|
//------------------------------------------------------------------------------
// <copyright file="SqlDependency.cs" company="Microsoft">
// Copyright (c) Microsoft Corporation. All rights reserved.
// </copyright>
// <owner current="true" primary="true">Microsoft</owner>
// <owner current="true" primary="true">Microsoft</owner>
// <owner current="false" primary="false">Microsoft</owner>
//------------------------------------------------------------------------------
namespace System.Data.SqlClient {
using System;
using System.Collections;
using System.Collections.Generic;
using System.Data;
using System.Data.Common;
using System.Data.ProviderBase;
using System.Data.Sql;
using System.Data.SqlClient;
using System.Diagnostics;
using System.Globalization;
using System.IO;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
using System.Runtime.Remoting;
using System.Runtime.Serialization.Formatters.Binary;
using System.Security;
using System.Security.Cryptography;
using System.Security.Permissions;
using System.Security.Principal;
using System.Text;
using System.Threading;
using System.Net;
using System.Xml;
using System.Runtime.Versioning;
public sealed class SqlDependency {
// ---------------------------------------------------------------------------------------------------------
// Private class encapsulating the user/identity information - either SQL Auth username or Windows identity.
// ---------------------------------------------------------------------------------------------------------
internal class IdentityUserNamePair {
private DbConnectionPoolIdentity _identity;
private string _userName;
internal IdentityUserNamePair(DbConnectionPoolIdentity identity, string userName) {
Debug.Assert( (identity == null && userName != null) ||
(identity != null && userName == null), "Unexpected arguments!");
_identity = identity;
_userName = userName;
}
internal DbConnectionPoolIdentity Identity {
get {
return _identity;
}
}
internal string UserName {
get {
return _userName;
}
}
override public bool Equals(object value) {
IdentityUserNamePair temp = (IdentityUserNamePair) value;
bool result = false;
if (null == temp) { // If passed value null - false.
result = false;
}
else if (this == temp) { // If instances equal - true.
result = true;
}
else {
if (_identity != null) {
if (_identity.Equals(temp._identity)) {
result = true;
}
}
else if (_userName == temp._userName) {
result = true;
}
}
return result;
}
override public int GetHashCode() {
int hashValue = 0;
if (null != _identity) {
hashValue = _identity.GetHashCode();
}
else {
hashValue = _userName.GetHashCode();
}
return hashValue;
}
}
// ----------------------------------------
// END IdentityHashHelper private class.
// ----------------------------------------
// ----------------------------------------------------------------------
// Private class encapsulating the database, service info and hash logic.
// ----------------------------------------------------------------------
private class DatabaseServicePair {
private string _database;
private string _service; // Store the value, but don't use for equality or hashcode!
internal DatabaseServicePair(string database, string service) {
Debug.Assert(database != null, "Unexpected argument!");
_database = database;
_service = service;
}
internal string Database {
get {
return _database;
}
}
internal string Service {
get {
return _service;
}
}
override public bool Equals(object value) {
DatabaseServicePair temp = (DatabaseServicePair) value;
bool result = false;
if (null == temp) { // If passed value null - false.
result = false;
}
else if (this == temp) { // If instances equal - true.
result = true;
}
else if (_database == temp._database) {
result = true;
}
return result;
}
override public int GetHashCode() {
return _database.GetHashCode();
}
}
// ----------------------------------------
// END IdentityHashHelper private class.
// ----------------------------------------
// ----------------------------------------------------------------------------
// Private class encapsulating the event and it's registered execution context.
// ----------------------------------------------------------------------------
internal class EventContextPair {
private OnChangeEventHandler _eventHandler;
private ExecutionContext _context;
private SqlDependency _dependency;
private SqlNotificationEventArgs _args;
static private ContextCallback _contextCallback = new ContextCallback(InvokeCallback);
internal EventContextPair(OnChangeEventHandler eventHandler, SqlDependency dependency) {
Debug.Assert(eventHandler != null && dependency != null, "Unexpected arguments!");
_eventHandler = eventHandler;
_context = ExecutionContext.Capture();
_dependency = dependency;
}
override public bool Equals(object value) {
EventContextPair temp = (EventContextPair) value;
bool result = false;
if (null == temp) { // If passed value null - false.
result = false;
}
else if (this == temp) { // If instances equal - true.
result = true;
}
else {
if (_eventHandler == temp._eventHandler) { // Handler for same delegates are reference equivalent.
result = true;
}
}
return result;
}
override public int GetHashCode() {
return _eventHandler.GetHashCode();
}
internal void Invoke(SqlNotificationEventArgs args) {
_args = args;
ExecutionContext.Run(_context, _contextCallback, this);
}
private static void InvokeCallback(object eventContextPair) {
EventContextPair pair = (EventContextPair) eventContextPair;
pair._eventHandler(pair._dependency, (SqlNotificationEventArgs) pair._args);
}
}
// ----------------------------------------
// END EventContextPair private class.
// ----------------------------------------
// ----------------
// Instance members
// ----------------
// SqlNotificationRequest required state members
// Only used for SqlDependency.Id.
private readonly string _id = Guid.NewGuid().ToString() + ";" + _appDomainKey;
private string _options; // Concat of service & db, in the form "service=x;local database=y".
private int _timeout;
// Various SqlDependency required members
private bool _dependencyFired = false;
// SQL BU DT 382314 - we are required to implement our own event collection to preserve ExecutionContext on callback.
private List<EventContextPair> _eventList = new List<EventContextPair>();
private object _eventHandlerLock = new object(); // Lock for event serialization.
