From 3b9b6d0b8e7f798023c9d109c490449d528fde80 Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Sun, 7 Apr 2024 17:59:48 +0200
Subject: Adding upstream version 1:9.18.19.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 lib/isc/include/isc/ratelimiter.h | 145 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 145 insertions(+)
 create mode 100644 lib/isc/include/isc/ratelimiter.h

(limited to 'lib/isc/include/isc/ratelimiter.h')

diff --git a/lib/isc/include/isc/ratelimiter.h b/lib/isc/include/isc/ratelimiter.h
new file mode 100644
index 0000000..45ec447
--- /dev/null
+++ b/lib/isc/include/isc/ratelimiter.h
@@ -0,0 +1,145 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, you can obtain one at https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+#pragma once
+
+/*****
+***** Module Info
+*****/
+
+/*! \file isc/ratelimiter.h
+ * \brief A rate limiter is a mechanism for dispatching events at a limited
+ * rate.  This is intended to be used when sending zone maintenance
+ * SOA queries, NOTIFY messages, etc.
+ */
+
+/***
+ *** Imports.
+ ***/
+
+#include <inttypes.h>
+#include <stdbool.h>
+
+#include <isc/lang.h>
+#include <isc/types.h>
+
+ISC_LANG_BEGINDECLS
+
+/*****
+***** Functions.
+*****/
+
+isc_result_t
+isc_ratelimiter_create(isc_mem_t *mctx, isc_timermgr_t *timermgr,
+		       isc_task_t *task, isc_ratelimiter_t **ratelimiterp);
+/*%<
+ * Create a rate limiter.  The execution interval is initially undefined.
+ */
+
+isc_result_t
+isc_ratelimiter_setinterval(isc_ratelimiter_t *rl, isc_interval_t *interval);
+/*!<
+ * Set the minimum interval between event executions.
+ * The interval value is copied, so the caller need not preserve it.
+ *
+ * Requires:
+ *	'*interval' is a nonzero interval.
+ */
+
+void
+isc_ratelimiter_setpertic(isc_ratelimiter_t *rl, uint32_t perint);
+/*%<
+ * Set the number of events processed per interval timer tick.
+ * If 'perint' is zero it is treated as 1.
+ */
+
+void
+isc_ratelimiter_setpushpop(isc_ratelimiter_t *rl, bool pushpop);
+/*%<
+ * Set / clear the ratelimiter to from push pop mode rather
+ * first in - first out mode (default).
+ */
+
+isc_result_t
+isc_ratelimiter_enqueue(isc_ratelimiter_t *rl, isc_task_t *task,
+			isc_event_t **eventp);
+/*%<
+ * Queue an event for rate-limited execution.
+ *
+ * This is similar
+ * to doing an isc_task_send() to the 'task', except that the
+ * execution may be delayed to achieve the desired rate of
+ * execution.
+ *
+ * '(*eventp)->ev_sender' is used to hold the task.  The caller
+ * must ensure that the task exists until the event is delivered.
+ *
+ * Requires:
+ *\li	An interval has been set by calling
+ *	isc_ratelimiter_setinterval().
+ *
+ *\li	'task' to be non NULL.
+ *\li	'(*eventp)->ev_sender' to be NULL.
+ */
+
+isc_result_t
+isc_ratelimiter_dequeue(isc_ratelimiter_t *rl, isc_event_t *event);
+/*
+ * Dequeue a event off the ratelimiter queue.
+ *
+ * Returns:
+ * \li	ISC_R_NOTFOUND if the event is no longer linked to the rate limiter.
+ * \li	ISC_R_SUCCESS
+ */
+
+void
+isc_ratelimiter_shutdown(isc_ratelimiter_t *ratelimiter);
+/*%<
+ * Shut down a rate limiter.
+ *
+ * Ensures:
+ *\li	All events that have not yet been
+ * 	dispatched to the task are dispatched immediately with
+ *	the #ISC_EVENTATTR_CANCELED bit set in ev_attributes.
+ *
+ *\li	Further attempts to enqueue events will fail with
+ * 	#ISC_R_SHUTTINGDOWN.
+ *
+ *\li	The rate limiter is no longer attached to its task.
+ */
+
+void
+isc_ratelimiter_attach(isc_ratelimiter_t *source, isc_ratelimiter_t **target);
+/*%<
+ * Attach to a rate limiter.
+ */
+
+void
+isc_ratelimiter_detach(isc_ratelimiter_t **ratelimiterp);
+/*%<
+ * Detach from a rate limiter.
+ */
+
+isc_result_t
+isc_ratelimiter_stall(isc_ratelimiter_t *rl);
+/*%<
+ * Stall event processing.
+ */
+
+isc_result_t
+isc_ratelimiter_release(isc_ratelimiter_t *rl);
+/*%<
+ * Release a stalled rate limiter.
+ */
+
+ISC_LANG_ENDDECLS
-- 
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