Files
sysprof/lib/util/pointcache.c
Christian Hergert 571c2320da pointcache: add PointCache utility class
This is a simple cache that keeps x,y pairs for use when drawing
visualizers. To keep this generic, and save on memory, we simply
store the x,y coordinates as floats between 0.0 and 1.0. This
saves us roughly 50% on each data point over the 2 8-byte
numbers we would otherwise store.

Obviously, we could take this further and make some fancy index
storage with run-length-encode values, but this should work for
now and allow us to get more exotic later.
2016-09-26 17:34:58 -07:00

104 lines
2.6 KiB
C

/* pointcache.c
*
* Copyright (C) 2016 Christian Hergert <chergert@redhat.com>
*
* 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 3 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, see <http://www.gnu.org/licenses/>.
*/
#define G_LOG_DOMAIN "pointcache"
#include "pointcache.h"
struct _PointCache
{
volatile gint ref_count;
GHashTable *sets;
};
static void
point_cache_destroy (PointCache *self)
{
g_clear_pointer (&self->sets, g_hash_table_unref);
g_slice_free (PointCache, self);
}
PointCache *
point_cache_ref (PointCache *self)
{
g_return_val_if_fail (self->ref_count > 0, NULL);
g_atomic_int_inc (&self->ref_count);
return self;
}
void
point_cache_unref (PointCache *self)
{
g_return_if_fail (self->ref_count > 0);
if (g_atomic_int_dec_and_test (&self->ref_count))
point_cache_destroy (self);
}
PointCache *
point_cache_new (void)
{
PointCache *self;
self = g_slice_new0 (PointCache);
self->ref_count = 1;
self->sets = g_hash_table_new_full (NULL, NULL, NULL, (GDestroyNotify)g_array_unref);
return self;
}
void
point_cache_add_set (PointCache *self,
guint set_id)
{
g_hash_table_insert (self->sets,
GUINT_TO_POINTER (set_id),
g_array_new (FALSE, FALSE, sizeof (Point)));
}
gboolean
point_cache_contains_set (PointCache *self,
guint set_id)
{
return g_hash_table_contains (self->sets, GUINT_TO_POINTER (set_id));
}
void
point_cache_add_point_to_set (PointCache *self,
guint set_id,
gfloat x,
gfloat y)
{
GArray *ar;
Point point = { x, y };
ar = g_hash_table_lookup (self->sets, GUINT_TO_POINTER (set_id));
g_array_append_val (ar, point);
}
const Point *
point_cache_get_points (PointCache *self,
guint set_id,
guint *n_points)
{
GArray *ar;
ar = g_hash_table_lookup (self->sets, GUINT_TO_POINTER (set_id));
*n_points = ar->len;
return &g_array_index (ar, const Point, 0);
}