Add liveliness interface

include/zenoh-pico/api/liveliness.h

@@ -0,0 +1,122 @@
+//
+// Copyright (c) 2024 ZettaScale Technology
+//
+// This program and the accompanying materials are made available under the
+// terms of the Eclipse Public License 2.0 which is available at
+// http://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
+// which is available at https://www.apache.org/licenses/LICENSE-2.0.
+//
+// SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
+//
+// Contributors:
+//   ZettaScale Zenoh Team, <zenoh@zettascale.tech>
+//
+#ifndef INCLUDE_ZENOH_PICO_API_LIVELINESS_H
+#define INCLUDE_ZENOH_PICO_API_LIVELINESS_H
+
+#include <bits/types/stack_t.h>
+#include <stdbool.h>
+#include <stdint.h>
+
+#include "olv_macros.h"
+#include "zenoh-pico/api/types.h"
+
+typedef struct {
+    // TODO(sashacmc): add real data
+    uint8_t __dummy;
+} _z_liveliness_token_t;
+
+_Z_OWNED_TYPE_VALUE(_z_liveliness_token_t, liveliness_token)
+
+/**
+ * The options for `z_liveliness_declare_token()`.
+ */
+typedef struct z_liveliness_declaration_options_t {
+    uint8_t __dummy;
+} z_liveliness_declaration_options_t;
+
+/**
+ * The options for `z_liveliness_declare_subscriber()`
+ */
+typedef struct z_liveliness_subscriber_options_t {
+    uint8_t __dummy;
+} z_liveliness_subscriber_options_t;
+
+/**
+ * The options for `z_liveliness_get()`
+ */
+typedef struct z_liveliness_get_options_t {
+    uint32_t timeout_ms;
+} z_liveliness_get_options_t;
+
+/**
+ * Constructs default value for `z_liveliness_declaration_options_t`.
+ */
+int8_t z_liveliness_declaration_options_default(z_liveliness_declaration_options_t *options);
+
+/**
+ * Declares a subscriber on liveliness tokens that intersect `key_expr`.
+ *
+ * @param token: An uninitialized memory location where subscriber will be constructed.
+ * @param session: The Zenoh session.
+ * @param key_expr: The key expression to subscribe to.
+ * @param callback: The callback function that will be called each time a liveliness token status is changed.
+ * @param _options: The options to be passed to the liveliness subscriber declaration.
+ *
+ * @return 0 in case of success, negative error values otherwise.
+ */
+int8_t z_liveliness_declare_subscriber(z_owned_subscriber_t *token, const z_loaned_session_t *session,
+                                       const z_loaned_keyexpr_t *key_expr, z_moved_closure_sample_t *callback,
+                                       z_liveliness_subscriber_options_t *_options);
+/**
+ * Constructs and declares a liveliness token on the network.
+ *
+ * Liveliness token subscribers on an intersecting key expression will receive a PUT sample when connectivity
+ * is achieved, and a DELETE sample if it's lost.
+ *
+ * @param token: An uninitialized memory location where liveliness token will be constructed.
+ * @param session: A Zenos session to declare the liveliness token.
+ * @param key_expr: A keyexpr to declare a liveliess token for.
+ * @param _options: Liveliness token declaration properties.
+ */
+int8_t z_liveliness_declare_token(z_owned_liveliness_token_t *token, const z_loaned_session_t *session,
+                                  const z_loaned_keyexpr_t *key_expr,
+                                  const z_liveliness_declaration_options_t *_options);
+
+/**
+ * Queries liveliness tokens currently on the network with a key expression intersecting with `key_expr`.
+ *
+ * @param session: The Zenoh session.
+ * @param key_expr: The key expression to query liveliness tokens for.
+ * @param callback: The callback function that will be called for each received reply.
+ * @param options: Additional options for the liveliness get operation.
+ */
+int8_t z_liveliness_get(const z_loaned_session_t *session, const z_loaned_keyexpr_t *key_expr,
+                        z_moved_closure_reply_t *callback, z_liveliness_get_options_t *options);
+
+/**
+ * Constructs default value `z_liveliness_get_options_t`.
+ */
+int8_t z_liveliness_get_options_default(z_liveliness_get_options_t *options);
+
+/**
+ * Constucts default value for `z_liveliness_declare_subscriber_options_t`.
+ */
+int8_t z_liveliness_subscriber_options_default(z_liveliness_subscriber_options_t *options);
+
+/**
+ * Undeclares liveliness token, frees memory and resets it to a gravestone state.
+ */
+int8_t z_liveliness_token_drop(z_moved_liveliness_token_t *token);
+
+/**
+ * Borrows token.
+ */
+const z_loaned_liveliness_token_t *z_liveliness_token_loan(const z_owned_liveliness_token_t *token);
+
+/**
+ * Destroys a liveliness token, notifying subscribers of its destruction.
+ */
+int8_t z_liveliness_undeclare_token(z_moved_liveliness_token_t *token);
+
+#endif  // INCLUDE_ZENOH_PICO_API_LIVELINESS_H

