ziver/zutil
1
0
Fork 0
Code Issues Pull requests Activity Actions

Added CircularBuffer class

Browse source
This commit is contained in:
Ziver Koc 2015-09-22 14:52:53 +00:00
parent 02b0838af3
commit 887423b659
3 changed files with 224 additions and 0 deletions
Download patch file Download diff file Expand all files Collapse all files

BIN
Zutil.jar
View file

Binary file not shown.

108
src/zutil/struct/CircularBuffer.java Normal file
View file

@ -0,0 +1,108 @@
/*
* Copyright (c) 2015 ezivkoc
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package zutil.struct;
import sun.reflect.generics.reflectiveObjects.NotImplementedException;
import java.util.Iterator;
import java.util.NoSuchElementException;
/**
* This class is a first in first out circular buffer with a fixed size.
* If the size is exceed then the oldest item will be removed.
* Created by Ziver on 2015-09-22.
*/
public class CircularBuffer<T> implements Iterable<T>{
private Object[] buffer;
private int buffSize;
private int buffPos;
private long addCount;
/**
* Initiates the buffer with a maximum size of maxSize.
*/
public CircularBuffer(int maxSize){
buffer = new Object[maxSize];
buffSize = 0;
buffPos = 0;
}
public void add(T obj){
if(buffPos+1 >= buffer.length)
buffPos = 0;
else
++buffPos;
if(buffSize < buffer.length)
++buffSize;
buffer[buffPos] = obj;
++addCount;
}
public T get(int index) {
if(index >= buffSize)
throw new IndexOutOfBoundsException("Index "+ index +" is larger than actual buffer size "+ buffSize);
int buffIndex = buffPos - index;
if(buffIndex < 0)
buffIndex = buffer.length - Math.abs(buffIndex);
return (T)buffer[buffIndex];
}
public int size() {
return buffSize;
}
/**
* @return the total amount of insertions into the buffer, this value only increments and will never decrease.
*/
public long getInsertionCount() {
return addCount;
}
@Override
public Iterator<T> iterator() {
return new CircularBufferIterator();
}
protected class CircularBufferIterator implements Iterator<T> {
private int iteratorPos = 0;
@Override
public boolean hasNext() {
return iteratorPos < buffSize;
}
@Override
public T next() {
if(iteratorPos >= buffSize)
throw new NoSuchElementException();
return get(iteratorPos++);
}
@Override
public void remove() {
throw new NotImplementedException();
}
}
}

116
src/zutil/test/CircularBufferTest.java Normal file
View file

@ -0,0 +1,116 @@
/*
* Copyright (c) 2015 ezivkoc
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package zutil.test;
import org.junit.Test;
import zutil.struct.CircularBuffer;
import java.util.Iterator;
import java.util.NoSuchElementException;
import static org.junit.Assert.*;
/**
* Created by Ziver on 2015-09-22.
*/
public class CircularBufferTest {
@Test
public void addToEmpty() {
CircularBuffer<Integer> buff = new CircularBuffer<Integer>(0);
try {
buff.add(10);
fail("IndexOutOfBoundsException was not thrown");
} catch (IndexOutOfBoundsException e) {}
}
@Test
public void addOneElement() {
CircularBuffer<Integer> buff = new CircularBuffer<Integer>(1);
assertEquals(0, buff.size());
buff.add(10);
assertEquals(1, buff.size());
assertEquals((Integer) 10, buff.get(0));
}
@Test
public void addThreeElements() {
CircularBuffer<Integer> buff = new CircularBuffer<Integer>(10);
buff.add(10);
buff.add(11);
buff.add(12);
assertEquals(3, buff.size());
assertEquals((Integer) 12, buff.get(0));
assertEquals((Integer) 11, buff.get(1));
assertEquals((Integer) 10, buff.get(2));
}
@Test
public void addOutOfRange() {
CircularBuffer<Integer> buff = new CircularBuffer<Integer>(2);
buff.add(10);
buff.add(11);
buff.add(12);
assertEquals(2, buff.size());
assertEquals((Integer) 12, buff.get(0));
assertEquals((Integer) 11, buff.get(1));
try {
buff.get(2);
fail("IndexOutOfBoundsException was not thrown");
} catch (IndexOutOfBoundsException e) {}
}
@Test
public void iteratorEmpty() {
CircularBuffer<Integer> buff = new CircularBuffer<Integer>(10);
Iterator<Integer> it = buff.iterator();
assert (!it.hasNext());
try {
it.next();
fail("NoSuchElementException was not thrown");
} catch (NoSuchElementException e) {}
}
@Test
public void iteratorThreeElements() {
CircularBuffer<Integer> buff = new CircularBuffer<Integer>(10);
buff.add(10);
buff.add(11);
buff.add(12);
Iterator<Integer> it = buff.iterator();
assert (it.hasNext());
assertEquals((Integer) 12, it.next());
assert (it.hasNext());
assertEquals((Integer) 11, it.next());
assert (it.hasNext());
assertEquals((Integer) 10, it.next());
assert (!it.hasNext());
try {
it.next();
fail("NoSuchElementException was not thrown");
} catch (NoSuchElementException e) {}
}
}