#include "pn_buffer.h"

#include <glib.h>

#define BUFFER_SIZE 0x1000

struct pn_buffer *
pn_buffer_new(void)
{
	struct pn_buffer *buffer;
	buffer = g_malloc0(sizeof(*buffer));
	return buffer;
}

struct pn_buffer *
pn_buffer_new_and_alloc(size_t size)
{
	struct pn_buffer *buffer;

	if (size <= 0)
		size = BUFFER_SIZE;

	buffer = g_malloc(sizeof(*buffer));
	buffer->data = buffer->alloc_data = g_malloc(size);
	buffer->size = size;
	buffer->len = 0;
	buffer->offset = 0;

	return buffer;
}

struct pn_buffer *
pn_buffer_new_use(void *data,
		  size_t size)
{
	struct pn_buffer *buffer;

	buffer = g_malloc(sizeof(*buffer));
	buffer->size = buffer->len = size;
	buffer->data = buffer->alloc_data = data;
	buffer->offset = 0;

	return buffer;
}

struct pn_buffer *
pn_buffer_new_memdup(const void *data,
		     size_t size)
{
	return pn_buffer_new_use(g_memdup(data, size), size);
}

void
pn_buffer_free(struct pn_buffer *buffer)
{
	if (!buffer)
		return;

	g_free(buffer->alloc_data);
	g_free(buffer);
}

void
pn_buffer_resize(struct pn_buffer *buffer,
		 size_t new_size)
{
	new_size = ((new_size / BUFFER_SIZE) + 1) * BUFFER_SIZE;
	buffer->data = buffer->alloc_data = g_realloc(buffer->data, new_size);
	buffer->size = new_size;
}

void
pn_buffer_prepare(struct pn_buffer *buffer,
		  size_t extra_size)
{
	if (extra_size <= buffer->size - buffer->len)
		return;

	pn_buffer_resize(buffer, buffer->len + extra_size);
}