ReplaySubject
Related Docs:
class ReplaySubject
| package subjects
Creates an unbounded replay subject with the specified initial buffer capacity.
Creates an unbounded replay subject with the specified initial buffer capacity.
Use this method to avoid excessive array reallocation while the internal buffer grows to accomodate new
items. For example, if you know that the buffer will hold 32k items, you can ask the
ReplaySubject to preallocate its internal array with a capacity to hold that many items. Once
the items start to arrive, the internal array won't need to grow, creating less garbage and no overhead
due to frequent array-copying.
the initial buffer capacity
the created subject
Creates an unbounded replay subject.
Creates an unbounded replay subject.
The internal buffer is backed by an ArrayList and starts with an initial capacity of 16. Once the
number of items reaches this capacity, it will grow as necessary (usually by 50%). However, as the
number of items grows, this causes frequent array reallocation and copying, and may hurt performance
and latency. This can be avoided with the apply(Int) overload which takes an initial capacity
parameter and can be tuned to reduce the array reallocation frequency as needed.
the created subject
Creates a size-bounded replay subject.
Creates a size-bounded replay subject.
In this setting, the ReplaySubject holds at most size items in its internal buffer and
discards the oldest item.
When observers subscribe to a terminated ReplaySubject, they are guaranteed to see at most
size onNext events followed by a termination event.
If an observer subscribes while the ReplaySubject is active, it will observe all items in the
buffer at that point in time and each item observed afterwards, even if the buffer evicts items due to
the size constraint in the mean time. In other words, once an Observer subscribes, it will receive items
without gaps in the sequence.
the maximum number of buffered items
the created subject
Creates a time-bounded replay subject.
Creates a time-bounded replay subject.
In this setting, the ReplaySubject internally tags each observed item with a timestamp value
supplied by the Scheduler and keeps only those whose age is less than the supplied time value
converted to milliseconds. For example, an item arrives at T=0 and the max age is set to 5; at T>=5
this first item is then evicted by any subsequent item or termination event, leaving the buffer empty.
Once the subject is terminated, observers subscribing to it will receive items that remained in the buffer after the terminal event, regardless of their age.
If an observer subscribes while the ReplaySubject is active, it will observe only those items
from within the buffer that have an age less than the specified time, and each item observed thereafter,
even if the buffer evicts items due to the time constraint in the mean time. In other words, once an
observer subscribes, it observes items without gaps in the sequence except for any outdated items at the
beginning of the sequence.
Note that terminal notifications onError and onCompleted trigger eviction as well. For
example, with a max age of 5, the first item is observed at T=0, then an onCompleted notification
arrives at T=10. If an observer subscribes at T=11, it will find an empty ReplaySubject with just
an onCompleted notification.
the maximum age of the contained items
the Scheduler that provides the current time
the created subject
Creates a time- and size-bounded replay subject.
Creates a time- and size-bounded replay subject.
In this setting, the ReplaySubject internally tags each received item with a timestamp value
supplied by the Scheduler and holds at most size items in its internal buffer. It evicts
items from the start of the buffer if their age becomes less-than or equal to the supplied age in
milliseconds or the buffer reaches its size limit.
When observers subscribe to a terminated ReplaySubject, they observe the items that remained in
the buffer after the terminal notification, regardless of their age, but at most size items.
If an observer subscribes while the ReplaySubject is active, it will observe only those items
from within the buffer that have age less than the specified time and each subsequent item, even if the
buffer evicts items due to the time constraint in the mean time. In other words, once an observer
subscribes, it observes items without gaps in the sequence except for the outdated items at the beginning
of the sequence.
Note that terminal notifications (onError and onCompleted) trigger eviction as well. For
example, with a max age of 5, the first item is observed at T=0, then an onCompleted notification
arrives at T=10. If an observer subscribes at T=11, it will find an empty ReplaySubject with just
an onCompleted notification.
the maximum age of the contained items
the maximum number of buffered items
the Scheduler that provides the current time
the created subject
Subject that buffers all items it observes and replays them to any
Observerthat subscribes.