dev-npgsql/npgsql: Npgsql is the .NET data provider for PostgreSQL.

src/Npgsql/NpgsqlDataAdapter.cs
229 строк9 KB
Nikita Kazmin
Made everything to dispose asynchronously if possible (#3703)
04 май 2021, 18:16
04 май 2021, 18:1693e74c0
using System;
using System.Data;
using System.Data.Common;
using System.Threading;
using System.Threading.Tasks;
using JetBrains.Annotations;

namespace Npgsql
{
    /// <summary>
    /// Represents the method that handles the <see cref="NpgsqlDataAdapter.RowUpdated">RowUpdated</see> events.
    /// </summary>
    /// <param name="sender">The source of the event.</param>
    /// <param name="e">A <see cref="NpgsqlRowUpdatedEventArgs">NpgsqlRowUpdatedEventArgs</see> that contains the event data.</param>
    public delegate void NpgsqlRowUpdatedEventHandler(object sender, NpgsqlRowUpdatedEventArgs e);

    /// <summary>
    /// Represents the method that handles the <see cref="NpgsqlDataAdapter.RowUpdating">RowUpdating</see> events.
    /// </summary>
    /// <param name="sender">The source of the event.</param>
    /// <param name="e">A <see cref="NpgsqlRowUpdatingEventArgs">NpgsqlRowUpdatingEventArgs</see> that contains the event data.</param>
    public delegate void NpgsqlRowUpdatingEventHandler(object sender, NpgsqlRowUpdatingEventArgs e);

    /// <summary>
    /// This class represents an adapter from many commands: select, update, insert and delete to fill <see cref="System.Data.DataSet">Datasets.</see>
    /// </summary>
    [System.ComponentModel.DesignerCategory("")]
    public sealed class NpgsqlDataAdapter : DbDataAdapter
    {
        /// <summary>
        /// Row updated event.
        /// </summary>
        public event NpgsqlRowUpdatedEventHandler? RowUpdated;

        /// <summary>
        /// Row updating event.
        /// </summary>
        public event NpgsqlRowUpdatingEventHandler? RowUpdating;

        /// <summary>
        /// Default constructor.
        /// </summary>
        public NpgsqlDataAdapter() {}

        /// <summary>
        /// Constructor.
        /// </summary>
        /// <param name="selectCommand"></param>
        public NpgsqlDataAdapter(NpgsqlCommand selectCommand)
            => SelectCommand = selectCommand;

        /// <summary>
        /// Constructor.
        /// </summary>
        /// <param name="selectCommandText"></param>
        /// <param name="selectConnection"></param>
        public NpgsqlDataAdapter(string selectCommandText, NpgsqlConnection selectConnection)
            : this(new NpgsqlCommand(selectCommandText, selectConnection)) {}

        /// <summary>
        /// Constructor.
        /// </summary>
        /// <param name="selectCommandText"></param>
        /// <param name="selectConnectionString"></param>
        public NpgsqlDataAdapter(string selectCommandText, string selectConnectionString)
            : this(selectCommandText, new NpgsqlConnection(selectConnectionString)) {}

        /// <summary>
        /// Create row updated event.
        /// </summary>
        protected override RowUpdatedEventArgs CreateRowUpdatedEvent(DataRow dataRow, IDbCommand? command,
                                                                     System.Data.StatementType statementType,
                                                                     DataTableMapping tableMapping)
            => new NpgsqlRowUpdatedEventArgs(dataRow, command, statementType, tableMapping);

        /// <summary>
        /// Create row updating event.
        /// </summary>
        protected override RowUpdatingEventArgs CreateRowUpdatingEvent(DataRow dataRow, IDbCommand? command,
                                                                       System.Data.StatementType statementType,
                                                                       DataTableMapping tableMapping)
            => new NpgsqlRowUpdatingEventArgs(dataRow, command, statementType, tableMapping);

        /// <summary>
        /// Raise the RowUpdated event.
        /// </summary>
        /// <param name="value"></param>
        protected override void OnRowUpdated(RowUpdatedEventArgs value)
        {
            //base.OnRowUpdated(value);
            if (value is NpgsqlRowUpdatedEventArgs args)
                RowUpdated?.Invoke(this, args);
            //if (RowUpdated != null && value is NpgsqlRowUpdatedEventArgs args)
            //    RowUpdated(this, args);
        }

