Initial commit

src/frame/head.rs

@@ -0,0 +1,82 @@
+use super::Error;
+
+#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+pub struct Head {
+    kind: Kind,
+    flag: u8,
+    stream_id: StreamId,
+}
+
+#[repr(u8)]
+#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+pub enum Kind {
+    Data = 0,
+    Headers = 1,
+    Priority = 2,
+    Reset = 3,
+    Settings = 4,
+    PushPromise = 5,
+    Ping = 6,
+    GoAway = 7,
+    WindowUpdate = 8,
+    Continuation = 9,
+    Unknown,
+}
+
+pub type StreamId = u32;
+
+// ===== impl Head =====
+
+impl Head {
+    /// Parse an HTTP/2.0 frame header
+    pub fn parse(header: &[u8]) -> Head {
+        Head {
+            kind: Kind::new(header[3]),
+            flag: header[4],
+            stream_id: parse_stream_id(&header[5..]),
+        }
+    }
+
+    pub fn stream_id(&self) -> u32 {
+        self.stream_id
+    }
+
+    pub fn kind(&self) -> Kind {
+        self.kind
+    }
+
+    pub fn flag(&self) -> u8 {
+        self.flag
+    }
+}
+
+/// Parse the next 4 octets in the given buffer, assuming they represent an
+/// HTTP/2 stream ID.  This means that the most significant bit of the first
+/// octet is ignored and the rest interpreted as a network-endian 31-bit
+/// integer.
+#[inline]
+fn parse_stream_id(buf: &[u8]) -> StreamId {
+    let unpacked = unpack_octets_4!(buf, 0, u32);
+    // Now clear the most significant bit, as that is reserved and MUST be ignored when received.
+    unpacked & !0x80000000
+}
+
+// ===== impl Kind =====
+
+impl Kind {
+    pub fn new(byte: u8) -> Kind {
+        return match byte {
+            0 => Kind::Data,
+            1 => Kind::Headers,
+            2 => Kind::Priority,
+            3 => Kind::Reset,
+            4 => Kind::Settings,
+            5 => Kind::PushPromise,
+            6 => Kind::Ping,
+            7 => Kind::GoAway,
+            8 => Kind::WindowUpdate,
+            9 => Kind::Continuation,
+            _ => Kind::Unknown,
+        }
+    }
+}