1 files changed, 123 insertions, 0 deletions
diff --git a/karyons_p2p/src/routing_table/bucket.rs b/karyons_p2p/src/routing_table/bucket.rs
new file mode 100644
index 0000000..13edd24
--- /dev/null
+++ b/karyons_p2p/src/routing_table/bucket.rs
@@ -0,0 +1,123 @@
+use super::{Entry, Key};
+
+use rand::{rngs::OsRng, seq::SliceRandom};
+
+/// BITFLAGS represent the status of an Entry within a bucket.
+pub type EntryStatusFlag = u16;
+
+/// The entry is connected.
+pub const CONNECTED_ENTRY: EntryStatusFlag = 0b00001;
+
+/// The entry is disconnected. This will increase the failure counter.
+pub const DISCONNECTED_ENTRY: EntryStatusFlag = 0b00010;
+
+/// The entry is ready to reconnect, meaning it has either been added and
+/// has no connection attempts, or it has been refreshed.
+pub const PENDING_ENTRY: EntryStatusFlag = 0b00100;
+
+/// The entry is unreachable. This will increase the failure counter.
+pub const UNREACHABLE_ENTRY: EntryStatusFlag = 0b01000;
+
+/// The entry is unstable. This will increase the failure counter.
+pub const UNSTABLE_ENTRY: EntryStatusFlag = 0b10000;
+
+#[allow(dead_code)]
+pub const ALL_ENTRY: EntryStatusFlag = 0b11111;
+
+/// A BucketEntry represents a peer in the routing table.
+#[derive(Clone, Debug)]
+pub struct BucketEntry {
+    pub status: EntryStatusFlag,
+    pub entry: Entry,
+    pub failures: u32,
+    pub last_seen: i64,
+}
+
+impl BucketEntry {
+    pub fn is_connected(&self) -> bool {
+        self.status ^ CONNECTED_ENTRY == 0
+    }
+
+    pub fn is_unreachable(&self) -> bool {
+        self.status ^ UNREACHABLE_ENTRY == 0
+    }
+
+    pub fn is_unstable(&self) -> bool {
+        self.status ^ UNSTABLE_ENTRY == 0
+    }
+}
+
+/// The number of entries that can be stored within a single bucket.
+pub const BUCKET_SIZE: usize = 20;
+
+/// A Bucket represents a group of entries in the routing table.
+#[derive(Debug, Clone)]
+pub struct Bucket {
+    entries: Vec<BucketEntry>,
+}
+
+impl Bucket {
+    /// Creates a new empty Bucket
+    pub fn new() -> Self {
+        Self {
+            entries: Vec::with_capacity(BUCKET_SIZE),
+        }
+    }
+
+    /// Add an entry to the bucket.
+    pub fn add(&mut self, entry: &Entry) {
+        self.entries.push(BucketEntry {
+            status: PENDING_ENTRY,
+            entry: entry.clone(),
+            failures: 0,
+            last_seen: chrono::Utc::now().timestamp(),
+        })
+    }
+
+    /// Get the number of entries in the bucket.
+    pub fn len(&self) -> usize {
+        self.entries.len()
+    }
+
+    /// Returns an iterator over the entries in the bucket.
+    pub fn iter(&self) -> impl Iterator<Item = &BucketEntry> {
+        self.entries.iter()
+    }
+
+    /// Remove an entry.
+    pub fn remove(&mut self, key: &Key) {
+        let position = self.entries.iter().position(|e| &e.entry.key == key);
+        if let Some(i) = position {
+            self.entries.remove(i);
+        }
+    }
+
+    /// Returns an iterator of entries in random order.
+    pub fn random_iter(&self, amount: usize) -> impl Iterator<Item = &BucketEntry> {
+        self.entries.choose_multiple(&mut OsRng, amount)
+    }
+
+    /// Updates the status of an entry in the bucket identified by the given key.
+    ///
+    /// If the key is not found in the bucket, no action is taken.
+    ///
+    /// This will also update the last_seen field and increase the failures
+    /// counter for the bucket entry according to the new status.
+    pub fn update_entry(&mut self, key: &Key, entry_flag: EntryStatusFlag) {
+        if let Some(e) = self.entries.iter_mut().find(|e| &e.entry.key == key) {
+            e.status = entry_flag;
+            if e.is_unreachable() || e.is_unstable() {
+                e.failures += 1;
+            }
+
+            if !e.is_unreachable() {
+                e.last_seen = chrono::Utc::now().timestamp();
+            }
+        }
+    }
+
+    /// Check if the bucket contains the given key.
+    pub fn contains_key(&self, key: &Key) -> bool {
+        self.entries.iter().any(|e| &e.entry.key == key)
+    }
+}