Disable chunked transfer encoding of responses

This also implicitly adds the content-length header, which improves
compatibility with CDN caches such as Cloudflare when using range requests.

src/lib.rs

@@ -1252,6 +1252,10 @@ async fn ranged_file_head_resp<S: Store + 'static>(
             if let Some(content_range) = range::to_content_range(range, len) {
                 let mut builder = HttpResponse::PartialContent();
                 builder.insert_header(content_range);
+                builder.insert_header((
+                    actix_web::http::header::CONTENT_LENGTH,
+                    range::to_ranged_content_length(range, len).ok_or(UploadError::Range)?,
+                ));
                 builder
             } else {
                 HttpResponse::RangeNotSatisfiable()
@@ -1261,7 +1265,12 @@ async fn ranged_file_head_resp<S: Store + 'static>(
         }
     } else {
         // no range header
-        HttpResponse::Ok()
+        let mut builder = HttpResponse::Ok();
+        builder.insert_header((
+            actix_web::http::header::CONTENT_LENGTH,
+            store.len(&identifier).await?,
+        ));
+        builder
     };
 
     Ok(srv_head(
@@ -1288,6 +1297,9 @@ async fn ranged_file_resp<S: Store + 'static>(
             if let Some(content_range) = range::to_content_range(range, len) {
                 let mut builder = HttpResponse::PartialContent();
                 builder.insert_header(content_range);
+                builder.no_chunking(
+                    range::to_ranged_content_length(range, len).ok_or(UploadError::Range)?,
+                );
                 (
                     builder,
                     Either::left(Either::left(
@@ -1310,7 +1322,9 @@ async fn ranged_file_resp<S: Store + 'static>(
         if not_found {
             (HttpResponse::NotFound(), Either::right(stream))
         } else {
-            (HttpResponse::Ok(), Either::right(stream))
+            let mut builder = HttpResponse::Ok();
+            builder.no_chunking(store.len(&identifier).await?);
+            (builder, Either::right(stream))
         }
     };
 

src/range.rs

@@ -51,3 +51,15 @@ pub(crate) fn to_content_range(
             })
         })
 }
+
+pub(crate) fn to_ranged_content_length(
+    byte_range: &ByteRangeSpec,
+    total_content_length: u64,
+) -> Option<u64> {
+    byte_range
+        .to_satisfiable_range(total_content_length)
+        .map(|(start, end)| {
+            // END IS INCLUSIVE
+            end + 1 - start
+        })
+}