public async Task <IQueryResult <T> > QueryAsync <T>(string statement, QueryOptions options)
{
if (string.IsNullOrEmpty(options.CurrentContextId))
{
options.ClientContextId(Guid.NewGuid().ToString());
}
using var rootSpan = _tracer.RootSpan(RequestTracing.ServiceIdentifier.Query, OperationNames.N1qlQuery)
.WithTag(CouchbaseTags.OperationId, options.CurrentContextId !)
.WithTag(CouchbaseTags.OpenTracingTags.DbStatement, statement)
.WithLocalAddress();
// does this query use a prepared plan?
if (options.IsAdHoc)
{
// don't use prepared plan, execute query directly
options.Statement(statement);
return(await ExecuteQuery <T>(options, options.Serializer ?? _serializer, rootSpan).ConfigureAwait(false));
}
// try find cached query plan
if (_queryCache.TryGetValue(statement, out var queryPlan))
{
// if an upgrade has happened, don't use query plans that have an encoded plan
if (!EnhancedPreparedStatementsEnabled || string.IsNullOrWhiteSpace(queryPlan.EncodedPlan))
{
using var prepareAndExecuteSpan = _tracer.InternalSpan(OperationNames.PrepareAndExecute, rootSpan);
// plan is valid, execute query with it
options.Prepared(queryPlan, statement);
return(await ExecuteQuery <T>(options, options.Serializer ?? _serializer, rootSpan).ConfigureAwait(false));
}
// entry is stale, remove from cache
_queryCache.TryRemove(statement, out _);
}
// create prepared statement
var prepareStatement = statement;
if (!prepareStatement.StartsWith("PREPARE ", StringComparison.InvariantCultureIgnoreCase))
{
prepareStatement = $"PREPARE {statement}";
}
// set prepared statement
options.Statement(prepareStatement);
// server supports combined prepare & execute
if (EnhancedPreparedStatementsEnabled)
{
_logger.LogDebug("Using enhanced prepared statement behavior for request {currentContextId}", options.CurrentContextId);
// execute combined prepare & execute query
options.AutoExecute(true);
var result = await ExecuteQuery <T>(options, options.Serializer ?? _serializer, rootSpan).ConfigureAwait(false);
// add/replace query plan name in query cache
if (result is StreamingQueryResult <T> streamingResult) // NOTE: hack to not make 'PreparedPlanName' property public
{
var plan = new QueryPlan {
Name = streamingResult.PreparedPlanName, Text = statement
};
_queryCache.AddOrUpdate(statement, plan, (k, p) => plan);
}
return(result);
}
_logger.LogDebug("Using legacy prepared statement behavior for request {currentContextId}", options.CurrentContextId);
// older style, prepare then execute
var preparedResult = await ExecuteQuery <QueryPlan>(options, _queryPlanSerializer, rootSpan).ConfigureAwait(false);
queryPlan = await preparedResult.FirstAsync().ConfigureAwait(false);
// add plan to cache and execute
_queryCache.TryAdd(statement, queryPlan);
options.Prepared(queryPlan, statement);
// execute query using plan
return(await ExecuteQuery <T>(options, options.Serializer ?? _serializer, rootSpan).ConfigureAwait(false));
}
private async Task <IQueryResult <T> > ExecuteQuery <T>(QueryOptions options, ITypeSerializer serializer, IInternalSpan span)
{
var currentContextId = options.CurrentContextId ?? DefaultClientContextId;
QueryErrorContext ErrorContextFactory(QueryResultBase <T> failedQueryResult, HttpStatusCode statusCode)
{
// We use a local function to capture context like options and currentContextId
return(new QueryErrorContext
{
ClientContextId = options.CurrentContextId,
Parameters = options.GetAllParametersAsJson(),
Statement = options.ToString(),
Message = GetErrorMessage(failedQueryResult, currentContextId, statusCode),
