mpd/src/page.c
2009-12-31 20:58:43 -08:00

90 lines
1.8 KiB
C

/*
* Copyright (C) 2003-2010 The Music Player Daemon Project
* http://www.musicpd.org
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "config.h"
#include "page.h"
#include <glib.h>
#include <assert.h>
#include <string.h>
/**
* Allocates a new #page object, without filling the data element.
*/
static struct page *
page_new(size_t size)
{
struct page *page = g_malloc(sizeof(*page) + size -
sizeof(page->data));
assert(size > 0);
page->ref = 1;
page->size = size;
return page;
}
struct page *
page_new_copy(const void *data, size_t size)
{
struct page *page = page_new(size);
assert(data != NULL);
memcpy(page->data, data, size);
return page;
}
struct page *
page_new_concat(const struct page *a, const struct page *b)
{
struct page *page = page_new(a->size + b->size);
memcpy(page->data, a->data, a->size);
memcpy(page->data + a->size, b->data, b->size);
return page;
}
void
page_ref(struct page *page)
{
g_atomic_int_inc(&page->ref);
}
static void
page_free(struct page *page)
{
assert(page->ref == 0);
g_free(page);
}
bool
page_unref(struct page *page)
{
bool unused = g_atomic_int_dec_and_test(&page->ref);
if (unused)
page_free(page);
return unused;
}