/*
* Copyright (C) 2010, 2011 Igalia S.L.
*
* Contact: Iago Toral Quiroga <itoral@igalia.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; version 2.1 of
* the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA
*
*/
/**
* SECTION:grl-util
* @short_description: utility functions
*/
#include "grl-util.h"
#include <string.h>
/**
* grl_paging_translate:
* @skip: number of elements to skip
* @count: number of elements to retrieve
* @max_page_size: maximum value for page size (0 for unlimited size)
* @page_size: optimal page size
* @page_number: page which contain the first element to retrieve (starting at 1)
* @internal_offset: in the @page_number, offset where first element can be found (starting at 0)
*
* Grilo browsing implements a paging mechanism through @skip and @count values.
*
* But there are some services (like Jamendo or Flickr) where paging is done
* through a page number and page size: user request all elements in a page,
* specifying in most cases what is the page size.
*
* This function is a helper for this task, computing from @skip and @count what
* is the optimal value of page size (limited by @max_page_size), which page
* should the user request, and where requested data start inside the page.
*
* By optimal we mean that it computes those values so only one page is required
* to satisfy the data, using the smallest page size. If user is limiting page
* size, then more requests to services might be needed. But still page size
* will be an optimal value.
*
* If @page_size is @NULL, then page size will be @max_page_size. If the later
* is also 0, then page size will be #G_MAXUINT.
*
* Since: 0.1.6
**/
void grl_paging_translate (guint skip,
guint count,
guint max_page_size,
guint *page_size,
guint *page_number,
guint *internal_offset)
{
gulong _page_size;
gulong last_element;
if (!page_size) {
if (max_page_size > 0) {
_page_size = max_page_size;
} else {
_page_size = G_MAXUINT;
}
} else {
if (skip < count) {
_page_size = skip + count;
if (max_page_size > 0) {
_page_size = CLAMP (_page_size, 0, max_page_size);
}
} else {
_page_size = count;
last_element = skip + count - 1;
while (skip/_page_size != last_element/_page_size &&
(max_page_size == 0 || _page_size < max_page_size)) {
_page_size++;
}
}
_page_size = CLAMP (_page_size, 0, G_MAXUINT);
}
if (page_size) {
*page_size = _page_size;
}
if (page_number) {
*page_number = skip/_page_size + 1;
}
if (internal_offset) {
*internal_offset = skip%_page_size;
}
}
/**
* grl_list_from_va: (skip)
* @p: first pointer
* @...: va_list pointers
*
* Returns a #GList containing the va_list pointers. Use @NULL to finalize them,
*
* Returns: a #GList.
*
* Since: 0.1.6
**/
GList *
grl_list_from_va (gpointer p, ...)
{
GList *pointer_list = NULL;
gpointer next_pointer;
va_list va_pointers;
va_start (va_pointers, p);
next_pointer = p;
while (next_pointer) {
pointer_list = g_list_prepend (pointer_list, next_pointer);
next_pointer = va_arg (va_pointers, gpointer);
}
va_end (va_pointers);
return g_list_reverse (pointer_list);
}
/**
* grl_date_time_from_iso8601:
* @date: a date expressed in iso8601 format
*
* Returns: a newly-allocated #GDateTime set to the time corresponding to
* @date, or %NULL if @date could not be parsed properly.
*
* Since: 0.2.0
*/
GDateTime *
grl_date_time_from_iso8601 (const gchar *date)
{
GTimeVal t = { 0, };
gboolean ret;
gchar *date_time;
gint date_length;
if (!date) {
return NULL;
}
ret = g_time_val_from_iso8601 (date, &t);
/* second condition works around
* https://bugzilla.gnome.org/show_bug.cgi?id=650968 */
if (!ret || (t.tv_sec == 0 && t.tv_usec == 0)) {
/* We might be in the case where there is a date alone. In that case, we
* take the convention of setting it to noon GMT */
/* Date can could be YYYY, YYYY-MM, YYYY-MM-DD or YYYYMMDD */
date_length = strlen (date);
switch (date_length) {
case 4:
date_time = g_strdup_printf ("%s-01-01T12:00:00Z", date);
break;
case 7:
date_time = g_strdup_printf ("%s-01T12:00:00Z", date);
break;
default:
date_time = g_strdup_printf ("%sT12:00:00Z", date);
}
ret = g_time_val_from_iso8601 (date_time, &t);
g_free (date_time);
}
if (ret)
return g_date_time_new_from_timeval_utc (&t);
return NULL;
}