rename header to meta

src/response/success/default/meta.rs

@@ -0,0 +1,55 @@
+pub const CODE: &[u8] = b"20";
+
+pub struct Meta {
+    pub mime: String,
+}
+
+impl Meta {
+    /// Build `Self` from UTF-8 meta bytes
+    /// * expected buffer includes leading status code, message, CRLF
+    pub fn from_bytes(buffer: &[u8]) -> Result<Self> {
+        use crate::Header;
+        use regex::Regex;
+        use std::str::from_utf8;
+        let h = buffer.header_bytes()?;
+        if h.get(..2)
+            .is_none_or(|c| c[0] != CODE[0] || c[1] != CODE[1])
+        {
+            bail!("Invalid status code")
+        }
+        Ok(Self {
+            mime: match Regex::new(r"^([^\/]+\/[^\s;]+)")?.captures(from_utf8(&h[3..])?) {
+                Some(c) => match c.get(1) {
+                    Some(m) => m.as_str().to_string(),
+                    None => bail!("Content type required"),
+                },
+                None => bail!("Could not parse content type"),
+            },
+        })
+    }
+
+    /// Convert `Self` into UTF-8 bytes presentation
+    pub fn into_bytes(self) -> Vec<u8> {
+        self.to_bytes()
+    }
+
+    pub fn to_bytes(&self) -> Vec<u8> {
+        let mut bytes = Vec::with_capacity(3 + self.mime.len() + 2);
+        bytes.extend(CODE);
+        bytes.push(b' ');
+        bytes.extend(self.mime.as_bytes());
+        bytes.extend([b'\r', b'\n']);
+        bytes
+    }
+}
+
+#[test]
+fn test() {
+    const BYTES: &[u8] = "20 text/gemini\r\nDATA".as_bytes();
+    let meta = Meta::from_bytes(BYTES).unwrap();
+
+    assert_eq!(meta.mime, "text/gemini".to_string());
+    assert_eq!(meta.into_bytes(), BYTES[..BYTES.len() - 4]); // skip DATA
+}
+
+use anyhow::{bail, Result};