/// <summary>
/// The Live Pricing Service (flight query) returns all the flights available for a specific route and
/// date (or single date for one-way searches).
/// </summary>
/// <param name="flightQuerySettings">Settings for the query</param>
/// <param name="interimResultCallback">The callback that is called when interim results are recieved</param>
/// <returns>The collection of itineraries from SkyScanner</returns>
public async Task <List <Itinerary> > QueryFlight(
FlightQuerySettings flightQuerySettings,
Action <InterimChangeSet <Itinerary> > interimResultCallback,
CancellationToken cancellationToken = default(CancellationToken))
{
var interimResultHandler = new InterimResultProvider <FlightResponse, Itinerary>();
var flightService = new Flight(_apiKey, flightQuerySettings);
return(await _executionStrategy.Execute(async() =>
{
var pinger = await flightService.SendQuery(cancellationToken);
if (interimResultCallback != null)
{
pinger.OnInterimResultsRecieved += (sender, args) =>
{
interimResultCallback(interimResultHandler.Calculate(args));
};
}
var response = await pinger.SendQuery(cancellationToken);
return response.Itineraries;
}, cancellationToken));
}
/// <summary>
/// Executes the strategy
/// </summary>
public void Execute(object sender, EventArgs args)
{
if (strategy != null)
{
if (strategy.Route.IsSendEventArgs)
{
strategy.Execute(new object[] { CommandParameter, sender, args });
}
else
{
//注入
strategy.Execute(CommandParameter);
}
}
}
/// <summary>
/// Executes the strategy
/// </summary>
public void Execute()
{
if (strategy != null)
{
strategy.Execute(CommandParameter);
}
}
public bool MoveNext()
{
try
{
using (_relationalQueryContext.ConcurrencyDetector.EnterCriticalSection())
{
if (_dataReader == null)
{
if (_executionStrategy == null)
{
_executionStrategy = _relationalQueryContext.ExecutionStrategyFactory.Create();
}
_executionStrategy.Execute(true, InitializeReader, null);
}
var hasNext = _dataReader.Read();
Current = hasNext
? _shaper(_relationalQueryContext, _dataReader.DbDataReader, _indexMap)
: default;
return(hasNext);
}
}
catch (Exception exception)
{
_queryLogger.QueryIterationFailed(_contextType, exception);
throw;
}
}
private void ExecuteTask(ICakeContext context, IExecutionStrategy strategy, Stopwatch stopWatch, CakeTask task, CakeReport report)
{
// Reset the stop watch.
stopWatch.Reset();
stopWatch.Start();
PerformTaskSetup(context, strategy, task, false);
bool exceptionWasThrown = false;
try
{
// Execute the task.
strategy.Execute(task, context);
}
catch (Exception exception)
{
_log.Error("An error occurred when executing task '{0}'.", task.Name);
exceptionWasThrown = true;
// Got an error reporter?
if (task.ErrorReporter != null)
{
ReportErrors(strategy, task.ErrorReporter, exception);
}
// Got an error handler?
if (task.ErrorHandler != null)
{
HandleErrors(strategy, task.ErrorHandler, exception);
}
else
{
// No error handler defined for this task.
// Rethrow the exception and let it propagate.
