rg1/server/Sog/3rd/MySql.Data/Interceptors/CommandInterceptor.cs

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using System;
using System.Collections.Generic;
using System.Data;
using Sog.Properties;

namespace MySql.Data.MySqlClient
{
    /// <summary>
    /// BaseCommandInterceptor is the base class that should be used for all userland 
    /// command interceptors
    /// </summary>
    public abstract class BaseCommandInterceptor
    {
        /// <summary>
        /// Gets the active connection.
        /// </summary>
        protected MySqlConnection ActiveConnection { get; private set; }

        /// <summary>
        /// Executes an SQL statements that returns a scalar value such as a calculation.
        /// </summary>
        /// <param name="sql">The SQL statement to execute.</param>
        /// <param name="returnValue">A scalar value that represents the result returned by the execution of the SQL statement.</param>
        /// <returns><c>false</c>.</returns>
        /// <remarks>This method is intended to be overriden.</remarks>
        public virtual bool ExecuteScalar(string sql, ref object returnValue)
        {
            return false;
        }

        /// <summary>
        /// Executes an SQL statement that returns the number of affected rows.
        /// </summary>
        /// <param name="sql">The SQL statement to execute.</param>
        /// <param name="returnValue">The number of affected rows.</param>
        /// <returns><c>false</c>.</returns>
        /// <remarks>This method is intended to be overriden.</remarks>
        public virtual bool ExecuteNonQuery(string sql, ref int returnValue)
        {
            return false;
        }

        /// <summary>
        /// Executes an SQL statement that will return a resultset.
        /// </summary>
        /// <param name="sql">The SQL statement to execute.</param>
        /// <param name="behavior">A value that describes the results of the query and its effect on the database.</param>
        /// <param name="returnValue">A <see cref="MySqlDataReader"/> object containing the result of the statement execution.</param>
        /// <returns><c>false</c>.</returns>
        /// <remarks>This method is intended to be overriden.</remarks>
        public virtual bool ExecuteReader(string sql, CommandBehavior behavior, ref MySqlDataReader returnValue)
        {
            return false;
        }

        /// <summary>
        /// Sets the active connection.
        /// </summary>
        /// <param name="connection">The active connection.</param>
        public virtual void Init(MySqlConnection connection)
        {
            this.ActiveConnection = connection;
        }
    }

    /// <summary>
    /// CommandInterceptor is the "manager" class that keeps the list of registered interceptors
    /// for the given connection.
    /// </summary>
    internal sealed partial class CommandInterceptor : Interceptor
    {
        bool _insideInterceptor = false;
        readonly List<BaseCommandInterceptor> _interceptors = new List<BaseCommandInterceptor>();

        public CommandInterceptor(MySqlConnection connection)
        {
            this.Connection = connection;

            this.LoadInterceptors(connection.Settings.CommandInterceptors);
        }

        public bool ExecuteScalar(string sql, ref object returnValue)
        {
            if (this._insideInterceptor)
            {
                return false;
            }

            this._insideInterceptor = true;

            bool handled = false;

            foreach (BaseCommandInterceptor bci in this._interceptors)
            {
                handled |= bci.ExecuteScalar(sql, ref returnValue);
            }

            this._insideInterceptor = false;
            return handled;
        }

        public bool ExecuteNonQuery(string sql, ref int returnValue)
        {
            if (this._insideInterceptor)
            {
                return false;
            }

            this._insideInterceptor = true;

            bool handled = false;

            foreach (BaseCommandInterceptor bci in this._interceptors)
            {
                handled |= bci.ExecuteNonQuery(sql, ref returnValue);
            }

            this._insideInterceptor = false;
            return handled;
        }

        public bool ExecuteReader(string sql, CommandBehavior behavior, ref MySqlDataReader returnValue)
        {
            if (this._insideInterceptor)
            {
                return false;
            }

            this._insideInterceptor = true;

            bool handled = false;

            foreach (BaseCommandInterceptor bci in this._interceptors)
            {
                handled |= bci.ExecuteReader(sql, behavior, ref returnValue);
            }

            this._insideInterceptor = false;
            return handled;
        }

        protected override void AddInterceptor(object o)
        {
            if (o == null)
            {
                throw new ArgumentException("Unable to instantiate CommandInterceptor");
            }

            if (!(o is BaseCommandInterceptor))
            {
                throw new InvalidOperationException(string.Format(
                    Resources.TypeIsNotCommandInterceptor,
                    o.GetType()));
            }

            BaseCommandInterceptor ie = (BaseCommandInterceptor)o;
            ie.Init(this.Connection);
            this._interceptors.Insert(0, (BaseCommandInterceptor)o);
        }


#if !NETCOREAPP
        protected override string ResolveType(string nameOrType)
    {
      if (MySqlConfiguration.Settings == null || MySqlConfiguration.Settings.CommandInterceptors == null)
        return base.ResolveType(nameOrType);
      foreach (InterceptorConfigurationElement e in MySqlConfiguration.Settings.CommandInterceptors)
        if (String.Compare(e.Name, nameOrType, true) == 0)
          return e.Type;
      return base.ResolveType(nameOrType);
    }
#endif

    }
}