Many resources are needed to download a project. Please understand that we have to compensate our server costs. Thank you in advance.
Project price only 1 $
You can buy this project and download/modify it how often you want.
hu.akarnokd.rxjava2.internal.operators.OperatorReplay Maven / Gradle / Ivy
/**
* Copyright 2015 David Karnok and Netflix, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in
* compliance with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software distributed under the License is
* distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See
* the License for the specific language governing permissions and limitations under the License.
*/
package hu.akarnokd.rxjava2.internal.operators;
import java.util.*;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.*;
import org.reactivestreams.*;
import hu.akarnokd.rxjava2.Observable;
import hu.akarnokd.rxjava2.Scheduler;
import hu.akarnokd.rxjava2.disposables.*;
import hu.akarnokd.rxjava2.functions.*;
import hu.akarnokd.rxjava2.internal.subscriptions.*;
import hu.akarnokd.rxjava2.internal.util.*;
import hu.akarnokd.rxjava2.observables.ConnectableObservable;
import hu.akarnokd.rxjava2.plugins.RxJavaPlugins;
import hu.akarnokd.rxjava2.schedulers.Timed;
public final class OperatorReplay extends ConnectableObservable {
/** The source observable. */
final Publisher source;
/** Holds the current subscriber that is, will be or just was subscribed to the source observable. */
final AtomicReference> current;
/** A factory that creates the appropriate buffer for the ReplaySubscriber. */
final Supplier> bufferFactory;
@SuppressWarnings("rawtypes")
static final Supplier DEFAULT_UNBOUNDED_FACTORY = new Supplier() {
@Override
public Object get() {
return new UnboundedReplayBuffer(16);
}
};
/**
* Given a connectable observable factory, it multicasts over the generated
* ConnectableObservable via a selector function.
* @param the connectable observable type
* @param the result type
* @param connectableFactory
* @param selector
* @return the new Observable instance
*/
public static Observable multicastSelector(
final Supplier> connectableFactory,
final Function, ? extends Publisher> selector) {
return Observable.create(new Publisher() {
@Override
public void subscribe(Subscriber child) {
ConnectableObservable co;
Publisher observable;
try {
co = connectableFactory.get();
} catch (Throwable e) {
EmptySubscription.error(e, child);
return;
}
if (co == null) {
EmptySubscription.error(new NullPointerException("The connectableFactory returned null"), child);
return;
}
try {
observable = selector.apply(co);
} catch (Throwable e) {
EmptySubscription.error(e, child);
return;
}
if (observable == null) {
EmptySubscription.error(new NullPointerException("The selector returned a null Publisher"), child);
return;
}
final SubscriberResourceWrapper srw = new SubscriberResourceWrapper(child, Disposables.consumeAndDispose());
observable.subscribe(srw);
co.connect(new Consumer() {
@Override
public void accept(Disposable r) {
srw.setResource(r);
}
});
}
});
}
/**
* Child Subscribers will observe the events of the ConnectableObservable on the
* specified scheduler.
* @param the value type
* @param co
* @param scheduler
* @return the new ConnectableObservable instance
*/
public static ConnectableObservable observeOn(final ConnectableObservable co, final Scheduler scheduler) {
final Observable observable = co.observeOn(scheduler);
return new ConnectableObservable(observable) {
@Override
public void connect(Consumer connection) {
co.connect(connection);
}
};
}
/**
* Creates a replaying ConnectableObservable with an unbounded buffer.
* @param the value type
* @param source
* @return the new ConnectableObservable instance
*/
@SuppressWarnings("unchecked")
public static ConnectableObservable createFrom(Observable source) {
return create(source, DEFAULT_UNBOUNDED_FACTORY);
}
/**
* Creates a replaying ConnectableObservable with a size bound buffer.
* @param the value type
* @param source
* @param bufferSize
* @return the new ConnectableObservable instance
*/
public static ConnectableObservable create(Observable source,
final int bufferSize) {
if (bufferSize == Integer.MAX_VALUE) {
return createFrom(source);
}
return create(source, new Supplier>() {
@Override
public ReplayBuffer get() {
return new SizeBoundReplayBuffer(bufferSize);
}
});
}
/**
* Creates a replaying ConnectableObservable with a time bound buffer.