// Track the time that this dependency should time out. If the server didn't send a change
// notification or a time-out before this point then the client will perform a client-side
// timeout.
private DateTime _expirationTime = DateTime.MaxValue;
// Used for invalidation of dependencies based on which servers they rely upon.
// It's possible we will over invalidate if unexpected server failure occurs (but not server down).
private List<string> _serverList = new List<string>();
// --------------
// Static members
// --------------
private static object _startStopLock = new object();
private static readonly string _appDomainKey = Guid.NewGuid().ToString();
// Hashtable containing all information to match from a server, user, database triple to the service started for that
// triple. For each server, there can be N users. For each user, there can be N databases. For each server, user,
// database, there can only be one service.
private static Dictionary<string, Dictionary<IdentityUserNamePair, List<DatabaseServicePair>>> _serverUserHash =
new Dictionary<string, Dictionary<IdentityUserNamePair, List<DatabaseServicePair>>>(StringComparer.OrdinalIgnoreCase);
private static SqlDependencyProcessDispatcher _processDispatcher = null;
// The following two strings are used for AppDomain.CreateInstance.
private static readonly string _assemblyName = (typeof(SqlDependencyProcessDispatcher)).Assembly.FullName;
private static readonly string _typeName = (typeof(SqlDependencyProcessDispatcher)).FullName;
// -----------
// BID members
// -----------
internal const Bid.ApiGroup NotificationsTracePoints = (Bid.ApiGroup)0x2000;
private readonly int _objectID = System.Threading.Interlocked.Increment(ref _objectTypeCount);
private static int _objectTypeCount; // Bid counter
internal int ObjectID {
get {
return _objectID;
}
}
// ------------
// Constructors
// ------------
[System.Security.Permissions.HostProtectionAttribute(ExternalThreading = true)]
public SqlDependency() : this(null, null, SQL.SqlDependencyTimeoutDefault) {
}
[System.Security.Permissions.HostProtectionAttribute(ExternalThreading = true)]
public SqlDependency(SqlCommand command) : this(command, null, SQL.SqlDependencyTimeoutDefault) {
}
[System.Security.Permissions.HostProtectionAttribute(ExternalThreading = true)]
public SqlDependency(SqlCommand command, string options, int timeout) {
IntPtr hscp;
Bid.NotificationsScopeEnter(out hscp, "<sc.SqlDependency|DEP> %d#, options: '%ls', timeout: '%d'", ObjectID, options, timeout);
try {
if (InOutOfProcHelper.InProc) {
throw SQL.SqlDepCannotBeCreatedInProc();
}
if (timeout < 0) {
throw SQL.InvalidSqlDependencyTimeout("timeout");
}
_timeout = timeout;
if (null != options) { // Ignore null value - will force to default.
_options = options;
}
AddCommandInternal(command);
SqlDependencyPerAppDomainDispatcher.SingletonInstance.AddDependencyEntry(this); // Add dep to hashtable with Id.
}
finally {
Bid.ScopeLeave(ref hscp);
}
}
// -----------------
// Public Properties
// -----------------
[
ResCategoryAttribute(Res.DataCategory_Data),
ResDescriptionAttribute(Res.SqlDependency_HasChanges)
]
public bool HasChanges {
get {
return _dependencyFired;
}
}
[
ResCategoryAttribute(Res.DataCategory_Data),
ResDescriptionAttribute(Res.SqlDependency_Id)
]
public string Id {
get {
return _id;
}
}
// -------------------
// Internal Properties
// -------------------
internal static string AppDomainKey {
get {
return _appDomainKey;
}
}
internal DateTime ExpirationTime {
get {
return _expirationTime;
}
}
internal string Options {
get {
string result = null;
if (null != _options) {
result = _options;
}
return result;
}
}
internal static SqlDependencyProcessDispatcher ProcessDispatcher {
get {
return _processDispatcher;
}
}
internal int Timeout {
get {
return _timeout;
}
}
// ------
// Events
// ------
[
ResCategoryAttribute(Res.DataCategory_Data),
ResDescriptionAttribute(Res.SqlDependency_OnChange)
]
public event OnChangeEventHandler OnChange {
// EventHandlers to be fired when dependency is notified.
add {
IntPtr hscp;
Bid.NotificationsScopeEnter(out hscp, "<sc.SqlDependency.OnChange-Add|DEP> %d#", ObjectID);
try {
if (null != value) {
SqlNotificationEventArgs sqlNotificationEvent = null;
lock (_eventHandlerLock) {
if (_dependencyFired) { // If fired, fire the new event immediately.
