Merge pull request #301 from http-rs/transfer

Add `Transfer-Encoding` and `TE` headers

Author: yoshuawuyts

src/lib.rs

@@ -127,6 +127,9 @@ pub mod mime;
 pub mod other;
 pub mod proxies;
 pub mod server;
+pub mod trace;
+pub mod transfer;
+pub mod upgrade;
 
 mod body;
 mod error;
@@ -140,9 +143,6 @@ mod status;
 mod status_code;
 mod version;
 
-pub mod trace;
-pub mod upgrade;
-
 pub use body::Body;
 pub use error::{Error, Result};
 pub use method::Method;

src/transfer/encoding.rs

@@ -0,0 +1,64 @@
+use crate::headers::HeaderValue;
+use std::fmt::{self, Display};
+
+/// Available compression algorithms.
+///
+/// [MDN Documentation](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Transfer-Encoding#Directives)
+#[non_exhaustive]
+#[derive(Debug, Clone, Copy, Eq, PartialEq)]
+pub enum Encoding {
+    /// Send a series of chunks.
+    Chunked,
+    /// The Gzip encoding.
+    Gzip,
+    /// The Deflate encoding.
+    Deflate,
+    /// The Brotli encoding.
+    Brotli,
+    /// The Zstd encoding.
+    Zstd,
+    /// No encoding.
+    Identity,
+}
+
+impl Encoding {
+    /// Parses a given string into its corresponding encoding.
+    pub(crate) fn from_str(s: &str) -> Option<Encoding> {
+        let s = s.trim();
+
+        // We're dealing with an empty string.
+        if s.is_empty() {
+            return None;
+        }
+
+        match s {
+            "chunked" => Some(Encoding::Chunked),
+            "gzip" => Some(Encoding::Gzip),
+            "deflate" => Some(Encoding::Deflate),
+            "br" => Some(Encoding::Brotli),
+            "zstd" => Some(Encoding::Zstd),
+            "identity" => Some(Encoding::Identity),
+            _ => None,
+        }
+    }
+}
+
+impl Display for Encoding {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Encoding::Gzip => write!(f, "gzip"),
+            Encoding::Deflate => write!(f, "deflate"),
+            Encoding::Brotli => write!(f, "br"),
+            Encoding::Zstd => write!(f, "zstd"),
+            Encoding::Identity => write!(f, "identity"),
+            Encoding::Chunked => write!(f, "chunked"),
+        }
+    }
+}
+
+impl From<Encoding> for HeaderValue {
+    fn from(directive: Encoding) -> Self {
+        let s = directive.to_string();
+        unsafe { HeaderValue::from_bytes_unchecked(s.into_bytes()) }
+    }
+}

