src/Stack.c

   1 /**
   2  * @file Stack.c
   3  */
   4
   5 #include "cgds/Stack.h"
   6
   7 void _stack_init(Stack* stack, size_t dataSize)
   8 {
   9     stack->size = 0;
  10     stack->dataSize = dataSize;
  11     stack->top = NULL;
  12 }
  13
  14 Stack* _stack_new(size_t dataSize)
  15 {
  16     Stack* stack = (Stack*) safe_malloc(sizeof (Stack));
  17     _stack_init(stack, dataSize);
  18     return stack;
  19 }
  20
  21 Stack* stack_copy(Stack* stack)
  22 {
  23     // since a stack is a single-linked list, an auxiliary storage is required
  24     void** tmpStorage = (void**) malloc(stack->size * sizeof (void*));
  25     StackCell* stackCell = stack->top;
  26     for (UInt i = 0; i < stack->size; i++)
  27     {
  28         tmpStorage[stack->size - 1 - i] = stackCell->data;
  29         stackCell = stackCell->previous;
  30     }
  31     // now transfer tmpStorage contents (pushed in right order) in a new stack
  32     Stack* stackCopy = _stack_new(stack->dataSize);
  33     for (UInt i = 0; i < stack->size; i++)
  34         _stack_push(stackCopy, tmpStorage[i]);
  35     free(tmpStorage);
  36     return stackCopy;
  37 }
  38
  39 Bool stack_empty(Stack* stack)
  40 {
  41     return (stack->size == 0);
  42 }
  43
  44 UInt stack_size(Stack* stack)
  45 {
  46     return stack->size;
  47 }
  48
  49 void _stack_push(Stack* stack, void* data)
  50 {
  51     StackCell* newStackTop = (StackCell*) safe_malloc(sizeof (StackCell));
  52     newStackTop->data = safe_malloc(stack->dataSize);
  53     memcpy(newStackTop->data, data, stack->dataSize);
  54     newStackTop->previous = stack->top;
  55     stack->top = newStackTop;
  56     stack->size++;
  57 }
  58
  59 void* _stack_top(Stack* stack)
  60 {
  61     return stack->top->data;
  62 }
  63
  64 void stack_pop(Stack* stack)
  65 {
  66     StackCell* toTrash = stack->top;
  67     stack->top = stack->top->previous;
  68     safe_free(toTrash->data);
  69     safe_free(toTrash);
  70     stack->size--;
  71 }
  72
  73 void stack_clear(Stack* stack)
  74 {
  75     while (stack->size > 0)
  76         stack_pop(stack);
  77     _stack_init(stack, stack->dataSize);
  78 }
  79
  80 void stack_destroy(Stack* stack)
  81 {
  82     stack_clear(stack);
  83     safe_free(stack);
  84 }