Bid.NotificationsTrace("<sc.SqlDependency.OnChange-Add|DEP> Dependency already fired, firing new event.\n");
sqlNotificationEvent = new SqlNotificationEventArgs(SqlNotificationType.Subscribe, SqlNotificationInfo.AlreadyChanged, SqlNotificationSource.Client);
}
else {
Bid.NotificationsTrace("<sc.SqlDependency.OnChange-Add|DEP> Dependency has not fired, adding new event.\n");
EventContextPair pair = new EventContextPair(value, this);
if (!_eventList.Contains(pair)) {
_eventList.Add(pair);
}
else {
throw SQL.SqlDependencyEventNoDuplicate(); // SQL BU DT 382314
}
}
}
if (null != sqlNotificationEvent) { // Delay firing the event until outside of lock.
value(this, sqlNotificationEvent);
}
}
}
finally {
Bid.ScopeLeave(ref hscp);
}
}
remove {
IntPtr hscp;
Bid.NotificationsScopeEnter(out hscp, "<sc.SqlDependency.OnChange-Remove|DEP> %d#", ObjectID);
try {
if (null != value) {
EventContextPair pair = new EventContextPair(value, this);
lock (_eventHandlerLock) {
int index = _eventList.IndexOf(pair);
if (0 <= index) {
_eventList.RemoveAt(index);
}
}
}
}
finally {
Bid.ScopeLeave(ref hscp);
}
}
}
// --------------
// Public Methods
// --------------
[
ResCategoryAttribute(Res.DataCategory_Data),
ResDescriptionAttribute(Res.SqlDependency_AddCommandDependency)
]
public void AddCommandDependency(SqlCommand command) {
// Adds command to dependency collection so we automatically create the SqlNotificationsRequest object
// and listen for a notification for the added commands.
IntPtr hscp;
Bid.NotificationsScopeEnter(out hscp, "<sc.SqlDependency.AddCommandDependency|DEP> %d#", ObjectID);
try {
if (command == null) {
throw ADP.ArgumentNull("command");
}
AddCommandInternal(command);
}
finally {
Bid.ScopeLeave(ref hscp);
}
}
[System.Security.Permissions.ReflectionPermission(System.Security.Permissions.SecurityAction.Assert, MemberAccess=true)]
private static ObjectHandle CreateProcessDispatcher(_AppDomain masterDomain) {
return masterDomain.CreateInstance(_assemblyName, _typeName);
}
// ----------------------------------
// Static Methods - public & internal
// ----------------------------------
// Method to obtain AppDomain reference and then obtain the reference to the process wide dispatcher for
// Start() and Stop() method calls on the individual SqlDependency instances.
// SxS: this method retrieves the primary AppDomain stored in native library. Since each System.Data.dll has its own copy of native
// library, this call is safe in SxS
[ResourceExposure(ResourceScope.None)]
[ResourceConsumption(ResourceScope.Process, ResourceScope.Process)]
private static void ObtainProcessDispatcher() {
byte[] nativeStorage = SNINativeMethodWrapper.GetData();
if (nativeStorage == null) {
Bid.NotificationsTrace("<sc.SqlDependency.ObtainProcessDispatcher|DEP> nativeStorage null, obtaining dispatcher AppDomain and creating ProcessDispatcher.\n");
#if DEBUG // Possibly expensive, limit to debug.
Bid.NotificationsTrace("<sc.SqlDependency.ObtainProcessDispatcher|DEP> AppDomain.CurrentDomain.FriendlyName: %ls\n", AppDomain.CurrentDomain.FriendlyName);
#endif
_AppDomain masterDomain = SNINativeMethodWrapper.GetDefaultAppDomain();
if (null != masterDomain) {
ObjectHandle handle = CreateProcessDispatcher(masterDomain);
if (null != handle) {
SqlDependencyProcessDispatcher dependency = (SqlDependencyProcessDispatcher) handle.Unwrap();
if (null != dependency) {
_processDispatcher = dependency.SingletonProcessDispatcher; // Set to static instance.
// Serialize and set in native.
ObjRef objRef = GetObjRef(_processDispatcher);
BinaryFormatter formatter = new BinaryFormatter();
MemoryStream stream = new MemoryStream();
GetSerializedObject(objRef, formatter, stream);
SNINativeMethodWrapper.SetData(stream.GetBuffer()); // Native will be forced to synchronize and not overwrite.
}
else {
Bid.NotificationsTrace("<sc.SqlDependency.ObtainProcessDispatcher|DEP|ERR> ERROR - ObjectHandle.Unwrap returned null!\n");
throw ADP.InternalError(ADP.InternalErrorCode.SqlDependencyObtainProcessDispatcherFailureObjectHandle);
}
}
else {
Bid.NotificationsTrace("<sc.SqlDependency.ObtainProcessDispatcher|DEP|ERR> ERROR - AppDomain.CreateInstance returned null!\n");
throw ADP.InternalError(ADP.InternalErrorCode.SqlDependencyProcessDispatcherFailureCreateInstance);
}
}
else {
Bid.NotificationsTrace("<sc.SqlDependency.ObtainProcessDispatcher|DEP|ERR> ERROR - unable to obtain default AppDomain!\n");
throw ADP.InternalError(ADP.InternalErrorCode.SqlDependencyProcessDispatcherFailureAppDomain);
}
}
else {
Bid.NotificationsTrace("<sc.SqlDependency.ObtainProcessDispatcher|DEP> nativeStorage not null, obtaining existing dispatcher AppDomain and ProcessDispatcher.\n");
#if DEBUG // Possibly expensive, limit to debug.
Bid.NotificationsTrace("<sc.SqlDependency.ObtainProcessDispatcher|DEP> AppDomain.CurrentDomain.FriendlyName: %ls\n", AppDomain.CurrentDomain.FriendlyName);
#endif
BinaryFormatter formatter = new BinaryFormatter();
MemoryStream stream = new MemoryStream(nativeStorage);
_processDispatcher = GetDeserializedObject(formatter, stream); // Deserialize and set for appdomain.
