/**
* Pushes a value onto the stack.
* @param value The value to be pushed onto the stack.
* @return 0 upon success or 1 if an memory error occurs.
*/
int push(int value) {
if (!stack && new_stack(INITIAL_CAPACITY)) {
return 1;
}
if (stack->size == stack->capacity && extend_capacity(stack->capacity * 2)) {
return 1;
}
stack->values[stack->size++] = value;
return 0;
}
/**
* If this is an in memory cache, writes bufsize bytes to it. Returns true
* on success, false on failure.
*/
inline bool write_bytes_to_memory_cache(const char* c,
std::streamsize bufsize) {
if (data == NULL) return false;
// either we have enough capacity
// or we are able to extend enough capacity to write it
if (size + bufsize <= capacity || extend_capacity(size + bufsize)) {
memcpy(data + size, c, bufsize);
size += bufsize;
return true;
} else {
return false;
}
}
/**
* Extends the capacity of the stack (for big values, allows not to reallocate several successive times the stack).
* Values added on the stack are left uninitialized.
* @param size The number of blocs to add.
* @return 0 upon success or 1 if an memory error occurs.
*/
int extend_stack(int size) {
int required_cap = stack->size + size, new_size;
if (!stack && new_stack(size > INITIAL_CAPACITY ? size : INITIAL_CAPACITY)) {
return 1;
}
if (required_cap > stack->capacity) {
new_size = stack->capacity * 2;
if (extend_capacity(new_size > required_cap ? new_size : required_cap)) {
return 1;
}
}
stack->size += size;
return 0;
}
