/// <summary>
/// The core queue processing method
/// </summary>
/// <param name="state"></param>
private void ProcessQueue()
{
CancellationToken token = this.processQueueCancelToken.Token;
WaitHandle[] waitHandles = new WaitHandle[2]
{
this.itemQueuedEvent,
token.WaitHandle
};
while (true)
{
// wait for with an item to be queued or the a cancellation request
WaitHandle.WaitAny(waitHandles);
if (token.IsCancellationRequested)
{
break;
}
try
{
// dispatch all pending queue items
while (this.HasPendingQueueItems)
{
QueueItem queueItem = GetNextQueueItem();
if (queueItem == null)
{
continue;
}
IBindingContext bindingContext = GetOrCreateBindingContext(queueItem.Key);
if (bindingContext == null)
{
queueItem.ItemProcessed.Set();
continue;
}
bool lockTaken = false;
try
{
// prefer the queue item binding item, otherwise use the context default timeout
int bindTimeout = queueItem.BindingTimeout ?? bindingContext.BindingTimeout;
// handle the case a previous binding operation is still running
if (!bindingContext.BindingLock.WaitOne(queueItem.WaitForLockTimeout ?? 0))
{
queueItem.Result = queueItem.TimeoutOperation != null
? queueItem.TimeoutOperation(bindingContext)
: null;
continue;
}
bindingContext.BindingLock.Reset();
lockTaken = true;
// execute the binding operation
object result = null;
CancellationTokenSource cancelToken = new CancellationTokenSource();
var bindTask = Task.Run(() =>
{
result = queueItem.BindOperation(
bindingContext,
cancelToken.Token);
});
// check if the binding tasks completed within the binding timeout
if (bindTask.Wait(bindTimeout))
{
queueItem.Result = result;
}
else
{
cancelToken.Cancel();
// if the task didn't complete then call the timeout callback
if (queueItem.TimeoutOperation != null)
{
queueItem.Result = queueItem.TimeoutOperation(bindingContext);
}
lockTaken = false;
bindTask.ContinueWith((a) => bindingContext.BindingLock.Set());
}
}
catch (Exception ex)
{
// catch and log any exceptions raised in the binding calls
// set item processed to avoid deadlocks
Logger.Write(LogLevel.Error, "Binding queue threw exception " + ex.ToString());
}
finally
{
if (lockTaken)
{
bindingContext.BindingLock.Set();
}
queueItem.ItemProcessed.Set();
}
// if a queue processing cancellation was requested then exit the loop
if (token.IsCancellationRequested)
{
break;
}
}
}
finally
{
lock (this.bindingQueueLock)
{
// verify the binding queue is still empty
if (this.bindingQueue.Count == 0)
{
// reset the item queued event since we've processed all the pending items
this.itemQueuedEvent.Reset();
}
}
}
}
}
/// <summary>
/// Return the completion item list for the current text position.
/// This method does not await cache builds since it expects to return quickly
/// </summary>
/// <param name="textDocumentPosition"></param>
public CompletionItem[] GetCompletionItems(
TextDocumentPosition textDocumentPosition,
ScriptFile scriptFile,
ConnectionInfo connInfo)
{
// initialize some state to parse and bind the current script file
this.currentCompletionParseInfo = null;
CompletionItem[] resultCompletionItems = null;
string filePath = textDocumentPosition.TextDocument.Uri;
int startLine = textDocumentPosition.Position.Line;
int parserLine = textDocumentPosition.Position.Line + 1;
int startColumn = TextUtilities.PositionOfPrevDelimeter(
scriptFile.Contents,
textDocumentPosition.Position.Line,
textDocumentPosition.Position.Character);
int endColumn = TextUtilities.PositionOfNextDelimeter(
scriptFile.Contents,
textDocumentPosition.Position.Line,
textDocumentPosition.Position.Character);
int parserColumn = textDocumentPosition.Position.Character + 1;
bool useLowerCaseSuggestions = this.CurrentSettings.SqlTools.IntelliSense.LowerCaseSuggestions.Value;
// get the current script parse info object
