We now use a non-blocking state switch to determine whether to invoke drainLoop(…) from Subscriber completion.
Previously, we relied on same thread identification assuming if the subscription thread and the completion thread were the same, that we're already running inside the drain loop.
It turns out that a I/O thread could also run in event-loop mode where subscription and completion happens on the same thread but in between there's some processing and so the the call to completion is a delayed signal and not being called on the same stack as drainLoop(…).
The same-thread assumption was in place to avoid StackOverflow caused by infinite recursions.
We now use a state lock to enter the drain loop. Any concurrent attempts to re-enter the drain loop in Subscriber completion is now prevented to make sure that we continue draining while not causing stack recursions.
Original Pull Request: #807
Projections used within an aggregation pipeline can result in empty documents emitted by the driver. We now guarded those cases and skip those documents within a Flux or simply return an empty Mono depending on the methods signature.
Original pull request: #804.
AsyncInputStreamAdapter now properly splits and buffers incoming DataBuffers according the read requests of AsyncInputStream.read(…) calls.
Previously, the adapter used the input buffer size to be used as the output buffer size. A larger DataBuffer than the transfer buffer handed in through read(…) caused a BufferOverflow.
Original Pull Request: #799
We now rely on an outer drain-loop when GridFS reads complete on the same thread instead of using recursive subscriptions to avoid StackOverflow. Previously, we recursively invoked subscriptions that lead to an increased stack size.
Original Pull Request: #799
Add author tags. Move integration tests to existing test class.
Apply more appropriate in existing tests assertions. Use diamond syntax.
Original pull request: #796.
We now consistently use GridFSFile.getId() to allow custom Id usage instead of enforcing the Id to be an ObjectId. Using the native Id allows interaction with files that use a custom Id type.
Original pull request: #796.
Internal field references to $$this and $$value are now no longer mapped against exposed fields which had caused errors before.
Original pull request: #792.
Exceptions during CursorReadingTask startup and during polling are handled now by the same exception handling to handle Exceptions only once and notify ErrorHandler exactly once per exception.
Previously, startup exceptions relied on exception handling in the execute closure and notified ErrorHandler potentially multiple times.
Original Pull Request: #790
