private void AppendToBack(RopeString ropeString, int fromIndex, int length)
{
if (length == 0)
return;
// First we search sector with lesser or equals first index to fromIndex
int anotherStringSectorIndex = SearchSectorByGlobalIndex(ropeString, fromIndex);
if (anotherStringSectorIndex == -1)
throw new InvalidOperationException("fromIndex ouside of bounds");
// Cope from found sector from fromIndex to end to another new sector.
var firstNewSector = new RopeSector();
var firstOldSector = ropeString._descriptors[anotherStringSectorIndex].Sector;
var indexInsideFirstSector = fromIndex -
ropeString._descriptors[anotherStringSectorIndex].FirstIndexInGlobal;
// If index inside sector is zero --- just copy full sector.
if (indexInsideFirstSector > 0)
{
while (indexInsideFirstSector < firstOldSector.Length && firstNewSector.Length < length)
{
firstNewSector.AppendToBack(firstOldSector[indexInsideFirstSector++]);
}
// Add new first sector to back of current string.
_descriptors.Add(
new RopeSectorDescriptor
{
FirstIndexInGlobal = Length,
Sector = firstNewSector
});
Length += firstNewSector.Length;
++anotherStringSectorIndex;
}
int lastIndex = fromIndex + length - 1;
// First we search sector with lesser or equals first index to fromIndex
int anotherStringSectorFinishIndex = SearchSectorByGlobalIndex(ropeString, lastIndex);
if (anotherStringSectorFinishIndex == -1)
throw new InvalidOperationException("fromIndex + length ouside of bounds");
// Batch add all next sectors to back of currect string.
while (anotherStringSectorIndex < anotherStringSectorFinishIndex)
{
RopeSector sector = ropeString._descriptors[anotherStringSectorIndex++].Sector;
_descriptors.Add(
new RopeSectorDescriptor
{
FirstIndexInGlobal = Length,
Sector = sector
});
Length += sector.Length;
}
// Add last sector if needed.
if (anotherStringSectorFinishIndex >= anotherStringSectorIndex &&
anotherStringSectorFinishIndex < ropeString._descriptors.Count &&
ropeString._descriptors[anotherStringSectorFinishIndex].FirstIndexInGlobal <= lastIndex)
{
var lastSector = ropeString._descriptors[anotherStringSectorFinishIndex].Sector;
int countOfCopiedChars = lastIndex -
ropeString._descriptors[anotherStringSectorFinishIndex].FirstIndexInGlobal + 1;
var newSector = new RopeSector();
for (int indexInsideSector = 0; indexInsideSector < countOfCopiedChars; ++indexInsideSector)
newSector.AppendToBack(lastSector[indexInsideSector]);
_descriptors.Add(new RopeSectorDescriptor { FirstIndexInGlobal = Length, Sector = newSector });
Length += newSector.Length;
}
}
private void PushSectorToBack(RopeSector sector)
{
_descriptors.Add(
new RopeSectorDescriptor
{
FirstIndexInGlobal = Length,
Sector = sector
});
Length += sector.Length;
}
private static RopeString ConvertFromRegularString(string regularString)
{
var ropeString = new RopeString();
int currentIndex = 0;
while (currentIndex < regularString.Length)
{
var sector = new RopeSector();
while (sector.Length < RopeSector.SectorSize && currentIndex < regularString.Length)
{
sector.AppendToBack(regularString[currentIndex++]);
}
ropeString.PushSectorToBack(sector);
}
return ropeString;
}
