/// <summary>
/// Inserts an element into the <see cref="BigArray{T}"/> at the specified index.
/// </summary>
/// <param name="index">Index of <see cref="BigArray{T}"/> where the value will be.</param>
/// <param name="item">The data to be placed.</param>
public void Insert(int index, T item)
{
if (index == Count)
{
Add(item);
return;
}
var blockInfo = _arrayMap.BlockInfo(index);
int blockSubindex = index - blockInfo.CommonStartIndex;
int indexOfBlock = blockInfo.IndexOfBlock;
var block = _blockCollection[blockInfo.IndexOfBlock];
bool isMaxSize = (block.Count == _balancer.GetMaxBlockSize(indexOfBlock));
bool isNeedToAddPreviosBlock = (blockSubindex == 0 && blockInfo.Count >= _balancer.GetDefaultBlockSize(indexOfBlock));
if (isMaxSize)
{
_blockCollection.TryToDivideBlock(blockInfo.IndexOfBlock);
_arrayMap.DataChanged(blockInfo.IndexOfBlock);
Insert(index, item);
return;
}
//Insertion
if (!isNeedToAddPreviosBlock)
{
_blockCollection[blockInfo.IndexOfBlock].Insert(blockSubindex, item);
_blockCollection.TryToDivideBlock(blockInfo.IndexOfBlock);
_arrayMap.DataChanged(blockInfo.IndexOfBlock);
}
//Try to add to the previous block
else
{
//If there is need - add new block
bool isStartBlock = (blockInfo.IndexOfBlock == 0);
bool isPrevBlockFull = false;
if (!isStartBlock)
{
isPrevBlockFull = (_blockCollection[blockInfo.IndexOfBlock].Count == _balancer.GetMaxBlockSize(indexOfBlock));
}
if (isStartBlock || isPrevBlockFull)
{
_blockCollection.InsertNewBlock(blockInfo.IndexOfBlock);
blockInfo.IndexOfBlock++;
}
_blockCollection[blockInfo.IndexOfBlock - 1].Add(item);
_arrayMap.DataChanged(blockInfo.IndexOfBlock - 1);
}
Count++;
}
/// <summary>
/// Divide specified block into several blocks(if it's needed) according to correspond default block sizes.
/// </summary>
/// <param name="collection">Collection, which must be divided.</param>
/// <param name="collectionIndex">The zero-based starting index of the <see cref="collection"/> of elements to divide.</param>
/// <param name="countToDivide">The number of elements of the <see cref="collection"/> to divide.</param>
/// <returns>Collection of new blocks.</returns>
private IList <Block <T> > DivideIntoBlocks(ICollection <T> collection, int collectionIndex, int countToDivide)
{
if (collection == null)
{
throw new ArgumentNullException("collection");
}
if (!collection.IsValidRange(collectionIndex, countToDivide))
{
throw new ArgumentOutOfRangeException();
}
List <Block <T> > blockList = new List <Block <T> >();
int alreadyProcessedCount = 0;
var collectionEnumerator = collection.GetEnumerator();
for (int i = 0; i < collectionIndex; i++) //Move item to the index position
{
collectionEnumerator.MoveNext();
}
for (int i = 0; alreadyProcessedCount != countToDivide; i++)
{
int currentBlockSize = _balancer.GetDefaultBlockSize(i);
Block <T> newBlock = new Block <T>(currentBlockSize);
blockList.Add(newBlock);
currentBlockSize = Math.Min(currentBlockSize, countToDivide - alreadyProcessedCount);
for (int j = 0; j < currentBlockSize; j++)
{
collectionEnumerator.MoveNext();
newBlock.Add(collectionEnumerator.Current);
}
alreadyProcessedCount += currentBlockSize;
}
return(blockList);
}