src/transfer/encoding_proposal.rs

@@ -0,0 +1,147 @@
+use crate::ensure;
+use crate::headers::HeaderValue;
+use crate::transfer::Encoding;
+use crate::utils::parse_weight;
+
+use std::cmp::{Ordering, PartialEq};
+use std::ops::{Deref, DerefMut};
+
+/// A proposed `Encoding` in `AcceptEncoding`.
+///
+/// [MDN Documentation](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/TE#Directives)
+#[derive(Debug, Clone, Copy, PartialEq)]
+pub struct EncodingProposal {
+    /// The proposed encoding.
+    pub(crate) encoding: Encoding,
+
+    /// The weight of the proposal.
+    ///
+    /// This is a number between 0.0 and 1.0, and is max 3 decimal points.
+    weight: Option<f32>,
+}
+
+impl EncodingProposal {
+    /// Create a new instance of `EncodingProposal`.
+    pub fn new(encoding: impl Into<Encoding>, weight: Option<f32>) -> crate::Result<Self> {
+        if let Some(weight) = weight {
+            ensure!(
+                weight.is_sign_positive() && weight <= 1.0,
+                "EncodingProposal should have a weight between 0.0 and 1.0"
+            )
+        }
+
+        Ok(Self {
+            encoding: encoding.into(),
+            weight,
+        })
+    }
+
+    /// Get the proposed encoding.
+    pub fn encoding(&self) -> &Encoding {
+        &self.encoding
+    }
+
+    /// Get the weight of the proposal.
+    pub fn weight(&self) -> Option<f32> {
+        self.weight
+    }
+
+    pub(crate) fn from_str(s: &str) -> crate::Result<Option<Self>> {
+        let mut parts = s.split(';');
+        let encoding = match Encoding::from_str(parts.next().unwrap()) {
+            Some(encoding) => encoding,
+            None => return Ok(None),
+        };
+        let weight = parts.next().map(parse_weight).transpose()?;
+
+        Ok(Some(Self::new(encoding, weight)?))
+    }
+}
+
+impl From<Encoding> for EncodingProposal {
+    fn from(encoding: Encoding) -> Self {
+        Self {
+            encoding,
+            weight: None,
+        }
+    }
+}
+
+impl PartialEq<Encoding> for EncodingProposal {
+    fn eq(&self, other: &Encoding) -> bool {
+        self.encoding == *other
+    }
+}
+
+impl PartialEq<Encoding> for &EncodingProposal {
+    fn eq(&self, other: &Encoding) -> bool {
+        self.encoding == *other
+    }
+}
+
+impl Deref for EncodingProposal {
+    type Target = Encoding;
+    fn deref(&self) -> &Self::Target {
+        &self.encoding
+    }
+}
+
+impl DerefMut for EncodingProposal {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.encoding
+    }
+}
+
+// NOTE: Firefox populates Accept-Encoding as `gzip, deflate, br`. This means
+// when parsing encodings we should choose the last value in the list under
+// equal weights. This impl doesn't know which value was passed later, so that
+// behavior needs to be handled separately.
+//
+// NOTE: This comparison does not include a notion of `*` (any value is valid).
+// that needs to be handled separately.
+impl PartialOrd for EncodingProposal {
+    fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
+        match (self.weight, other.weight) {
+            (Some(left), Some(right)) => left.partial_cmp(&right),
+            (Some(_), None) => Some(Ordering::Greater),
+            (None, Some(_)) => Some(Ordering::Less),
+            (None, None) => None,
+        }
+    }
+}
+
+impl From<EncodingProposal> for HeaderValue {
+    fn from(entry: EncodingProposal) -> HeaderValue {
+        let s = match entry.weight {
+            Some(weight) => format!("{};q={:.3}", entry.encoding, weight),
+            None => entry.encoding.to_string(),
+        };
+        unsafe { HeaderValue::from_bytes_unchecked(s.into_bytes()) }
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn smoke() -> crate::Result<()> {
+        let _ = EncodingProposal::new(Encoding::Gzip, Some(0.0)).unwrap();
+        let _ = EncodingProposal::new(Encoding::Gzip, Some(0.5)).unwrap();
+        let _ = EncodingProposal::new(Encoding::Gzip, Some(1.0)).unwrap();
+        Ok(())
+    }
+
+    #[test]
+    fn error_code_500() -> crate::Result<()> {
+        let err = EncodingProposal::new(Encoding::Gzip, Some(1.1)).unwrap_err();
+        assert_eq!(err.status(), 500);
+
+        let err = EncodingProposal::new(Encoding::Gzip, Some(-0.1)).unwrap_err();
+        assert_eq!(err.status(), 500);
+
+        let err = EncodingProposal::new(Encoding::Gzip, Some(-0.0)).unwrap_err();
+        assert_eq!(err.status(), 500);
+        Ok(())
+    }
+}

src/transfer/mod.rs

@@ -0,0 +1,13 @@
+//! HTTP transfer headers.
+//!
+//! [MDN Documentation](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers#Transfer_coding)
+
+mod encoding;
+mod encoding_proposal;
+mod te;
+mod transfer_encoding;
+
+pub use encoding::Encoding;
+pub use encoding_proposal::EncodingProposal;
+pub use te::TE;
+pub use transfer_encoding::TransferEncoding;