IObjectPool.cs :  » Inversion-of-Control-Dependency-Injection » Spring.net » Spring » Pool » C# / CSharp Open Source

#region License

/*
* Copyright  2002-2005 the original author or authors.
* 
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
* 
*      http://www.apache.org/licenses/LICENSE-2.0
* 
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/

#endregion

using System;

namespace Spring.Pool{
  /// <summary>
  /// A simple pooling interface for managing and monitoring a pool
  /// of objects.  
  /// </summary>
  /// <remarks>
  /// <p>
  /// Based on the Jakarta Commons Pool API.
  /// </p>
  /// </remarks>
  /// <author>Federico Spinazzi</author>
  /// <seealso cref="Spring.Pool.IPoolableObjectFactory"/>
  public interface IObjectPool
  {
    /// <summary>
    /// Obtain an instance from the pool.
    /// </summary>
    /// <remarks>
    /// <p>
    /// By contract, clients <b>must</b> return the borrowed 
    /// instance using <see cref="Spring.Pool.IObjectPool.ReturnObject"/>
    /// or a related method as defined in an implementation or
    /// sub-interface.
    /// </p>
    /// </remarks>
    /// <returns>An instance from the pool.</returns>
    /// <exception cref="Spring.Pool.PoolException">
    /// In case the pool is unusable.
    /// </exception>
    /// <seealso cref="Spring.Pool.IPoolableObjectFactory.ActivateObject"/>
    object BorrowObject();

    /// <summary>
    /// Return an instance to the pool.
    /// </summary>
    /// <remarks>
    /// <p>
    /// By contract, the object <b>must</b> have been obtained using 
    /// <see cref="Spring.Pool.IObjectPool.BorrowObject"/>
    /// or a related method as defined in an implementation or sub-interface.
    /// </p>
    /// </remarks>
    /// <param name="target">The instance to be returned to the pool.</param>
    /// <seealso cref="Spring.Pool.IPoolableObjectFactory.PassivateObject"/>
    void ReturnObject(object target);

        /// <summary>
        /// Create an object using the factory set by
        /// the <see cref="PoolableObjectFactory"/> property
        /// or other implementation dependent mechanism
        /// and place it into the pool. 
        /// </summary>
        /// <remarks>
        /// <p>
        /// This is an optional operation. AddObject is useful for "pre-loading" a 
        /// pool with idle objects.
        /// </p>
        /// </remarks>
        /// <exception cref="NotSupportedException">
        /// If the implementation does not support the operation.
        /// </exception>
        void AddObject();

        /// <summary>
        /// Close the pool and free any resources associated with it.
        /// </summary>
        void Close();

        /// <summary>
        /// Clear objects sitting idle in the pool, releasing any
        /// associated resources.
        /// </summary>
        /// <remarks>
        /// <p>
        /// This is an optional operation.
        /// </p>
        /// </remarks>
        /// <exception cref="NotSupportedException">
        /// If the implementation does not support the operation.
        /// </exception>
        void Clear();

    /// <summary>
    /// Gets the number of instances currently borrowed from the pool. 
    /// </summary>
    /// <remarks>
    /// <p>
    /// This is an optional operation.
    /// </p>
    /// </remarks>
        /// <exception cref="NotSupportedException">
        /// If the implementation does not support the operation.
        /// </exception>       
        int NumActive { get; }        
        
        /// <summary>
    /// Gets the number of instances currently idle in the pool.
    /// </summary>
    /// <remarks>
    /// <p>
    /// This is an optional operation.
    /// </p>
    /// <p>
    /// This may be considered an <i>approximation</i> of the number of objects
    /// that can be borrowed without creating any new instances.
    /// </p>
    /// </remarks>
        /// <exception cref="NotSupportedException">
        /// If the implementation does not support the operation.
        /// </exception>
        int NumIdle { get; }

        /// <summary>
        /// Set the factory used to create new instances.
    /// </summary>
    /// <remarks>
    /// <p>
    /// This is an optional operation.
    /// </p>
    /// </remarks>
        /// <exception cref="NotSupportedException">
        /// If the implementation does not support the operation.
        /// </exception>
        IPoolableObjectFactory PoolableObjectFactory { set; }
    }
}