More hpack work

src/hpack/entry.rs

@@ -1,4 +1,7 @@
+use super::DecoderError;
+
 use tower::http::{HeaderName, Method, StatusCode, Str};
+use bytes::Bytes;
 
 /// HPack table entry
 #[derive(Debug, Clone)]
@@ -14,6 +17,16 @@ pub enum Entry {
     Status(StatusCode),
 }
 
+/// The name component of an Entry
+pub enum Key<'a> {
+    Header(&'a HeaderName),
+    Authority,
+    Method,
+    Scheme,
+    Path,
+    Status,
+}
+
 impl Entry {
     pub fn len(&self) -> usize {
         match *self {
@@ -38,4 +51,46 @@ impl Entry {
             }
         }
     }
+
+    pub fn key(&self) -> Key {
+        match *self {
+            Entry::Header { ref name, .. } => Key::Header(name),
+            Entry::Authority(..) => Key::Authority,
+            Entry::Method(..) => Key::Method,
+            Entry::Scheme(..) => Key::Scheme,
+            Entry::Path(..) => Key::Path,
+            Entry::Status(..) => Key::Status,
+        }
+    }
+}
+
+impl<'a> Key<'a> {
+    pub fn into_entry(self, value: Bytes) -> Result<Entry, DecoderError> {
+        match self {
+            Key::Header(name) => {
+                Ok(Entry::Header {
+                    name: name.clone(),
+                    value: try!(Str::from_utf8(value)),
+                })
+            }
+            Key::Authority => {
+                Ok(Entry::Authority(try!(Str::from_utf8(value))))
+            }
+            Key::Method => {
+                Ok(Entry::Scheme(try!(Str::from_utf8(value))))
+            }
+            Key::Scheme => {
+                Ok(Entry::Scheme(try!(Str::from_utf8(value))))
+            }
+            Key::Path => {
+                Ok(Entry::Path(try!(Str::from_utf8(value))))
+            }
+            Key::Status => {
+                match StatusCode::parse(&value) {
+                    Some(status) => Ok(Entry::Status(status)),
+                    None => Err(DecoderError::InvalidStatusCode),
+                }
+            }
+        }
+    }
 }