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|
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 = 0b000001;
/// The entry is disconnected. This will increase the failure counter.
pub const DISCONNECTED_ENTRY: EntryStatusFlag = 0b000010;
/// 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 = 0b000100;
/// The entry is unreachable. This will increase the failure counter.
pub const UNREACHABLE_ENTRY: EntryStatusFlag = 0b001000;
/// The entry is unstable. This will increase the failure counter.
pub const UNSTABLE_ENTRY: EntryStatusFlag = 0b010000;
/// The entry is incompatible. This entry will not contribute to an increase in
/// failure attempts, instead, it will persist in the routing table for the
/// lookup process and will only be removed in the presence of a new entry.
pub const INCOMPATIBLE_ENTRY: EntryStatusFlag = 0b100000;
#[allow(dead_code)]
pub const ALL_ENTRY: EntryStatusFlag = 0b111111;
/// 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_incompatible(&self) -> bool {
self.status ^ INCOMPATIBLE_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)
}
}
|
