static size_t DecompressMultiFrame()

in csharp/src/ZStdDecompress.cs [2096:2160]
43 lines of code
9 McCabe index (conditional complexity)

		static size_t DecompressMultiFrame(ZSTD_DCtx dctx,
												void* dst, size_t dstCapacity,
										  void* src, size_t srcSize,
										  void* dict, size_t dictSize
										  /*,ZSTD_DDict ddict is constant null*/)
		{
			void* dststart = dst;
			Debug.Assert(dict == null /*|| ddict == null*/);  /* either dict or ddict set, not both */

			//if (ddict != 0)
			//{
			//	dict = ZSTD_DDictDictContent(ddict);
			//	dictSize = ZSTD_DDictDictSize(ddict);
			//}

			while (srcSize >= ZSTD_frameHeaderSize_prefix)
			{
				U32 magicNumber;

				magicNumber = MEM_readLE32(src);
				if (magicNumber != ZSTD_MAGICNUMBER)
				{
					if ((magicNumber & 0xFFFFFFF0U) == ZSTD_MAGIC_SKIPPABLE_START)
					{
						size_t skippableSize;
						if (srcSize < ZSTD_skippableHeaderSize)
							return ERROR(Error.srcSize_wrong);
						skippableSize = MEM_readLE32((BYTE*)src + ZSTD_frameIdSize) + ZSTD_skippableHeaderSize;
						if (srcSize < skippableSize)
							return ERROR(Error.srcSize_wrong);

						src = (BYTE*)src + skippableSize;
						srcSize -= skippableSize;
						continue;
					}
					return ERROR(Error.prefix_unknown);
				}

				//if (ddict)
				//{
				//	/* we were called from ZSTD_decompress_usingDDict */
				//	{ size_t errcod = ZSTD_decompressBegin_usingDDict(dctx, ddict); if ( IsError(errcod)) return errcod; }
				//}
				//else
				{
					/* this will initialize correctly with no dict if dict == null, so
					 * use this in all cases but ddict */
					{ size_t errcod = ZSTD_decompressBegin_usingDict(dctx, dict, dictSize); if (IsError(errcod)) return errcod; }
				}
				CheckContinuity(dctx, dst);

				{
					size_t res = DecompressFrame(dctx, dst, dstCapacity, &src, &srcSize);
					if (IsError(res)) return res;
					/* no need to bound check, ZSTD_decompressFrame already has */
					dst = (BYTE*)dst + res;
					dstCapacity -= res;
				}
			}  /* while (srcSize >= ZSTD_frameHeaderSize_prefix) */

			if (srcSize != 0)
				return ERROR(Error.srcSize_wrong); /* input not entirely consumed */

			return (size_t)((BYTE*)dst - (BYTE*)dststart);
		}