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1 package com.thoughtworks.xstream.core.util;
2
3 public final class FastStack {
4
5 private Object  [] stack;
6 private int pointer;
7
8 public FastStack(int initialCapacity) {
9 stack = new Object [initialCapacity];
10 }
11
12 public Object push(Object value) {
13 if (pointer + 1 >= stack.length) {
14 resizeStack(stack.length * 2);
15 }
16 stack[pointer++] = value;
17 return value;
18 }
19
20 public void popSilently() {
21 pointer--;
22 }
23
24 public Object pop() {
25 return stack[--pointer];
26 }
27
28 public Object peek() {
29 return pointer == 0 ? null : stack[pointer - 1];
30 }
31
32 public int size() {
33 return pointer;
34 }
35
36 public boolean hasStuff() {
37 return pointer > 0;
38 }
39
40 public Object get(int i) {
41 return stack[i];
42 }
43
44 private void resizeStack(int newCapacity) {
45 Object [] newStack = new Object [newCapacity];
46 System.arraycopy(stack, 0, newStack, 0, Math.min(stack.length, newCapacity));
47 stack = newStack;
48 }
49
50 public String toString() {
51 StringBuffer result = new StringBuffer ("[");
52 for (int i = 0; i < pointer; i++) {
53 if (i > 0) {
54 result.append(", ");
55 }
56 result.append(stack[i]);
57 }
58 result.append(']');
59 return result.toString();
60 }
61 }
62 |
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