ScriptParseInfo scriptParseInfo = GetScriptParseInfo(textDocumentPosition.TextDocument.Uri);
if (scriptParseInfo == null)
{
return(AutoCompleteHelper.GetDefaultCompletionItems(
startLine,
startColumn,
endColumn,
useLowerCaseSuggestions));
}
// reparse and bind the SQL statement if needed
if (RequiresReparse(scriptParseInfo, scriptFile))
{
ParseAndBind(scriptFile, connInfo);
}
// if the parse failed then return the default list
if (scriptParseInfo.ParseResult == null)
{
return(AutoCompleteHelper.GetDefaultCompletionItems(
startLine,
startColumn,
endColumn,
useLowerCaseSuggestions));
}
// need to adjust line & column for base-1 parser indices
Token token = GetToken(scriptParseInfo, parserLine, parserColumn);
string tokenText = token != null ? token.Text : null;
// check if the file is connected and the file lock is available
if (scriptParseInfo.IsConnected && Monitor.TryEnter(scriptParseInfo.BuildingMetadataLock))
{
try
{
// queue the completion task with the binding queue
QueueItem queueItem = this.BindingQueue.QueueBindingOperation(
key: scriptParseInfo.ConnectionKey,
bindingTimeout: LanguageService.BindingTimeout,
bindOperation: (bindingContext, cancelToken) =>
{
// get the completion list from SQL Parser
scriptParseInfo.CurrentSuggestions = Resolver.FindCompletions(
scriptParseInfo.ParseResult,
parserLine,
parserColumn,
bindingContext.MetadataDisplayInfoProvider);
// cache the current script parse info object to resolve completions later
this.currentCompletionParseInfo = scriptParseInfo;
// convert the suggestion list to the VS Code format
return(AutoCompleteHelper.ConvertDeclarationsToCompletionItems(
scriptParseInfo.CurrentSuggestions,
startLine,
startColumn,
endColumn));
},
timeoutOperation: (bindingContext) =>
{
// return the default list if the connected bind fails
return(AutoCompleteHelper.GetDefaultCompletionItems(
startLine,
startColumn,
endColumn,
useLowerCaseSuggestions,
tokenText));
});
// wait for the queue item
queueItem.ItemProcessed.WaitOne();
var completionItems = queueItem.GetResultAsT <CompletionItem[]>();
if (completionItems != null && completionItems.Length > 0)
{
resultCompletionItems = completionItems;
}
else if (!ShouldShowCompletionList(token))
{
resultCompletionItems = AutoCompleteHelper.EmptyCompletionList;
}
}
finally
{
Monitor.Exit(scriptParseInfo.BuildingMetadataLock);
}
}
// if there are no completions then provide the default list
if (resultCompletionItems == null)
{
resultCompletionItems = AutoCompleteHelper.GetDefaultCompletionItems(
startLine,
startColumn,
endColumn,
useLowerCaseSuggestions,
tokenText);
}
return(resultCompletionItems);
}
/// <summary>
/// Preinitialize the parser and binder with common metadata.
/// This should front load the long binding wait to the time the
/// connection is established. Once this is completed other binding
/// requests should be faster.
/// </summary>
/// <param name="info"></param>
/// <param name="scriptInfo"></param>
internal static void PrepopulateCommonMetadata(
ConnectionInfo info,
ScriptParseInfo scriptInfo,
ConnectedBindingQueue bindingQueue)
{
if (scriptInfo.IsConnected)
{
var scriptFile = AutoCompleteHelper.WorkspaceServiceInstance.Workspace.GetFile(info.OwnerUri);
LanguageService.Instance.ParseAndBind(scriptFile, info);
if (Monitor.TryEnter(scriptInfo.BuildingMetadataLock, LanguageService.OnConnectionWaitTimeout))
{
try
{
QueueItem queueItem = bindingQueue.QueueBindingOperation(
key: scriptInfo.ConnectionKey,
bindingTimeout: AutoCompleteHelper.PrepopulateBindTimeout,
waitForLockTimeout: AutoCompleteHelper.PrepopulateBindTimeout,
bindOperation: (bindingContext, cancelToken) =>
{
// parse a simple statement that returns common metadata
ParseResult parseResult = Parser.Parse(
"select ",
bindingContext.ParseOptions);
List <ParseResult> parseResults = new List <ParseResult>();