        /// <summary>
        /// Raise the RowUpdating event.
        /// </summary>
        /// <param name="value"></param>
        protected override void OnRowUpdating(RowUpdatingEventArgs value)
        {
            if (value is NpgsqlRowUpdatingEventArgs args)
                RowUpdating?.Invoke(this, args);
        }

        /// <summary>
        /// Delete command.
        /// </summary>
        public new NpgsqlCommand? DeleteCommand
        {
            get => (NpgsqlCommand?)base.DeleteCommand;
            set => base.DeleteCommand = value;
        }

        /// <summary>
        /// Select command.
        /// </summary>
        public new NpgsqlCommand? SelectCommand
        {
            get => (NpgsqlCommand?)base.SelectCommand;
            set => base.SelectCommand = value;
        }

        /// <summary>
        /// Update command.
        /// </summary>
        public new NpgsqlCommand? UpdateCommand
        {
            get => (NpgsqlCommand?)base.UpdateCommand;
            set => base.UpdateCommand = value;
        }

        /// <summary>
        /// Insert command.
        /// </summary>
        public new NpgsqlCommand? InsertCommand
        {
            get => (NpgsqlCommand?)base.InsertCommand;
            set => base.InsertCommand = value;
        }

        // Temporary implementation, waiting for official support in System.Data via https://github.com/dotnet/runtime/issues/22109
        internal async Task<int> Fill(DataTable dataTable, bool async, CancellationToken cancellationToken = default)
        {
            var command = SelectCommand;
            var activeConnection = command?.Connection ?? throw new InvalidOperationException("Connection required");
            var originalState = ConnectionState.Closed;

            try
            {
                originalState = activeConnection.State;
                if (ConnectionState.Closed == originalState)
                    await activeConnection.Open(async, cancellationToken);

                var dataReader = await command.ExecuteReader(CommandBehavior.Default, async, cancellationToken);
                try
                {
                    return await Fill(dataTable, dataReader, async, cancellationToken);
                }
                finally
                {
                    if (async)
                        await dataReader.DisposeAsync();
                    else
                        dataReader.Dispose();
                }
            }
            finally
            {
                if (ConnectionState.Closed == originalState)
                    activeConnection.Close();
            }
        }

        async Task<int> Fill(DataTable dataTable, NpgsqlDataReader dataReader, bool async, CancellationToken cancellationToken = default)
        {
            dataTable.BeginLoadData();
            try
            {
                var rowsAdded = 0;
                var count = dataReader.FieldCount;
                var columnCollection = dataTable.Columns;
                for (var i = 0; i < count; ++i)
                {
                    var fieldName = dataReader.GetName(i);
                    if (!columnCollection.Contains(fieldName))
                    {
                        var fieldType = dataReader.GetFieldType(i);
                        var dataColumn = new DataColumn(fieldName, fieldType);
                        columnCollection.Add(dataColumn);
                    }
                }

                var values = new object[count];

                while (async ? await dataReader.ReadAsync(cancellationToken) : dataReader.Read())
                {
                    dataReader.GetValues(values);
                    dataTable.LoadDataRow(values, true);
                    rowsAdded++;
                }
                return rowsAdded;
            }
            finally
            {
                dataTable.EndLoadData();
            }
        }
    }

#pragma warning disable 1591

    public class NpgsqlRowUpdatingEventArgs : RowUpdatingEventArgs
    {
        public NpgsqlRowUpdatingEventArgs(DataRow dataRow, IDbCommand? command, System.Data.StatementType statementType,
                                          DataTableMapping tableMapping)
            : base(dataRow, command, statementType, tableMapping) {}
    }

    public class NpgsqlRowUpdatedEventArgs : RowUpdatedEventArgs
    {
        public NpgsqlRowUpdatedEventArgs(DataRow dataRow, IDbCommand? command, System.Data.StatementType statementType,
                                         DataTableMapping tableMapping)
            : base(dataRow, command, statementType, tableMapping) {}
    }

#pragma warning restore 1591
}