apewer-dotnet/Apewer.Source/Externals/MySql.Data-6.10.9/MySqlClient/Schema.cs

#if MYSQL_6_10

// Copyright ?2013, 2018, Oracle and/or its affiliates. All rights reserved.
//
// MySQL Connector/NET is licensed under the terms of the GPLv2
// <http://www.gnu.org/licenses/old-licenses/gpl-2.0.html>, like most 
// MySQL Connectors. There are special exceptions to the terms and 
// conditions of the GPLv2 as it is applied to this software, see the 
// FLOSS License Exception
// <http://www.mysql.com/about/legal/licensing/foss-exception.html>.
//
// This program is free software; you can redistribute it and/or modify 
// it under the terms of the GNU General Public License as published 
// by the Free Software Foundation; version 2 of the License.
//
// This program is distributed in the hope that it will be useful, but 
// WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
// or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 
// for more details.
//
// You should have received a copy of the GNU General Public License along 
// with this program; if not, write to the Free Software Foundation, Inc., 
// 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA

using System;
using System.Collections;
using System.Collections.Generic;
using System.Data;
using System.Text;

namespace Externals.MySql.Data.MySqlClient
{
    /// <summary>
    /// Represents a schema and its contents.
    /// </summary>
    internal partial class MySqlSchemaCollection
    {
        private readonly List<SchemaColumn> _columns = new List<SchemaColumn>();
        private readonly List<MySqlSchemaRow> _rows = new List<MySqlSchemaRow>();
#if !NETSTANDARD1_3
        private readonly DataTable _table = null;
#endif

        public MySqlSchemaCollection()
        {
            Mapping = new Dictionary<string, int>(StringComparer.OrdinalIgnoreCase);
            LogicalMappings = new Dictionary<int, int>();
        }

        public MySqlSchemaCollection(string name) : this()
        {
            Name = name;
        }

#if !NETSTANDARD1_3
        public MySqlSchemaCollection(DataTable dt) : this()
        {
            // cache the original datatable to avoid the overhead of creating again whenever possible.
            _table = dt;
            int i = 0;
            foreach (DataColumn dc in dt.Columns)
            {
                Columns.Add(new SchemaColumn() { Name = dc.ColumnName, Type = dc.DataType });
                Mapping.Add(dc.ColumnName, i++);
                LogicalMappings[Columns.Count - 1] = Columns.Count - 1;
            }

            foreach (DataRow dr in dt.Rows)
            {
                MySqlSchemaRow row = new MySqlSchemaRow(this);
                for (i = 0; i < Columns.Count; i++)
                {
                    row[i] = dr[i];
                }
                Rows.Add(row);
            }
        }
#endif

        internal Dictionary<string, int> Mapping;
        internal Dictionary<int, int> LogicalMappings;

        /// <summary>
        /// Gets or sets the name of the schema.
        /// </summary>
        public string Name { get; set; }

        /// <summary>
        /// Gets the list of columns in the schema.
        /// </summary>
        public IList<SchemaColumn> Columns => _columns;

        /// <summary>
        /// Gets the list of rows in the schema.
        /// </summary>
        public IList<MySqlSchemaRow> Rows => _rows;

        internal SchemaColumn AddColumn(string name, Type t)
        {
            SchemaColumn c = new SchemaColumn
            {
                Name = name,
                Type = t
            };

            _columns.Add(c);
            Mapping.Add(name, _columns.Count - 1);
            LogicalMappings[_columns.Count - 1] = _columns.Count - 1;
            return c;
        }

        internal int ColumnIndex(string name)
        {
            int index = -1;
            for (int i = 0; i < _columns.Count; i++)
            {
                SchemaColumn c = _columns[i];
                if (String.Compare(c.Name, name, StringComparison.OrdinalIgnoreCase) != 0) continue;
                index = i;
                break;
            }
            return index;
        }

        internal void RemoveColumn(string name)
        {
            int index = ColumnIndex(name);
            if (index == -1)
                throw new InvalidOperationException();
            _columns.RemoveAt(index);
            for (int i = index; i < Columns.Count; i++)
                LogicalMappings[i] = LogicalMappings[i] + 1;
        }

        internal bool ContainsColumn(string name)
        {
            return ColumnIndex(name) >= 0;
        }

        internal MySqlSchemaRow AddRow()
        {
            MySqlSchemaRow r = new MySqlSchemaRow(this);
            _rows.Add(r);
            return r;
        }

        internal MySqlSchemaRow NewRow()
        {
            MySqlSchemaRow r = new MySqlSchemaRow(this);
            return r;
        }

#if !NETSTANDARD1_3
        internal DataTable AsDataTable()
        {
            if (_table != null) return _table;
            DataTable dt = new DataTable(Name);
            foreach (SchemaColumn col in Columns)
                dt.Columns.Add(col.Name, col.Type);
            foreach (MySqlSchemaRow row in Rows)
            {
                DataRow newRow = dt.NewRow();
                for (int i = 0; i < dt.Columns.Count; i++)
                    newRow[i] = row[i] == null ? DBNull.Value : row[i];
                dt.Rows.Add(newRow);
            }
            return dt;
        }
#endif
    }

    /// <summary>
    /// Represents a row within a schema.
    /// </summary>
    internal class MySqlSchemaRow
    {
        private Dictionary<int, object> _data;

        public MySqlSchemaRow(MySqlSchemaCollection c)
        {
            Collection = c;
            InitMetadata();
        }

        internal void InitMetadata()
        {
            _data = new Dictionary<int, object>();
        }

        internal MySqlSchemaCollection Collection { get; }

        internal object this[string s]
        {
            get { return GetValueForName(s); }
            set { SetValueForName(s, value); }
        }

        internal object this[int i]
        {
            get
            {
                int idx = Collection.LogicalMappings[i];
                if (!_data.ContainsKey(idx))
                    _data[idx] = null;
                return _data[idx];
            }
            set { _data[Collection.LogicalMappings[i]] = value; }
        }

        private void SetValueForName(string colName, object value)
        {
            int index = Collection.Mapping[colName];
            this[index] = value;
        }

        private object GetValueForName(string colName)
        {
            int index = Collection.Mapping[colName];
            if (!_data.ContainsKey(index))
                _data[index] = null;
            return this[index];
        }

        internal void CopyRow(MySqlSchemaRow row)
        {
            if (Collection.Columns.Count != row.Collection.Columns.Count)
                throw new InvalidOperationException("column count doesn't match");
            for (int i = 0; i < Collection.Columns.Count; i++)
                row[i] = this[i];
        }
    }

    /// <summary>
    /// Represents a column within a schema.
    /// </summary>
    internal class SchemaColumn
    {
        /// <summary>
        /// The name of the column.
        /// </summary>
        public string Name { get; set; }

        /// <summary>
        /// The type of the column.
        /// </summary>
        public Type Type { get; set; }
    }
}

#endif