LRU算法和JVM第一次作业

group24/121111914/src/com/github/ipk2015/coding2017/basic/Queue.java

@@ -1,19 +1,21 @@
-package com.github.ipk2015.coding2017.basic;
-
-public class Queue {
-	private LinkedList elementDatas=new LinkedList();
-	public void enQueue(Object o){		
-		elementDatas.add(o);
-	}
-	public Object deQueue(){
-		return elementDatas.removeFirst();
-	}
-
-	public boolean isEmpty(){
-		return size()==0;
-	}
-
-	public int size(){
-		return elementDatas.size();
-	}
-}
+package com.github.ipk2015.coding2017.basic;
+
+import com.github.ipk2015.coding2017.basic.linkedlist.LinkedList;
+
+public class Queue {
+	private LinkedList elementDatas=new LinkedList();
+	public void enQueue(Object o){		
+		elementDatas.add(o);
+	}
+	public Object deQueue(){
+		return elementDatas.removeFirst();
+	}
+
+	public boolean isEmpty(){
+		return size()==0;
+	}
+
+	public int size(){
+		return elementDatas.size();
+	}
+}

group24/121111914/src/com/github/ipk2015/coding2017/basic/linkedlist/LRUPageFrame.java

@@ -0,0 +1,119 @@
+package com.github.ipk2015.coding2017.basic.linkedlist;
+
+
+
+/**
+ * 用双向链表实现LRU算法
+ * @author liuxin
+ *
+ */
+public class LRUPageFrame {
+
+	private static class Node {
+
+		Node prev;
+		Node next;
+		int pageNum;
+
+		Node() {
+		}
+	}
+
+	private int capacity;
+	private int size=0;
+
+	private Node first;// 链表头
+	private Node last;// 链表尾
+
+
+	public LRUPageFrame(int capacity) {
+
+		this.capacity = capacity;
+
+	}
+
+	/**
+	 * 获取缓存中对象
+	 * 
+	 * @param key
+	 * @return
+	 */
+	public void access(int pageNum) {
+		if(this.capacity<=1){
+			throw new RuntimeException("MeaningLess");
+		}
+		int pos=searchPageNum(pageNum);
+		if(pos==-1){
+			addFirst(pageNum);
+			return;
+		}
+		if(pos==0){
+			return;
+		}
+		Node tempNode=first;
+		for(int i=0;i<pos;i++){
+			tempNode=tempNode.next;
+		}
+		tempNode.prev.next=tempNode.next;
+		if(null!=tempNode.next){
+			tempNode.next.prev=tempNode.prev;
+		}else{
+			last=tempNode.prev;
+		}
+		tempNode.prev=null;
+		tempNode.next=first;
+		first=tempNode;
+	}
+	private int searchPageNum(int num){
+		int pos=-1;
+		boolean flag=false;
+		Node tempNode=first;
+		while(null!=tempNode){
+			pos++;
+			if(tempNode.pageNum==num){
+				flag=true;
+				break;
+			}
+			tempNode=tempNode.next;
+		}
+		return flag?pos:-1;
+	}
+	private void addFirst(int num){
+		Node addNode=new Node();
+		addNode.pageNum=num;
+		addNode.next=first;
+		if(size<capacity){
+			if(null!=first){
+				first.prev=addNode;
+			}else{
+				last=addNode;
+			}
+			first=addNode;
+			size++;
+			return;
+		}
+		first.prev=addNode;
+		first=addNode;
+		Node tempNode=last;
+		last=last.prev;
+		last.next=null;
+		tempNode.prev=null;
+
+	}
+
+
+	public String toString(){
+		StringBuilder buffer = new StringBuilder();
+		Node node = first;
+		while(node != null){
+			buffer.append(node.pageNum);			
+
+			node = node.next;
+			if(node != null){
+				buffer.append(",");
+			}
+		}
+		return buffer.toString();
+	}
+
+}

group24/121111914/src/com/github/ipk2015/coding2017/basic/linkedlist/LRUPageFrameTest.java

@@ -0,0 +1,33 @@
+package com.github.ipk2015.coding2017.basic.linkedlist;
+
+
+
+import  org.junit.Assert;
+
+import org.junit.Test;
+
+
+public class LRUPageFrameTest {
+
+	@Test
+	public void testAccess() {
+		LRUPageFrame frame = new LRUPageFrame(3);
+		frame.access(7);
+		frame.access(0);
+		frame.access(1);
+		Assert.assertEquals("1,0,7", frame.toString());
+		frame.access(2);
+		Assert.assertEquals("2,1,0", frame.toString());
+		frame.access(0);
+		Assert.assertEquals("0,2,1", frame.toString());
+		frame.access(0);
+		Assert.assertEquals("0,2,1", frame.toString());
+		frame.access(3);
+		Assert.assertEquals("3,0,2", frame.toString());
+		frame.access(0);
+		Assert.assertEquals("0,3,2", frame.toString());
+		frame.access(4);
+		Assert.assertEquals("4,0,3", frame.toString());
+	}
+
+}

group24/121111914/src/com/github/ipk2015/coding2017/basic/LinkedList.java → group24/121111914/src/com/github/ipk2015/coding2017/basic/linkedlist/LinkedList.java

@@ -1,7 +1,11 @@
-package com.github.ipk2015.coding2017.basic;
+package com.github.ipk2015.coding2017.basic.linkedlist;
 
 import java.util.NoSuchElementException;
 