throw;
}
}
finally
{
if (task.FinallyHandler != null)
{
strategy.InvokeFinally(task.FinallyHandler);
}
PerformTaskTeardown(context, strategy, task, stopWatch.Elapsed, false, exceptionWasThrown);
}
// Add the task results to the report
if (IsDelegatedTask(task))
{
report.AddDelegated(task.Name, stopWatch.Elapsed);
}
else
{
report.Add(task.Name, stopWatch.Elapsed);
}
}
public bool MoveNext()
{
try
{
using (_relationalQueryContext.ConcurrencyDetector.EnterCriticalSection())
{
if (_dataReader == null)
{
if (_executionStrategy == null)
{
_executionStrategy = _relationalQueryContext.ExecutionStrategyFactory.Create();
}
_executionStrategy.Execute(true, InitializeReader, null);
}
var hasNext = _resultCoordinator.HasNext ?? _dataReader.Read();
Current = default;
if (hasNext)
{
while (true)
{
_resultCoordinator.ResultReady = true;
_resultCoordinator.HasNext = null;
Current = _shaper(
_relationalQueryContext, _dataReader.DbDataReader,
_resultCoordinator.ResultContext, _indexMap, _resultCoordinator);
if (_resultCoordinator.ResultReady)
{
// We generated a result so null out previously stored values
_resultCoordinator.ResultContext.Values = null;
break;
}
if (!_dataReader.Read())
{
_resultCoordinator.HasNext = false;
// Enumeration has ended, materialize last element
_resultCoordinator.ResultReady = true;
Current = _shaper(
_relationalQueryContext, _dataReader.DbDataReader,
_resultCoordinator.ResultContext, _indexMap, _resultCoordinator);
break;
}
}
}
return(hasNext);
}
}
catch (Exception exception)
{
_logger.QueryIterationFailed(_contextType, exception);
throw;
}
}
/// <summary>
/// Executes the strategy
/// </summary>
public void Execute()
{
if (strategy == null)
{
return; //DataGrid的添加操作可能为空
}
strategy.Execute(CommandParameter);
}
/// <summary>
/// Executes the specified operation and returns the result.
/// </summary>
/// <remarks>
/// See <see href="https://aka.ms/efcore-docs-connection-resiliency">Connection resiliency and database retries</see>
/// for more information and examples.
/// </remarks>
/// <param name="strategy">The strategy that will be used for the execution.</param>
/// <param name="operation">
/// A delegate representing an executable operation that returns the result of type <typeparamref name="TResult" />.
/// </param>
/// <typeparam name="TResult">The return type of <paramref name="operation" />.</typeparam>
/// <returns>The result from the operation.</returns>
public static TResult Execute <TResult>(
this IExecutionStrategy strategy,
Func <TResult> operation)
{
Check.NotNull(operation, nameof(operation));
return(strategy.Execute(operation, operationScoped => operationScoped()));
}
/// <summary>
/// Executes the specified operation.
/// </summary>
/// <param name="strategy">The strategy that will be used for the execution.</param>
/// <param name="operation">A delegate representing an executable operation that doesn't return any results.</param>
public static void Execute(
[NotNull] this IExecutionStrategy strategy,
[NotNull] Action operation)
=> strategy.Execute(operationScoped =>
{
operationScoped();
return(true);
}, operation);
/// <summary>
/// Executes the specified operation and returns the result.
/// </summary>
/// <remarks>
/// See <see href="https://aka.ms/efcore-docs-connection-resiliency">Connection resiliency and database retries</see>
/// for more information and examples.
/// </remarks>
/// <param name="strategy">The strategy that will be used for the execution.</param>
/// <param name="operation">
/// A delegate representing an executable operation that returns the result of type <typeparamref name="TResult" />.
/// </param>
/// <param name="verifySucceeded">A delegate that tests whether the operation succeeded even though an exception was thrown.</param>
/// <param name="state">The state that will be passed to the operation.</param>
/// <typeparam name="TState">The type of the state.</typeparam>
/// <typeparam name="TResult">The return type of <paramref name="operation" />.</typeparam>
/// <returns>The result from the operation.</returns>
/// <exception cref="RetryLimitExceededException">
/// The operation has not succeeded after the configured number of retries.
/// </exception>
public static TResult Execute <TState, TResult>(
this IExecutionStrategy strategy,
TState state,
Func <TState, TResult> operation,
Func <TState, ExecutionResult <TResult> >?verifySucceeded)
=> strategy.Execute(
state,
(c, s) => operation(s),
verifySucceeded == null ? null : (c, s) => verifySucceeded(s));
public static TResult Execute <TState, TResult>(
[NotNull] this IExecutionStrategy strategy,
[NotNull] Func <TState, TResult> operation,
[CanBeNull] Func <TState, ExecutionResult <TResult> > verifySucceeded,
[CanBeNull] TState state)
=> strategy.Execute(
state,
operation,
verifySucceeded);
/// <summary>
/// Executes the specified operation.
