Files
sysprof/src/libsysprof-capture/mapped-ring-buffer.h
2020-02-16 17:57:06 -07:00

93 lines
4.2 KiB
C

/* mapped-ring-buffer.h
*
* Copyright 2020 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/>.
*
* SPDX-License-Identifier: GPL-3.0-or-later
*/
#pragma once
#include <glib.h>
G_BEGIN_DECLS
typedef struct _MappedRingBuffer MappedRingBuffer;
/**
* MappedRingBufferCallback:
* @data: a pointer into the mapped buffer containing the data frame
* @length: (inout): the number of bytes to advance
* @user_data: closure data provided to mapped_ring_buffer_drain()
*
* Functions matching this prototype will be called from the
* mapped_ring_buffer_drain() function for each data frame read from the
* underlying memory mapping.
*
* @length is initially set to the max bytes that @data could contain, but
* should be set by the caller to the amount of bytes known to have been
* consumed. This allows MappedRingBuffer to avoid storing length data or
* framing information as that can come from the buffer content.
*
* The callback should shorten @length if it knows the frame is less than
* what was provided.
*
* This function can also be used with mapped_ring_buffer_create_source()
* to automatically drain the ring buffer as part of the main loop progress.
*
* Returns: %TRUE to coninue draining, otherwise %FALSE and draining stops
*/
typedef gboolean (*MappedRingBufferCallback) (gconstpointer data,
gsize *length,
gpointer user_data);
G_GNUC_INTERNAL
MappedRingBuffer *mapped_ring_buffer_new_reader (gsize buffer_size);
G_GNUC_INTERNAL
MappedRingBuffer *mapped_ring_buffer_new_readwrite (gsize buffer_size);
G_GNUC_INTERNAL
MappedRingBuffer *mapped_ring_buffer_new_writer (gint fd);
G_GNUC_INTERNAL
gint mapped_ring_buffer_get_fd (MappedRingBuffer *self);
G_GNUC_INTERNAL
MappedRingBuffer *mapped_ring_buffer_ref (MappedRingBuffer *self);
G_GNUC_INTERNAL
void mapped_ring_buffer_unref (MappedRingBuffer *self);
G_GNUC_INTERNAL
void mapped_ring_buffer_clear (MappedRingBuffer *self);
G_GNUC_INTERNAL
gpointer mapped_ring_buffer_allocate (MappedRingBuffer *self,
gsize length);
G_GNUC_INTERNAL
void mapped_ring_buffer_advance (MappedRingBuffer *self,
gsize length);
G_GNUC_INTERNAL
gboolean mapped_ring_buffer_drain (MappedRingBuffer *self,
MappedRingBufferCallback callback,
gpointer user_data);
G_GNUC_INTERNAL
guint mapped_ring_buffer_create_source (MappedRingBuffer *self,
MappedRingBufferCallback callback,
gpointer user_data);
G_GNUC_INTERNAL
guint mapped_ring_buffer_create_source_full (MappedRingBuffer *self,
MappedRingBufferCallback callback,
gpointer user_data,
GDestroyNotify destroy);
G_DEFINE_AUTOPTR_CLEANUP_FUNC (MappedRingBuffer, mapped_ring_buffer_unref)
G_END_DECLS