Errors = failedQueryResult.Errors,
HttpStatus = statusCode,
QueryStatus = failedQueryResult.MetaData?.Status ?? QueryStatus.Fatal
});
}
// try get Query node
var queryUri = _serviceUriProvider.GetRandomQueryUri();
span.WithRemoteAddress(queryUri);
using var encodingSpan = span.StartPayloadEncoding();
var body = options.GetFormValuesAsJson();
encodingSpan.Dispose();
_logger.LogDebug("Sending query {contextId} to node {endpoint}.", options.CurrentContextId, queryUri);
QueryResultBase <T> queryResult;
using var content = new StringContent(body, System.Text.Encoding.UTF8, MediaType.Json);
try
{
using var dispatchSpan = span.StartDispatch();
var response = await HttpClient.PostAsync(queryUri, content, options.Token).ConfigureAwait(false);
dispatchSpan.Dispose();
var stream = await response.Content.ReadAsStreamAsync().ConfigureAwait(false);
if (serializer is IStreamingTypeDeserializer streamingDeserializer)
{
queryResult = new StreamingQueryResult <T>(stream, streamingDeserializer, ErrorContextFactory);
}
else
{
queryResult = new BlockQueryResult <T>(stream, serializer);
}
queryResult.HttpStatusCode = response.StatusCode;
queryResult.Success = response.StatusCode == HttpStatusCode.OK;
//read the header and stop when we reach the queried rows
await queryResult.InitializeAsync(options.Token).ConfigureAwait(false);
if (response.StatusCode != HttpStatusCode.OK || queryResult.MetaData?.Status != QueryStatus.Success)
{
_logger.LogDebug("Request {currentContextId} has failed because {status}.",
currentContextId, queryResult.MetaData?.Status);
if (queryResult.ShouldRetry(EnhancedPreparedStatementsEnabled))
{
if (queryResult.Errors.Any(x => x.Code == 4040 && EnhancedPreparedStatementsEnabled))
{
//clear the cache of stale query plan
var statement = options.StatementValue ?? string.Empty;
if (_queryCache.TryRemove(statement, out var queryPlan))
{
_logger.LogDebug("Query plan is stale for {currentContextId}. Purging plan {queryPlanName}.", currentContextId, queryPlan.Name);
}
;
}
_logger.LogDebug("Request {currentContextId} is being retried.", currentContextId);
return(queryResult);
}
var context = ErrorContextFactory(queryResult, response.StatusCode);
if (queryResult.MetaData?.Status == QueryStatus.Timeout)
{
if (options.IsReadOnly)
{
throw new AmbiguousTimeoutException
{
Context = context
};
}
throw new UnambiguousTimeoutException
{
Context = context
};
}
queryResult.ThrowExceptionOnError(context);
}
}
catch (OperationCanceledException e)
{
var context = new QueryErrorContext
{
ClientContextId = options.CurrentContextId,
Parameters = options.GetAllParametersAsJson(),
Statement = options.ToString(),
HttpStatus = HttpStatusCode.RequestTimeout,
QueryStatus = QueryStatus.Fatal
};
_logger.LogDebug(LoggingEvents.QueryEvent, e, "Request timeout.");
if (options.IsReadOnly)
{
throw new UnambiguousTimeoutException("The query was timed out via the Token.", e)
{
Context = context
};
}
throw new AmbiguousTimeoutException("The query was timed out via the Token.", e)
{
Context = context
};
}
catch (HttpRequestException e)
{
_logger.LogDebug(LoggingEvents.QueryEvent, e, "Request canceled");
var context = new QueryErrorContext
{
ClientContextId = options.CurrentContextId,
Parameters = options.GetAllParametersAsJson(),
Statement = options.ToString(),
HttpStatus = HttpStatusCode.RequestTimeout,
QueryStatus = QueryStatus.Fatal
};
throw new RequestCanceledException("The query was canceled.", e)
{
Context = context
};
}
_logger.LogDebug($"Request {options.CurrentContextId} has succeeded.");
return(queryResult);
}