src/api/liveliness.c

@@ -0,0 +1,75 @@
+//
+// Copyright (c) 2024 ZettaScale Technology
+//
+// This program and the accompanying materials are made available under the
+// terms of the Eclipse Public License 2.0 which is available at
+// http://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
+// which is available at https://www.apache.org/licenses/LICENSE-2.0.
+//
+// SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
+//
+// Contributors:
+//   ZettaScale Zenoh Team, <zenoh@zettascale.tech>
+//
+
+#include "zenoh-pico/api/liveliness.h"
+#include "zenoh-pico/utils/result.h"
+
+int8_t z_liveliness_declaration_options_default(z_liveliness_declaration_options_t *options) {
+    options->__dummy = 0;
+    return _Z_RES_OK;
+}
+
+int8_t z_liveliness_declare_subscriber(z_owned_subscriber_t *token, const z_loaned_session_t *session,
+                                       const z_loaned_keyexpr_t *key_expr, z_moved_closure_sample_t *callback,
+                                       z_liveliness_subscriber_options_t *_options) {
+    // TODO(sashacmc): Implement
+    (void)token;
+    (void)session;
+    (void)key_expr;
+    (void)callback;
+    (void)_options;
+    return _Z_RES_OK;
+}
+int8_t z_liveliness_declare_token(z_owned_liveliness_token_t *token, const z_loaned_session_t *session,
+                                  const z_loaned_keyexpr_t *key_expr,
+                                  const z_liveliness_declaration_options_t *_options) {
+    // TODO(sashacmc): Implement
+    (void)token;
+    (void)session;
+    (void)key_expr;
+    (void)_options;
+    return _Z_RES_OK;
+}
+
+int8_t z_liveliness_get(const z_loaned_session_t *session, const z_loaned_keyexpr_t *key_expr,
+                        z_moved_closure_reply_t *callback, z_liveliness_get_options_t *options) {
+    // TODO(sashacmc): Implement
+    (void)session;
+    (void)key_expr;
+    (void)callback;
+    (void)options;
+    return _Z_RES_OK;
+}
+
+int8_t z_liveliness_get_options_default(z_liveliness_get_options_t *options) {
+    options->timeout_ms = 0;  // TODO(sashacmc): correct value;
+    return _Z_RES_OK;
+}
+
+int8_t z_liveliness_subscriber_options_default(z_liveliness_subscriber_options_t *options) {
+    options->__dummy = 0;
+    return _Z_RES_OK;
+}
+
+int8_t z_liveliness_token_drop(z_moved_liveliness_token_t *token) {
+    // TODO(sashacmc): Implement
+    (void)token;
+    return _Z_RES_OK;
+}
+
+int8_t z_liveliness_undeclare_token(z_moved_liveliness_token_t *token) {
+    // TODO(sashacmc): Implement
+    (void)token;
+    return _Z_RES_OK;
+}