diff --git a/group17/240094626/work_jvm_1/data-structure/src/com/coding/basic/linklist/LRUPageFrame.java b/group17/240094626/work_jvm_1/data-structure/src/com/coding/basic/linklist/LRUPageFrame.java new file mode 100644 index 0000000000..638cf181ae --- /dev/null +++ b/group17/240094626/work_jvm_1/data-structure/src/com/coding/basic/linklist/LRUPageFrame.java @@ -0,0 +1,126 @@ +package com.coding.basic.linklist; + +/** + * 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 currentSize; + + private Node first;// 链表头 + private Node last;// 链表尾 + + + public LRUPageFrame(int capacity) { + + this.capacity = capacity; + currentSize = 0; + } + + /** + * 获取缓存中对象 + * + * @param key + * @return + */ + public void access(int pageNum) { + + // 判断缓存是否命中 + Node n = find(pageNum); + if(n != null){ + // 命中，则把节点提到表头 + moveNodeToHead(n); + }else{ + // 若未命中，新增节点放到表头，如果链表长度超过capacity，移除链表尾部节点 + n = new Node(); + n.pageNum = pageNum; + + if(currentSize >= capacity){ + removeLast(); + } + addNodeToHead(n); + } + } + + + + private void addNodeToHead(Node n) { + if(first == null){ + first = n; + last = n; + }else{ + n.next = first; + first.prev = n; + first = n; + } + currentSize++; + } + + private void removeLast() { + Node prevN = last.prev; + prevN.next = null; + last.prev = null; + last = prevN; + currentSize--; + } + + private void moveNodeToHead(Node n) { + if(n == first){ + return ; + }else if(n == last){ + Node preN = n.prev; + preN.next = null; + last.prev = null; + last = preN; + }else{ + // 中间节点 + Node preN = n.prev; + Node nextN = n.next; + preN.next = nextN; + nextN.prev = preN; + } + n.prev = null; + n.next = first; + first.prev = n; + first = n; + } + + private Node find(int pageNum) { + Node n = first; + while(n != null){ + if(n.pageNum == pageNum){ + return n; + } + n = n.next; + } + return 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(); + } + +} diff --git a/group17/240094626/work_jvm_1/data-structure/src/com/coding/basic/linklist/LRUPageFrameTest.java b/group17/240094626/work_jvm_1/data-structure/src/com/coding/basic/linklist/LRUPageFrameTest.java new file mode 100644 index 0000000000..67cf36067b --- /dev/null +++ b/group17/240094626/work_jvm_1/data-structure/src/com/coding/basic/linklist/LRUPageFrameTest.java @@ -0,0 +1,31 @@ +package com.coding.basic.linklist; + +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()); + } + +} diff --git a/group17/240094626/work_jvm_1/data-structure/src/com/coding/basic/linklist/LinkedList.java b/group17/240094626/work_jvm_1/data-structure/src/com/coding/basic/linklist/LinkedList.java new file mode 100644 index 0000000000..f4c7556a2e --- /dev/null +++ b/group17/240094626/work_jvm_1/data-structure/src/com/coding/basic/linklist/LinkedList.java @@ -0,0 +1,125 @@ +package com.coding.basic.linklist; + +import com.coding.basic.Iterator; +import com.coding.basic.List; + +public class LinkedList implements List { + + private Node head; + + public void add(Object o){ + + } + public void add(int index , Object o){ + + } + public Object get(int index){ + return null; + } + public Object remove(int index){ + return null; + } + + public int size(){ + return -1; + } + + public void addFirst(Object o){ + + } + public void addLast(Object o){ + + } + public Object removeFirst(){ + return null; + } + public Object removeLast(){ + return null; + } + public Iterator iterator(){ + return null; + } + + + private static class Node{ + Object data; + Node next; + + } + + /** + * 把该链表逆置 + * 例如链表为 3->7->10 , 逆置后变为 10->7->3 + */ + public void reverse(){ + + } + + /** + * 删除一个单链表的前半部分 + * 例如：list = 2->5->7->8 , 删除以后的值为 7->8 + * 如果list = 2->5->7->8->10 ,删除以后的值为7,8,10 + + */ + public void removeFirstHalf(){ + + } + + /** + * 从第i个元素开始， 删除length 个元素 ， 注意i从0开始 + * @param i + * @param length + */ + public void remove(int i, int length){ + + } + /** + * 假定当前链表和listB均包含已升序排列的整数 + * 从当前链表中取出那些listB所指定的元素 + * 例如当前链表 = 11->101->201->301->401->501->601->701 + * listB = 1->3->4->6 + * 返回的结果应该是[101,301,401,601] + * @param list + */ + public int[] getElements(LinkedList list){ + return null; + } + + /** + * 已知链表中的元素以值递增有序排列，并以单链表作存储结构。 + * 从当前链表中中删除在listB中出现的元素 + + * @param list + */ + + public void subtract(LinkedList list){ + + } + + /** + * 已知当前链表中的元素以值递增有序排列，并以单链表作存储结构。 + * 删除表中所有值相同的多余元素（使得操作后的线性表中所有元素的值均不相同） + */ + public void removeDuplicateValues(){ + + } + + /** + * 已知链表中的元素以值递增有序排列，并以单链表作存储结构。 + * 试写一高效的算法，删除表中所有值大于min且小于max的元素（若表中存在这样的元素） + * @param min + * @param max + */ + public void removeRange(int min, int max){ + + } + + /** + * 假设当前链表和参数list指定的链表均以元素依值递增有序排列（同一表中的元素值各不相同） + * 现要求生成新链表C，其元素为当前链表和list中元素的交集，且表C中的元素有依值递增有序排列 + * @param list + */ + public LinkedList intersection( LinkedList list){ + return null; + } +} diff --git a/group17/240094626/work_jvm_1/src/com/coderising/jvm/loader/ClassFileLoader.java b/group17/240094626/work_jvm_1/src/com/coderising/jvm/loader/ClassFileLoader.java new file mode 100644 index 0000000000..b9d924a887 --- /dev/null +++ b/group17/240094626/work_jvm_1/src/com/coderising/jvm/loader/ClassFileLoader.java @@ -0,0 +1,73 @@ +package com.coderising.jvm.loader; + +import java.io.ByteArrayOutputStream; +import java.io.File; +import java.io.FileInputStream; +import java.io.InputStream; +import java.util.ArrayList; +import java.util.Iterator; +import java.util.List; + + + +public class ClassFileLoader { + + private List clzPaths = new ArrayList(); + + public byte[] readBinaryCode(String className) { + if(null == className || "".equals(className)){ + return null; + } + className = className.replace(".", File.separator)+".class"; + Iterator it = clzPaths.iterator(); + byte[] bytes = null; + while(it.hasNext() && bytes == null){ + String filePath = it.next()+File.separator+className; + bytes = getClassFile(filePath); + } + return bytes; + + } + + + private byte[] getClassFile(String filePath) { + ByteArrayOutputStream bos = new ByteArrayOutputStream(); + try { + InputStream is = new FileInputStream(new File(filePath)); + byte[] buffer = new byte[1024]; + int len = 0; + while((len=is.read(buffer)) > 0){ + bos.write(buffer,0, len); + } + } catch (Exception e) { + e.printStackTrace(); + } + return bos.toByteArray(); + } + + + public void addClassPath(String path) { + if(null != path && !"".equals(path)){ + clzPaths.add(path); + } + } + + + + public String getClassPath(){ + StringBuilder sb = new StringBuilder(); + Iterator it = clzPaths.iterator(); + while(it.hasNext()){ + if(sb.length() > 0){ + sb.append(";"); + } + sb.append(it.next()); + } + return sb.toString(); + } + + + + + +} diff --git a/group17/240094626/work_jvm_1/src/com/coderising/jvm/test/ClassFileloaderTest.java b/group17/240094626/work_jvm_1/src/com/coderising/jvm/test/ClassFileloaderTest.java new file mode 100644 index 0000000000..a205045d2e --- /dev/null +++ b/group17/240094626/work_jvm_1/src/com/coderising/jvm/test/ClassFileloaderTest.java @@ -0,0 +1,92 @@ +package com.coderising.jvm.test; + +import java.io.File; + +import org.junit.After; +import org.junit.Assert; +import org.junit.Before; +import org.junit.Test; + +import com.coderising.jvm.loader.ClassFileLoader; + + + + + +public class ClassFileloaderTest { + + + static String path1 = "E:\\workspace-indigo-32-statsdb\\warm-up\\bin";//"C:\\Users\\liuxin\\git\\coding2017\\liuxin\\mini-jvm\\bin"; + static String path2 = "C:\temp"; + + + + @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() { + ClassFileLoader loader = new ClassFileLoader(); + loader.addClassPath(path1); + + String className = "com.coderising.jvm.test.EmployeeV1"; + + byte[] byteCodes = loader.readBinaryCode(className); + + // 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(1056, byteCodes.length); + + } + + @Test + public void testMagicNumber(){ + ClassFileLoader loader = new ClassFileLoader(); + loader.addClassPath(path1); + 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