* @param the value type
* @param source
* @param maxAge
* @param unit
* @param scheduler
* @return the new ConnectableObservable instance
*/
public static ConnectableObservable create(Observable source,
long maxAge, TimeUnit unit, Scheduler scheduler) {
return create(source, maxAge, unit, scheduler, Integer.MAX_VALUE);
}
/**
* Creates a replaying ConnectableObservable with a size and time bound buffer.
* @param the value type
* @param source
* @param maxAge
* @param unit
* @param scheduler
* @param bufferSize
* @return the new NbpConnectableObservable instance
*/
public static ConnectableObservable create(Observable source,
final long maxAge, final TimeUnit unit, final Scheduler scheduler, final int bufferSize) {
return create(source, new Supplier>() {
@Override
public ReplayBuffer get() {
return new SizeAndTimeBoundReplayBuffer(bufferSize, maxAge, unit, scheduler);
}
});
}
/**
* Creates a OperatorReplay instance to replay values of the given source observable.
* @param source the source observable
* @param bufferFactory the factory to instantiate the appropriate buffer when the observable becomes active
* @return the connectable observable
*/
static ConnectableObservable create(Observable source,
final Supplier> bufferFactory) {
// the current connection to source needs to be shared between the operator and its onSubscribe call
final AtomicReference> curr = new AtomicReference>();
Publisher onSubscribe = new Publisher() {
@Override
public void subscribe(Subscriber child) {
// concurrent connection/disconnection may change the state,
// we loop to be atomic while the child subscribes
for (;;) {
// get the current subscriber-to-source
ReplaySubscriber r = curr.get();
// if there isn't one
if (r == null) {
// create a new subscriber to source
ReplaySubscriber u = new ReplaySubscriber(curr, bufferFactory.get());
// let's try setting it as the current subscriber-to-source
if (!curr.compareAndSet(r, u)) {
// didn't work, maybe someone else did it or the current subscriber
// to source has just finished
continue;
}
// we won, let's use it going onwards
r = u;
}
// create the backpressure-managing producer for this child
InnerSubscription inner = new InnerSubscription(r, child);
// we try to add it to the array of producers
// if it fails, no worries because we will still have its buffer
// so it is going to replay it for us
r.add(inner);
// trigger the capturing of the current node and total requested
r.buffer.replay(inner);
// the producer has been registered with the current subscriber-to-source so
// at least it will receive the next terminal event
// setting the producer will trigger the first request to be considered by
// the subscriber-to-source.
child.onSubscribe(inner);
break;
}
}
};
return new OperatorReplay(onSubscribe, source, curr, bufferFactory);
}
private OperatorReplay(Publisher onSubscribe, Observable source,
final AtomicReference> current,
final Supplier> bufferFactory) {
super(onSubscribe);
this.source = source;
this.current = current;
this.bufferFactory = bufferFactory;
}
@Override
public void connect(Consumer connection) {
boolean doConnect = false;
ReplaySubscriber ps;
// we loop because concurrent connect/disconnect and termination may change the state
for (;;) {
// retrieve the current subscriber-to-source instance
ps = current.get();
// if there is none yet or the current has unsubscribed
if (ps == null || ps.isDisposed()) {
// create a new subscriber-to-source
ReplaySubscriber u = new ReplaySubscriber(current, bufferFactory.get());
// try setting it as the current subscriber-to-source
if (!current.compareAndSet(ps, u)) {
// did not work, perhaps a new subscriber arrived
// and created a new subscriber-to-source as well, retry
continue;
}
ps = u;
}
// if connect() was called concurrently, only one of them should actually
// connect to the source
doConnect = !ps.shouldConnect.get() && ps.shouldConnect.compareAndSet(false, true);
break;
}
/*
* Notify the callback that we have a (new) connection which it can unsubscribe
* but since ps is unique to a connection, multiple calls to connect() will return the
* same Subscription and even if there was a connect-disconnect-connect pair, the older
* references won't disconnect the newer connection.
