mcs/class/referencesource/System.Xml/System/Xml/ByteStack.cs

   1 //------------------------------------------------------------------------------
   2 // <copyright file="ByteStack.cs" company="Microsoft">
   3 //     Copyright (c) Microsoft Corporation.  All rights reserved.
   4 // </copyright>
   5 // <owner current="true" primary="true">[....]</owner>
   6 //------------------------------------------------------------------------------
   7
   8 using System;
   9
  10 namespace System.Xml {
  11
  12 // This stack is designed to minimize object creation for the
  13 // objects being stored in the stack by allowing them to be
  14 // re-used over time.  It basically pushes the objects creating
  15 // a high water mark then as Pop() is called they are not removed
  16 // so that next time Push() is called it simply returns the last
  17 // object that was already on the stack.
  18
  19     internal class ByteStack {
  20         private byte[] stack;
  21         private int growthRate;
  22         private int top;
  23         private int size;
  24
  25         public ByteStack(int growthRate) {
  26             this.growthRate = growthRate;
  27             top = 0;
  28             stack = new byte[growthRate];
  29             size = growthRate;
  30         }
  31
  32         public void Push(byte data) {
  33             if (size == top) {
  34                 byte[] newstack = new byte[size + growthRate];
  35                 if (top > 0) {
  36                     Buffer.BlockCopy(stack, 0, newstack, 0, top);
  37                 }
  38                 stack = newstack;
  39                 size += growthRate;
  40             }
  41             stack[top++] = data;
  42         }
  43
  44         public byte Pop() {
  45             if (top > 0) {
  46                 return stack[--top];
  47             } else {
  48                 return 0;
  49             }
  50         }
  51
  52         public byte Peek() {
  53             if (top > 0) {
  54                 return stack[top - 1];
  55             } else {
  56                 return 0;
  57             }
  58         }
  59
  60         public int Length {
  61             get {
  62                 return top;
  63             }
  64         }
  65     }
  66 }