/// </summary>
/// <param name="strategy">The strategy that will be used for the execution.</param>
/// <param name="operation">A delegate representing an executable operation that doesn't return any results.</param>
/// <param name="state">The state that will be passed to the operation.</param>
/// <typeparam name="TState">The type of the state.</typeparam>
public static void Execute <TState>(
[NotNull] this IExecutionStrategy strategy,
[NotNull] Action <TState> operation,
[CanBeNull] TState state)
=> strategy.Execute(s =>
{
s.operation(s.state);
return(true);
}, new { operation, state });
/// <summary>
/// Executes the strategy
/// </summary>
public void Execute()
{
if (strategy == null)
{
System.Diagnostics.Debug.Print("CommandBehaviorBinding.Execute: Command or Action undefined.");
}
else
{
strategy.Execute(this);
}
}
/// <summary>
/// Executes the strategy
/// </summary>
public void Execute()
{
try
{
strategy.Execute(CommandParameter);
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
};
}
/// <summary>
/// Executes the specified operation.
/// </summary>
/// <param name="strategy">The strategy that will be used for the execution.</param>
/// <param name="operation">A delegate representing an executable operation that doesn't return any results.</param>
public static void Execute(
[NotNull] this IExecutionStrategy strategy,
[NotNull] Action operation)
{
Check.NotNull(operation, nameof(operation));
strategy.Execute(operation, operationScoped =>
{
operationScoped();
return(true);
});
}
/// <summary>
/// Executes the specified operation.
/// </summary>
/// <param name="strategy">The strategy that will be used for the execution.</param>
/// <param name="state">The state that will be passed to the operation.</param>
/// <param name="operation">A delegate representing an executable operation that doesn't return any results.</param>
/// <typeparam name="TState">The type of the state.</typeparam>
public static void Execute <TState>(
[NotNull] this IExecutionStrategy strategy,
[CanBeNull] TState state,
[NotNull] Action <TState> operation)
{
Check.NotNull(operation, nameof(operation));
strategy.Execute(new { operation, state }, s =>
{
s.operation(s.state);
return(true);
});
}
public void Test2()
{
IExecutionStrategy strategy = dbContext.Database.CreateExecutionStrategy();
strategy.Execute(() =>
{
using (DbTransaction transaction = dbConnection.BeginTransaction())
{
Client client = new Client();
client.ClientId = 3;
client.Name = "New Client 3";
dbContext.Database.UseTransaction(transaction);
dbContext.Entry <Client>(client).State = EntityState.Modified;
List <Client> clients = new List <Client>();
clients.Add(new Client
{
ClientId = 1,
Name = "New Client 1",
});
clients.Add(new Client
{
ClientId = 2,
Name = "New Client 2",
});
clients.Add(new Client
{
ClientId = 4,
Name = "New Client 4",
});
string sql = "UPDATE Client SET Name = @Name WHERE ClientId = @ClientId;";
try
{
dbContext.SaveChanges();
dbConnection.Execute(sql, clients, transaction: transaction);
transaction.Commit();
}
catch (System.Exception ex)
{
}
}
});
}
/// <summary>
/// Executes the specified action in a database transaction and returns a collection of records.
/// </summary>
/// <typeparam name="T">Result model class</typeparam>
/// <param name="collection">Action returning a collection of records</param>
public IQueryable <T> Transaction <T>(Func <IQueryable <T> > collection) where T : class
{
IQueryable <T> result = null;
IExecutionStrategy strategy = Database.CreateExecutionStrategy(); // retry on transient exceptions (we have to do it manually because of transactions)
strategy.Execute(() => // note: all transient exceptions outside of the BeginTransaction block are handled globally
{
using (IDbContextTransaction transaction = Database.BeginTransaction())
{
result = collection().ToList().AsQueryable();; // cannot iterate through the collection before committing changes
transaction.Commit();
}
});
return(result);
}
/// <summary>
/// Executes the strategy
/// </summary>
public void Execute(string eventName, object eventArgs)
{
try
{
if (_strategy == null)
{
return;
}
_strategy.Execute(CommandParameter, eventName, eventArgs);
}
catch (Exception ex)
{
Debug.WriteLine(ex.Message);
}
}
private void ExecuteTask(ICakeContext context, IExecutionStrategy strategy, Stopwatch stopWatch, CakeTask task, CakeReport report)
{
// Reset the stop watch.