* Synchronous source consumers have the opportunity to disconnect via unsubscribe on the
* Subscription as unsafeSubscribe may never return in its own.
*
* Note however, that asynchronously disconnecting a running source might leave
* child-subscribers without any terminal event; ReplaySubject does not have this
* issue because the unsubscription was always triggered by the child-subscribers
* themselves.
*/
connection.accept(ps);
if (doConnect) {
source.subscribe(ps);
}
}
@SuppressWarnings("rawtypes")
static final class ReplaySubscriber implements Subscriber, Disposable {
/** Holds notifications from upstream. */
final ReplayBuffer buffer;
/** The notification-lite factory. */
/** Contains either an onCompleted or an onError token from upstream. */
boolean done;
/** Indicates an empty array of inner producers. */
static final InnerSubscription[] EMPTY = new InnerSubscription[0];
/** Indicates a terminated ReplaySubscriber. */
static final InnerSubscription[] TERMINATED = new InnerSubscription[0];
/** Tracks the subscribed producers. */
final AtomicReference producers;
/**
* Atomically changed from false to true by connect to make sure the
* connection is only performed by one thread.
*/
final AtomicBoolean shouldConnect;
/** Guarded by this. */
boolean emitting;
/** Guarded by this. */
boolean missed;
/** Contains the maximum element index the child Subscribers requested so far. Accessed while emitting is true. */
long maxChildRequested;
/** Counts the outstanding upstream requests until the producer arrives. */
long maxUpstreamRequested;
/** The upstream producer. */
volatile Subscription subscription;
volatile boolean cancelled;
public ReplaySubscriber(AtomicReference> current,
ReplayBuffer buffer) {
this.buffer = buffer;
this.producers = new AtomicReference(EMPTY);
this.shouldConnect = new AtomicBoolean();
}
boolean isDisposed() {
return cancelled;
}
@Override
public void dispose() {
producers.getAndSet(TERMINATED);
// unlike OperatorPublish, we can't null out the terminated so
// late subscribers can still get replay
// current.compareAndSet(ReplaySubscriber.this, null);
// we don't care if it fails because it means the current has
// been replaced in the meantime
subscription.cancel();
}
/**
* Atomically try adding a new InnerProducer to this Subscriber or return false if this
* Subscriber was terminated.
* @param producer the producer to add
* @return true if succeeded, false otherwise
*/
boolean add(InnerSubscription producer) {
if (producer == null) {
throw new NullPointerException();
}
// the state can change so we do a CAS loop to achieve atomicity
for (;;) {
// get the current producer array
InnerSubscription[] c = producers.get();
// if this subscriber-to-source reached a terminal state by receiving
// an onError or onCompleted, just refuse to add the new producer
if (c == TERMINATED) {
return false;
}
// we perform a copy-on-write logic
int len = c.length;
InnerSubscription[] u = new InnerSubscription[len + 1];
System.arraycopy(c, 0, u, 0, len);
u[len] = producer;
// try setting the producers array
if (producers.compareAndSet(c, u)) {
return true;
}
// if failed, some other operation succeded (another add, remove or termination)
// so retry
}
}
/**
* Atomically removes the given producer from the producers array.