parseResults.Add(parseResult);
bindingContext.Binder.Bind(
parseResults,
info.ConnectionDetails.DatabaseName,
BindMode.Batch);
// get the completion list from SQL Parser
var suggestions = Resolver.FindCompletions(
parseResult, 1, 8,
bindingContext.MetadataDisplayInfoProvider);
// this forces lazy evaluation of the suggestion metadata
AutoCompleteHelper.ConvertDeclarationsToCompletionItems(suggestions, 1, 8, 8);
parseResult = Parser.Parse(
"exec ",
bindingContext.ParseOptions);
parseResults = new List <ParseResult>();
parseResults.Add(parseResult);
bindingContext.Binder.Bind(
parseResults,
info.ConnectionDetails.DatabaseName,
BindMode.Batch);
// get the completion list from SQL Parser
suggestions = Resolver.FindCompletions(
parseResult, 1, 6,
bindingContext.MetadataDisplayInfoProvider);
// this forces lazy evaluation of the suggestion metadata
AutoCompleteHelper.ConvertDeclarationsToCompletionItems(suggestions, 1, 6, 6);
return(null);
});
queueItem.ItemProcessed.WaitOne();
}
catch
{
}
finally
{
Monitor.Exit(scriptInfo.BuildingMetadataLock);
}
}
}
}
/// <summary>
/// Parses the SQL text and binds it to the SMO metadata provider if connected
/// </summary>
/// <param name="filePath"></param>
/// <param name="sqlText"></param>
/// <returns>The ParseResult instance returned from SQL Parser</returns>
public ParseResult ParseAndBind(ScriptFile scriptFile, ConnectionInfo connInfo)
{
// get or create the current parse info object
ScriptParseInfo parseInfo = GetScriptParseInfo(scriptFile.ClientFilePath, createIfNotExists: true);
if (Monitor.TryEnter(parseInfo.BuildingMetadataLock, LanguageService.BindingTimeout))
{
try
{
if (connInfo == null || !parseInfo.IsConnected)
{
// parse current SQL file contents to retrieve a list of errors
ParseResult parseResult = Parser.IncrementalParse(
scriptFile.Contents,
parseInfo.ParseResult,
this.DefaultParseOptions);
parseInfo.ParseResult = parseResult;
}
else
{
QueueItem queueItem = this.BindingQueue.QueueBindingOperation(
key: parseInfo.ConnectionKey,
bindingTimeout: LanguageService.BindingTimeout,
bindOperation: (bindingContext, cancelToken) =>
{
try
{
ParseResult parseResult = Parser.IncrementalParse(
scriptFile.Contents,
parseInfo.ParseResult,
bindingContext.ParseOptions);
parseInfo.ParseResult = parseResult;
List <ParseResult> parseResults = new List <ParseResult>();
parseResults.Add(parseResult);
bindingContext.Binder.Bind(
parseResults,
connInfo.ConnectionDetails.DatabaseName,
BindMode.Batch);
}
catch (ConnectionException)
{
Logger.Write(LogLevel.Error, "Hit connection exception while binding - disposing binder object...");
}
catch (SqlParserInternalBinderError)
{
Logger.Write(LogLevel.Error, "Hit connection exception while binding - disposing binder object...");
}
catch (Exception ex)
{
Logger.Write(LogLevel.Error, "Unknown exception during parsing " + ex.ToString());
}
return(null);
});
queueItem.ItemProcessed.WaitOne();
}
}
catch (Exception ex)
{
// reset the parse result to do a full parse next time
parseInfo.ParseResult = null;
Logger.Write(LogLevel.Error, "Unknown exception during parsing " + ex.ToString());
}
finally
{
Monitor.Exit(parseInfo.BuildingMetadataLock);
}
}
else
{
Logger.Write(LogLevel.Warning, "Binding metadata lock timeout in ParseAndBind");
}
return(parseInfo.ParseResult);
}
/// <summary>
/// The core queue processing method
/// </summary>
/// <param name="state"></param>
private void ProcessQueue()
{
CancellationToken token = this.processQueueCancelToken.Token;
WaitHandle[] waitHandles = new WaitHandle[2]
{
this.itemQueuedEvent,
token.WaitHandle
};
while (true)
{
// wait for with an item to be queued or the a cancellation request
WaitHandle.WaitAny(waitHandles);
if (token.IsCancellationRequested)
{
break;
}
try
{
