Enforce downsampling config id unicity (#1785)

* Enforce downsampling id unicity

* Add downsampling config validation test

* Fix incorrect config field name in test

Author: oteffahi

zenoh/src/net/routing/interceptor/downsampling.rs

@@ -19,7 +19,7 @@
 //! [Click here for Zenoh's documentation](https://docs.rs/zenoh/latest/zenoh)
 
 use std::{
-    collections::HashMap,
+    collections::{HashMap, HashSet},
     sync::{Arc, Mutex},
 };
 
@@ -38,7 +38,14 @@ pub(crate) fn downsampling_interceptor_factories(
 ) -> ZResult<Vec<InterceptorFactory>> {
     let mut res: Vec<InterceptorFactory> = vec![];
 
+    let mut id_set = HashSet::new();
     for ds in config {
+        // check unicity of rule id
+        if let Some(id) = &ds.id {
+            if !id_set.insert(id.clone()) {
+                bail!("Invalid Downsampling config: id '{id}' is repeated");
+            }
+        }
         res.push(Box::new(DownsamplingInterceptorFactory::new(ds.clone())));
     }
 

zenoh/tests/interceptors.rs

@@ -265,8 +265,41 @@ fn downsampling_config_error_wrong_strategy() {
                 {
                   flow: "down",
                   rules: [
-                    { keyexpr: "test/downsamples_by_keyexp/r100", freq: 10, },
-                    { keyexpr: "test/downsamples_by_keyexp/r50", freq: 20, }
+                    { key_expr: "test/downsamples_by_keyexp/r100", freq: 10, },
+                    { key_expr: "test/downsamples_by_keyexp/r50", freq: 20, }
+                  ],
+                },
+              ]
+            "#,
+        )
+        .unwrap();
+
+    zenoh::open(config).wait().unwrap();
+}
+
+#[test]
+#[should_panic(expected = "Invalid Downsampling config: id 'REPEATED' is repeated")]
+fn downsampling_config_error_repeated_id() {
+    zenoh::init_log_from_env_or("error");
+
+    let mut config = Config::default();
+    config
+        .insert_json5(
+            "downsampling",
+            r#"
+              [
+                {
+                  id: "REPEATED",
+                  flow: "egress",
+                  rules: [
+                    { key_expr: "test/downsamples_by_keyexp/r100", freq: 10, },
+                  ],
+                },
+                {
+                  id: "REPEATED",
+                  flow: "ingress",
+                  rules: [
+                    { key_expr: "test/downsamples_by_keyexp/r50", freq: 20, }
                   ],
                 },
               ]