* @param producer the producer to remove
*/
void remove(InnerSubscription producer) {
// the state can change so we do a CAS loop to achieve atomicity
for (;;) {
// let's read the current producers array
InnerSubscription[] c = producers.get();
// if it is either empty or terminated, there is nothing to remove so we quit
if (c == EMPTY || c == TERMINATED) {
return;
}
// let's find the supplied producer in the array
// although this is O(n), we don't expect too many child subscribers in general
int j = -1;
int len = c.length;
for (int i = 0; i < len; i++) {
if (c[i].equals(producer)) {
j = i;
break;
}
}
// we didn't find it so just quit
if (j < 0) {
return;
}
// we do copy-on-write logic here
InnerSubscription[] u;
// we don't create a new empty array if producer was the single inhabitant
// but rather reuse an empty array
if (len == 1) {
u = EMPTY;
} else {
// otherwise, create a new array one less in size
u = new InnerSubscription[len - 1];
// copy elements being before the given producer
System.arraycopy(c, 0, u, 0, j);
// copy elements being after the given producer
System.arraycopy(c, j + 1, u, j, len - j - 1);
}
// try setting this new array as
if (producers.compareAndSet(c, u)) {
return;
}
// if we failed, it means something else happened
// (a concurrent add/remove or termination), we need to retry
}
}
@Override
public void onSubscribe(Subscription p) {
Subscription p0 = subscription;
if (p0 != null) {
RxJavaPlugins.onError(new IllegalStateException("Only a single producer can be set on a Subscriber."));
return;
}
subscription = p;
manageRequests();
replay();
}
@Override
public void onNext(T t) {
if (!done) {
buffer.next(t);
replay();
}
}
@Override
public void onError(Throwable e) {
// The observer front is accessed serially as required by spec so
// no need to CAS in the terminal value
if (!done) {
done = true;
try {
buffer.error(e);
replay();
} finally {
dispose(); // expectation of testIssue2191
}
}
}
@Override
public void onComplete() {
// The observer front is accessed serially as required by spec so
// no need to CAS in the terminal value
if (!done) {
done = true;
try {
buffer.complete();
replay();
} finally {
dispose();
}
}
}
/**
* Coordinates the request amounts of various child Subscribers.
*/
void manageRequests() {
// if the upstream has completed, no more requesting is possible
if (isDisposed()) {
return;
}
synchronized (this) {
if (emitting) {
missed = true;
return;
}
emitting = true;
}
for (;;) {
// if the upstream has completed, no more requesting is possible
if (isDisposed()) {
return;
}
@SuppressWarnings("unchecked")
InnerSubscription[] a = producers.get();
long ri = maxChildRequested;
long maxTotalRequests = ri;
for (InnerSubscription rp : a) {
maxTotalRequests = Math.max(maxTotalRequests, rp.totalRequested.get());
}
long ur = maxUpstreamRequested;
Subscription p = subscription;
long diff = maxTotalRequests - ri;
if (diff != 0L) {
maxChildRequested = maxTotalRequests;
if (p != null) {
if (ur != 0L) {
maxUpstreamRequested = 0L;
p.request(ur + diff);
} else {
p.request(diff);
}
} else {
// collect upstream request amounts until there is a producer for them
long u = ur + diff;
if (u < 0) {
u = Long.MAX_VALUE;
}
maxUpstreamRequested = u;
}
} else
// if there were outstanding upstream requests and we have a producer
if (ur != 0L && p != null) {
maxUpstreamRequested = 0L;
// fire the accumulated requests
p.request(ur);
}
synchronized (this) {
if (!missed) {
emitting = false;
return;
}
missed = false;
}
}
}
/**
* Tries to replay the buffer contents to all known subscribers.
*/
void replay() {
@SuppressWarnings("unchecked")
InnerSubscription[] a = producers.get();
for (InnerSubscription rp : a) {
buffer.replay(rp);
}
}
}
/**
* A Producer and Subscription that manages the request and unsubscription state of a
* child subscriber in thread-safe manner.
* We use AtomicLong as a base class to save on extra allocation of an AtomicLong and also
* save the overhead of the AtomicIntegerFieldUpdater.
* @param the value type
*/
static final class InnerSubscription extends AtomicLong implements Subscription, Disposable {
/** */
private static final long serialVersionUID = -4453897557930727610L;
/**
* The parent subscriber-to-source used to allow removing the child in case of
* child unsubscription.
*/
final ReplaySubscriber parent;
/** The actual child subscriber. */
final Subscriber child;
/**
* Holds an object that represents the current location in the buffer.
* Guarded by the emitter loop.
*/
Object index;
/**
* Keeps the sum of all requested amounts.