+import com.github.ipk2015.coding2017.basic.Iterator;
+import com.github.ipk2015.coding2017.basic.List;
+import com.github.ipk2015.coding2017.basic.ListUtils;
+
 public class LinkedList implements List {
 
 	private Node head;

group24/121111914/src/com/github/ipk2015/coding2017/basic/test/LinkedListTest.java

@@ -8,7 +8,8 @@
 import org.junit.Test;
 
 import com.github.ipk2015.coding2017.basic.Iterator;
-import com.github.ipk2015.coding2017.basic.LinkedList;
+import com.github.ipk2015.coding2017.basic.linkedlist.LinkedList;
+
 
 public class LinkedListTest {
 	LinkedList list;

group24/121111914/src/com/github/ipk2015/coding2017/minijvm/loader/ClassFileLoader.java

@@ -0,0 +1,72 @@
+package com.github.ipk2015.coding2017.minijvm.loader;
+
+
+
+import java.io.BufferedInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+
+
+
+public class ClassFileLoader {
+
+	private List<String> clzPaths = new ArrayList<String>();
+
+	public byte[] readBinaryCode(String className) throws IOException {
+		className=getCompleteClassName(className);
+		File file=null;
+		for(String path:clzPaths){
+			file=new File(path+"\\"+className);
+			if(file.exists()){
+				break;
+			}
+		}
+		if(null==file){
+			throw new FileNotFoundException(className);
+		}
+		ByteArrayOutputStream bos=new ByteArrayOutputStream((int)file.length());
+		BufferedInputStream in=new BufferedInputStream(new FileInputStream(file));
+		int size=1024;
+		byte[] buffer=new byte[size];
+		int length=0;
+		while((length=in.read(buffer, 0, size))!=-1){
+			bos.write(buffer,0,length);
+		}
+		return bos.toByteArray();	
+	}
+
+
+	public void addClassPath(String path) {
+		clzPaths.add(path);
+	}
+
+
+
+	public String getClassPath(){
+		StringBuffer buffer=new StringBuffer();
+		for(String path:clzPaths){
+			buffer.append(path+";");
+		}
+		buffer.deleteCharAt(buffer.length()-1);
+		return buffer.toString();
+	}
+
+	private String getCompleteClassName(String name){
+		if(!name.endsWith(".class")){
+			name=name+".class";
+		}
+		int pointPos=name.lastIndexOf(".", name.length()-7);
+		if(pointPos>-1){
+			name=name.substring(pointPos+1);
+		}
+		return name;
+	}
+
+
+
+}

group24/121111914/src/com/github/ipk2015/coding2017/minijvm/test/ClassFileloaderTest.java

@@ -0,0 +1,97 @@
+package com.github.ipk2015.coding2017.minijvm.test;
+
+
+
+import java.io.IOException;
+
+import org.junit.After;
+import  org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+
+import com.github.ipk2015.coding2017.minijvm.loader.ClassFileLoader;
+
+
+
+
+
+
+public class ClassFileloaderTest {
+
+
+	static String path1 = "C:\\Users\\liuxin\\git\\coding2017\\liuxin\\mini-jvm\\bin";
+	static String path2 = "C:\temp";
+	static String path3 = "E:\\javaImprove\\git\\group24\\121111914\\src\\com\\github\\ipk2015\\coding2017\\minijvm\\bin";
+
+
+
+	@Before
+	public void setUp() throws Exception {		 
+	}
+
+	@After
+	public void tearDown() throws Exception {
+	}
+
+	@Test
+	public void testClassPath(){		
+
+		ClassFileLoader loader = new ClassFileLoader();
+		loader.addClassPath(path1);
+		loader.addClassPath(path2);
+
+		String clzPath = loader.getClassPath();
+
+		Assert.assertEquals(path1+";"+path2,clzPath);
+
+	}
+
+	@Test
+	public void testClassFileLength() throws IOException {		
+
+		ClassFileLoader loader = new ClassFileLoader();
+		loader.addClassPath(path3);
+
+		String className = "com.coderising.jvm.test.EmployeeV1";
+		byte[] byteCodes = loader.readBinaryCode(className);
+		System.out.println( byteCodes.length+"");
+		// 注意：这个字节数可能和你的JVM版本有关系， 你可以看看编译好的类到底有多大
+		Assert.assertEquals(835, byteCodes.length);
+
+	}
+
+
+    @Test	
+	public void testMagicNumber() throws IOException{
+    	ClassFileLoader loader = new ClassFileLoader();
+		loader.addClassPath(path3);
+		String className = "com.coderising.jvm.test.EmployeeV1";
+		byte[] byteCodes = loader.readBinaryCode(className);
+		byte[] codes = new byte[]{byteCodes[0],byteCodes[1],byteCodes[2],byteCodes[3]};
+
+
+		String acctualValue = this.byteToHexString(codes);
+
+		Assert.assertEquals("cafebabe", acctualValue);
+	}
+
+
+
+
+
+
+	private String byteToHexString(byte[] codes ){
+		StringBuffer buffer = new StringBuffer();
+		for(int i=0;i<codes.length;i++){
+			byte b = codes[i];
+			int value = b & 0xFF;
+			String strHex = Integer.toHexString(value);
+			if(strHex.length()< 2){
+				strHex = "0" + strHex;
+			}		
+			buffer.append(strHex);
+		}
+		return buffer.toString();
+	}
+
+}