refactor: use z_id_to_string for displaying z_id_t

docs/api.rst

@@ -479,6 +479,7 @@ Functions
 .. doxygenfunction:: z_info_zid
 .. doxygenfunction:: z_info_routers_zid
 .. doxygenfunction:: z_info_peers_zid
+.. doxygenfunction:: z_id_to_string
 
 .. doxygenfunction:: z_closure_zid_drop
 .. doxygenfunction:: z_closure_zid_call
@@ -829,4 +830,4 @@ Other
 
 Functions
 ---------
-.. doxygenfunction:: zc_stop_z_runtime
+.. doxygenfunction:: zc_stop_z_runtime

examples/z_info.c

@@ -16,15 +16,15 @@
 #include "parse_args.h"
 #include "zenoh.h"
 
-void parse_args(int argc, char** argv, z_owned_config_t* config);
-
-void print_zid(const z_id_t* id, void* ctx) {
-    for (int i = 0; i < 16; i++) {
-        printf("%02x", id->id[i]);
-    }
-    printf("\n");
+void print_zid(const z_id_t *id, void *ctx) {
+    z_owned_string_t str;
+    z_id_to_string(id, &str);
+    printf("%.*s\n", (int)z_string_len(z_loan(str)), z_string_data(z_loan(str)));
+    z_drop(z_move(str));
 }
 
+void parse_args(int argc, char** argv, z_owned_config_t* config);
+
 int main(int argc, char** argv) {
     z_owned_config_t config;
     parse_args(argc, argv, &config);

src/info.rs

@@ -11,13 +11,16 @@
 // Contributors:
 //   ZettaScale Zenoh team, <[email protected]>
 //
+use std::mem::MaybeUninit;
+
 use zenoh::{prelude::*, session::ZenohId};
 
 pub use crate::opaque_types::z_id_t;
 use crate::{
     result,
-    transmute::{CTypeRef, IntoCType, RustTypeRef, TakeRustType},
+    transmute::{CTypeRef, IntoCType, RustTypeRef, RustTypeRefUninit, TakeRustType},
     z_closure_zid_call, z_closure_zid_loan, z_loaned_session_t, z_moved_closure_zid_t,
+    z_owned_string_t,
 };
 decl_c_type!(copy(z_id_t, ZenohId));
 
@@ -27,6 +30,13 @@ impl From<[u8; 16]> for z_id_t {
     }
 }
 
+/// Formats the `z_id_t` into 16-digit hex string (LSB-first order)
+#[no_mangle]
+pub extern "C" fn z_id_to_string(zid: &z_id_t, dst: &mut MaybeUninit<z_owned_string_t>) {
+    let zid = zid.as_rust_type_ref();
+    dst.as_rust_type_mut_uninit().write(zid.to_string().into());
+}
+
 /// Returns the session's Zenoh ID.
 ///
 /// Unless the `session` is invalid, that ID is guaranteed to be non-zero.

tests/z_api_alignment_test.c

@@ -203,11 +203,10 @@ int main(int argc, char **argv) {
 
 #ifdef UNSTABLE
     z_id_t _ret_zid = z_info_zid(z_loan(s1));
-    printf("Session 1 with PID: 0x");
-    for (unsigned long i = 0; i < sizeof(_ret_zid); i++) {
-        printf("%.2X", _ret_zid.id[i]);
-    }
-    printf("\n");
+    z_owned_string_t str;
+    z_id_to_string(&_ret_zid, &str);
+    printf("Session 1 with PID: 0x%.*s\n", (int)z_string_len(z_loan(str)), z_string_data(z_loan(str)));
+    z_drop(z_move(str));
 
     z_owned_closure_zid_t _ret_closure_zid;
     z_closure(&_ret_closure_zid, zid_handler, NULL, NULL);
@@ -248,11 +247,9 @@ int main(int argc, char **argv) {
 
 #ifdef UNSTABLE
     _ret_zid = z_info_zid(z_loan(s2));
-    printf("Session 2 with PID: 0x");
-    for (unsigned long i = 0; i < sizeof(_ret_zid); i++) {
-        printf("%.2X", _ret_zid.id[i]);
-    }
-    printf("\n");
+    z_id_to_string(&_ret_zid, &str);
+    printf("Session 2 with PID: 0x%.*s\n", (int)z_string_len(z_loan(str)), z_string_data(z_loan(str)));
+    z_drop(z_move(str));
 #endif
 
 #ifdef ZENOH_PICO