From 1b5fb3cc5e451b49d8b3ad5f997e20c0e79c09f0 Mon Sep 17 00:00:00 2001
From: Sean McArthur <sean@seanmonstar.com>
Date: Wed, 30 May 2018 14:22:08 -0700
Subject: [PATCH] perf(h1): reduce clock checks for date rendering when
 pipelined

---
 src/proto/h1/date.rs     | 36 +++++++++++++++++++++++++-----------
 src/proto/h1/dispatch.rs |  1 +
 src/proto/h1/mod.rs      |  2 ++
 src/proto/h1/role.rs     | 32 ++++----------------------------
 4 files changed, 32 insertions(+), 39 deletions(-)

diff --git a/src/proto/h1/date.rs b/src/proto/h1/date.rs
index 38a18e1e..48bcdfcd 100644
--- a/src/proto/h1/date.rs
+++ b/src/proto/h1/date.rs
@@ -9,12 +9,13 @@ pub const DATE_VALUE_LENGTH: usize = 29;
 
 pub fn extend(dst: &mut Vec<u8>) {
     CACHED.with(|cache| {
-        let mut cache = cache.borrow_mut();
-        let now = time::get_time();
-        if now > cache.next_update {
-            cache.update(now);
-        }
-        dst.extend_from_slice(cache.buffer());
+        dst.extend_from_slice(cache.borrow().buffer());
+    })
+}
+
+pub fn update() {
+    CACHED.with(|cache| {
+        cache.borrow_mut().check();
     })
 }
 
@@ -24,17 +25,30 @@ struct CachedDate {
     next_update: time::Timespec,
 }
 
-thread_local!(static CACHED: RefCell<CachedDate> = RefCell::new(CachedDate {
-    bytes: [0; DATE_VALUE_LENGTH],
-    pos: 0,
-    next_update: time::Timespec::new(0, 0),
-}));
+thread_local!(static CACHED: RefCell<CachedDate> = RefCell::new(CachedDate::new()));
 
 impl CachedDate {
+    fn new() -> Self {
+        let mut cache = CachedDate {
+            bytes: [0; DATE_VALUE_LENGTH],
+            pos: 0,
+            next_update: time::Timespec::new(0, 0),
+        };
+        cache.update(time::get_time());
+        cache
+    }
+
     fn buffer(&self) -> &[u8] {
         &self.bytes[..]
     }
 
+    fn check(&mut self) {
+        let now = time::get_time();
+        if now > self.next_update {
+            self.update(now);
+        }
+    }
+
     fn update(&mut self, now: time::Timespec) {
         self.pos = 0;
         let _ = write!(self, "{}", time::at_utc(now).rfc822());
diff --git a/src/proto/h1/dispatch.rs b/src/proto/h1/dispatch.rs
index 2de161ba..364048c7 100644
--- a/src/proto/h1/dispatch.rs
+++ b/src/proto/h1/dispatch.rs
@@ -89,6 +89,7 @@ where
     }
 
     fn poll_inner(&mut self, should_shutdown: bool) -> Poll<(), ::Error> {
+        T::update_date();
         loop {
             self.poll_read()?;
             self.poll_write()?;
diff --git a/src/proto/h1/mod.rs b/src/proto/h1/mod.rs
index d3576fa4..46f0eeab 100644
--- a/src/proto/h1/mod.rs
+++ b/src/proto/h1/mod.rs
@@ -36,6 +36,8 @@ pub(crate) trait Http1Transaction {
 
     fn should_error_on_parse_eof() -> bool;
     fn should_read_first() -> bool;
+
+    fn update_date() {}
 }
 
 pub(crate) type ParseResult<T> = Result<Option<ParsedMessage<T>>, ::error::Parse>;
diff --git a/src/proto/h1/role.rs b/src/proto/h1/role.rs
index 605010ec..261179eb 100644
--- a/src/proto/h1/role.rs
+++ b/src/proto/h1/role.rs
@@ -182,34 +182,6 @@ where
         }))
     }
 
-    /*
-    fn decoder(head: &MessageHead<Self::Incoming>, method: &mut Option<Method>) -> ::Result<Decode> {
-        *method = Some(head.subject.0.clone());
-        if head.headers.contains_key(TRANSFER_ENCODING) {
-            // https://tools.ietf.org/html/rfc7230#section-3.3.3
-            // If Transfer-Encoding header is present, and 'chunked' is
-            // not the final encoding, and this is a Request, then it is
-            // mal-formed. A server should respond with 400 Bad Request.
-            if head.version == Version::HTTP_10 {
-                debug!("HTTP/1.0 cannot have Transfer-Encoding header");
-                Err(::Error::new_header())
-            } else if headers::transfer_encoding_is_chunked(&head.headers) {
-                Ok(Decode::Normal(Decoder::chunked()))
-            } else {
-                debug!("request with transfer-encoding header, but not chunked, bad request");
-                Err(::Error::new_header())
-            }
-        } else if let Some(len) = headers::content_length_parse(&head.headers) {
-            Ok(Decode::Normal(Decoder::length(len)))
-        } else if head.headers.contains_key(CONTENT_LENGTH) {
-            debug!("illegal Content-Length header");
-            Err(::Error::new_header())
-        } else {
-            Ok(Decode::Normal(Decoder::length(0)))
-        }
-    }*/
-
-
     fn encode(mut msg: Encode<Self::Outgoing>, dst: &mut Vec<u8>) -> ::Result<Encoder> {
         trace!("Server::encode body={:?}, method={:?}", msg.body, msg.req_method);
         debug_assert!(!msg.title_case_headers, "no server config for title case headers");
@@ -464,6 +436,10 @@ where
     fn should_read_first() -> bool {
         true
     }
+
+    fn update_date() {
+        date::update();
+    }
 }
 
 impl Server<()> {