// dispatch all pending queue items
while (this.HasPendingQueueItems)
{
QueueItem queueItem = GetNextQueueItem();
if (queueItem == null)
{
continue;
}
IBindingContext bindingContext = GetOrCreateBindingContext(queueItem.Key);
if (bindingContext == null)
{
queueItem.ItemProcessed.Set();
continue;
}
var bindingContextTask = this.BindingContextTasks[bindingContext];
// Run in the binding context task in case this task has to wait for a previous binding operation
this.BindingContextTasks[bindingContext] = bindingContextTask.ContinueWith((task) =>
{
bool lockTaken = false;
try
{
// prefer the queue item binding item, otherwise use the context default timeout
int bindTimeout = queueItem.BindingTimeout ?? bindingContext.BindingTimeout;
// handle the case a previous binding operation is still running
if (!bindingContext.BindingLock.WaitOne(queueItem.WaitForLockTimeout ?? 0))
{
try
{
Logger.Write(TraceEventType.Warning, "Binding queue operation timed out waiting for previous operation to finish");
queueItem.Result = queueItem.TimeoutOperation != null
? queueItem.TimeoutOperation(bindingContext)
: null;
}
catch (Exception ex)
{
Logger.Write(TraceEventType.Error, "Exception running binding queue lock timeout handler: " + ex.ToString());
}
finally
{
queueItem.ItemProcessed.Set();
}
return;
}
bindingContext.BindingLock.Reset();
lockTaken = true;
// execute the binding operation
object result = null;
CancellationTokenSource cancelToken = new CancellationTokenSource();
// run the operation in a separate thread
var bindTask = Task.Run(() =>
{
try
{
result = queueItem.BindOperation(
bindingContext,
cancelToken.Token);
}
catch (Exception ex)
{
Logger.Write(TraceEventType.Error, "Unexpected exception on the binding queue: " + ex.ToString());
if (queueItem.ErrorHandler != null)
{
try
{
result = queueItem.ErrorHandler(ex);
}
catch (Exception ex2)
{
Logger.Write(TraceEventType.Error, "Unexpected exception in binding queue error handler: " + ex2.ToString());
}
}
if (IsExceptionOfType(ex, typeof(SqlException)) || IsExceptionOfType(ex, typeof(SocketException)))
{
if (this.OnUnhandledException != null)
{
this.OnUnhandledException(queueItem.Key, ex);
}
RemoveBindingContext(queueItem.Key);
}
}
});
Task.Run(() =>
{
try
{
// check if the binding tasks completed within the binding timeout
if (bindTask.Wait(bindTimeout))
{
queueItem.Result = result;
}
else
{
cancelToken.Cancel();
// if the task didn't complete then call the timeout callback
if (queueItem.TimeoutOperation != null)
{
queueItem.Result = queueItem.TimeoutOperation(bindingContext);
}
bindTask.ContinueWithOnFaulted(t => Logger.Write(TraceEventType.Error, "Binding queue threw exception " + t.Exception.ToString()));
// Give the task a chance to complete before moving on to the next operation
bindTask.Wait();
}
}
catch (Exception ex)
{
Logger.Write(TraceEventType.Error, "Binding queue task completion threw exception " + ex.ToString());
}
finally
{
// set item processed to avoid deadlocks
if (lockTaken)
{
bindingContext.BindingLock.Set();
}
queueItem.ItemProcessed.Set();
}
});
}
catch (Exception ex)
{
// catch and log any exceptions raised in the binding calls
// set item processed to avoid deadlocks
Logger.Write(TraceEventType.Error, "Binding queue threw exception " + ex.ToString());
// set item processed to avoid deadlocks
if (lockTaken)
{
bindingContext.BindingLock.Set();
}
queueItem.ItemProcessed.Set();
}
}, TaskContinuationOptions.None);
// if a queue processing cancellation was requested then exit the loop
if (token.IsCancellationRequested)
{
break;
}
}
}
finally
{
lock (this.bindingQueueLock)
{
// verify the binding queue is still empty
if (this.bindingQueue.Count == 0)
{
// reset the item queued event since we've processed all the pending items
this.itemQueuedEvent.Reset();
}
}
}
}
}