Bid.NotificationsTrace("<sc.SqlDependency.ObtainProcessDispatcher|DEP> processDispatcher obtained, ID: %d\n", _processDispatcher.ObjectID);
}
}
// ---------------------------------------------------------
// Static security asserted methods - limit scope of assert.
// ---------------------------------------------------------
[SecurityPermission(SecurityAction.Assert, Flags=SecurityPermissionFlag.RemotingConfiguration)]
private static ObjRef GetObjRef(SqlDependencyProcessDispatcher _processDispatcher) {
return RemotingServices.Marshal(_processDispatcher);
}
[SecurityPermission(SecurityAction.Assert, Flags=SecurityPermissionFlag.SerializationFormatter)]
private static void GetSerializedObject(ObjRef objRef, BinaryFormatter formatter, MemoryStream stream) {
formatter.Serialize(stream, objRef);
}
[SecurityPermission(SecurityAction.Assert, Flags=SecurityPermissionFlag.SerializationFormatter)]
private static SqlDependencyProcessDispatcher GetDeserializedObject(BinaryFormatter formatter, MemoryStream stream) {
object result = formatter.Deserialize(stream);
Debug.Assert(result.GetType() == typeof(SqlDependencyProcessDispatcher), "Unexpected type stored in native!");
return (SqlDependencyProcessDispatcher) result;
}
// -------------------------
// Static Start/Stop methods
// -------------------------
[System.Security.Permissions.HostProtectionAttribute(ExternalThreading = true)]
public static bool Start(string connectionString) {
return Start(connectionString, null, true);
}
[System.Security.Permissions.HostProtectionAttribute(ExternalThreading = true)]
public static bool Start(string connectionString, string queue) {
return Start(connectionString, queue, false);
}
internal static bool Start(string connectionString, string queue, bool useDefaults) {
IntPtr hscp;
Bid.NotificationsScopeEnter(out hscp, "<sc.SqlDependency.Start|DEP> AppDomainKey: '%ls', queue: '%ls'", AppDomainKey, queue);
try {
// The following code exists in Stop as well. It exists here to demand permissions as high in the stack
// as possible.
if (InOutOfProcHelper.InProc) {
throw SQL.SqlDepCannotBeCreatedInProc();
}
if (ADP.IsEmpty(connectionString)) {
if (null == connectionString) {
throw ADP.ArgumentNull("connectionString");
}
else {
throw ADP.Argument("connectionString");
}
}
if (!useDefaults && ADP.IsEmpty(queue)) { // If specified but null or empty, use defaults.
useDefaults = true;
queue = null; // Force to null - for proper hashtable comparison for default case.
}
// Create new connection options for demand on their connection string. We modify the connection string
// and assert on our modified string when we create the container.
SqlConnectionString connectionStringObject = new SqlConnectionString(connectionString);
connectionStringObject.DemandPermission();
if (connectionStringObject.LocalDBInstance!=null) {
LocalDBAPI.DemandLocalDBPermissions();
}
// End duplicate Start/Stop logic.
bool errorOccurred = false;
bool result = false;
lock (_startStopLock) {
try {
if (null == _processDispatcher) { // Ensure _processDispatcher reference is present - inside lock.
ObtainProcessDispatcher();
}
if (useDefaults) { // Default listener.
string server = null;
DbConnectionPoolIdentity identity = null;
string user = null;
string database = null;
string service = null;
bool appDomainStart = false;
RuntimeHelpers.PrepareConstrainedRegions();
try { // CER to ensure that if Start succeeds we add to hash completing setup.
// Start using process wide default service/queue & database from connection string.
result = _processDispatcher.StartWithDefault( connectionString,
out server,
out identity,
out user,
out database,
ref service,
_appDomainKey,
SqlDependencyPerAppDomainDispatcher.SingletonInstance,
out errorOccurred,
out appDomainStart);
Bid.NotificationsTrace("<sc.SqlDependency.Start|DEP> Start (defaults) returned: '%d', with service: '%ls', server: '%ls', database: '%ls'\n", result, service, server, database);
}
finally {
if (appDomainStart && !errorOccurred) { // If success, add to hashtable.
IdentityUserNamePair identityUser = new IdentityUserNamePair(identity, user);
DatabaseServicePair databaseService = new DatabaseServicePair(database, service);
if (!AddToServerUserHash(server, identityUser, databaseService)) {
try {
Stop(connectionString, queue, useDefaults, true);
}
catch (Exception e) { // Discard stop failure!
if (!ADP.IsCatchableExceptionType(e)) {
throw;
}
ADP.TraceExceptionWithoutRethrow(e); // Discard failure, but trace for now.
Bid.NotificationsTrace("<sc.SqlDependency.Start|DEP|ERR> Exception occurred from Stop() after duplicate was found on Start().\n");
}
throw SQL.SqlDependencyDuplicateStart();
}
}
}
}
else { // Start with specified service/queue & database.
result = _processDispatcher.Start(connectionString,
queue,
_appDomainKey,
SqlDependencyPerAppDomainDispatcher.SingletonInstance);
Bid.NotificationsTrace("<sc.SqlDependency.Start|DEP> Start (user provided queue) returned: '%d'\n", result);
// No need to call AddToServerDatabaseHash since if not using default queue user is required
// to provide options themselves.
}
}
catch (Exception e) {
if (!ADP.IsCatchableExceptionType(e)) {
throw;
}
ADP.TraceExceptionWithoutRethrow(e); // Discard failure, but trace for now.