stopWatch.Reset();
stopWatch.Start();
try
{
// Execute the task.
strategy.Execute(task, context);
}
catch (Exception exception)
{
_log.Error("An error occured when executing task.", task.Name);
// Got an error reporter?
if (task.ErrorReporter != null)
{
ReportErrors(strategy, task.ErrorReporter, exception);
}
// Got an error handler?
if (task.ErrorHandler != null)
{
HandleErrors(strategy, task.ErrorHandler, exception);
}
else
{
// No error handler defined for this task.
// Rethrow the exception and let it propagate.
throw;
}
}
finally
{
if (task.FinallyHandler != null)
{
strategy.InvokeFinally(task.FinallyHandler);
}
}
// Add the task results to the report.
report.Add(task.Name, stopWatch.Elapsed);
}
/// <summary>
/// Executes the specified operation in a transaction and returns the result after commiting it.
/// </summary>
/// <param name="strategy">The strategy that will be used for the execution.</param>
/// <param name="operation">
/// A delegate representing an executable operation that returns the result of type <typeparamref name="TResult" />.
/// </param>
/// <param name="verifySucceeded">
/// A delegate that tests whether the operation succeeded even though an exception was thrown when the
/// transaction was being committed.
/// </param>
/// <param name="state"> The state that will be passed to the operation. </param>
/// <param name="context"> The context that will be used to start the transaction. </param>
/// <typeparam name="TState"> The type of the state. </typeparam>
/// <typeparam name="TResult"> The return type of <paramref name="operation" />. </typeparam>
/// <returns> The result from the operation. </returns>
/// <exception cref="RetryLimitExceededException">
/// Thrown if the operation has not succeeded after the configured number of retries.
/// </exception>
public static TResult ExecuteInTransaction <TState, TResult>(
[NotNull] this IExecutionStrategy strategy,
[NotNull] Func <TState, TResult> operation,
[CanBeNull] Func <TState, bool> verifySucceeded,
[CanBeNull] TState state,
[NotNull] DbContext context)
=> strategy.Execute(s =>
{
using (var transaction = s.Context.Database.BeginTransaction())
{
s.CommitFailed = false;
s.Result = s.Operation(s.State);
s.CommitFailed = true;
transaction.Commit();
}
return(s.Result);
},
s => new ExecutionResult <TResult>(s.CommitFailed && s.VerifySucceeded != null && s.VerifySucceeded(s.State), s.Result),
new ExecutionState <TState, TResult>(operation, verifySucceeded, state, context));
/// <summary>
/// Executes the strategy
/// </summary>
public void Execute(object sender, object eventArgs)
{
bool isExecutionAllowed = false;
// No EventFilter, so just pass it through freely...
if (EventFilter == null)
{
isExecutionAllowed = true;
}
// ...otherwise test if EventFilter allows this concrete event or not
else if (EventFilter is IEventFilter && (EventFilter as IEventFilter).IsMatchingEvent(sender, eventArgs))
{
isExecutionAllowed = true;
}
if (isExecutionAllowed)
{
strategy.Execute(CommandParameter);
}
}
public void UseExplicitTransactionWithExecutionStrategy()
{
var context = CreateContext(useDefaultRetry: true);
IExecutionStrategy strategy = context.Database.CreateExecutionStrategy();
strategy.Execute(() =>
{
using (var transaction = context.Database.BeginTransaction())
{
var count = context.Product.Count();
var product1 = TestHelpers.CreateProduct("1");
context.Product.Add(product1);
var product2 = TestHelpers.CreateProduct("2");
context.Product.Add(product2);
context.SaveChanges();
transaction.Rollback();
}
});
}
public void ApplyMigrations(Type contextType)
{
this.logger.LogInformation($"Applying Pending EF Data Migrations for {contextType.Name}");
var dataContext = this.serviceProvider.CreateScope().ServiceProvider.GetService(contextType);
var ctx = dataContext as DbContext ?? throw new ArgumentNullException(nameof(dataContext), "must derive from DbContext");
var conn = ctx.Database.GetDbConnection();
this.dataContextConnectionString = conn.ConnectionString;
this.dataContextDbName = conn.Database;
EnsureDatabase();
// make sure the semaphore lock table exists in the db
EnsureTransactionLockTable();
// create an execution strategy to avoid azure retries if the lock fails
IExecutionStrategy strategy = ctx.Database.CreateExecutionStrategy();
strategy.Execute(() =>
{
// start the transaction
using (ctx.Database.BeginTransaction(IsolationLevel.ReadCommitted))
{
// acquire the distributed lock
if (AcquireLock(ctx))
{
// anything that happens here will only happen on
// a single instance of the application service at one time.
