From ece032f0de35f9f209c6dfcc69aaa5cb57d59ddc Mon Sep 17 00:00:00 2001
From: pearzl <pearzl>
Date: Sat, 24 Aug 2024 21:10:52 +0800
Subject: [PATCH] feat: add accept_encoding

---
 src/common/accept_encoding.rs | 61 +++++++++++++++++++++++++++++++++++
 src/common/mod.rs             |  4 +--
 2 files changed, 63 insertions(+), 2 deletions(-)
 create mode 100644 src/common/accept_encoding.rs

diff --git a/src/common/accept_encoding.rs b/src/common/accept_encoding.rs
new file mode 100644
index 00000000..3f3dd2a4
--- /dev/null
+++ b/src/common/accept_encoding.rs
@@ -0,0 +1,61 @@
+use std::iter::FromIterator;
+
+use bytes::BytesMut;
+use http::HeaderValue;
+
+use crate::util::FlatCsv;
+
+/// `Accept-Encoding` header, defined in
+/// [RFC7231](https://datatracker.ietf.org/doc/html/rfc7231#section-5.3.4)
+///
+/// The `Accept-Encoding` header field can be used by user agents to
+/// indicate what response content-codings are
+/// acceptable in the response.  An  `identity` token is used as a synonym
+/// for "no encoding" in order to communicate when no encoding is
+/// preferred.
+///
+/// # ABNF
+///
+/// ```text
+/// Accept-Encoding  = #( codings [ weight ] )
+/// codings          = content-coding / "identity" / "*"
+/// ```
+///
+/// # Example values
+/// * `compress, gzip`
+/// * ``
+/// * `*`
+/// * `compress;q=0.5, gzip;q=1`
+/// * `gzip;q=1.0, identity; q=0.5, *;q=0`
+#[derive(Clone, Debug, PartialEq)]
+pub struct AcceptEncoding(FlatCsv);
+
+derive_header! {
+    AcceptEncoding(_),
+    name: ACCEPT_ENCODING
+}
+
+impl AcceptEncoding {
+    /// Iterator the codings with weight.
+    pub fn iter(&self) -> impl Iterator<Item = &str> {
+        self.0.iter()
+    }
+
+    /// Create from a iterator of given codings with optional weigth.
+    pub fn from_pairs<'a>(pairs: impl Iterator<Item = (&'a str, Option<f32>)>) -> Self {
+        let iter = pairs.into_iter().filter_map(|(coding, q)| {
+            if let Some(q) = q {
+                let mut buf = BytesMut::new();
+                buf.extend_from_slice(coding.as_bytes());
+                buf.extend_from_slice(&[b';']);
+                buf.extend_from_slice(format!("{:.1}", q).as_bytes());
+                HeaderValue::from_maybe_shared(buf.freeze()).ok()
+            } else {
+                HeaderValue::from_str(coding).ok()
+            }
+        });
+        let csv: FlatCsv = FlatCsv::from_iter(iter);
+
+        AcceptEncoding(csv)
+    }
+}
diff --git a/src/common/mod.rs b/src/common/mod.rs
index be50e2e9..ef70d3e8 100644
--- a/src/common/mod.rs
+++ b/src/common/mod.rs
@@ -7,7 +7,7 @@
 //! is used, such as `ContentType(pub Mime)`.
 
 //pub use self::accept_charset::AcceptCharset;
-//pub use self::accept_encoding::AcceptEncoding;
+pub use self::accept_encoding::AcceptEncoding;
 //pub use self::accept_language::AcceptLanguage;
 pub use self::accept_ranges::AcceptRanges;
 //pub use self::accept::Accept;
@@ -128,7 +128,7 @@ macro_rules! bench_header {
 
 //mod accept;
 //mod accept_charset;
-//mod accept_encoding;
+mod accept_encoding;
 //mod accept_language;
 mod accept_ranges;
 mod access_control_allow_credentials;