static void BuildFSETable()

in csharp/src/ZStdDecompress.cs [958:1034]
67 lines of code
8 McCabe index (conditional complexity)

		static void BuildFSETable(SeqSymbol* dt,
			short[] normalizedCounter, uint maxSymbolValue,
			U32[] baseValue, U32[] nbAdditionalBits,
			uint tableLog)
		{
			{

				SeqSymbol* tableDecode = dt + 1;
				U16[] symbolNext = new U16[MaxSeq + 1];

				U32 maxSV1 = maxSymbolValue + 1;
				U32 tableSize = (U32)1 << (int)tableLog;
				U32 highThreshold = tableSize - 1;

				/* Sanity Checks */
				Debug.Assert(maxSymbolValue <= MaxSeq);
				Debug.Assert(tableLog <= MaxFSELog);

				/* Init, lay down lowprob symbols */
				{
					ZSTD_seqSymbol_header DTableH;
					DTableH.tableLog = tableLog;
					DTableH.fastMode = 1;
					{
						S16 largeLimit = (S16)(1 << (int)(tableLog - 1));
						U32 s;
						for (s = 0; s < maxSV1; s++)
						{
							if (normalizedCounter[s] == -1)
							{
								tableDecode[highThreshold--].baseValue = s;
								symbolNext[s] = 1;
							}
							else
							{
								if (normalizedCounter[s] >= largeLimit) DTableH.fastMode = 0;
								symbolNext[s] = (U16)normalizedCounter[s];
							}
						}
					}
					*(ZSTD_seqSymbol_header*)dt = DTableH; //memcpy(dt, &DTableH, sizeof(ZSTD_seqSymbol_header /*DTableH*/));
				}

				/* Spread symbols */
				{
					U32 tableMask = tableSize - 1;
					U32 step = Fse.FSE_TABLESTEP(tableSize);
					U32 s, position = 0;
					for (s = 0; s < maxSV1; s++)
					{
						int i;
						for (i = 0; i < normalizedCounter[s]; i++)
						{
							tableDecode[position].baseValue = s;
							position = (position + step) & tableMask;
							while (position > highThreshold) position = (position + step) & tableMask; /* lowprob area */
						}
					}
					Debug.Assert(position == 0); /* position must reach all cells once, otherwise normalizedCounter is incorrect */
				}

				/* Build Decoding table */
				{
					U32 u;
					for (u = 0; u < tableSize; u++)
					{
						U32 symbol = tableDecode[u].baseValue;
						U32 nextState = symbolNext[symbol]++;
						tableDecode[u].nbBits = (BYTE)(tableLog - BIT_highbit32(nextState));
						tableDecode[u].nextState = (U16)((nextState << tableDecode[u].nbBits) - tableSize);
						Debug.Assert(nbAdditionalBits[symbol] < 255);
						tableDecode[u].nbAdditionalBits = (BYTE)nbAdditionalBits[symbol];
						tableDecode[u].baseValue = baseValue[symbol];
					}
				}
			}
		}