Move unused forked code to external directory (#1192)

* Move unused forked code to external directory

* Fix SLN build errors

* Add back resource provider core since it's referenced by main resource provider project

* Update PackageProjects step of pipeline

external/Microsoft.SqlTools.CoreServices/Connection/ReliableConnection/RetryPolicyUtils.cs

@@ -0,0 +1,486 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
+using System;
+using System.Collections.Generic;
+using Microsoft.Data.SqlClient;
+using System.Diagnostics;
+using System.Runtime.InteropServices;
+using Microsoft.SqlTools.Hosting.Utility;
+
+namespace Microsoft.SqlTools.CoreServices.Connection.ReliableConnection
+{
+    internal static class RetryPolicyUtils
+    {
+        /// <summary>
+        /// Approved list of transient errors that should be retryable during Network connection stages
+        /// </summary>
+        private static readonly HashSet<int> _retryableNetworkConnectivityErrors;
+        /// <summary>
+        /// Approved list of transient errors that should be retryable on Azure
+        /// </summary>
+        private static readonly HashSet<int> _retryableAzureErrors;
+        /// <summary>
+        /// Blocklist of non-transient errors that should stop retry during data transfer operations
+        /// </summary>
+        private static readonly HashSet<int> _nonRetryableDataTransferErrors;
+
+        static RetryPolicyUtils()
+        {
+            _retryableNetworkConnectivityErrors = new HashSet<int>
+            {
+                /// A severe error occurred on the current command.  The results, if any, should be discarded.
+                0,
+
+                //// DBNETLIB Error Code: 20
+                //// The instance of SQL Server you attempted to connect to does not support encryption.
+                (int) ProcessNetLibErrorCode.EncryptionNotSupported,
+
+                //// DBNETLIB Error Code: -2
+                //// Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding.
+                (int)ProcessNetLibErrorCode.Timeout,
+
+                //// SQL Error Code: 64
+                //// A connection was successfully established with the server, but then an error occurred during the login process. 
+                //// (provider: TCP Provider, error: 0 - The specified network name is no longer available.) 
+                64,
+                
+                //// SQL Error Code: 233
+                //// The client was unable to establish a connection because of an error during connection initialization process before login. 
+                //// Possible causes include the following: the client tried to connect to an unsupported version of SQL Server; the server was too busy 
+                //// to accept new connections; or there was a resource limitation (insufficient memory or maximum allowed connections) on the server. 
+                //// (provider: TCP Provider, error: 0 - An existing connection was forcibly closed by the remote host.)
+                233,
+
+                //// SQL Error Code: 10053
+                //// A transport-level error has occurred when receiving results from the server.
+                //// An established connection was aborted by the software in your host machine.
+                10053,
+
+                //// SQL Error Code: 10054
+                //// A transport-level error has occurred when sending the request to the server. 
+                //// (provider: TCP Provider, error: 0 - An existing connection was forcibly closed by the remote host.)
+                10054,
+
+                //// SQL Error Code: 10060
+                //// A network-related or instance-specific error occurred while establishing a connection to SQL Server. 
+                //// The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server 
+                //// is configured to allow remote connections. (provider: TCP Provider, error: 0 - A connection attempt failed 
+                //// because the connected party did not properly respond after a period of time, or established connection failed 
+                //// because connected host has failed to respond.)"}
+                10060,
+
+                // SQL Error Code: 11001
+                // A network-related or instance-specific error occurred while establishing a connection to SQL Server. 
+                // The server was not found or was not accessible. Verify that the instance name is correct and that SQL 
+                // Server is configured to allow remote connections. (provider: TCP Provider, error: 0 - No such host is known.)
+                11001,
+
+                //// SQL Error Code: 40613
+                //// Database XXXX on server YYYY is not currently available. Please retry the connection later. If the problem persists, contact customer 
+                //// support, and provide them the session tracing ID of ZZZZZ.
+                40613,                
+            };
+
+            _retryableAzureErrors = new HashSet<int>
+                                        {
+                //// SQL Error Code: 40
+                //// Could not open a connection to SQL Server
+                //// (provider: Named Pipes Provider, error: 40 Could not open a connection to SQL Server)
+                40,
+                
+                //// SQL Error Code: 121
+                //// A transport-level error has occurred when receiving results from the server. 
+                //// (provider: TCP Provider, error: 0 - The semaphore timeout period has expired.)
+                121,
+                
+                //// SQL Error Code: 913 (noticed intermittently on SNAP runs with connected unit tests)
+                //// Could not find database ID %d. Database may not be activated yet or may be in transition. Reissue the query once the database is available.
+                //// If you do not think this error is due to a database that is transitioning its state and this error continues to occur, contact your primary support provider.
