Squashed 'external/toxcore/c-toxcore/' content from commit 67badf69

git-subtree-dir: external/toxcore/c-toxcore
git-subtree-split: 67badf69416a74e74f6d7eb51dd96f37282b8455

toxcore/announce.h

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+/* SPDX-License-Identifier: GPL-3.0-or-later
+ * Copyright © 2020-2021 The TokTok team.
+ */
+
+#ifndef C_TOXCORE_TOXCORE_ANNOUNCE_H
+#define C_TOXCORE_TOXCORE_ANNOUNCE_H
+
+#include "forwarding.h"
+
+#define MAX_ANNOUNCEMENT_SIZE 512
+
+typedef void announce_on_retrieve_cb(void *object, const uint8_t *data, uint16_t length);
+
+uint8_t announce_response_of_request_type(uint8_t request_type);
+
+typedef struct Announcements Announcements;
+
+non_null()
+Announcements *new_announcements(const Logger *log, const Random *rng, const Mono_Time *mono_time, Forwarding *forwarding);
+
+/**
+ * @brief If data is stored, run `on_retrieve_callback` on it.
+ *
+ * @return true if data is stored, false otherwise.
+ */
+non_null(1, 2) nullable(3, 4)
+bool announce_on_stored(const Announcements *announce, const uint8_t *data_public_key,
+                        announce_on_retrieve_cb *on_retrieve_callback, void *object);
+
+non_null()
+void announce_set_synch_offset(Announcements *announce, int32_t synch_offset);
+
+nullable(1)
+void kill_announcements(Announcements *announce);
+
+
+/* The declarations below are not public, they are exposed only for tests. */
+
+/** @private
+ * Return xor of first ANNOUNCE_BUCKET_PREFIX_LENGTH bits from one bit after
+ * base and pk first differ
+ */
+non_null()
+uint16_t announce_get_bucketnum(const uint8_t *base, const uint8_t *pk);
+
+/** @private */
+non_null(1, 2) nullable(3)
+bool announce_store_data(Announcements *announce, const uint8_t *data_public_key,
+                         const uint8_t *data, uint32_t length, uint32_t timeout);
+
+/** @private */
+#define MAX_MAX_ANNOUNCEMENT_TIMEOUT 900
+#define MIN_MAX_ANNOUNCEMENT_TIMEOUT 10
+#define MAX_ANNOUNCEMENT_TIMEOUT_UPTIME_RATIO 4
+
+/** @private
+ * For efficient lookup and updating, entries are stored as a hash table keyed
+ * to the first ANNOUNCE_BUCKET_PREFIX_LENGTH bits starting from one bit after
+ * the first bit in which data public key first differs from the dht key, with
+ * (2-adically) closest keys preferentially stored within a given bucket. A
+ * given key appears at most once (even if timed out).
+ */
+#define ANNOUNCE_BUCKET_SIZE 8
+#define ANNOUNCE_BUCKET_PREFIX_LENGTH 5
+#define ANNOUNCE_BUCKETS 32 // ANNOUNCE_BUCKETS = 2 ** ANNOUNCE_BUCKET_PREFIX_LENGTH
+
+#endif