Use MediaType accept header parser (#4216)

## Issue Addressed

#3510 

## Proposed Changes

- Replace mime with MediaTypeList
- Remove parse_accept fn as MediaTypeList does it built-in
- Get the supported media type of the highest q-factor in a single list iteration without sorting

## Additional Info

I have addressed the suggested changes in previous [PR](https://github.com/sigp/lighthouse/pull/3520#discussion_r959048633)

Cargo.lock

@@ -2290,7 +2290,7 @@ dependencies = [
  "futures-util",
  "libsecp256k1",
  "lighthouse_network",
- "mime",
+ "mediatype",
  "procinfo",
  "proto_array",
  "psutil",
@@ -4962,6 +4962,12 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "mediatype"
+version = "0.19.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fea6e62614ab2fc0faa58bb15102a0382d368f896a9fa4776592589ab55c4de7"
+
 [[package]]
 name = "memchr"
 version = "2.5.0"

common/eth2/Cargo.toml

@@ -10,7 +10,7 @@ edition = "2021"
 serde = { version = "1.0.116", features = ["derive"] }
 serde_json = "1.0.58"
 types = { path = "../../consensus/types" }
-reqwest = { version = "0.11.0", features = ["json","stream"] }
+reqwest = { version = "0.11.0", features = ["json", "stream"] }
 lighthouse_network = { path = "../../beacon_node/lighthouse_network" }
 proto_array = { path = "../../consensus/proto_array", optional = true }
 ethereum_serde_utils = "0.5.0"
@@ -26,7 +26,7 @@ futures-util = "0.3.8"
 futures = "0.3.8"
 store = { path = "../../beacon_node/store", optional = true }
 slashing_protection = { path = "../../validator_client/slashing_protection", optional = true }
-mime = "0.3.16"
+mediatype = "0.19.13"
 
 [target.'cfg(target_os = "linux")'.dependencies]
 psutil = { version = "3.2.2", optional = true }
@@ -34,4 +34,10 @@ procinfo = { version = "0.4.2", optional = true }
 
 [features]
 default = ["lighthouse"]
-lighthouse = ["proto_array", "psutil", "procinfo", "store", "slashing_protection"]
+lighthouse = [
+    "proto_array",
+    "psutil",
+    "procinfo",
+    "store",
+    "slashing_protection",
+]

common/eth2/src/types.rs

@@ -3,9 +3,8 @@
 
 use crate::Error as ServerError;
 use lighthouse_network::{ConnectionDirection, Enr, Multiaddr, PeerConnectionStatus};
-use mime::{Mime, APPLICATION, JSON, OCTET_STREAM, STAR};
+use mediatype::{names, MediaType, MediaTypeList};
 use serde::{Deserialize, Serialize};
-use std::cmp::Reverse;
 use std::convert::TryFrom;
 use std::fmt;
 use std::str::{from_utf8, FromStr};
@@ -1172,35 +1171,58 @@ impl FromStr for Accept {
     type Err = String;
 
     fn from_str(s: &str) -> Result<Self, Self::Err> {
-        let mut mimes = parse_accept(s)?;
+        let media_type_list = MediaTypeList::new(s);
 
         // [q-factor weighting]: https://datatracker.ietf.org/doc/html/rfc7231#section-5.3.2
         // find the highest q-factor supported accept type
-        mimes.sort_by_key(|m| {
+        let mut highest_q = 0_u16;
-            Reverse(m.get_param("q").map_or(1000_u16, |n| {
+        let mut accept_type = None;
-                (n.as_ref().parse::<f32>().unwrap_or(0_f32) * 1000_f32) as u16
-            }))
-        });
-        mimes
-            .into_iter()
-            .find_map(|m| match (m.type_(), m.subtype()) {
-                (APPLICATION, OCTET_STREAM) => Some(Accept::Ssz),
-                (APPLICATION, JSON) => Some(Accept::Json),
-                (STAR, STAR) => Some(Accept::Any),
-                _ => None,
-            })
-            .ok_or_else(|| "accept header is not supported".to_string())
-    }
-}
 
-fn parse_accept(accept: &str) -> Result<Vec<Mime>, String> {
+        const APPLICATION: &str = names::APPLICATION.as_str();
-    accept
+        const OCTET_STREAM: &str = names::OCTET_STREAM.as_str();
-        .split(',')
+        const JSON: &str = names::JSON.as_str();
-        .map(|part| {
+        const STAR: &str = names::_STAR.as_str();
-            part.parse()
+        const Q: &str = names::Q.as_str();
-                .map_err(|e| format!("error parsing Accept header: {}", e))
+
-        })
+        media_type_list.into_iter().for_each(|item| {
-        .collect()
+            if let Ok(MediaType {
+                ty,
+                subty,
+                suffix: _,
+                params,
+            }) = item
+            {
+                let q_accept = match (ty.as_str(), subty.as_str()) {
+                    (APPLICATION, OCTET_STREAM) => Some(Accept::Ssz),
+                    (APPLICATION, JSON) => Some(Accept::Json),
+                    (STAR, STAR) => Some(Accept::Any),
+                    _ => None,
+                }
+                .map(|item_accept_type| {
+                    let q_val = params
+                        .iter()
+                        .find_map(|(n, v)| match n.as_str() {
+                            Q => {
+                                Some((v.as_str().parse::<f32>().unwrap_or(0_f32) * 1000_f32) as u16)
+                            }
+                            _ => None,
+                        })
+                        .or(Some(1000_u16));
+
+                    (q_val.unwrap(), item_accept_type)
+                });
+
+                match q_accept {
+                    Some((q, accept)) if q > highest_q => {
+                        highest_q = q;
+                        accept_type = Some(accept);
+                    }
+                    _ => (),
+                }
+            }
+        });
+        accept_type.ok_or_else(|| "accept header is not supported".to_string())
+    }
 }
 
 #[derive(Debug, Serialize, Deserialize)]
@@ -1268,6 +1290,11 @@ mod tests {
         assert_eq!(
             Accept::from_str("text/plain"),
             Err("accept header is not supported".to_string())
-        )
+        );
+
+        assert_eq!(
+            Accept::from_str("application/json;message=\"Hello, world!\";q=0.3,*/*;q=0.6").unwrap(),
+            Accept::Any
+        );
     }
 }