+                //// Please have available for review the Microsoft SQL Server error log and any additional information relevant to the circumstances when the error occurred.
+                913,
+
+                //// SQL Error Code: 1205
+                //// Transaction (Process ID %d) was deadlocked on %.*ls resources with another process and has been chosen as the deadlock victim. Rerun the transaction.
+                1205,
+
+                //// SQL Error Code: 40501
+                //// The service is currently busy. Retry the request after 10 seconds. Code: (reason code to be decoded).
+                RetryPolicy.ThrottlingReason.ThrottlingErrorNumber,
+                
+                //// SQL Error Code: 10928
+                //// Resource ID: %d. The %s limit for the database is %d and has been reached.
+                10928,
+
+                //// SQL Error Code: 10929
+                //// Resource ID: %d. The %s minimum guarantee is %d, maximum limit is %d and the current usage for the database is %d.
+                //// However, the server is currently too busy to support requests greater than %d for this database.
+                10929,
+
+                //// SQL Error Code: 40143
+                //// The service has encountered an error processing your request. Please try again.
+                40143,
+
+                //// SQL Error Code: 40197
+                //// The service has encountered an error processing your request. Please try again.
+                40197,
+
+                //// Sql Error Code: 40549 (not supposed to be used anymore as of Q2 2011)
+                //// Session is terminated because you have a long-running transaction. Try shortening your transaction.
+                40549,
+
+                //// Sql Error Code: 40550 (not supposed to be used anymore as of Q2 2011)
+                //// The session has been terminated because it has acquired too many locks. Try reading or modifying fewer rows in a single transaction.
+                40550,
+
+                //// Sql Error Code: 40551 (not supposed to be used anymore as of Q2 2011)
+                //// The session has been terminated because of excessive TEMPDB usage. Try modifying your query to reduce the temporary table space usage.
+                40551,
+
+                //// Sql Error Code: 40552 (not supposed to be used anymore as of Q2 2011)
+                //// The session has been terminated because of excessive transaction log space usage. Try modifying fewer rows in a single transaction.
+                40552,
+
+                //// Sql Error Code: 40553 (not supposed to be used anymore as of Q2 2011)
+                //// The session has been terminated because of excessive memory usage. Try modifying your query to process fewer rows.
+                40553,
+                
+                //// SQL Error Code: 40627
+                //// Operation on server YYY and database XXX is in progress.  Please wait a few minutes before trying again.
+                40627,
+
+                //// SQL Error Code: 40671 (DB CRUD)
+                //// Unable to '%.*ls' '%.*ls' on server '%.*ls'. Please retry the connection later.
+                40671,
+
+                //// SQL Error Code: 40676 (DB CRUD)
+                //// '%.*ls' request was received but may not be processed completely at this time, 
+                //// please query the sys.dm_operation_status table in the master database for status.
+                40676,
+
+                //// SQL Error Code: 45133
+                //// A connection failed while the operation was still in progress, and the outcome of the operation is unknown.
+                45133,
+            };
+
+            foreach(int errorNum in _retryableNetworkConnectivityErrors)
+            {
+                _retryableAzureErrors.Add(errorNum);
+            }
+
+            _nonRetryableDataTransferErrors = new HashSet<int>
+                                                  {
+                //// Syntax error
+                156,
+                
+                //// Cannot insert duplicate key row in object '%.*ls' with unique index '%.*ls'. The duplicate key value is %ls.
+                2601,
+
+                //// Violation of %ls constraint '%.*ls'. Cannot insert duplicate key in object '%.*ls'. The duplicate key value is %ls.
+                2627,
+                
+                //// Cannot find index '%.*ls'.
+                2727, 
+                
+                //// SqlClr stack error
+                6522,
+
+                //// Divide by zero error encountered.
+                8134,
+
+                //// Could not repair this error.
+                8922,
+
+                //// Bug 1110540: This error means the table is corrupted due to hardware failure, so we do not want to retry.
+                //// Table error: Object ID %d. The text, ntext, or image node at page %S_PGID, slot %d, text ID %I64d is referenced by page %S_PGID, slot %d, but was not seen in the scan.
+                8965,
+
+                //// The query processor is unable to produce a plan because the clustered index is disabled.
+                8655,
+                
+                //// The query processor is unable to produce a plan because table is unavailable because the heap is corrupted
+                8674,
+
+                //// SqlClr permission / load error. 
+                //// Example Message: An error occurred in the Microsoft .NET Framework while trying to load assembly 
+                10314,
+
+                //// '%ls' is not supported in this version of SQL Server.
