/src/SqlServer/TransientDbConnection/RetryPolicyConfigurationSettings.cs

//=======================================================================================

// Microsoft Windows Server AppFabric Customer Advisory Team (CAT) Best Practices Series

//

// This sample is supplemental to the technical guidance published on the community

// blog at http://blogs.msdn.com/appfabriccat/. 

//

//=======================================================================================

// Copyright © 2010 Microsoft Corporation. All rights reserved.

// 

// THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER 

// EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF 

// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. YOU BEAR THE RISK OF USING IT.

//=======================================================================================



using System;



namespace HashFoo.SqlServer.TransientDbConnection

{

    #region Using references

    

    #endregion



    /// <summary>

    /// Implements a configuration section containing retry policy settings.

    /// </summary>

    [Serializable]

    public sealed class RetryPolicyConfigurationSettings : ConfigurationSection

    {

        #region Private members

        private const string DefaultPolicyProperty = "defaultPolicy";

        private const string DefaultSqlConnectionPolicyProperty = "defaultSqlConnectionPolicy";

        private const string DefaultSqlCommandPolicyProperty = "defaultSqlCommandPolicy";

        private const string DefaultStoragePolicyProperty = "defaultStoragePolicy";

        private const string DefaultCommunicationPolicyProperty = "defaultCommunicationPolicy";

        #endregion



        #region Public members

        /// <summary>

        /// The name of the configuration section represented by this type.

        /// </summary>

        public const string SectionName = "RetryPolicyConfiguration";

        #endregion



        #region Constructor

        /// <summary>

        /// Initializes a new instance of a <see cref="RetryPolicyConfigurationSettings"/> object using default settings.

        /// </summary>

        public RetryPolicyConfigurationSettings()

        {

        }

        #endregion



        #region Public properties

        /// <summary>

        /// Gets or sets the name of the default general-purpose retry policy.

        /// </summary>

        [ConfigurationProperty(DefaultPolicyProperty, IsRequired = true)]

        public string DefaultPolicy

        {

            get { return (string)base[DefaultPolicyProperty]; }

            set { base[DefaultPolicyProperty] = value; }

        }



        /// <summary>

        /// Gets or sets the name of a retry policy dedicated to handling transient conditions with SQL connections.

        /// </summary>

        [ConfigurationProperty(DefaultSqlConnectionPolicyProperty, IsRequired = false)]

        public string DefaultSqlConnectionPolicy

        {

            get { return (string)base[DefaultSqlConnectionPolicyProperty]; }

            set { base[DefaultSqlConnectionPolicyProperty] = value; }

        }



        /// <summary>

        /// Gets or sets the name of a retry policy dedicated to handling transient conditions with SQL commands.

        /// </summary>

        [ConfigurationProperty(DefaultSqlCommandPolicyProperty, IsRequired = false)]

        public string DefaultSqlCommandPolicy

        {

            get { return (string)base[DefaultSqlCommandPolicyProperty]; }

            set { base[DefaultSqlCommandPolicyProperty] = value; }

        }



        /// <summary>

        /// Gets or sets the name of a retry policy dedicated to handling transient conditions in Windows Azure storage services.

        /// </summary>

        [ConfigurationProperty(DefaultStoragePolicyProperty, IsRequired = false)]

        public string DefaultStoragePolicy

        {

            get { return (string)base[DefaultStoragePolicyProperty]; }

            set { base[DefaultStoragePolicyProperty] = value; }

        }



        /// <summary>

        /// Gets or sets the name of a retry policy dedicated to handling transient conditions in the WCF communication infrastructure.

        /// </summary>

        [ConfigurationProperty(DefaultCommunicationPolicyProperty, IsRequired = false)]

        public string DefaultCommunicationPolicy

        {

            get { return (string)base[DefaultCommunicationPolicyProperty]; }

            set { base[DefaultCommunicationPolicyProperty] = value; }

        }



        /// <summary>

        /// Returns a collection of retry policy definitions represented by the <see cref="RetryPolicyInfo"/> object instances.

