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Copy pathStack.c
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102 lines (90 loc) · 1.99 KB
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#include "Prototypes.h"
#include <stdbool.h>
#include <stdlib.h>
/*{
struct StackItem_ {
void* data;
int size;
StackItem* next;
};
struct Stack_ {
ObjectClass* type;
StackItem* head;
bool owner;
int size;
};
}*/
Stack* Stack_new(ObjectClass* type, bool owner) {
Stack* this = (Stack*) malloc(sizeof(Stack));
this->type = type;
this->head = NULL;
this->owner = owner;
this->size = 0;
return this;
}
void Stack_delete(Stack* this) {
StackItem* item = this->head;
while (item) {
StackItem* saved = item;
if (this->owner) {
if (this->type) {
Object* obj = (Object*)item->data;
Msg0(Object, delete, obj);
} else {
if (item->data)
free(item->data);
}
}
item = item->next;
free(saved);
}
free(this);
}
void Stack_push(Stack* this, void* data, int size) {
assert( !this->type || Call(Object, instanceOf, data, this->type) );
assert( data );
StackItem* item = (StackItem*) malloc(sizeof(StackItem));
item->data = data;
item->size = size;
item->next = this->head;
this->head = item;
this->size++;
}
void* Stack_pop(Stack* this, int* size) {
if (!this->head)
return NULL;
void* result = this->head->data;
if (size)
*size = this->head->size;
StackItem* headNext = this->head->next;
free(this->head);
this->head = headNext;
assert( !this->type || Call(Object, instanceOf, result, this->type) );
this->size--;
return result;
}
void* Stack_peek(Stack* this, int* size) {
if (!this->head) {
if (size)
*size = 0;
return NULL;
}
if (size)
*size = this->head->size;
return this->head->data;
}
void* Stack_peekAt(Stack* this, int n, int* size) {
StackItem* at = this->head;
for (int i = 0; i < n; i++) {
if (at)
at = at->next;
}
if (!at) {
if (size)
*size = 0;
return NULL;
}
if (size)
*size = at->size;
return at->data;
}