+                40514,
+
+                //// The database 'XYZ' has reached its size quota. Partition or delete data, drop indexes, or consult the documentation for possible resolutions
+                40544,
+            };
+        }
+
+        public static bool IsRetryableNetworkConnectivityError(int errorNumber)
+        {
+            // .NET core has a bug on OSX/Linux that makes this error number always zero (issue 12472)
+            if (!RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
+            {
+                return errorNumber != 0 && _retryableNetworkConnectivityErrors.Contains(errorNumber);
+            }
+            return _retryableNetworkConnectivityErrors.Contains(errorNumber);
+        }
+
+        public static bool IsRetryableAzureError(int errorNumber)
+        {
+            return _retryableAzureErrors.Contains(errorNumber) || _retryableNetworkConnectivityErrors.Contains(errorNumber);
+        }
+
+        public static bool IsNonRetryableDataTransferError(int errorNumber)
+        {
+            return _nonRetryableDataTransferErrors.Contains(errorNumber);
+        }
+
+        public static void AppendThrottlingDataIfIsThrottlingError(SqlException sqlException, SqlError error)
+        {
+            //// SQL Error Code: 40501
+            //// The service is currently busy. Retry the request after 10 seconds. Code: (reason code to be decoded).
+            if(error.Number ==  RetryPolicy.ThrottlingReason.ThrottlingErrorNumber)
+            {
+                // Decode the reason code from the error message to determine the grounds for throttling.
+                var condition = RetryPolicy.ThrottlingReason.FromError(error);
+
+                // Attach the decoded values as additional attributes to the original SQL exception.
+                sqlException.Data[condition.ThrottlingMode.GetType().Name] = condition.ThrottlingMode.ToString();
+                sqlException.Data[condition.GetType().Name] = condition;
+            }
+        }
+        /// <summary>
+        /// Calculates the length of time to delay a retry based on the number of retries up to this point.
+        /// As the number of retries increases, the timeout increases exponentially based on the intervalFactor.
+        /// Uses default values for the intervalFactor (<see cref="RetryPolicyDefaults.DefaultBackoffIntervalFactor"/>), minInterval
+        /// (<see cref="RetryPolicyDefaults.DefaultSchemaMinInterval"/>) and maxInterval (<see cref="RetryPolicyDefaults.DefaultMaxRetryInterval"/>)
+        /// </summary>
+        /// <param name="currentRetryCount">Total number of retries including the current retry</param>
+        /// <returns>TimeSpan defining the length of time to delay</returns>
+        internal static TimeSpan CalcExponentialRetryDelayWithSchemaDefaults(int currentRetryCount)
+        {
+            return CalcExponentialRetryDelay(currentRetryCount,
+                RetryPolicyDefaults.DefaultBackoffIntervalFactor,
+                RetryPolicyDefaults.DefaultSchemaMinInterval,
+                RetryPolicyDefaults.DefaultMaxRetryInterval);
+        }
+
+        /// <summary>
+        /// Calculates the length of time to delay a retry based on the number of retries up to this point.
+        /// As the number of retries increases, the timeout increases exponentially based on the intervalFactor.
+        /// A very large retry count can cause huge delay, so the maxInterval is used to cap delay time at a sensible
+        /// upper bound
+        /// </summary>
+        /// <param name="currentRetryCount">Total number of retries including the current retry</param>
+        /// <param name="intervalFactor">Controls the speed at which the delay increases - the retryCount is raised to this power as
+        /// part of the function </param>
+        /// <param name="minInterval">Minimum interval between retries. The basis for all backoff calculations</param>
+        /// <param name="maxInterval">Maximum interval between retries. Backoff will not take longer than this period.</param>
+        /// <returns>TimeSpan defining the length of time to delay</returns>
+        internal static TimeSpan CalcExponentialRetryDelay(int currentRetryCount, double intervalFactor, TimeSpan minInterval, TimeSpan maxInterval)
+        {
+            try
+            {
+                return checked(TimeSpan.FromMilliseconds(
+                    Math.Max(
+                        Math.Min(
+                            Math.Pow(intervalFactor, currentRetryCount - 1) * minInterval.TotalMilliseconds,
+                            maxInterval.TotalMilliseconds
+                        ),
+                        minInterval.TotalMilliseconds)
+                    ));
+            }
+            catch (OverflowException)
+            {
+                // If numbers are too large, could conceivably overflow the double.