Bid.NotificationsTrace("<sc.SqlDependency.Start|DEP|ERR> Exception occurred from _processDispatcher.Start(...), calling Invalidate(...).\n");
throw;
}
}
return result;
}
finally {
Bid.ScopeLeave(ref hscp);
}
}
[System.Security.Permissions.HostProtectionAttribute(ExternalThreading = true)]
public static bool Stop(string connectionString) {
return Stop(connectionString, null, true, false);
}
[System.Security.Permissions.HostProtectionAttribute(ExternalThreading = true)]
public static bool Stop(string connectionString, string queue) {
return Stop(connectionString, queue, false, false);
}
internal static bool Stop(string connectionString, string queue, bool useDefaults, bool startFailed) {
IntPtr hscp;
Bid.NotificationsScopeEnter(out hscp, "<sc.SqlDependency.Stop|DEP> AppDomainKey: '%ls', queue: '%ls'", AppDomainKey, queue);
try {
// The following code exists in Stop as well. It exists here to demand permissions as high in the stack
// as possible.
if (InOutOfProcHelper.InProc) {
throw SQL.SqlDepCannotBeCreatedInProc();
}
if (ADP.IsEmpty(connectionString)) {
if (null == connectionString) {
throw ADP.ArgumentNull("connectionString");
}
else {
throw ADP.Argument("connectionString");
}
}
if (!useDefaults && ADP.IsEmpty(queue)) { // If specified but null or empty, use defaults.
useDefaults = true;
queue = null; // Force to null - for proper hashtable comparison for default case.
}
// Create new connection options for demand on their connection string. We modify the connection string
// and assert on our modified string when we create the container.
SqlConnectionString connectionStringObject = new SqlConnectionString(connectionString);
connectionStringObject.DemandPermission();
if (connectionStringObject.LocalDBInstance!=null) {
LocalDBAPI.DemandLocalDBPermissions();
}
// End duplicate Start/Stop logic.
bool result = false;
lock (_startStopLock) {
if (null != _processDispatcher) { // If _processDispatcher null, no Start has been called.
try {
string server = null;
DbConnectionPoolIdentity identity = null;
string user = null;
string database = null;
string service = null;
if (useDefaults) {
bool appDomainStop = false;
RuntimeHelpers.PrepareConstrainedRegions();
try { // CER to ensure that if Stop succeeds we remove from hash completing teardown.
// Start using process wide default service/queue & database from connection string.
result = _processDispatcher.Stop( connectionString,
out server,
out identity,
out user,
out database,
ref service,
_appDomainKey,
out appDomainStop);
}
finally {
if (appDomainStop && !startFailed) { // If success, remove from hashtable.
Debug.Assert(!ADP.IsEmpty(server) && !ADP.IsEmpty(database), "Server or Database null/Empty upon successfull Stop()!");
IdentityUserNamePair identityUser = new IdentityUserNamePair(identity, user);
DatabaseServicePair databaseService = new DatabaseServicePair(database, service);
RemoveFromServerUserHash(server, identityUser, databaseService);
}
}
}
else {
bool ignored = false;
result = _processDispatcher.Stop( connectionString,
out server,
out identity,
out user,
out database,
ref queue,
_appDomainKey,
out ignored);
// No need to call RemoveFromServerDatabaseHash since if not using default queue user is required
// to provide options themselves.
}
}
catch (Exception e) {
if (!ADP.IsCatchableExceptionType(e)) {
throw;
}
ADP.TraceExceptionWithoutRethrow(e); // Discard failure, but trace for now.
}
}
}
return result;
}
finally {
Bid.ScopeLeave(ref hscp);
}
}
// --------------------------------
// General static utility functions
// --------------------------------
private static bool AddToServerUserHash(string server, IdentityUserNamePair identityUser, DatabaseServicePair databaseService) {
IntPtr hscp;
Bid.NotificationsScopeEnter(out hscp, "<sc.SqlDependency.AddToServerUserHash|DEP> server: '%ls', database: '%ls', service: '%ls'", server, databaseService.Database, databaseService.Service);
try {
bool result = false;
lock (_serverUserHash) {
Dictionary<IdentityUserNamePair, List<DatabaseServicePair>> identityDatabaseHash;
if (!_serverUserHash.ContainsKey(server)) {
Bid.NotificationsTrace("<sc.SqlDependency.AddToServerUserHash|DEP> Hash did not contain server, adding.\n");
identityDatabaseHash = new Dictionary<IdentityUserNamePair, List<DatabaseServicePair>>();
_serverUserHash.Add(server, identityDatabaseHash);
}
else {
identityDatabaseHash = _serverUserHash[server];
}
List<DatabaseServicePair> databaseServiceList;
if (!identityDatabaseHash.ContainsKey(identityUser)) {
Bid.NotificationsTrace("<sc.SqlDependency.AddToServerUserHash|DEP> Hash contained server but not user, adding user.\n");
databaseServiceList = new List<DatabaseServicePair>();
