private bool Decode()

in src/ICSharpCode.SharpZipLib/Zip/Compression/Inflater.cs [429:552]
108 lines of code
28 McCabe index (conditional complexity)

		private bool Decode()
		{
			switch (mode)
			{
				case DECODE_HEADER:
					return DecodeHeader();

				case DECODE_DICT:
					return DecodeDict();

				case DECODE_CHKSUM:
					return DecodeChksum();

				case DECODE_BLOCKS:
					if (isLastBlock)
					{
						if (noHeader)
						{
							mode = FINISHED;
							return false;
						}
						else
						{
							input.SkipToByteBoundary();
							neededBits = 32;
							mode = DECODE_CHKSUM;
							return true;
						}
					}

					int type = input.PeekBits(3);
					if (type < 0)
					{
						return false;
					}
					input.DropBits(3);

					isLastBlock |= (type & 1) != 0;
					switch (type >> 1)
					{
						case DeflaterConstants.STORED_BLOCK:
							input.SkipToByteBoundary();
							mode = DECODE_STORED_LEN1;
							break;

						case DeflaterConstants.STATIC_TREES:
							litlenTree = InflaterHuffmanTree.defLitLenTree;
							distTree = InflaterHuffmanTree.defDistTree;
							mode = DECODE_HUFFMAN;
							break;

						case DeflaterConstants.DYN_TREES:
							dynHeader = new InflaterDynHeader(input);
							mode = DECODE_DYN_HEADER;
							break;

						default:
							throw new SharpZipBaseException("Unknown block type " + type);
					}
					return true;

				case DECODE_STORED_LEN1:
					{
						if ((uncomprLen = input.PeekBits(16)) < 0)
						{
							return false;
						}
						input.DropBits(16);
						mode = DECODE_STORED_LEN2;
					}
					goto case DECODE_STORED_LEN2; // fall through

				case DECODE_STORED_LEN2:
					{
						int nlen = input.PeekBits(16);
						if (nlen < 0)
						{
							return false;
						}
						input.DropBits(16);
						if (nlen != (uncomprLen ^ 0xffff))
						{
							throw new SharpZipBaseException("broken uncompressed block");
						}
						mode = DECODE_STORED;
					}
					goto case DECODE_STORED; // fall through

				case DECODE_STORED:
					{
						int more = outputWindow.CopyStored(input, uncomprLen);
						uncomprLen -= more;
						if (uncomprLen == 0)
						{
							mode = DECODE_BLOCKS;
							return true;
						}
						return !input.IsNeedingInput;
					}

				case DECODE_DYN_HEADER:
					if (!dynHeader.AttemptRead())
					{
						return false;
					}

					litlenTree = dynHeader.LiteralLengthTree;
					distTree = dynHeader.DistanceTree;
					mode = DECODE_HUFFMAN;
					goto case DECODE_HUFFMAN; // fall through

				case DECODE_HUFFMAN:
				case DECODE_HUFFMAN_LENBITS:
				case DECODE_HUFFMAN_DIST:
				case DECODE_HUFFMAN_DISTBITS:
					return DecodeHuffman();

				case FINISHED:
					return false;

				default:
					throw new SharpZipBaseException("Inflater.Decode unknown mode");
			}
		}