        /// </summary>

        [ConfigurationProperty("", Options = ConfigurationPropertyOptions.IsDefaultCollection)]

        [ConfigurationCollection(typeof(RetryPolicyInfo))]

        public RetryPolicyCollection Policies

        {

            get { return (RetryPolicyCollection)base[String.Empty]; }

        }

        #endregion



        #region Public methods

        /// <summary>

        /// Returns an instance of the <see cref="RetryPolicy"/> object initialized for a given policy name.

        /// </summary>

        /// <typeparam name="T">The type implementing the <see cref="ITransientErrorDetectionStrategy"/> interface which is responsible for detecting transient conditions.</typeparam>

        /// <param name="policyName">The name under which a retry policy definition is registered in the application configuration.</param>

        /// <returns>The retry policy initialized from the specified policy definition, or a null reference if no such policy definition was found.</returns>

        public RetryPolicy<T> GetRetryPolicy<T>(string policyName) where T : ITransientErrorDetectionStrategy, new()

        {

            RetryPolicy<T> retryPolicy = null;



            if (!String.IsNullOrEmpty(policyName) && Policies.Contains(policyName))

            {

                RetryPolicyInfo retryPolicyInfo = Policies.Get(policyName);

                return retryPolicyInfo != null ? retryPolicyInfo.CreatePolicy<T>() : null;

            }



            return retryPolicy;

        }



        /// <summary>

        /// Adds a new definition describing a retry policy based on fixed interval retry mode.

        /// </summary>

        /// <param name="policyName">The name under which a retry policy definition will be registered in the application configuration.</param>

        /// <param name="maxRetryCount">The maximum number of retry attempts.</</param>

        /// <param name="retryInterval">The interval in milliseconds between retry attempts.</param>

        public void AddFixedIntervalPolicy(string policyName, int maxRetryCount, int retryInterval)

        {

            Policies.Add(new RetryPolicyInfo() { Name = policyName, MaxRetryCount = maxRetryCount, RetryInterval = retryInterval });

        }



        /// <summary>

        /// Adds a new definition describing a retry policy based on incremental interval retry mode.

        /// </summary>

        /// <param name="policyName">The name under which a retry policy definition will be registered in the application configuration.</param>

        /// <param name="maxRetryCount">The maximum number of retry attempts.</param>

        /// <param name="retryInterval">The initial interval in milliseconds which will apply for the first retry.</param>

        /// <param name="retryIncrement">The incremental time value in milliseconds for calculating progressive delay between retry attempts.</param>

        public void AddIncrementalIntervalPolicy(string policyName, int maxRetryCount, int retryInterval, int retryIncrement)

        {

            Policies.Add(new RetryPolicyInfo() { Name = policyName, MaxRetryCount = maxRetryCount, RetryInterval = retryInterval, RetryIncrement = retryIncrement });

        }



        /// <summary>

        /// Adds a new definition describing a retry policy based on random exponential back-off retry mode.

        /// </summary>

        /// <param name="policyName">The name under which a retry policy definition will be registered in the application configuration.</param>

        /// <param name="maxRetryCount">The maximum number of retry attempts.</param>

        /// <param name="minBackoff">The minimum back-off time in milliseconds.</param>

        /// <param name="maxBackoff">The maximum back-off time in milliseconds.</param>

        /// <param name="deltaBackof">The delta value in milliseconds to calculate random exponential delay between retry attempts.</param>

        public void AddExponentialIntervalPolicy(string policyName, int maxRetryCount, int minBackoff, int maxBackoff, int deltaBackof)

        {

            Policies.Add(new RetryPolicyInfo() { Name = policyName, MaxRetryCount = maxRetryCount, MinBackoff = minBackoff, MaxBackoff = maxBackoff, DeltaBackoff = deltaBackof });

        }

        #endregion

    }

}