// Apply any pending EF migrations
RunMigrations(contextType, this.serviceProvider);
// Release the lock
ReleaseLock();
this.logger.LogInformation($"EF Data Migrations for {contextType.Name} has completed.");
}
}
});
}
public bool MoveNext()
{
if (_buffer == null)
{
if (_executionStrategy == null)
{
_executionStrategy = _relationalQueryContext.ExecutionStrategyFactory.Create();
}
return(_executionStrategy.Execute(_executionStrategy.RetriesOnFailure, _bufferlessMoveNext, null));
}
if (_buffer.Count > 0)
{
Current = _shaper.Shape(_relationalQueryContext, _buffer.Dequeue());
return(true);
}
return(false);
}
/// <summary>
/// Executes the specified operation in a transaction and returns the result. Allows to check whether
/// the transaction has been rolled back if an error occurs during commit.
/// </summary>
/// <param name="strategy"> The strategy that will be used for the execution. </param>
/// <param name="state"> The state that will be passed to the operation. </param>
/// <param name="operation">
/// A delegate representing an executable operation that returns the result of type <typeparamref name="TResult" />.
/// </param>
/// <param name="verifySucceeded">
/// A delegate that tests whether the operation succeeded even though an exception was thrown when the
/// transaction was being committed.
/// </param>
/// <param name="beginTransaction"> A delegate that begins a transaction using the given context. </param>
/// <typeparam name="TState"> The type of the state. </typeparam>
/// <typeparam name="TResult"> The return type of <paramref name="operation" />. </typeparam>
/// <returns> The result from the operation. </returns>
/// <exception cref="RetryLimitExceededException">
/// The operation has not succeeded after the configured number of retries.
/// </exception>
public static TResult ExecuteInTransaction <TState, TResult>(
[NotNull] IExecutionStrategy strategy,
[CanBeNull] TState state,
[NotNull] Func <TState, TResult> operation,
[NotNull] Func <TState, bool> verifySucceeded,
[NotNull] Func <DbContext, IDbContextTransaction> beginTransaction)
=> strategy.Execute(
new ExecutionState <TState, TResult>(
Check.NotNull(operation, nameof(operation)), Check.NotNull(verifySucceeded, nameof(verifySucceeded)), state),
(c, s) =>
{
Check.NotNull(beginTransaction, nameof(beginTransaction));
using (var transaction = beginTransaction(c))
{
s.CommitFailed = false;
s.Result = s.Operation(s.State);
s.CommitFailed = true;
transaction.Commit();
}
return(s.Result);
}, (c, s) => new ExecutionResult <TResult>(s.CommitFailed && s.VerifySucceeded(s.State), s.Result));
public bool MoveNext()
{
try
{
using (_relationalQueryContext.ConcurrencyDetector.EnterCriticalSection())
{
if (_dataReader == null)
{
if (_executionStrategy == null)
{
_executionStrategy = _relationalQueryContext.ExecutionStrategyFactory.Create();
}
_executionStrategy.Execute(true, InitializeReader, null);
}
var hasNext = _dataReader.Read();
Current = default;
if (hasNext)
{
_resultCoordinator.ResultContext.Values = null;
_shaper(
_relationalQueryContext, _dataReader.DbDataReader, _resultCoordinator.ResultContext, _resultCoordinator);
_relatedDataLoaders?.Invoke(_relationalQueryContext, _executionStrategy, _resultCoordinator);
Current = _shaper(
_relationalQueryContext, _dataReader.DbDataReader, _resultCoordinator.ResultContext, _resultCoordinator);
}
return(hasNext);
}
}
catch (Exception exception)
{
_queryLogger.QueryIterationFailed(_contextType, exception);
throw;
}
}
private void ProcessSubmission(Submission submission)
{
// TODO: Check for N+1 queries problem
this.logger.InfoFormat("Work on submission №{0} started.", submission.Id);
