Add (de-)serializable NoteId type

Cargo.lock

@@ -26,7 +26,7 @@ dependencies = [
  "cfg-if",
  "once_cell",
  "version_check",
- "zerocopy",
+ "zerocopy 0.7.35",
 ]
 
 [[package]]
@@ -1459,6 +1459,7 @@ dependencies = [
 name = "gdn-app"
 version = "0.0.0"
 dependencies = [
+ "rand 0.9.0",
  "serde",
  "serde_json",
  "tauri",
@@ -3993,7 +3994,7 @@ version = "0.2.20"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "77957b295656769bb8ad2b6a6b09d897d94f05c41b069aede1fcdaa675eaea04"
 dependencies = [
- "zerocopy",
+ "zerocopy 0.7.35",
 ]
 
 [[package]]
@@ -4176,6 +4177,17 @@ dependencies = [
  "rand_core 0.6.4",
 ]
 
+[[package]]
+name = "rand"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3779b94aeb87e8bd4e834cee3650289ee9e0d5677f976ecdb6d219e5f4f6cd94"
+dependencies = [
+ "rand_chacha 0.9.0",
+ "rand_core 0.9.0",
+ "zerocopy 0.8.17",
+]
+
 [[package]]
 name = "rand_chacha"
 version = "0.2.2"
@@ -4196,6 +4208,16 @@ dependencies = [
  "rand_core 0.6.4",
 ]
 
+[[package]]
+name = "rand_chacha"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d3022b5f1df60f26e1ffddd6c66e8aa15de382ae63b3a0c1bfc0e4d3e3f325cb"
+dependencies = [
+ "ppv-lite86",
+ "rand_core 0.9.0",
+]
+
 [[package]]
 name = "rand_core"
 version = "0.5.1"
@@ -4214,6 +4236,16 @@ dependencies = [
  "getrandom 0.2.15",
 ]
 
+[[package]]
+name = "rand_core"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b08f3c9802962f7e1b25113931d94f43ed9725bebc59db9d0c3e9a23b67e15ff"
+dependencies = [
+ "getrandom 0.3.1",
+ "zerocopy 0.8.17",
+]
+
 [[package]]
 name = "rand_hc"
 version = "0.2.0"
@@ -6616,7 +6648,16 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1b9b4fd18abc82b8136838da5d50bae7bdea537c574d8dc1a34ed098d6c166f0"
 dependencies = [
  "byteorder",
- "zerocopy-derive",
+ "zerocopy-derive 0.7.35",
+]
+
+[[package]]
+name = "zerocopy"
+version = "0.8.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "aa91407dacce3a68c56de03abe2760159582b846c6a4acd2f456618087f12713"
+dependencies = [
+ "zerocopy-derive 0.8.17",
 ]
 
 [[package]]
@@ -6630,6 +6671,17 @@ dependencies = [
  "syn 2.0.98",
 ]
 
+[[package]]
+name = "zerocopy-derive"
+version = "0.8.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "06718a168365cad3d5ff0bb133aad346959a2074bd4a85c121255a11304a8626"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.98",
+]
+
 [[package]]
 name = "zerofrom"
 version = "0.1.5"

Cargo.toml

@@ -12,6 +12,7 @@ clap = { version = "4.5.28", features = ["derive", "deprecated"] }
 directories = "6.0.0"
 gdn = { path = "gdn" }
 gix = "0.70.0"
+rand = "0.9.0"
 serde = { version = "1.0.217", features = ["derive"] }
 serde_json = "1.0.138"
 tauri = { version = "2.2.5", features = [] }

gdn-app/src-tauri/Cargo.toml

@@ -14,6 +14,7 @@ crate-type = ["staticlib", "cdylib", "rlib"]
 tauri-build = { workspace = true }
 
 [dependencies]
+rand = { workspace = true }
 serde = { workspace = true }
 serde_json = { workspace = true }
 tauri = { workspace = true }

gdn-app/src-tauri/src/ids.rs

@@ -0,0 +1,99 @@
+use std::{fmt, ops::Shl, str::FromStr, time::SystemTime};
+
+use serde::{Deserialize, Deserializer, Serialize, Serializer};
+
+/// A timestamp- and randomness-based id.
+///
+/// The id consists of 8 bytes. The first 5 bytes are an epoch timestamp in
+/// seconds, while the remaining 3 bytes are a random number, meant to avoid
+/// collisions when two ids are created at the same time on different devices.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
+struct TimestampId(u64);
+
+impl TimestampId {
+    fn new() -> Self {
+        let secs = SystemTime::now()
+            .duration_since(SystemTime::UNIX_EPOCH)
+            .expect("duration is positive")
+            .as_secs();
+
+        let random = rand::random::<u64>();
+
+        // Zeroing the last three bytes just in case. They should already be
+        // zero under normal circumstances.
+        let first_part = secs.shl(3 * 8) & 0xFFFFFFFF_FF000000_u64;
+        let second_part = random & 0x00000000_00FFFFFF_u64;
+
+        Self(first_part | second_part)
+    }
+}
+
+impl fmt::Display for TimestampId {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{:016X}", self.0)
+    }
+}
+
+impl FromStr for TimestampId {
+    type Err = ();
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        if s.len() != 16 {
+            return Err(());
+        }
+
+        if s.chars().any(|c| c.is_lowercase()) {
+            return Err(());
+        }
+
+        let n = u64::from_str_radix(s, 16).map_err(|_| ())?;
+
+        Ok(Self(n))
+    }
+}
+
+/// The id for a single note.
+#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub struct NoteId(TimestampId);
+
+impl NoteId {
+    #[allow(clippy::new_without_default)] // Because side-effects
+    pub fn new() -> Self {
+        Self(TimestampId::new())
+    }
+}
+
+impl fmt::Debug for NoteId {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "NoteId({self})")
+    }
+}
+
+impl fmt::Display for NoteId {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "n{}", self.0)
+    }
+}
+
+impl FromStr for NoteId {
+    type Err = ();
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        let s = s.strip_prefix("n").ok_or(())?;
+        Ok(Self(s.parse()?))
+    }
+}
+
+impl Serialize for NoteId {
+    fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
+        format!("{self}").serialize(serializer)
+    }
+}
+
+impl<'de> Deserialize<'de> for NoteId {
+    fn deserialize<D: Deserializer<'de>>(deserializer: D) -> Result<Self, D::Error> {
+        <&'de str as Deserialize<'de>>::deserialize(deserializer)?
+            .parse()
+            .map_err(|()| serde::de::Error::custom("invalid note id"))
+    }
+}

gdn-app/src-tauri/src/lib.rs

@@ -1,3 +1,5 @@
+mod ids;
+
 // Learn more about Tauri commands at https://tauri.app/develop/calling-rust/
 #[tauri::command]
 fn greet(name: &str) -> String {

gdn-app/src-tauri/src/main.rs

@@ -1,5 +1,7 @@
 // Prevents additional console window on Windows in release, DO NOT REMOVE!!
 #![cfg_attr(not(debug_assertions), windows_subsystem = "windows")]
+// This warning does not apply here - the lib uses the dependencies.
+#![allow(unused_crate_dependencies)]
 
 fn main() {
     gdn_app_lib::run()