identityDatabaseHash.Add(identityUser, databaseServiceList);
}
else {
databaseServiceList = identityDatabaseHash[identityUser];
}
if (!databaseServiceList.Contains(databaseService)) {
Bid.NotificationsTrace("<sc.SqlDependency.AddToServerUserHash|DEP> Adding database.\n");
databaseServiceList.Add(databaseService);
result = true;
}
else {
Bid.NotificationsTrace("<sc.SqlDependency.AddToServerUserHash|DEP|ERR> ERROR - hash already contained server, user, and database - we will throw!.\n");
}
}
return result;
}
finally {
Bid.ScopeLeave(ref hscp);
}
}
private static void RemoveFromServerUserHash(string server, IdentityUserNamePair identityUser, DatabaseServicePair databaseService) {
IntPtr hscp;
Bid.NotificationsScopeEnter(out hscp, "<sc.SqlDependency.RemoveFromServerUserHash|DEP> server: '%ls', database: '%ls', service: '%ls'", server, databaseService.Database, databaseService.Service);
try {
lock (_serverUserHash) {
Dictionary<IdentityUserNamePair, List<DatabaseServicePair>> identityDatabaseHash;
if (_serverUserHash.ContainsKey(server)) {
identityDatabaseHash = _serverUserHash[server];
List<DatabaseServicePair> databaseServiceList;
if (identityDatabaseHash.ContainsKey(identityUser)) {
databaseServiceList = identityDatabaseHash[identityUser];
int index = databaseServiceList.IndexOf(databaseService);
if (index >= 0) {
Bid.NotificationsTrace("<sc.SqlDependency.RemoveFromServerUserHash|DEP> Hash contained server, user, and database - removing database.\n");
databaseServiceList.RemoveAt(index);
if (databaseServiceList.Count == 0) {
Bid.NotificationsTrace("<sc.SqlDependency.RemoveFromServerUserHash|DEP> databaseServiceList count 0, removing the list for this server and user.\n");
identityDatabaseHash.Remove(identityUser);
if (identityDatabaseHash.Count == 0) {
Bid.NotificationsTrace("<sc.SqlDependency.RemoveFromServerUserHash|DEP> identityDatabaseHash count 0, removing the hash for this server.\n");
_serverUserHash.Remove(server);
}
}
}
else {
Bid.NotificationsTrace("<sc.SqlDependency.RemoveFromServerUserHash|DEP|ERR> ERROR - hash contained server and user but not database!\n");
Debug.Assert(false, "Unexpected state - hash did not contain database!");
}
}
else {
Bid.NotificationsTrace("<sc.SqlDependency.RemoveFromServerUserHash|DEP|ERR> ERROR - hash contained server but not user!\n");
Debug.Assert(false, "Unexpected state - hash did not contain user!");
}
}
else {
Bid.NotificationsTrace("<sc.SqlDependency.RemoveFromServerUserHash|DEP|ERR> ERROR - hash did not contain server!\n");
Debug.Assert(false, "Unexpected state - hash did not contain server!");
}
}
}
finally {
Bid.ScopeLeave(ref hscp);
}
}
internal static string GetDefaultComposedOptions(string server, string failoverServer, IdentityUserNamePair identityUser, string database) {
// Server must be an exact match, but user and database only needs to match exactly if there is more than one
// for the given user or database passed. That is ambiguious and we must fail.
IntPtr hscp;
Bid.NotificationsScopeEnter(out hscp, "<sc.SqlDependency.GetDefaultComposedOptions|DEP> server: '%ls', failoverServer: '%ls', database: '%ls'", server, failoverServer, database);
try {
string result;
lock (_serverUserHash) {
if (!_serverUserHash.ContainsKey(server)) {
if (0 == _serverUserHash.Count) { // Special error for no calls to start.
Bid.NotificationsTrace("<sc.SqlDependency.GetDefaultComposedOptions|DEP|ERR> ERROR - no start calls have been made, about to throw.\n");
throw SQL.SqlDepDefaultOptionsButNoStart();
}
else if (!ADP.IsEmpty(failoverServer) && _serverUserHash.ContainsKey(failoverServer)) {
Bid.NotificationsTrace("<sc.SqlDependency.GetDefaultComposedOptions|DEP> using failover server instead\n");
server = failoverServer;
}
else {
Bid.NotificationsTrace("<sc.SqlDependency.GetDefaultComposedOptions|DEP|ERR> ERROR - not listening to this server, about to throw.\n");
throw SQL.SqlDependencyNoMatchingServerStart();
}
}
Dictionary<IdentityUserNamePair, List<DatabaseServicePair>> identityDatabaseHash = _serverUserHash[server];
List<DatabaseServicePair> databaseList = null;
if (!identityDatabaseHash.ContainsKey(identityUser)) {
if (identityDatabaseHash.Count > 1) {
Bid.NotificationsTrace("<sc.SqlDependency.GetDefaultComposedOptions|DEP|ERR> ERROR - not listening for this user, but listening to more than one other user, about to throw.\n");
throw SQL.SqlDependencyNoMatchingServerStart();
}
else {
// Since only one user, - use that.
// Foreach - but only one value present.
foreach (KeyValuePair<IdentityUserNamePair, List<DatabaseServicePair>> entry in identityDatabaseHash) {
databaseList = entry.Value;
break; // Only iterate once.
