示例#1
0
        //method buildWaveletTree() constructs wavelet tree. It calls creation of RRR lookup table and
        //adds RRR data structure to every node.
        public void buildWaveletTree(ArrayList currentAlphabet, String currentLabel, WaveletNode currentNode)
        {
            if (currentAlphabet.Count > 2)
            {
                StringBuilder bitmapBuilder = new StringBuilder();
                StringBuilder leftLabel     = new StringBuilder();
                StringBuilder rightLabel    = new StringBuilder();
                StringBuilder RRRbitmap     = new StringBuilder();
                int           blockSize;
                int           superblockSize;


                int mid = (currentAlphabet.Count + 1) / 2;

                //creation of node bitmap
                foreach (char c in currentLabel)
                {
                    if (getIndex(Char.ToUpper(c), currentAlphabet) < mid)
                    {
                        bitmapBuilder.Append("0");
                        leftLabel.Append(Char.ToUpper(c));
                    }
                    else
                    {
                        bitmapBuilder.Append("1");
                        rightLabel.Append(Char.ToUpper(c));
                    }
                }


                currentNode.setBitmap(bitmapBuilder.ToString());

                blockSize = (int)(Math.Log(currentNode.getBitmap().Length, 2) / 2);
                if (blockSize == 0)
                {
                    blockSize = 1;
                }
                superblockSize = (int)(blockSize * Math.Floor(Math.Log(currentNode.getBitmap().Length, 2)));

                //creation of RRRLookupTable
                currentNode.RRRTable.BlockSize       = blockSize;
                currentNode.RRRTable.SuperblockSize  = superblockSize;
                currentNode.RRRTable.ClassBitsNeeded = (int)Math.Floor(Math.Log(blockSize, 2)) + 1;
                currentNode.RRRTable.buildTableG();

                //filling the bitmap with additional zeroes so that every block is equal in size
                if (bitmapBuilder.Length % blockSize != 0)
                {
                    do
                    {
                        bitmapBuilder.Append("0");
                    } while (bitmapBuilder.Length % blockSize != 0);
                }

                //creation of bitmap which is being used for creation od RRR data structure
                currentNode.setHelpBitmap(bitmapBuilder.ToString());

                //creation od RRR Data Structure
                int totalPopcount = 0;
                for (int i = 0; i < currentNode.getHelpBitmap().Length; i = i + blockSize)
                {
                    int popCount = popcount(currentNode.getHelpBitmap().Substring(i, blockSize));
                    RRRbitmap.Append(ToBin(popCount, currentNode.RRRTable.ClassBitsNeeded)); //spremi klasu sa potrebnim brojem bitova
                    RRRbitmap.Append(ToBin(currentNode.RRRTable.TableG.FirstOrDefault(t => t.Key == popCount).Value.IndexOf(currentNode.getHelpBitmap().Substring(i, blockSize)), (int)Math.Ceiling(Math.Log((GetBinCoeff(blockSize, popCount)), 2))));
                    totalPopcount += popCount;
                    if (((i + blockSize) % superblockSize) == 0 || (i + blockSize) >= currentNode.getHelpBitmap().Length)
                    {
                        currentNode.RRRStruct.superblockSums.Add(totalPopcount);
                        currentNode.RRRStruct.superblockOffsets.Add(RRRbitmap.Length);
                    }
                }
                currentNode.RRRStruct.Bitmap = RRRbitmap.ToString();
                currentNode.setLeftChild(new WaveletNode());
                currentNode.getLeftChild().setParent(currentNode);
                buildWaveletTree(currentAlphabet.GetRange(0, mid), leftLabel.ToString(), currentNode.getLeftChild());

                //if current alphabet has more than 3 characters, than it creates right child and calls recursion on this child
                if (currentAlphabet.Count > 3)
                {
                    currentNode.setRightChild(new WaveletNode());
                    currentNode.getRightChild().setParent(currentNode);
                    buildWaveletTree(currentAlphabet.GetRange(mid, (currentAlphabet.Count - mid)),
                                     rightLabel.ToString(), currentNode.getRightChild());
                }
            }
            else
            {   //creation of child nodes
                if (currentAlphabet.Count == 2)
                {
                    StringBuilder bitmapBuilder = new StringBuilder();
                    StringBuilder RRRbitmap     = new StringBuilder();
                    int           blockSize;
                    int           superblockSize;

                    foreach (char c in currentLabel)
                    {
                        if (getIndex(Char.ToUpper(c), currentAlphabet) + 1 == 1)
                        {
                            bitmapBuilder.Append("0");
                        }
                        else
                        {
                            bitmapBuilder.Append("1");
                        }
                    }

                    currentNode.setBitmap(bitmapBuilder.ToString());
                    blockSize      = (int)(Math.Log(currentNode.getBitmap().Length, 2) / 2);
                    superblockSize = (int)(blockSize * Math.Floor(Math.Log(currentNode.getBitmap().Length, 2)));
                    currentNode.RRRTable.BlockSize       = blockSize;
                    currentNode.RRRTable.SuperblockSize  = superblockSize;
                    currentNode.RRRTable.ClassBitsNeeded = (int)Math.Floor(Math.Log(blockSize, 2)) + 1;
                    currentNode.RRRTable.buildTableG();

                    if (bitmapBuilder.Length % blockSize != 0)
                    {
                        do
                        {
                            bitmapBuilder.Append("0");
                        } while (bitmapBuilder.Length % blockSize != 0);
                    }

                    currentNode.setHelpBitmap(bitmapBuilder.ToString());

                    int totalPopcount = 0;
                    for (int i = 0; i < currentNode.getHelpBitmap().Length; i = i + blockSize)
                    {
                        int popCount = popcount(currentNode.getHelpBitmap().Substring(i, blockSize));
                        RRRbitmap.Append(ToBin(popCount, currentNode.RRRTable.ClassBitsNeeded)); //spremi klasu sa potrebnim brojem bitova
                        RRRbitmap.Append(ToBin(currentNode.RRRTable.TableG.FirstOrDefault(t => t.Key == popCount).Value.IndexOf(currentNode.getHelpBitmap().Substring(i, blockSize)), (int)Math.Ceiling(Math.Log((GetBinCoeff(blockSize, popCount)), 2))));
                        totalPopcount += popCount;
                        if (((i + blockSize) % superblockSize) == 0 || (i + blockSize) >= currentNode.getHelpBitmap().Length)
                        {
                            currentNode.RRRStruct.superblockSums.Add(totalPopcount);
                            currentNode.RRRStruct.superblockOffsets.Add(RRRbitmap.Length);
                        }
                    }
                    currentNode.RRRStruct.Bitmap = RRRbitmap.ToString();
                }
                return;
            }
        }