*/
final AtomicLong totalRequested;
/** Indicates an emission state. Guarded by this. */
boolean emitting;
/** Indicates a missed update. Guarded by this. */
boolean missed;
/**
* Indicates this child has been unsubscribed: the state is swapped in atomically and
* will prevent the dispatch() to emit (too many) values to a terminated child subscriber.
*/
static final long UNSUBSCRIBED = Long.MIN_VALUE;
public InnerSubscription(ReplaySubscriber parent, Subscriber child) {
this.parent = parent;
this.child = child;
this.totalRequested = new AtomicLong();
}
@Override
public void request(long n) {
// ignore negative requests
if (SubscriptionHelper.validateRequest(n)) {
return;
}
// In general, RxJava doesn't prevent concurrent requests (with each other or with
// an unsubscribe) so we need a CAS-loop, but we need to handle
// request overflow and unsubscribed/not requested state as well.
for (;;) {
// get the current request amount
long r = get();
// if child called unsubscribe() do nothing
if (r == UNSUBSCRIBED) {
return;
}
// ignore zero requests except any first that sets in zero
if (r >= 0L && n == 0) {
return;
}
// otherwise, increase the request count
long u = BackpressureHelper.addCap(r, n);
// try setting the new request value
if (compareAndSet(r, u)) {
// increment the total request counter
BackpressureHelper.add(totalRequested, n);
// if successful, notify the parent dispacher this child can receive more
// elements
parent.manageRequests();
parent.buffer.replay(this);
return;
}
// otherwise, someone else changed the state (perhaps a concurrent
// request or unsubscription so retry
}
}
/**
* Indicate that values have been emitted to this child subscriber by the dispatch() method.
* @param n the number of items emitted
* @return the updated request value (may indicate how much can be produced or a terminal state)
*/
public long produced(long n) {
// we don't allow producing zero or less: it would be a bug in the operator
if (n <= 0) {
throw new IllegalArgumentException("Cant produce zero or less");
}
for (;;) {
// get the current request value
long r = get();
// if the child has unsubscribed, simply return and indicate this
if (r == UNSUBSCRIBED) {
return UNSUBSCRIBED;
}
// reduce the requested amount
long u = r - n;
// if the new amount is less than zero, we have a bug in this operator
if (u < 0) {
throw new IllegalStateException("More produced (" + n + ") than requested (" + r + ")");
}
// try updating the request value
if (compareAndSet(r, u)) {
// and return the udpated value
return u;
}
// otherwise, some concurrent activity happened and we need to retry
}
}
public boolean isDisposed() {
return get() == UNSUBSCRIBED;
}
@Override
public void cancel() {
dispose();
}
@Override
public void dispose() {
long r = get();
// let's see if we are unsubscribed
if (r != UNSUBSCRIBED) {
// if not, swap in the terminal state, this is idempotent
// because other methods using CAS won't overwrite this value,
// concurrent calls to unsubscribe will atomically swap in the same
// terminal value
r = getAndSet(UNSUBSCRIBED);
// and only one of them will see a non-terminated value before the swap
if (r != UNSUBSCRIBED) {
// remove this from the parent
parent.remove(this);
// After removal, we might have unblocked the other child subscribers:
// let's assume this child had 0 requested before the unsubscription while
// the others had non-zero. By removing this 'blocking' child, the others
// are now free to receive events
parent.manageRequests();
}
}
}
/**
* Convenience method to auto-cast the index object.
* @return
*/
@SuppressWarnings("unchecked")
U index() {
return (U)index;
}
}
/**
* The interface for interacting with various buffering logic.
*
* @param the value type
*/
interface ReplayBuffer {
/**
* Adds a regular value to the buffer.
* @param value
*/
void next(T value);
/**
* Adds a terminal exception to the buffer
* @param e
*/
void error(Throwable e);
/**
* Adds a completion event to the buffer
*/
void complete();
/**
* Tries to replay the buffered values to the
* subscriber inside the output if there
* is new value and requests available at the
* same time.
* @param output
*/
void replay(InnerSubscription output);
}
/**
* Holds an unbounded list of events.
