diff options
Diffstat (limited to 'third_party/rust/h2/src/frame/data.rs')
| -rw-r--r-- | third_party/rust/h2/src/frame/data.rs | 227 |
1 files changed, 227 insertions, 0 deletions
diff --git a/third_party/rust/h2/src/frame/data.rs b/third_party/rust/h2/src/frame/data.rs new file mode 100644 index 0000000000..5ed3c31b50 --- /dev/null +++ b/third_party/rust/h2/src/frame/data.rs @@ -0,0 +1,227 @@ +use crate::frame::{util, Error, Frame, Head, Kind, StreamId}; +use bytes::{Buf, BufMut, Bytes}; + +use std::fmt; + +/// Data frame +/// +/// Data frames convey arbitrary, variable-length sequences of octets associated +/// with a stream. One or more DATA frames are used, for instance, to carry HTTP +/// request or response payloads. +#[derive(Eq, PartialEq)] +pub struct Data<T = Bytes> { + stream_id: StreamId, + data: T, + flags: DataFlags, + pad_len: Option<u8>, +} + +#[derive(Copy, Clone, Default, Eq, PartialEq)] +struct DataFlags(u8); + +const END_STREAM: u8 = 0x1; +const PADDED: u8 = 0x8; +const ALL: u8 = END_STREAM | PADDED; + +impl<T> Data<T> { + /// Creates a new DATA frame. + pub fn new(stream_id: StreamId, payload: T) -> Self { + assert!(!stream_id.is_zero()); + + Data { + stream_id, + data: payload, + flags: DataFlags::default(), + pad_len: None, + } + } + + /// Returns the stream identifier that this frame is associated with. + /// + /// This cannot be a zero stream identifier. + pub fn stream_id(&self) -> StreamId { + self.stream_id + } + + /// Gets the value of the `END_STREAM` flag for this frame. + /// + /// If true, this frame is the last that the endpoint will send for the + /// identified stream. + /// + /// Setting this flag causes the stream to enter one of the "half-closed" + /// states or the "closed" state (Section 5.1). + pub fn is_end_stream(&self) -> bool { + self.flags.is_end_stream() + } + + /// Sets the value for the `END_STREAM` flag on this frame. + pub fn set_end_stream(&mut self, val: bool) { + if val { + self.flags.set_end_stream(); + } else { + self.flags.unset_end_stream(); + } + } + + /// Returns whether the `PADDED` flag is set on this frame. + #[cfg(feature = "unstable")] + pub fn is_padded(&self) -> bool { + self.flags.is_padded() + } + + /// Sets the value for the `PADDED` flag on this frame. + #[cfg(feature = "unstable")] + pub fn set_padded(&mut self) { + self.flags.set_padded(); + } + + /// Returns a reference to this frame's payload. + /// + /// This does **not** include any padding that might have been originally + /// included. + pub fn payload(&self) -> &T { + &self.data + } + + /// Returns a mutable reference to this frame's payload. + /// + /// This does **not** include any padding that might have been originally + /// included. + pub fn payload_mut(&mut self) -> &mut T { + &mut self.data + } + + /// Consumes `self` and returns the frame's payload. + /// + /// This does **not** include any padding that might have been originally + /// included. + pub fn into_payload(self) -> T { + self.data + } + + pub(crate) fn head(&self) -> Head { + Head::new(Kind::Data, self.flags.into(), self.stream_id) + } + + pub(crate) fn map<F, U>(self, f: F) -> Data<U> + where + F: FnOnce(T) -> U, + { + Data { + stream_id: self.stream_id, + data: f(self.data), + flags: self.flags, + pad_len: self.pad_len, + } + } +} + +impl Data<Bytes> { + pub(crate) fn load(head: Head, mut payload: Bytes) -> Result<Self, Error> { + let flags = DataFlags::load(head.flag()); + + // The stream identifier must not be zero + if head.stream_id().is_zero() { + return Err(Error::InvalidStreamId); + } + + let pad_len = if flags.is_padded() { + let len = util::strip_padding(&mut payload)?; + Some(len) + } else { + None + }; + + Ok(Data { + stream_id: head.stream_id(), + data: payload, + flags, + pad_len, + }) + } +} + +impl<T: Buf> Data<T> { + /// Encode the data frame into the `dst` buffer. + /// + /// # Panics + /// + /// Panics if `dst` cannot contain the data frame. + pub(crate) fn encode_chunk<U: BufMut>(&mut self, dst: &mut U) { + let len = self.data.remaining(); + + assert!(dst.remaining_mut() >= len); + + self.head().encode(len, dst); + dst.put(&mut self.data); + } +} + +impl<T> From<Data<T>> for Frame<T> { + fn from(src: Data<T>) -> Self { + Frame::Data(src) + } +} + +impl<T> fmt::Debug for Data<T> { + fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result { + let mut f = fmt.debug_struct("Data"); + f.field("stream_id", &self.stream_id); + if !self.flags.is_empty() { + f.field("flags", &self.flags); + } + if let Some(ref pad_len) = self.pad_len { + f.field("pad_len", pad_len); + } + // `data` bytes purposefully excluded + f.finish() + } +} + +// ===== impl DataFlags ===== + +impl DataFlags { + fn load(bits: u8) -> DataFlags { + DataFlags(bits & ALL) + } + + fn is_empty(&self) -> bool { + self.0 == 0 + } + + fn is_end_stream(&self) -> bool { + self.0 & END_STREAM == END_STREAM + } + + fn set_end_stream(&mut self) { + self.0 |= END_STREAM + } + + fn unset_end_stream(&mut self) { + self.0 &= !END_STREAM + } + + fn is_padded(&self) -> bool { + self.0 & PADDED == PADDED + } + + #[cfg(feature = "unstable")] + fn set_padded(&mut self) { + self.0 |= PADDED + } +} + +impl From<DataFlags> for u8 { + fn from(src: DataFlags) -> u8 { + src.0 + } +} + +impl fmt::Debug for DataFlags { + fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result { + util::debug_flags(fmt, self.0) + .flag_if(self.is_end_stream(), "END_STREAM") + .flag_if(self.is_padded(), "PADDED") + .finish() + } +} |