From 72b317b71428a1c0f63f920ebf2eecd26944f651 Mon Sep 17 00:00:00 2001
From: Douman <douman@gmx.se>
Date: Sun, 17 Mar 2019 09:22:05 +0300
Subject: Improve actix-web integration by creating bytes buffer instead of
 string

---
 askama/Cargo.toml |  3 ++-
 askama/src/lib.rs | 37 ++++++++++++++++++++++++++++++++++---
 2 files changed, 36 insertions(+), 4 deletions(-)

diff --git a/askama/Cargo.toml b/askama/Cargo.toml
index 172ade4..2b71d19 100644
--- a/askama/Cargo.toml
+++ b/askama/Cargo.toml
@@ -24,7 +24,7 @@ serde-json = ["askama_shared/serde_json"]
 serde-yaml = ["askama_shared/serde_yaml"]
 with-iron = ["iron", "askama_derive/iron"]
 with-rocket = ["rocket", "askama_derive/rocket"]
-with-actix-web = ["actix-web", "askama_derive/actix-web", "mime_guess"]
+with-actix-web = ["actix-web", "askama_derive/actix-web", "mime_guess", "bytes"]
 with-gotham = ["gotham", "askama_derive/gotham", "hyper", "mime_guess"]
 
 [dependencies]
@@ -37,6 +37,7 @@ actix-web = { version = "0.7", optional = true }
 mime_guess = { version = "2.0.0-alpha", optional = true }
 gotham = { version = "0.3", optional = true }
 hyper = { version = "0.12", optional = true }
+bytes = { version = "0.4", optional = true }
 
 [package.metadata.docs.rs]
 features = [ "serde-json" ]
diff --git a/askama/src/lib.rs b/askama/src/lib.rs
index dea5833..8492d8f 100644
--- a/askama/src/lib.rs
+++ b/askama/src/lib.rs
@@ -490,6 +490,36 @@ pub mod rocket {
 pub mod actix_web {
     extern crate actix_web;
     extern crate mime_guess;
+    extern crate bytes;
+
+    use std::fmt;
+
+    struct BytesWriter {
+        buf: bytes::BytesMut,
+    }
+
+    impl BytesWriter {
+        #[inline]
+        pub fn new() -> Self {
+            Self {
+                buf: bytes::BytesMut::with_capacity(4096)
+            }
+        }
+
+        #[inline]
+        pub fn freeze(self) -> bytes::Bytes {
+            self.buf.freeze()
+        }
+
+    }
+
+    impl fmt::Write for BytesWriter {
+        #[inline]
+        fn write_str(&mut self, buf: &str) -> fmt::Result {
+            self.buf.extend_from_slice(buf.as_bytes());
+            Ok(())
+        }
+    }
 
     // actix_web technically has this as a pub fn in later versions, fs::file_extension_to_mime.
     // Older versions that don't have it exposed are easier this way. If ext is empty or no
@@ -506,11 +536,12 @@ pub mod actix_web {
 
     impl<T: super::Template> TemplateIntoResponse for T {
         fn into_response(&self) -> Result<HttpResponse, Error> {
-            let rsp = self
-                .render()
+            let mut buffer = BytesWriter::new();
+            self.render_into(&mut buffer)
                 .map_err(|_| ErrorInternalServerError("Template parsing error"))?;
+
             let ctype = get_mime_type(T::extension().unwrap_or("txt")).to_string();
-            Ok(HttpResponse::Ok().content_type(ctype.as_str()).body(rsp))
+            Ok(HttpResponse::Ok().content_type(ctype.as_str()).body(buffer.freeze()))
         }
     }
 }
-- 
cgit