add Header trait with shared bytes impl

src/lib.rs

@@ -3,3 +3,29 @@ pub mod response;
 
 pub use request::Request;
 pub use response::Response;
+
+pub const HEADER_MAX_LEN: usize = 1024;
+
+pub trait Header {
+    fn header_bytes(&self) -> Result<&[u8]>;
+}
+
+impl Header for &[u8] {
+    fn header_bytes(&self) -> Result<&[u8]> {
+        match self.iter().position(|&b| b == b'\r') {
+            Some(n) => {
+                if n > HEADER_MAX_LEN {
+                    bail!("Header bytes length reached")
+                }
+                if self.get(n + 1).is_some_and(|&b| b == b'\n') {
+                    Ok(&self[..n])
+                } else {
+                    bail!("LF byte not found")
+                }
+            }
+            None => bail!("CR byte not found"),
+        }
+    }
+}
+
+use anyhow::{bail, Result};

src/request.rs

@@ -4,8 +4,7 @@ pub mod titan;
 pub use gemini::Gemini;
 pub use titan::Titan;
 
-pub const HEADER_MAX_LEN: usize = 1024;
-
+use super::Header;
 use anyhow::{bail, Result};
 
 /// https://geminiprotocol.net/docs/protocol-specification.gmi#requests
@@ -32,19 +31,3 @@ impl<'a> Request<'a> {
         }
     }
 }
-
-pub fn header_bytes(buffer: &[u8]) -> Result<&[u8]> {
-    match buffer.iter().position(|&b| b == b'\r') {
-        Some(n) => {
-            if n > HEADER_MAX_LEN {
-                bail!("Header bytes length reached")
-            }
-            if buffer.get(n + 1).is_some_and(|&b| b == b'\n') {
-                Ok(&buffer[..n])
-            } else {
-                bail!("LF byte not found")
-            }
-        }
-        None => bail!("CR byte not found"),
-    }
-}

src/request/gemini.rs

@@ -8,8 +8,9 @@ pub struct Gemini {
 
 impl Gemini {
     pub fn from_bytes(buffer: &[u8]) -> Result<Self> {
+        use super::Header;
         Ok(Self {
-            url: Url::parse(std::str::from_utf8(crate::request::header_bytes(buffer)?)?)?,
+            url: Url::parse(std::str::from_utf8(buffer.header_bytes()?)?)?,
         })
     }
     pub fn into_bytes(self) -> Vec<u8> {