/**
* Helios, OpenSource Monitoring
* Brought to you by the Helios Development Group
*
* Copyright 2007, Helios Development Group and individual contributors
* as indicated by the @author tags. See the copyright.txt file in the
* distribution for a full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*
*/
package org.helios.apmrouter.collections;
/**
* <p>Title: LongSlidingWindow</p>
* <p>Description: A fixed size sorted "list" of longs that when full, drops the oldest entry to make room for the newest.</p>
* <p>Company: Helios Development Group LLC</p>
* @author Whitehead (nwhitehead AT heliosdev DOT org)
* <p><code>org.helios.apmrouter.collections.LongSlidingWindow</code></p>
*/
public class LongSlidingWindow {
/** The underlying UnsafeLongArray */
protected final UnsafeLongArray array;
/**
* Deallocates this UnsafeLongArrray
*/
public void destroy() {
array.destroy();
}
/**
* Creates a new and empty LongSlidingWindow
* @param size The size of the sliding window
*/
public LongSlidingWindow(int size) {
array = UnsafeArrayBuilder.newBuilder().sorted(false).fixed(true).initialCapacity(size).maxCapacity(size).buildLongArray();
}
/**
* Creates a new LongSlidingWindow cloned from the passed array
* @param array The array to base this sliding window from
*/
protected LongSlidingWindow(UnsafeLongArray array) {
this.array = array;
}
public void reinitAndLoad(byte[] arr) {
array.initAndLoad(arr);
}
/**
* Returns this sliding window as a (copied) byte array
* @return this sliding window as a (copied) byte array
*/
public byte[] getBytes() {
return array.getBytes();
}
public boolean isFull() {
return array.size()==array.maxCapacity;
}
public String debug() {
return new StringBuilder("LongSlidingWindow:")
.append("\n\tSize:").append(array.size)
.append("\n\tMax Size:").append(array.maxCapacity)
.append("\n\tSorted:").append(array.sorted)
.toString();
}
/**
* Creates a new LongSlidingWindow with the provided initial values
* @param size The size of the sliding window
* @param values The initial values to load
*/
public LongSlidingWindow(int size, long[] values) {
array = UnsafeArrayBuilder.newBuilder().sorted(false).fixed(true).initialCapacity(size).maxCapacity(size).buildLongArray();
for(long v: values) {
array.rollRight(0, v);
}
}
/**
* Inserts the each passed value into the first slot position in the array dropping the values in the last slot to make room if required
* @param values The values to insert
*/
public void insert(long...values) {
for(long v: values) {
array.rollRight(0, v);
}
}
/**
* Inserts the passed value into the first slot of the array, moving all other other populated slots to the right.
* @param value The value to insert
* @return The dropped value if one was dropped, otherwise null
*/
public Long insert(long value) {
return array.rollRightCap(0, value);
}
/**
* Removes all the values from this array, keeping the capacity fixed.
*/
public void clear() {
array.clear();
}
/**
* Indicates if this set is empty
* @return true if this set is empty, false otherwise
*/
public boolean isEmpty() {
return array.size()==0;
}
/**
* {@inheritDoc}
* @see java.lang.Object#toString()
*/
@Override
public String toString() {
return array.toString();
}
/**
* {@inheritDoc}
* @see java.lang.Object#clone()
*/
@Override
public LongSlidingWindow clone() {
return new LongSlidingWindow(array.clone());
}
/**
* Returns the long value at the specified array index
* @param index the index of the value to retrieve
* @return the long value at the specified array index
*/
public long get(int index) {
return array.get(index);
}
/**
* Returns the first (chronologically the most recent) value in the array or -1L if the size is 0.
* @return the first value in the array or -1L if the size is 0.
*/
public long getFirst() {
if(size()<1) return -1L;
return array.get(0);
}
/**
* Returns the last value (chronologically the oldest) in the array or -1L if the size is 0.
* @return the last value in the array or -1L if the size is 0.
*/
public long getLast() {
if(size()<1) return -1L;
return array.get(size()-1);
}
/**
* Returns this sliding window as a double array
* @return a double array
*/
public double[] asDoubleArray() {
return array.asDoubleArray();
}
/**
* Returns this sliding window as a long array
* @return a long array
*/
public long[] asLongArray() {
return array.getArray();
}
/**
* Returns the number of entries in the array
* @return the number of entries in the array
*/
public int size() {
return array.size();
}
/**
* Returns the sum of all the longs in the array within the passed ending index range
* @param within The index of the last entry to sum
* @return the sum of all the longs in the array
*/
public long sum(int within) {
long total = 0;
int end = within<array.size ? within : array.size;
for(int i = 0; i < end; i++) {
total += array.get(i);
}
return total;
}
/**
* Returns the sum of all the longs in the array
* @return the sum of all the longs in the array
*/
public long sum() {
return sum(array.size);
}
/**
* Returns the average of all the longs in the array within the passed ending index range
* @param within The index of the last entry to average
* @return the average of all the longs in the array
*/
public long avg(int within) {
double total = 0;
double cnt = 0;
int end = within<array.size ? within : array.size;
for(int i = 0; i < end; i++) {
total += array.get(i);
cnt++;
}
if(total==0 || cnt==0) return 0;
double d = total/cnt;
return (long)d;
}
/**
* Returns the average of all the longs in the array
* @return the average of all the longs in the array
*/
public long avg() {
return avg(array.size);
}
public static void main(String[] args) {
log("Long Sliding Window Test");
LongSlidingWindow sw = new LongSlidingWindow(5, new long[]{1,2,3,4,5});
for(int i = 0; i < 5; i++) {
Long val = sw.insert(i);
log("Removed:" + val);
}
}
public static void log(Object msg) {
System.out.println(msg);
}
}