net.sf.eBus.client.ENotifyFeed Maven / Gradle / Ivy
//
// Copyright 2015, 2016, 2019 Charles W. Rapp
//
// 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 net.sf.eBus.client;
import net.sf.eBus.util.Validator;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Abstract base class for {@link EPublishFeed} and
* {@link ESubscribeFeed} classes. Tracks the current
* {@link EFeedState feed state}.
*
* @author Charles W. Rapp
*/
public abstract class ENotifyFeed
extends ESingleFeed
{
//---------------------------------------------------------------
// Member data.
//
//-----------------------------------------------------------
// Statics.
//
/**
* Logging subsystem interface.
*/
private static final Logger sLogger =
LoggerFactory.getLogger(ENotifyFeed.class);
//---------------------------------------------------------------
// Member methods.
//
//-----------------------------------------------------------
// Constructors.
//
/**
* Creates a new notification feed instance based on the
* builder's configuration.
* @param builder contains feed configuration.
*/
protected ENotifyFeed(final Builder builder)
{
super (builder);
} // end of ENotifyFeed(Builder)
//
// end of Constructors.
//-----------------------------------------------------------
//-----------------------------------------------------------
// Abstract Method Declarations.
//
/**
* Issues the appropriate client callback, informing the
* client that the feed state is changed. For a publish
* feed, issues a publish state callback; for a subscribe
* feed, issues a subscribe state callback.
* @param feedState the updated feed state.
*/
/* package */ abstract void update(EFeedState feedState);
//
// end of Abstract Method Declarations.
//-----------------------------------------------------------
//-----------------------------------------------------------
// Set Methods.
//
/**
* Sets the initial activation count to the given value and
* sets the feed state accordingly.
* @param actCount the initial activation count.
* @return the feed's state as a result of this activation
* count.
*/
/* package */ EFeedState updateActivate(final int actCount)
{
final EFeedState retval;
mActivationCount += actCount;
if (mActivationCount < 0)
{
sLogger.warn(
"{} client {}, feed {}: negative activation count ({}), setting to zero ({}).",
mEClient.location(),
mEClient.clientId(),
mFeedId,
key(),
mActivationCount,
mScope);
mActivationCount = 0;
}
// If the activation count is zero, that means this feed
// is down due to no contra-feeds. If the count is > 0,
// then the feed is up.
retval = (mActivationCount == 0 ?
EFeedState.DOWN :
EFeedState.UP);
// Did the feed state change?
if (retval != mFeedState)
{
// Yes. Update the feed.
update(retval);
}
sLogger.trace(
"{} client {}, feed {}: {} feed state={}, activation count={} ({}).",
mEClient.location(),
mEClient.clientId(),
mFeedId,
key(),
retval,
mActivationCount,
mScope);
return (retval);
} // end of updateActivation(int)
//
// end of Set Methods.
//-----------------------------------------------------------
//---------------------------------------------------------------
// Inner classes.
//
/**
* Base class for notification publish and subscribe feeds.
*
* @param feed type.
* @param {@link EObject} sub-type.
* @param builder leaf type.
*/
protected abstract static class Builder>
extends ESingleFeed.Builder
{
//-----------------------------------------------------------
// Member data.
//
//-------------------------------------------------------
// Locals.
//
/**
* Set to {@code true} if this is part of a multiple key
* feed. If {@code true}, this feed is not
* added to the client feed list.
*
* Defaults to {@code false}.
*
*/
protected boolean mIsMultiFlag;
//-----------------------------------------------------------
// Member methods.
//
//-------------------------------------------------------
// Constructors.
//
/**
* Creates a notification feed builder instance.
* @param feedType target feed type.
* @param targetClass target builder class.
*/
protected Builder(final FeedType feedType,
final Class targetClass)
{
super (feedType, targetClass);
mIsMultiFlag = false;
} // end of Builder(FeedType, Class)
//
// end of Constructors.
//-------------------------------------------------------
//-------------------------------------------------------
// Abstract Method Overrides.
//
/**
* Returns eBus subject for the given message key.
* @return eBus feed subject.
*/
@Override
protected final ESubject getSubject()
{
return (ENotifySubject.findOrCreate(mKey));
} // end of getSubject()
/**
* Checks if message key is a notification and the
* message key and scope are in agreement.
* @param problems place invalid configuration settings
* in this problems list.
* @return {@code problems} to allow for method chaining.
*/
@Override
@SuppressWarnings ({"java:S1067"})
protected Validator validate(final Validator problems)
{
return (super.validate(problems)
.requireTrue((mKey != null &&
mKey.isNotification()),
"messageKey",
"messageKey is not a notification")
.requireTrue(
(k, s) ->
(mKey != null &&
mScope != null &&
(!mKey.isLocalOnly() ||
mScope == FeedScope.LOCAL_ONLY)),
mKey,
mScope,
"messageKey",
"scope",
String.format(
"%s is local-only but feed scope is %s",
mKey,
mScope)));
} // end of validate(Validator)
//
// end of Abstract Method Overrides.
//-------------------------------------------------------
} // end of class Builder
} // end of class ENotifyFeed
© 2015 - 2025 Weber Informatics LLC | Privacy Policy