*
* @param the value type
*/
static final class UnboundedReplayBuffer extends ArrayList implements ReplayBuffer {
/** */
private static final long serialVersionUID = 7063189396499112664L;
/** The total number of events in the buffer. */
volatile int size;
public UnboundedReplayBuffer(int capacityHint) {
super(capacityHint);
}
@Override
public void next(T value) {
add(NotificationLite.next(value));
size++;
}
@Override
public void error(Throwable e) {
add(NotificationLite.error(e));
size++;
}
@Override
public void complete() {
add(NotificationLite.complete());
size++;
}
@Override
public void replay(InnerSubscription output) {
synchronized (output) {
if (output.emitting) {
output.missed = true;
return;
}
output.emitting = true;
}
final Subscriber child = output.child;
for (;;) {
if (output.isDisposed()) {
return;
}
int sourceIndex = size;
Integer destIndexObject = output.index();
int destIndex = destIndexObject != null ? destIndexObject.intValue() : 0;
long r = output.get();
long r0 = r;
long e = 0L;
while (r != 0L && destIndex < sourceIndex) {
Object o = get(destIndex);
try {
if (NotificationLite.accept(o, child)) {
return;
}
} catch (Throwable err) {
output.dispose();
if (!NotificationLite.isError(o) && !NotificationLite.isComplete(o)) {
child.onError(err);
}
return;
}
if (output.isDisposed()) {
return;
}
destIndex++;
r--;
e++;
}
if (e != 0L) {
output.index = destIndex;
if (r0 != Long.MAX_VALUE) {
output.produced(e);
}
}
synchronized (output) {
if (!output.missed) {
output.emitting = false;
return;
}
output.missed = false;
}
}
}
}
/**
* Represents a node in a bounded replay buffer's linked list.
*/
static final class Node extends AtomicReference {
/** */
private static final long serialVersionUID = 245354315435971818L;
final Object value;
final long index;
public Node(Object value, long index) {
this.value = value;
this.index = index;
}
}
/**
* Base class for bounded buffering with options to specify an
* enter and leave transforms and custom truncation behavior.
*
* @param the value type
*/
static class BoundedReplayBuffer extends AtomicReference implements ReplayBuffer {
/** */
private static final long serialVersionUID = 2346567790059478686L;
Node tail;
int size;
long index;
public BoundedReplayBuffer() {
Node n = new Node(null, 0);
tail = n;
set(n);
}
/**
* Add a new node to the linked list.
* @param n
*/
final void addLast(Node n) {
tail.set(n);
tail = n;
size++;
}
/**
* Remove the first node from the linked list.
*/
final void removeFirst() {
Node head = get();
Node next = head.get();
if (next == null) {
throw new IllegalStateException("Empty list!");
}
size--;
// can't just move the head because it would retain the very first value
// can't null out the head's value because of late replayers would see null
setFirst(next);
}
/* test */ final void removeSome(int n) {
Node head = get();
while (n > 0) {
head = head.get();
n--;
size--;
}
setFirst(head);
}
/**
* Arranges the given node is the new head from now on.
* @param n
*/
final void setFirst(Node n) {
set(n);
}
@Override
public final void next(T value) {
Object o = enterTransform(NotificationLite.next(value));
Node n = new Node(o, ++index);
addLast(n);
truncate();
}
@Override
public final void error(Throwable e) {
Object o = enterTransform(NotificationLite.error(e));
Node n = new Node(o, ++index);
addLast(n);
truncateFinal();
}
@Override
public final void complete() {
Object o = enterTransform(NotificationLite.complete());
Node n = new Node(o, ++index);
addLast(n);
truncateFinal();
}
@Override
public final void replay(InnerSubscription output) {
synchronized (output) {
if (output.emitting) {
output.missed = true;
return;
}
output.emitting = true;
}
for (;;) {
if (output.isDisposed()) {
return;
}
long r = output.get();
boolean unbounded = r == Long.MAX_VALUE;
long e = 0L;
Node node = output.index();
if (node == null) {
node = get();
output.index = node;
BackpressureHelper.add(output.totalRequested, node.index);
}
while (r != 0) {
Node v = node.get();
if (v != null) {
Object o = leaveTransform(v.value);
try {
if (NotificationLite.accept(o, output.child)) {
output.index = null;
return;
}
} catch (Throwable err) {
output.index = null;
output.dispose();
if (!NotificationLite.isError(o) && !NotificationLite.isComplete(o)) {
output.child.onError(err);
}
return;
}
e++;
r--;
node = v;
} else {
break;
}
if (output.isDisposed()) {
return;
}
}
if (e != 0L) {
output.index = node;
if (!unbounded) {
output.produced(e);
}
}
synchronized (output) {
if (!output.missed) {
output.emitting = false;
return;
}
output.missed = false;
}
}
}
/**
* Override this to wrap the NotificationLite object into a
* container to be used later by truncate.
