* 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.
/*
* Pool
- *
+ *
* Author: Jonathan
* 5/27/2011
*/
/**
* This Class pools on an As-Needed-Basis any particular kind of class, which is
* quite suitable for expensive operations.
- *
+ *
* The user calls "get" on a Pool, and if a waiting resource (T) is available,
* it will be returned. Otherwise, one will be created with the "Creator" class
* (must be defined for (T)).
- *
+ *
* You can Prime the instances to avoid huge startup costs
- *
+ *
* The returned "Pooled" object simply has to call "done()" and the object is
* returned to the pool. If the developer does not return the object, a memory
* leak does not occur. There are no references to the object once "get" is
* called. However, the developer who does not return the object when done
* obviates the point of the pool, as new Objects are created in place of the
* Object not returned when another call to "get" is made.
- *
+ *
* There is a cushion of extra objects, currently defaulted to MAX_RANGE. If the
* items returned become higher than the MAX_RANGE, the object is allowed to go
* out of scope, and be cleaned up. the default can be changed on a per-pool
* basis.
- *
+ *
* Class revamped for CadiExceptions and Access logging 10/4/2017
- *
+ *
* @author Jonathan
- *
+ *
* @param <T>
*/
public class Pool<T> {
/**
* only Simple List needed.
- *
+ *
* NOTE TO MAINTAINERS: THIS OBJECT DOES IT'S OWN SYNCHRONIZATION. All
* changes that touch list must account for correctly synchronizing list.
*/
/**
* Create a new Pool, given the implementation of Creator<T>, which must be
* able to create/destroy T objects at will.
- *
+ *
* @param creator
*/
public Pool(Creator<T> creator) {
list = new LinkedList<>();
logger = Log.NULL;
}
-
+
/**
* Attach Pool Logging activities to any other Logging Mechanism.
* @param logger
public void setLogger(Log logger) {
this.logger = logger;
}
-
+
public void log(Object ...objects) {
logger.log(objects);
}
/**
* Preallocate a certain number of T Objects. Useful for services so that
* the first transactions don't get hit with all the Object creation costs
- *
+ *
* @param lt
* @param prime
- * @throws CadiException
+ * @throws CadiException
*/
public void prime(int prime) throws CadiException {
for (int i = 0; i < prime; ++i) {
* This is the essential function for Pool. Get an Object "T" inside a
* "Pooled<T>" object. If there is a spare Object, then use it. If not, then
* create and pass back.
- *
+ *
* This one uses a Null LogTarget
- *
+ *
* IMPORTANT: When the use of this object is done (and the object is still
* in a valid state), then "done()" should be called immediately to allow
* the object to be reused. That is the point of the Pool...
- *
+ *
* If the Object is in an invalid state, then "toss()" should be used so the
* Pool doesn't pass on invalid objects to others.
- *
+ *
* @param lt
* @return
* @throws CadiException
* state. If not, they are tossed from the Pool. This is valuable to have
* when Remote Connections go down, and there is a question on whether the
* Pooled Objects are still functional.
- *
+ *
* @return
*/
public boolean validate() {
/**
* This is an internal method, used only by the Internal Pooled<T> class.
- *
+ *
* The Pooled<T> class "offers" it's Object back after use. It is an
* "offer", because Pool will simply destroy and remove the object if it has
* more than enough spares.
- *
+ *
* @param lt
* @param used
* @return
* The Creator Interface give the Pool the ability to Create, Destroy and
* Validate the Objects it is maintaining. Thus, it is a specially written
* Implementation for each type.
- *
+ *
* @author Jonathan
- *
+ *
* @param <T>
*/
public interface Creator<T> {
public interface Log {
public void log(Object ... o);
-
+
public final static Log NULL = new Log() {
@Override
public void log(Object ... o) {
* The "Pooled<T>" class is the transient class that wraps the actual Object
* T for API use/ It gives the ability to return ("done()", or "toss()") the
* Object to the Pool when processing is finished.
- *
+ *
* For Safety, i.e. to avoid memory leaks and invalid Object States, there
* is a "finalize" method. It is strictly for when coder forgets to return
* the object, or perhaps hasn't covered the case during Exceptions or
* However, we don't want Coding Mistakes to put the whole program in an
* invalid state, so if something happened such that "done()" or "toss()"
* were not called, the resource is still cleaned up as well as possible.
- *
+ *
* @author Jonathan
- *
+ *
* @param <T>
*/
public static class Pooled<T> {
/**
* Create the Wrapping Object Pooled<T>.
- *
+ *
* @param t
* @param pool
* @param logTarget
/**
* This is the key API for the Pool, as calling "done()" offers this
* object back to the Pool for reuse.
- *
+ *
* Do not use the Pooled<T> object again after calling "done()".
*/
public void done() {
* The user of the Object may discover that the Object t is no longer in
* a valid state. Don't put Garbage back in the Refrigerator... Toss it,
* if it's no longer valid.
- *
+ *
* toss() is also used for draining the Pool, etc.
- *
+ *
* toss() will attempt to destroy the Object by using the Creator
* Interface.
- *
+ *
*/
public void toss() {
if (pool != null) {
/**
* Get the maximum number of spare objects allowed at any moment
- *
+ *
* @return
*/
public int getMaxRange() {
/**
* Set a Max Range for numbers of spare objects waiting to be used.
- *
+ *
* No negative numbers are allowed
- *
+ *
* @return
*/
public void setMaxRange(int max_range) {