Make topics const initializable (#28)

* Make topics const initializable

* Fix test

* Derive Eq, PartialEq for topics

Cargo.lock

@@ -1094,7 +1094,6 @@ version = "0.1.0"
 dependencies = [
  "chrono",
  "crossterm",
- "once_cell",
  "prost",
  "tui",
  "unicode-width",

examples/toy-chat/Cargo.toml

@@ -13,5 +13,4 @@ tui = "0.19"
 crossterm = "0.25"
 unicode-width = "0.1"
 prost = "0.11"
-once_cell = "1.15"
 chrono = "0.4"

examples/toy-chat/src/protocol.rs

@@ -1,14 +1,9 @@
 use chrono::{DateTime, LocalResult, TimeZone, Utc};
-use once_cell::sync::Lazy;
 use prost::Message;
 use waku_bindings::{Encoding, WakuContentTopic};
 
-pub static TOY_CHAT_CONTENT_TOPIC: Lazy<WakuContentTopic> = Lazy::new(|| WakuContentTopic {
-    application_name: "toy-chat".into(),
-    version: 2,
-    content_topic_name: "huilong".into(),
-    encoding: Encoding::Proto,
-});
+pub static TOY_CHAT_CONTENT_TOPIC: WakuContentTopic =
+    WakuContentTopic::new("toy-chat", 2, "huilong", Encoding::Proto);
 
 #[derive(Clone, Message)]
 pub struct Chat2Message {

waku-bindings/src/general/mod.rs

@@ -1,5 +1,6 @@
 //! Waku [general](https://rfc.vac.dev/spec/36/#general) types
 
+use std::borrow::Cow;
 // std
 use std::fmt::{Display, Formatter};
 use std::str::FromStr;
@@ -285,7 +286,7 @@ pub struct MessageIndex {
 }
 
 /// WakuMessage encoding scheme
-#[derive(Copy, Clone, Debug)]
+#[derive(Copy, Clone, Debug, Eq, PartialEq)]
 pub enum Encoding {
     Proto,
     Rlp,
@@ -321,14 +322,30 @@ impl RegexRepresentation for Encoding {
 }
 
 /// A waku content topic `/{application_name}/{version}/{content_topic_name}/{encdoing}`
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, Eq, PartialEq)]
 pub struct WakuContentTopic {
-    pub application_name: String,
+    pub application_name: Cow<'static, str>,
     pub version: usize,
-    pub content_topic_name: String,
+    pub content_topic_name: Cow<'static, str>,
     pub encoding: Encoding,
 }
 
+impl WakuContentTopic {
+    pub const fn new(
+        application_name: &'static str,
+        version: usize,
+        content_topic_name: &'static str,
+        encoding: Encoding,
+    ) -> Self {
+        Self {
+            application_name: Cow::Borrowed(application_name),
+            version,
+            content_topic_name: Cow::Borrowed(content_topic_name),
+            encoding,
+        }
+    }
+}
+
 impl FromStr for WakuContentTopic {
     type Err = String;
 
@@ -337,9 +354,9 @@ impl FromStr for WakuContentTopic {
             scanf!(s, "/{}/{}/{}/{:/.+?/}", String, usize, String, Encoding)
         {
             Ok(WakuContentTopic {
-                application_name,
+                application_name: Cow::Owned(application_name),
                 version,
-                content_topic_name,
+                content_topic_name: Cow::Owned(content_topic_name),
                 encoding,
             })
         } else {
@@ -385,16 +402,23 @@ impl<'de> Deserialize<'de> for WakuContentTopic {
 }
 
 /// A waku pubsub topic in the form of `/waku/v2/{topic_name}/{encoding}`
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, Eq, PartialEq)]
 pub struct WakuPubSubTopic {
-    pub topic_name: String,
+    pub topic_name: Cow<'static, str>,
     pub encoding: Encoding,
 }
 
 impl WakuPubSubTopic {
-    pub fn new(topic_name: String, encoding: Encoding) -> Self {
+    pub const fn new(topic_name: &'static str, encoding: Encoding) -> Self {
         Self {
-            topic_name,
+            topic_name: Cow::Borrowed(topic_name),
+            encoding,
+        }
+    }
+
+    pub fn with_topic_name(topic_name: String, encoding: Encoding) -> Self {
+        Self {
+            topic_name: Cow::Owned(topic_name),
             encoding,
         }
     }
@@ -406,7 +430,7 @@ impl FromStr for WakuPubSubTopic {
     fn from_str(s: &str) -> std::result::Result<Self, Self::Err> {
         if let Ok((topic_name, encoding)) = scanf!(s, "/waku/2/{}/{:/.+?/}", String, Encoding) {
             Ok(WakuPubSubTopic {
-                topic_name,
+                topic_name: Cow::Owned(topic_name),
                 encoding,
             })
         } else {

waku-bindings/tests/node.rs

@@ -83,12 +83,7 @@ pub fn main() -> Result<(), String> {
 
     // subscribe to default channel
     node.relay_subscribe(None)?;
-    let content_topic = WakuContentTopic {
-        application_name: "toychat".to_string(),
-        version: 2,
-        content_topic_name: "huilong".to_string(),
-        encoding: Encoding::Proto,
-    };
+    let content_topic = WakuContentTopic::new("toychat", 2, "huilong", Encoding::Proto);
 
     let message = WakuMessage::new(
         content,