+                // Since the maxInterval is the largest TimeSpan expected, can safely return this here
+                return maxInterval;
+            }
+        }
+
+        internal static void RaiseAmbientRetryMessage(RetryState retryState, int errorCode)
+        {
+            Action<SqlServerRetryError> retryMsgHandler = AmbientSettings.ConnectionRetryMessageHandler;
+            if (retryMsgHandler != null)
+            {
+                string msg = SqlServerRetryError.FormatRetryMessage(
+                    retryState.RetryCount,
+                    retryState.Delay,
+                    retryState.LastError);
+
+                retryMsgHandler(new SqlServerRetryError(
+                                    msg,
+                                    retryState.LastError,
+                                    retryState.RetryCount,
+                                    errorCode,
+                                    ErrorSeverity.Warning));
+            }
+        }
+
+        internal static void RaiseAmbientIgnoreMessage(RetryState retryState, int errorCode)
+        {
+            Action<SqlServerRetryError> retryMsgHandler = AmbientSettings.ConnectionRetryMessageHandler;
+            if (retryMsgHandler != null)
+            {
+                string msg = SqlServerRetryError.FormatIgnoreMessage(
+                    retryState.RetryCount,
+                    retryState.LastError);
+
+                retryMsgHandler(new SqlServerRetryError(
+                                    msg,
+                                    retryState.LastError,
+                                    retryState.RetryCount,
+                                    errorCode,
+                                    ErrorSeverity.Warning));
+            }
+        }
+
+        /// <summary>
+        /// Traces the Schema retry information before raising the retry message
+        /// </summary>
+        /// <param name="retryState"></param>
+        /// <param name="errorCode"></param>
+        /// <param name="azureSessionId"></param>
+        internal static void RaiseSchemaAmbientRetryMessage(RetryState retryState, int errorCode, Guid azureSessionId)
+        {
+            if (azureSessionId != Guid.Empty)
+            {
+                Logger.Write(TraceEventType.Warning, string.Format(
+                    "Retry occurred: session: {0}; attempt - {1}; delay - {2}; exception - \"{3}\"",
+                    azureSessionId,
+                    retryState.RetryCount,
+                    retryState.Delay,
+                    retryState.LastError
+                 ));
+
+                RaiseAmbientRetryMessage(retryState, errorCode);
+            }
+        }
+
+        #region ProcessNetLibErrorCode enumeration
+
+        /// <summary>
+        /// Error codes reported by the DBNETLIB module.
+        /// </summary>
+        internal enum ProcessNetLibErrorCode
+        {
+            /// <summary>
+            /// Zero bytes were returned
+            /// </summary>
+            ZeroBytes = -3,
+
+            /// <summary>
+            /// Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding.
+            /// </summary>
+            Timeout = -2,
+
+            /// <summary>
+            /// An unknown net lib error
+            /// </summary>
+            Unknown = -1,
+
+            /// <summary>
+            /// Out of memory
+            /// </summary>
+            InsufficientMemory = 1,
+
+            /// <summary>
+            /// User or machine level access denied
+            /// </summary>
+            AccessDenied = 2,
+
+            /// <summary>
+            /// Connection was already busy processing another request
+            /// </summary>
+            ConnectionBusy = 3,
+
+            /// <summary>
+            /// The connection was broken without a proper disconnect
+            /// </summary>
+            ConnectionBroken = 4,
+
+            /// <summary>
+            /// The connection has reached a limit
+            /// </summary>
+            ConnectionLimit = 5,
+
+            /// <summary>
+            /// Name resolution failed for the given server name
+            /// </summary>
+            ServerNotFound = 6,
+
+            /// <summary>
+            /// Network transport could not be found
+            /// </summary>
+            NetworkNotFound = 7,
+
+            /// <summary>
+            /// A resource required could not be allocated
+            /// </summary>
+            InsufficientResources = 8,
+
+            /// <summary>
+            /// Network stack denied the request as too busy
+            /// </summary>
+            NetworkBusy = 9,
+
+            /// <summary>
+            /// Unable to access the requested network
+            /// </summary>
+            NetworkAccessDenied = 10,
+
+            /// <summary>
+            /// Internal error
+            /// </summary>
+            GeneralError = 11,
+
+            /// <summary>
+            /// The network mode was set incorrectly
+            /// </summary>
+            IncorrectMode = 12,
+
+            /// <summary>
+            /// The given name was not found
+            /// </summary>
+            NameNotFound = 13,
+
+            /// <summary>
+            /// Connection was invalid
+            /// </summary>
+            InvalidConnection = 14,
+
+            /// <summary>
+            /// A read or write error occurred
+            /// </summary>
+            ReadWriteError = 15,
+
+            /// <summary>
+            /// Unable to allocate an additional handle
+            /// </summary>
+            TooManyHandles = 16,
+
+            /// <summary>
+            /// The server reported an error
+            /// </summary>
+            ServerError = 17,
+
+            /// <summary>
+            /// SSL failed
+            /// </summary>
+            SSLError = 18,
+
+            /// <summary>
+            /// Encryption failed with an error
+            /// </summary>
+            EncryptionError = 19,
+
+            /// <summary>
+            /// Remote endpoint does not support encryption
+            /// </summary>
+            EncryptionNotSupported = 20
+        }
+
+        #endregion
+
+    }
+}