System.Data.ProviderBase.SchemaMapping.SetupMapping C# (CSharp) Method

        private object[] SetupMapping(int count, DataColumnCollection columnCollection, DataColumn chapterColumn, object chapterValue)
        {
            object[] dataValues = new object[count];

            if (null == _indexMap)
            {
                int mappingCount = columnCollection.Count;
                bool hasChapters = (null != _chapterMap);
                if ((count != mappingCount) || hasChapters)
                {
                    _mappedDataValues = new object[mappingCount];
                    if (hasChapters)
                    {
                        _mappedMode = MapChapters;
                        _mappedLength = count;
                    }
                    else
                    {
                        _mappedMode = MapDifferentSize;
                        _mappedLength = Math.Min(count, mappingCount);
                    }
                }
                else
                {
                    _mappedMode = MapExactMatch; /* _mappedLength doesn't matter */
                }
            }
            else
            {
                _mappedDataValues = new object[columnCollection.Count];
                _mappedMode = ((null == _chapterMap) ? MapReorderedValues : MapChaptersReordered);
                _mappedLength = count;
            }
            if (null != chapterColumn)
            { // value from parent tracked into child table
                _mappedDataValues[chapterColumn.Ordinal] = chapterValue;
            }
            return dataValues;
        }
    }