headers/private/fs_shell/Stack.h

   1 /* Stack - a template stack class (plus some handy methods)
   2  *
   3  * Copyright 2001-2005, Axel Dörfler, axeld@pinc-software.de.
   4  * This file may be used under the terms of the MIT License.
   5  */
   6 #ifndef _FSSH_STACK_H
   7 #define _FSSH_STACK_H
   8
   9
  10 #include "fssh_defs.h"
  11 #include "fssh_errors.h"
  12
  13
  14 namespace FSShell {
  15
  16
  17 template<class T> class Stack {
  18         public:
  19                 Stack()
  20                         :
  21                         fArray(NULL),
  22                         fUsed(0),
  23                         fMax(0)
  24                 {
  25                 }
  26
  27                 ~Stack()
  28                 {
  29                         free(fArray);
  30                 }
  31
  32                 bool IsEmpty() const
  33                 {
  34                         return fUsed == 0;
  35                 }
  36
  37                 void MakeEmpty()
  38                 {
  39                         // could also free the memory
  40                         fUsed = 0;
  41                 }
  42
  43                 fssh_status_t Push(T value)
  44                 {
  45                         if (fUsed >= fMax) {
  46                                 fMax += 16;
  47                                 T *newArray = (T *)realloc(fArray, fMax * sizeof(T));
  48                                 if (newArray == NULL)
  49                                         return FSSH_B_NO_MEMORY;
  50
  51                                 fArray = newArray;
  52                         }
  53                         fArray[fUsed++] = value;
  54                         return FSSH_B_OK;
  55                 }
  56
  57                 bool Pop(T *value)
  58                 {
  59                         if (fUsed == 0)
  60                                 return false;
  61
  62                         *value = fArray[--fUsed];
  63                         return true;
  64                 }
  65
  66                 T *Array()
  67                 {
  68                         return fArray;
  69                 }
  70
  71                 int32_t CountItems() const
  72                 {
  73                         return fUsed;
  74                 }
  75
  76         private:
  77                 T               *fArray;
  78                 int32_t fUsed;
  79                 int32_t fMax;
  80 };
  81
  82 }       // namespace FSShell
  83
  84 using FSShell::Stack;
  85
  86
  87 #endif  /* _FSSH_STACK_H */