}
}
}
else {
databaseList = identityDatabaseHash[identityUser];
}
DatabaseServicePair pair = new DatabaseServicePair(database, null);
DatabaseServicePair resultingPair = null;
int index = databaseList.IndexOf(pair);
if (index != -1) { // Exact match found, use it.
resultingPair = databaseList[index];
}
if (null != resultingPair) { // Exact database match.
database = FixupServiceOrDatabaseName(resultingPair.Database); // Fixup in place.
string quotedService = FixupServiceOrDatabaseName(resultingPair.Service);
result = "Service="+quotedService+";Local Database="+database;
}
else { // No exact database match found.
if (databaseList.Count == 1) { // If only one database for this server/user, use it.
object[] temp = databaseList.ToArray(); // Must copy, no other choice but foreach.
resultingPair = (DatabaseServicePair) temp[0];
Debug.Assert(temp.Length == 1, "If databaseList.Count==1, why does copied array have length other than 1?");
string quotedDatabase = FixupServiceOrDatabaseName(resultingPair.Database);
string quotedService = FixupServiceOrDatabaseName(resultingPair.Service);
result = "Service="+quotedService+";Local Database="+quotedDatabase;
}
else { // More than one database for given server, ambiguous - fail the default case!
Bid.NotificationsTrace("<sc.SqlDependency.GetDefaultComposedOptions|DEP|ERR> ERROR - SqlDependency.Start called multiple times for this server/user, but no matching database.\n");
throw SQL.SqlDependencyNoMatchingServerDatabaseStart();
}
}
}
Debug.Assert(!ADP.IsEmpty(result), "GetDefaultComposedOptions should never return null or empty string!");
Bid.NotificationsTrace("<sc.SqlDependency.GetDefaultComposedOptions|DEP> resulting options: '%ls'.\n", result);
return result;
}
finally {
Bid.ScopeLeave(ref hscp);
}
}
// ----------------
// Internal Methods
// ----------------
// Called by SqlCommand upon execution of a SqlNotificationRequest class created by this dependency. We
// use this list for a reverse lookup based on server.
internal void AddToServerList(string server) {
IntPtr hscp;
Bid.NotificationsScopeEnter(out hscp, "<sc.SqlDependency.AddToServerList|DEP> %d#, server: '%ls'", ObjectID, server);
try {
lock (_serverList) {
int index = _serverList.BinarySearch(server, StringComparer.OrdinalIgnoreCase);
if (0 > index) { // If less than 0, item was not found in list.
Bid.NotificationsTrace("<sc.SqlDependency.AddToServerList|DEP> Server not present in hashtable, adding server: '%ls'.\n", server);
index = ~index; // BinarySearch returns the 2's compliment of where the item should be inserted to preserver a sorted list after insertion.
_serverList.Insert(index, server);
}
}
}
finally {
Bid.ScopeLeave(ref hscp);
}
}
internal bool ContainsServer(string server) {
lock (_serverList) {
return _serverList.Contains(server);
}
}
internal string ComputeHashAndAddToDispatcher(SqlCommand command) {
IntPtr hscp;
Bid.NotificationsScopeEnter(out hscp, "<sc.SqlDependency.ComputeHashAndAddToDispatcher|DEP> %d#, SqlCommand: %d#", ObjectID, command.ObjectID);
try {
// Create a string representing the concatenation of the connection string, command text and .ToString on all parameter values.
// This string will then be mapped to unique notification ID (new GUID). We add the guid and the hash to the app domain
// dispatcher to be able to map back to the dependency that needs to be fired for a notification of this
// command.
// VSTS 59821: add Connection string to prevent redundant notifications when same command is running against different databases or SQL servers
//
string commandHash = ComputeCommandHash(command.Connection.ConnectionString, command); // calculate the string representation of command
string idString = SqlDependencyPerAppDomainDispatcher.SingletonInstance.AddCommandEntry(commandHash, this); // Add to map.
Bid.NotificationsTrace("<sc.SqlDependency.ComputeHashAndAddToDispatcher|DEP> computed id string: '%ls'.\n", idString);
return idString;
}
finally {
Bid.ScopeLeave(ref hscp);
}
}
internal void Invalidate(SqlNotificationType type, SqlNotificationInfo info, SqlNotificationSource source) {
IntPtr hscp;
Bid.NotificationsScopeEnter(out hscp, "<sc.SqlDependency.Invalidate|DEP> %d#", ObjectID);
try {
List<EventContextPair> eventList = null;
lock (_eventHandlerLock) {
if (_dependencyFired &&
SqlNotificationInfo.AlreadyChanged != info &&
SqlNotificationSource.Client != source) {
if (ExpirationTime < DateTime.UtcNow) {
// There is a small window in which SqlDependencyPerAppDomainDispatcher.TimeoutTimerCallback
// raises Timeout event but before removing this event from the list. If notification is received from
// server in this case, we will hit this code path.
// It is safe to ignore this race condition because no event is sent to user and no leak happens.
Bid.NotificationsTrace("<sc.SqlDependency.Invalidate|DEP> ignore notification received after timeout!");
}
else {
Debug.Assert(false, "Received notification twice - we should never enter this state!");
Bid.NotificationsTrace("<sc.SqlDependency.Invalidate|DEP|ERR> ERROR - notification received twice - we should never enter this state!");
}
}
else {
// It is the invalidators responsibility to remove this dependency from the app domain static hash.
_dependencyFired = true;
eventList = _eventList;
_eventList = new List<EventContextPair>(); // Since we are firing the events, null so we do not fire again.
