public async Task <T> RunAsync <T>(IQueryConverter queryConverter, IScalarQuery <T> queryObject, CancellationToken cancellationToken)
{
var query = new Spec.Query();
query.token = GetNextToken();
query.type = Spec.Query.QueryType.START;
query.query = queryObject.GenerateTerm(queryConverter);
var response = await InternalRunQuery(query, cancellationToken);
switch (response.type)
{
case Response.ResponseType.SUCCESS_SEQUENCE:
case Response.ResponseType.SUCCESS_ATOM:
if (response.response.Count != 1)
{
throw new RethinkDbRuntimeException(String.Format("Expected 1 object, received {0}", response.response.Count));
}
return(queryConverter.Get <T>().ConvertDatum(response.response[0]));
case Response.ResponseType.CLIENT_ERROR:
case Response.ResponseType.COMPILE_ERROR:
throw new RethinkDbInternalErrorException("Client error: " + response.response[0].r_str);
case Response.ResponseType.RUNTIME_ERROR:
throw new RethinkDbRuntimeException("Runtime error: " + response.response[0].r_str);
default:
throw new RethinkDbInternalErrorException("Unhandled response type: " + response.type);
}
}
public void Reset()
{
query = null;
lastResponse = null;
lastResponseIndex = 0;
disposed = false;
}
internal async Task <Response> InternalRunQuery(Spec.Query query, CancellationToken cancellationToken)
{
var tcs = new TaskCompletionSource <Response>();
tokenResponse[query.token] = tcs;
DateTime start = DateTime.UtcNow;
Logger.Debug("InternalRunQuery: beginning process of transmitting query w/ token {0}", query.token);
bool pastSpinLock = false;
Action abortToken = () => {
DateTime timeout = DateTime.UtcNow;
if (!pastSpinLock)
{
Logger.Warning(
"Query token {0} timed out after {1}; usually this happens because of a query timeout, but, query never acquired write lock on the connection in before timing out. Write lock is currently held by query token {2}.",
query.token,
timeout - start,
writeTokenLock);
}
else
{
Logger.Warning(
"Query token {0} timed out after {1} because CancellationToken was triggered; usually this happens because of a query timeout.",
query.token,
timeout - start);
}
if (tokenResponse.Remove(query.token))
{
tcs.SetCanceled();
}
};
using (cancellationToken.Register(abortToken))
{
// Put query.token into writeTokenLock if writeTokenLock is 0 (ie. unlocked). If it's not 0,
// spin-lock on the compare exchange.
while (Interlocked.CompareExchange(ref writeTokenLock, query.token, 0) != 0)
{
;
}
try
{
Logger.Debug("InternalRunQuery: acquired write lock for query token {0}", query.token);
pastSpinLock = true;
Logger.Debug("InternalRunQuery: writing query token {0}", query.token);
await Protocol.WriteQueryToStream(stream, Logger, query, cancellationToken);
}
finally
{
// Revert writeTokenLock to 0.
writeTokenLock = 0;
}
Logger.Debug("InternalRunQuery: waiting for response for query token {0}", query.token);
return(await tcs.Task);
}
}
internal async Task <Response> InternalRunQuery(Spec.Query query, CancellationToken cancellationToken)
{
var tcs = new TaskCompletionSource <Response>();
tokenResponse[query.token] = tcs;
Action abortToken = () => {
Logger.Warning("Query token {0} timed out after {1}", query.token, this.QueryTimeout);
if (tokenResponse.Remove(query.token))
{
tcs.SetCanceled();
}
};
using (cancellationToken.Register(abortToken))
{
using (var memoryBuffer = new MemoryStream(1024))
{
Serializer.Serialize(memoryBuffer, query);
var data = memoryBuffer.ToArray();
var header = BitConverter.GetBytes(data.Length);
if (!BitConverter.IsLittleEndian)
{
Array.Reverse(header, 0, header.Length);
}
// Put query.token into writeTokenLock if writeTokenLock is 0 (ie. unlocked). If it's not 0,
// spin-lock on the compare exchange.
while (Interlocked.CompareExchange(ref writeTokenLock, (long)query.token, 0) != 0)
{
;
}
try
{
Logger.Debug("Writing packet, {0} bytes", data.Length);
await stream.WriteAsync(header, 0, header.Length, cancellationToken);
await stream.WriteAsync(data, 0, data.Length, cancellationToken);
}
finally
{
// Revert writeTokenLock to 0.
writeTokenLock = 0;
}
}
return(await tcs.Task);
}
}
public async Task <bool> MoveNext(CancellationToken cancellationToken)
{
if (disposed)
{
throw new ObjectDisposedException(GetType().FullName);
}
if (lastResponse == null)
{
query = new Spec.Query();
query.token = connection.GetNextToken();
connection.Logger.Debug("QueryEnumerator: Token {0} is assigned to query {1}", query.token, queryObject);
query.type = Spec.Query.QueryType.START;
query.query = this.queryObject.GenerateTerm(queryConverter);
await ReissueQuery(cancellationToken);
}
if (lastResponseIndex < (LoadedRecordCount() - 1))
{
lastResponseIndex += 1;
return(true);
}
if (lastResponse.type == Response.ResponseType.SUCCESS_SEQUENCE ||
lastResponse.type == Response.ResponseType.SUCCESS_ATOM)
{
return(false);
}
else if (lastResponse.type == Response.ResponseType.SUCCESS_PARTIAL ||
lastResponse.type == (Response.ResponseType) 5)
{
query.type = RethinkDb.Spec.Query.QueryType.CONTINUE;
query.query = null;
await ReissueQuery(cancellationToken);
return(await MoveNext(cancellationToken));
}
else
{
throw new RethinkDbInternalErrorException("Unreachable code; ReissueQuery should prevent reaching this condition");
}
}
internal async Task <Response> InternalRunQuery(Spec.Query query, CancellationToken cancellationToken)
{
var tcs = new TaskCompletionSource <Response>();
tokenResponse[query.token] = tcs;
Action abortToken = () => {
Logger.Warning("Query token {0} timed out after {1}", query.token, this.QueryTimeout);
if (tokenResponse.Remove(query.token))
{
tcs.SetCanceled();
}
};
using (cancellationToken.Register(abortToken))
{
// Put query.token into writeTokenLock if writeTokenLock is 0 (ie. unlocked). If it's not 0,
// spin-lock on the compare exchange.
while (Interlocked.CompareExchange(ref writeTokenLock, query.token, 0) != 0)
{
;
}
try
{
await Protocol.WriteQueryToStream(stream, Logger, query, cancellationToken);
}
finally
{
// Revert writeTokenLock to 0.
writeTokenLock = 0;
}
return(await tcs.Task);
}
}