* @param value
* @return
*/
Object enterTransform(Object value) {
return value;
}
/**
* Override this to unwrap the transformed value into a
* NotificationLite object.
* @param value
* @return
*/
Object leaveTransform(Object value) {
return value;
}
/**
* Override this method to truncate a non-terminated buffer
* based on its current properties.
*/
void truncate() {
}
/**
* Override this method to truncate a terminated buffer
* based on its properties (i.e., truncate but the very last node).
*/
void truncateFinal() {
}
/* test */ final void collect(Collection output) {
Node n = get();
for (;;) {
Node next = n.get();
if (next != null) {
Object o = next.value;
Object v = leaveTransform(o);
if (NotificationLite.isComplete(v) || NotificationLite.isError(v)) {
break;
}
output.add(NotificationLite.getValue(v));
n = next;
} else {
break;
}
}
}
/* test */ boolean hasError() {
return tail.value != null && NotificationLite.isError(leaveTransform(tail.value));
}
/* test */ boolean hasCompleted() {
return tail.value != null && NotificationLite.isComplete(leaveTransform(tail.value));
}
}
/**
* A bounded replay buffer implementation with size limit only.
*
* @param the value type
*/
static final class SizeBoundReplayBuffer extends BoundedReplayBuffer {
/** */
private static final long serialVersionUID = -5898283885385201806L;
final int limit;
public SizeBoundReplayBuffer(int limit) {
this.limit = limit;
}
@Override
void truncate() {
// overflow can be at most one element
if (size > limit) {
removeFirst();
}
}
// no need for final truncation because values are truncated one by one
}
/**
* Size and time bound replay buffer.
*
* @param the buffered value type
*/
static final class SizeAndTimeBoundReplayBuffer extends BoundedReplayBuffer {
/** */
private static final long serialVersionUID = 3457957419649567404L;
final Scheduler scheduler;
final long maxAge;
final TimeUnit unit;
final int limit;
public SizeAndTimeBoundReplayBuffer(int limit, long maxAge, TimeUnit unit, Scheduler scheduler) {
this.scheduler = scheduler;
this.limit = limit;
this.maxAge = maxAge;
this.unit = unit;
}
@Override
Object enterTransform(Object value) {
return new Timed(value, scheduler.now(unit), unit);
}
@Override
Object leaveTransform(Object value) {
return ((Timed)value).value();
}
@Override
void truncate() {
long timeLimit = scheduler.now(unit) - maxAge;
Node prev = get();
Node next = prev.get();
int e = 0;
for (;;) {
if (next != null) {
if (size > limit) {
e++;
size--;
prev = next;
next = next.get();
} else {
Timed v = (Timed)next.value;
if (v.time() <= timeLimit) {
e++;
size--;
prev = next;
next = next.get();
} else {
break;
}
}
} else {
break;
}
}
if (e != 0) {
setFirst(prev);
}
}
@Override
void truncateFinal() {
long timeLimit = scheduler.now(unit) - maxAge;
Node prev = get();
Node next = prev.get();
int e = 0;
for (;;) {
if (next != null && size > 1) {
Timed v = (Timed)next.value;
if (v.time() <= timeLimit) {
e++;
size--;
prev = next;
next = next.get();
} else {
break;
}
} else {
break;
}
}
if (e != 0) {
setFirst(prev);
}
}
}
}
