feat(iroh-net): Add StaticDiscovery to provide static info to endpoints (#2825)

## Description

Add StaticProvider to provide static info to endpoints.

The long term plan is to reduce ways to interact directly with the
endpoint node map and instead provide this.

## Breaking Changes

None, this just adds stuff. Long term we want to remove
endpoint.add_node_info with this.

## Notes & open questions

<!-- Any notes, remarks or open questions you have to make about the PR.
-->

## Change checklist

- [ ] Self-review.
- [ ] Documentation updates following the [style
guide](https://rust-lang.github.io/rfcs/1574-more-api-documentation-conventions.html#appendix-a-full-conventions-text),
if relevant.
- [ ] Tests if relevant.
- [ ] All breaking changes documented.

Author: rklaehn

iroh-net/src/discovery.rs

@@ -114,6 +114,7 @@ pub mod dns;
 #[cfg_attr(iroh_docsrs, doc(cfg(feature = "discovery-local-network")))]
 pub mod local_swarm_discovery;
 pub mod pkarr;
+pub mod static_provider;
 
 /// Node discovery for [`super::Endpoint`].
 ///

iroh-net/src/discovery/static_provider.rs

@@ -0,0 +1,162 @@
+//! A static discovery implementation that allows adding info for nodes manually.
+use std::{
+    collections::{btree_map::Entry, BTreeMap},
+    sync::{Arc, RwLock},
+    time::SystemTime,
+};
+
+use futures_lite::stream::{self, StreamExt};
+use iroh_base::{
+    key::NodeId,
+    node_addr::{AddrInfo, NodeAddr},
+};
+
+use super::{Discovery, DiscoveryItem};
+
+/// A static discovery implementation that allows providing info for nodes manually.
+#[derive(Debug, Default)]
+#[repr(transparent)]
+pub struct StaticProvider {
+    nodes: Arc<RwLock<BTreeMap<NodeId, NodeInfo>>>,
+}
+
+#[derive(Debug)]
+struct NodeInfo {
+    info: AddrInfo,
+    last_updated: SystemTime,
+}
+
+impl StaticProvider {
+    /// The provenance string for this discovery implementation.
+    pub const PROVENANCE: &'static str = "static_discovery";
+
+    /// Create a new static discovery instance.
+    pub fn new() -> Self {
+        Self::default()
+    }
+
+    /// Creates a static discovery instance from something that can be converted into node addresses.
+    ///
+    /// Example:
+    /// ```rust
+    /// use std::str::FromStr;
+    ///
+    /// use iroh_base::ticket::NodeTicket;
+    /// use iroh_net::{Endpoint, discovery::static_provider::StaticProvider};
+    ///
+    /// # async fn example() -> anyhow::Result<()> {
+    /// # #[derive(Default)] struct Args { tickets: Vec<NodeTicket> }
+    /// # let args = Args::default();
+    /// // get tickets from command line args
+    /// let tickets: Vec<NodeTicket> = args.tickets;
+    /// // create a StaticProvider from the tickets. Ticket info will be combined if multiple tickets refer to the same node.
+    /// let discovery = StaticProvider::from_node_addrs(tickets);
+    /// // create an endpoint with the discovery
+    /// let endpoint = Endpoint::builder()
+    ///     .add_discovery(|_| Some(discovery))
+    ///     .bind().await?;
+    /// # Ok(())
+    /// # }
+    /// ```
+    pub fn from_node_addrs(infos: impl IntoIterator<Item = impl Into<NodeAddr>>) -> Self {
+        let res = Self::default();
+        for info in infos {
+            res.add_node_addr(info);
+        }
+        res
+    }
+
+    /// Add node info for the given node id.
+    ///
+    /// This will completely overwrite any existing info for the node.
+    pub fn set_node_addr(&self, info: impl Into<NodeAddr>) -> Option<NodeAddr> {
+        let last_updated = SystemTime::now();
+        let info: NodeAddr = info.into();
+        let mut guard = self.nodes.write().unwrap();
+        let previous = guard.insert(
+            info.node_id,
+            NodeInfo {
+                info: info.info,
+                last_updated,
+            },
+        );
+        previous.map(|x| NodeAddr {
+            node_id: info.node_id,
+            info: x.info,
+        })
+    }
+
+    /// Add node info for the given node id, combining it with any existing info.
+    ///
+    /// This will add any new direct addresses and overwrite the relay url.
+    pub fn add_node_addr(&self, info: impl Into<NodeAddr>) {
+        let info: NodeAddr = info.into();
+        let last_updated = SystemTime::now();
+        let mut guard = self.nodes.write().unwrap();
+        match guard.entry(info.node_id) {
+            Entry::Occupied(mut entry) => {
+                let existing = entry.get_mut();
+                existing
+                    .info
+                    .direct_addresses
+                    .extend(info.info.direct_addresses);
+                existing.info.relay_url = info.info.relay_url;
+                existing.last_updated = last_updated;
+            }
+            Entry::Vacant(entry) => {
+                entry.insert(NodeInfo {
+                    info: info.info,
+                    last_updated,
+                });
+            }
+        }
+    }
+
+    /// Get node info for the given node id.
+    pub fn get_node_addr(&self, node_id: NodeId) -> Option<NodeAddr> {
+        let guard = self.nodes.read().unwrap();
+        let info = guard.get(&node_id).map(|x| x.info.clone())?;
+        Some(NodeAddr { node_id, info })
+    }
+
+    /// Remove node info for the given node id.
+    pub fn remove_node_addr(&self, node_id: NodeId) -> Option<NodeAddr> {
+        let mut guard = self.nodes.write().unwrap();
+        let res = guard.remove(&node_id)?;
+        Some(NodeAddr {
+            node_id,
+            info: res.info,
+        })
+    }
+}
+
+impl Discovery for StaticProvider {
+    fn publish(&self, _info: &AddrInfo) {}
+
+    fn resolve(
+        &self,
+        _endpoint: crate::Endpoint,
+        node_id: NodeId,
+    ) -> Option<futures_lite::stream::Boxed<anyhow::Result<super::DiscoveryItem>>> {
+        let guard = self.nodes.read().unwrap();
+        let info = guard.get(&node_id);
+        match info {
+            Some(addr_info) => {
+                let item = DiscoveryItem {
+                    node_id,
+                    provenance: Self::PROVENANCE,
+                    last_updated: Some(
+                        addr_info
+                            .last_updated
+                            .duration_since(SystemTime::UNIX_EPOCH)
+                            .expect("time drift")
+                            .as_micros() as u64,
+                    ),
+                    addr_info: addr_info.info.clone(),
+                };
+                Some(stream::iter(Some(Ok(item))).boxed())
+            }
+            None => None,
+        }
+    }
+}