Google.Protobuf.ByteArray.Copy C# (CSharp) Method

        internal static void Copy(byte[] src, int srcOffset, byte[] dst, int dstOffset, int count)
        {
            if (count > CopyThreshold)
            {
                Buffer.BlockCopy(src, srcOffset, dst, dstOffset, count);
            }
            else
            {
                int stop = srcOffset + count;
                for (int i = srcOffset; i < stop; i++)
                {
                    dst[dstOffset++] = src[i];
                }
            }
        }

        /// <summary>
        /// Writes out part of an array of bytes.
        /// </summary>
        internal void WriteRawBytes(byte[] value, int offset, int length)
        {
            if (limit - position >= length)
            {
                ByteArray.Copy(value, offset, buffer, position, length);
                // We have room in the current buffer.
                position += length;
            }
            else
            {
                // Write extends past current buffer.  Fill the rest of this buffer and
                // flush.
                int bytesWritten = limit - position;
                ByteArray.Copy(value, offset, buffer, position, bytesWritten);
                offset  += bytesWritten;
                length  -= bytesWritten;
                position = limit;
                RefreshBuffer();

                // Now deal with the rest.
                // Since we have an output stream, this is our buffer
                // and buffer offset == 0
                if (length <= limit)
                {
                    // Fits in new buffer.
                    ByteArray.Copy(value, offset, buffer, 0, length);
                    position = length;
                }
                else
                {
                    // Write is very big.  Let's do it all at once.
                    output.Write(value, offset, length);
                }
            }
        }