diff options
Diffstat (limited to 'third_party/rust/neqo-http3/src/priority.rs')
| -rw-r--r-- | third_party/rust/neqo-http3/src/priority.rs | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/third_party/rust/neqo-http3/src/priority.rs b/third_party/rust/neqo-http3/src/priority.rs new file mode 100644 index 0000000000..87bb8ee2b4 --- /dev/null +++ b/third_party/rust/neqo-http3/src/priority.rs @@ -0,0 +1,205 @@ +use crate::{frames::HFrame, Error, Header, Res}; +use neqo_transport::StreamId; +use sfv::{BareItem, Item, ListEntry, Parser}; +use std::convert::TryFrom; +use std::fmt; + +#[derive(Debug, Copy, Clone, PartialEq, Eq)] +pub struct Priority { + urgency: u8, + incremental: bool, +} + +impl Default for Priority { + fn default() -> Self { + Priority { + urgency: 3, + incremental: false, + } + } +} + +impl Priority { + /// # Panics + /// If an invalid urgency (>7 is given) + #[must_use] + pub fn new(urgency: u8, incremental: bool) -> Priority { + assert!(urgency < 8); + Priority { + urgency, + incremental, + } + } + + /// Returns a header if required to send + #[must_use] + pub fn header(self) -> Option<Header> { + match self { + Priority { + urgency: 3, + incremental: false, + } => None, + other => Some(Header::new("priority", format!("{}", other))), + } + } + + /// Constructs a priority from raw bytes (either a field value of frame content). + /// # Errors + /// When the contained syntax is invalid. + /// # Panics + /// Never, but the compiler is not smart enough to work that out. + pub fn from_bytes(bytes: &[u8]) -> Res<Priority> { + let dict = Parser::parse_dictionary(bytes).map_err(|_| Error::HttpFrame)?; + let urgency = match dict.get("u") { + Some(ListEntry::Item(Item { + bare_item: BareItem::Integer(u), + .. + })) if (0..=7).contains(u) => u8::try_from(*u).unwrap(), + _ => 3, + }; + let incremental = match dict.get("i") { + Some(ListEntry::Item(Item { + bare_item: BareItem::Boolean(i), + .. + })) => *i, + _ => false, + }; + Ok(Priority { + urgency, + incremental, + }) + } +} + +impl fmt::Display for Priority { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + match self { + Priority { + urgency: 3, + incremental: false, + } => Ok(()), + Priority { + urgency: 3, + incremental: true, + } => write!(f, "i"), + Priority { + urgency, + incremental: false, + } => write!(f, "u={}", urgency), + Priority { + urgency, + incremental: true, + } => write!(f, "u={},i", urgency), + } + } +} + +#[derive(Debug)] +#[allow(clippy::module_name_repetitions)] +pub struct PriorityHandler { + push_stream: bool, + priority: Priority, + last_send_priority: Priority, +} + +impl PriorityHandler { + pub fn new(push_stream: bool, priority: Priority) -> PriorityHandler { + PriorityHandler { + push_stream, + priority, + last_send_priority: priority, + } + } + + /*pub fn priority(&self) -> Priority { + self.priority + }*/ + + /// Returns if an priority update will be issued + pub fn maybe_update_priority(&mut self, priority: Priority) -> bool { + if priority == self.priority { + false + } else { + self.priority = priority; + true + } + } + + pub fn priority_update_sent(&mut self) { + self.last_send_priority = self.priority; + } + + /// Returns `HFrame` if an priority update is outstanding + pub fn maybe_encode_frame(&self, stream_id: StreamId) -> Option<HFrame> { + if self.priority == self.last_send_priority { + None + } else if self.push_stream { + Some(HFrame::PriorityUpdatePush { + element_id: stream_id.as_u64(), + priority: self.priority, + }) + } else { + Some(HFrame::PriorityUpdateRequest { + element_id: stream_id.as_u64(), + priority: self.priority, + }) + } + } +} + +#[cfg(test)] +mod test { + use crate::priority::PriorityHandler; + use crate::{HFrame, Priority}; + use neqo_transport::StreamId; + + #[test] + fn priority_updates_ignore_same() { + let mut p = PriorityHandler::new(false, Priority::new(5, false)); + assert!(!p.maybe_update_priority(Priority::new(5, false))); + // updating with the same priority -> there should not be any priority frame sent + assert!(p.maybe_encode_frame(StreamId::new(4)).is_none()); + } + + #[test] + fn priority_updates_send_update() { + let mut p = PriorityHandler::new(false, Priority::new(5, false)); + assert!(p.maybe_update_priority(Priority::new(6, false))); + // updating with the a different priority -> there should be a priority frame sent + assert!(p.maybe_encode_frame(StreamId::new(4)).is_some()); + } + + #[test] + fn multiple_priority_updates_ignore_same() { + let mut p = PriorityHandler::new(false, Priority::new(5, false)); + assert!(p.maybe_update_priority(Priority::new(6, false))); + assert!(p.maybe_update_priority(Priority::new(5, false))); + // initial and last priority same -> there should not be any priority frame sent + assert!(p.maybe_encode_frame(StreamId::new(4)).is_none()); + } + + #[test] + fn multiple_priority_updates_send_update() { + let mut p = PriorityHandler::new(false, Priority::new(5, false)); + assert!(p.maybe_update_priority(Priority::new(6, false))); + assert!(p.maybe_update_priority(Priority::new(7, false))); + // updating two times with a different priority -> the last priority update should be in the next frame + let expected = HFrame::PriorityUpdateRequest { + element_id: 4, + priority: Priority::new(7, false), + }; + assert_eq!(p.maybe_encode_frame(StreamId::new(4)), Some(expected)); + } + + #[test] + fn priority_updates_incremental() { + let mut p = PriorityHandler::new(false, Priority::new(5, false)); + assert!(p.maybe_update_priority(Priority::new(5, true))); + // updating the incremental parameter -> there should be a priority frame sent + let expected = HFrame::PriorityUpdateRequest { + element_id: 4, + priority: Priority::new(5, true), + }; + assert_eq!(p.maybe_encode_frame(StreamId::new(4)), Some(expected)); + } +} |