IExecutionStrategy executionStrategy = this.CreateExecutionStrategy(submission.SubmissionType.ExecutionStrategyType);
var context = new ExecutionContext
{
AdditionalCompilerArguments = submission.SubmissionType.AdditionalCompilerArguments,
CheckerAssemblyName = submission.Problem.Checker.DllFile,
CheckerParameter = submission.Problem.Checker.Parameter,
CheckerTypeName = submission.Problem.Checker.ClassName,
FileContent = submission.Content,
AllowedFileExtensions = submission.SubmissionType.AllowedFileExtensions,
CompilerType = submission.SubmissionType.CompilerType,
MemoryLimit = submission.Problem.MemoryLimit,
TimeLimit = submission.Problem.TimeLimit,
};
context.Tests = submission.Problem.Tests.ToList().Select(x => new TestContext
{
Id = x.Id,
Input = x.InputDataAsString,
Output = x.OutputDataAsString,
IsTrialTest = x.IsTrialTest
});
ExecutionResult executionResult;
try
{
executionResult = executionStrategy.Execute(context);
}
catch (Exception exception)
{
this.logger.ErrorFormat("executionStrategy.Execute on submission №{0} has thrown an exception: {1}", submission.Id, exception);
submission.ProcessingComment = string.Format("Exception in executionStrategy.Execute: {0}", exception.Message);
return;
}
submission.IsCompiledSuccessfully = executionResult.IsCompiledSuccessfully;
submission.CompilerComment = executionResult.CompilerComment;
if (!executionResult.IsCompiledSuccessfully)
{
return;
}
foreach (var testResult in executionResult.TestResults)
{
var testRun = new TestRun
{
CheckerComment = testResult.CheckerComment,
ExecutionComment = testResult.ExecutionComment,
MemoryUsed = testResult.MemoryUsed,
ResultType = testResult.ResultType,
TestId = testResult.Id,
TimeUsed = testResult.TimeUsed,
};
submission.TestRuns.Add(testRun);
}
this.logger.InfoFormat("Work on submission №{0} ended.", submission.Id);
}
/// <summary>
/// Executes the specified operation and returns the result.
/// </summary>
/// <remarks>
/// See <see href="https://aka.ms/efcore-docs-connection-resiliency">Connection resiliency and database retries</see>
/// for more information and examples.
/// </remarks>
/// <param name="strategy">The strategy that will be used for the execution.</param>
/// <param name="state">The state that will be passed to the operation.</param>
/// <param name="operation">
/// A delegate representing an executable operation that returns the result of type <typeparamref name="TResult" />.
/// </param>
/// <typeparam name="TState">The type of the state.</typeparam>
/// <typeparam name="TResult">The return type of <paramref name="operation" />.</typeparam>
/// <returns>The result from the operation.</returns>
public static TResult Execute <TState, TResult>(
this IExecutionStrategy strategy,
TState state,
Func <TState, TResult> operation)
=> strategy.Execute(state, operation, verifySucceeded: null);
/// <summary>
/// Executes the specified operation and returns the result.
/// </summary>
/// <param name="strategy">The strategy that will be used for the execution.</param>
/// <param name="state">The state that will be passed to the operation.</param>
/// <param name="operation">
/// A delegate representing an executable operation that returns the result of type <typeparamref name="TResult" />.
/// </param>
/// <typeparam name="TState">The type of the state.</typeparam>
/// <typeparam name="TResult">The return type of <paramref name="operation" />.</typeparam>
/// <returns>The result from the operation.</returns>
public static TResult Execute <TState, TResult>(
[NotNull] this IExecutionStrategy strategy,
[CanBeNull] TState state,
[NotNull] Func <TState, TResult> operation)
=> strategy.Execute(operation, verifySucceeded: null, state: state);