}
}
if (eventList != null) {
Bid.NotificationsTrace("<sc.SqlDependency.Invalidate|DEP> Firing events.\n");
foreach(EventContextPair pair in eventList) {
pair.Invoke(new SqlNotificationEventArgs(type, info, source));
}
}
}
finally {
Bid.ScopeLeave(ref hscp);
}
}
// This method is used by SqlCommand.
internal void StartTimer(SqlNotificationRequest notificationRequest) {
IntPtr hscp;
Bid.NotificationsScopeEnter(out hscp, "<sc.SqlDependency.StartTimer|DEP> %d#", ObjectID);
try {
if(_expirationTime == DateTime.MaxValue) {
Bid.NotificationsTrace("<sc.SqlDependency.StartTimer|DEP> We've timed out, executing logic.\n");
int seconds = SQL.SqlDependencyServerTimeout;
if (0 != _timeout) {
seconds = _timeout;
}
if (notificationRequest != null && notificationRequest.Timeout < seconds && notificationRequest.Timeout != 0) {
seconds = notificationRequest.Timeout;
}
// VSDD 563926: we use UTC to check if SqlDependency is expired, need to use it here as well.
_expirationTime = DateTime.UtcNow.AddSeconds(seconds);
SqlDependencyPerAppDomainDispatcher.SingletonInstance.StartTimer(this);
}
}
finally {
Bid.ScopeLeave(ref hscp);
}
}
// ---------------
// Private Methods
// ---------------
private void AddCommandInternal(SqlCommand cmd) {
if (cmd != null) { // Don't bother with BID if command null.
IntPtr hscp;
Bid.NotificationsScopeEnter(out hscp, "<sc.SqlDependency.AddCommandInternal|DEP> %d#, SqlCommand: %d#", ObjectID, cmd.ObjectID);
try {
SqlConnection connection = cmd.Connection;
if (cmd.Notification != null) {
// Fail if cmd has notification that is not already associated with this dependency.
if (cmd._sqlDep == null || cmd._sqlDep != this) {
Bid.NotificationsTrace("<sc.SqlDependency.AddCommandInternal|DEP|ERR> ERROR - throwing command has existing SqlNotificationRequest exception.\n");
throw SQL.SqlCommandHasExistingSqlNotificationRequest();
}
}
else {
bool needToInvalidate = false;
lock (_eventHandlerLock) {
if (!_dependencyFired) {
cmd.Notification = new SqlNotificationRequest();
cmd.Notification.Timeout = _timeout;
// Add the command - A dependancy should always map to a set of commands which haven't fired.
if (null != _options) { // Assign options if user provided.
cmd.Notification.Options = _options;
}
cmd._sqlDep = this;
}
else {
// We should never be able to enter this state, since if we've fired our event list is cleared
// and the event method will immediately fire if a new event is added. So, we should never have
// an event to fire in the event list once we've fired.
Debug.Assert(0 == _eventList.Count, "How can we have an event at this point?");
if (0 == _eventList.Count) { // Keep logic just in case.
Bid.NotificationsTrace("<sc.SqlDependency.AddCommandInternal|DEP|ERR> ERROR - firing events, though it is unexpected we have events at this point.\n");
needToInvalidate = true; // Delay invalidation until outside of lock.
}
}
}
if (needToInvalidate) {
Invalidate(SqlNotificationType.Subscribe, SqlNotificationInfo.AlreadyChanged, SqlNotificationSource.Client);
}
}
}
finally {
Bid.ScopeLeave(ref hscp);
}
}
}
private string ComputeCommandHash(string connectionString, SqlCommand command) {
IntPtr hscp;
Bid.NotificationsScopeEnter(out hscp, "<sc.SqlDependency.ComputeCommandHash|DEP> %d#, SqlCommand: %d#", ObjectID, command.ObjectID);
try {
// Create a string representing the concatenation of the connection string, the command text and .ToString on all its parameter values.
// This string will then be mapped to the notification ID.
// All types should properly support a .ToString for the values except
// byte[], char[], and XmlReader.
// NOTE - I hope this doesn't come back to bite us. :(
StringBuilder builder = new StringBuilder();
// add the Connection string and the Command text
builder.AppendFormat("{0};{1}", connectionString, command.CommandText);
// append params
for (int i=0; i<command.Parameters.Count; i++) {
object value = command.Parameters[i].Value;
if (value == null || value == DBNull.Value) {
builder.Append("; NULL");
}
else {
Type type = value.GetType();
if (type == typeof(Byte[])) {
builder.Append(";");
byte[] temp = (byte[]) value;
for (int j=0; j<temp.Length; j++) {
builder.Append(temp[j].ToString("x2", CultureInfo.InvariantCulture));
}
}
else if (type == typeof(Char[])) {
builder.Append((char[]) value);
}
else if (type == typeof(XmlReader)) {
builder.Append(";");
// Cannot .ToString XmlReader - just allocate GUID.
// This means if XmlReader is used, we will not reuse IDs.
builder.Append(Guid.NewGuid().ToString());
}
else {
builder.Append(";");
builder.Append(value.ToString());
}
}
}
string result = builder.ToString();
Bid.NotificationsTrace("<sc.SqlDependency.ComputeCommandHash|DEP> ComputeCommandHash result: '%ls'.\n", result);
return result;
}
finally {
Bid.ScopeLeave(ref hscp);
}
}
// Basic copy of function in SqlConnection.cs for ChangeDatabase and similar functionality. Since this will
// only be used for default service and database provided by server, we do not need to worry about an already
// quoted value.
static internal string FixupServiceOrDatabaseName(string name) {
if (!ADP.IsEmpty(name)) {
return "\"" + name.Replace("\"", "\"\"") + "\"";
}
else {
return name;
}
}
}
}
|