than the bc input string. |
| if (!copyErrorTo(errorCode)) { |
| errorCode = U_ILLEGAL_ARGUMENT_ERROR; |
| } |
| return *this; |
| } |
| } |
| if (bc_bLength == 0) { |
| // The bc input string is shorter than the ab output string. |
| if (!copyErrorTo(errorCode)) { |
| errorCode = U_ILLEGAL_ARGUMENT_ERROR; |
| } |
| return *this; |
| } |
| // Done fetching: ab_bLength > 0 && bc_bLength > 0 |
| |
| // The current state has two parts: |
| // - Past: We accumulate a longer ac edit in the "pending" variables. |
| // - Current: We have copies of the current ab/bc edits in local variables. |
| // At least one side is newly fetched. |
| // One side might be a truncated remainder of an edit we fetched earlier. |
| |
| if (!abIter.hasChange() && !bcIter.hasChange()) { |
| // An unchanged span all the way from string a to string c. |
| if (pending_aLength != 0 || pending_cLength != 0) { |
| addReplace(pending_aLength, pending_cLength); |
| pending_aLength = pending_cLength = 0; |
| } |
| int32_t unchangedLength = aLength <= cLength ? aLength : cLength; |
| addUnchanged(unchangedLength); |
| ab_bLength = aLength -= unchangedLength; |
| bc_bLength = cLength -= unchangedLength; |
| // At least one of the unchanged spans is now empty. |
| continue; |
| } |
| if (!abIter.hasChange() && bcIter.hasChange()) { |
| // Unchanged a->b but changed b->c. |
| if (ab_bLength >= bc_bLength) { |
| // Split the longer unchanged span into change + remainder. |
| addReplace(pending_aLength + bc_bLength, pending_cLength + cLength); |
| pending_aLength = pending_cLength = 0; |
| 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 |
