1 files changed, 46 insertions, 7 deletions

diff --git a/http.ts b/http.ts
index 6954a48ba..bd45aea0d 100644
--- a/http.ts
+++ b/http.ts
@@ -1,4 +1,4 @@
-import { listen, Conn } from "deno";
+import { listen, Conn, toAsyncIterator, Reader, copy } from "deno";
 import { BufReader, BufState, BufWriter } from "./bufio.ts";
 import { TextProtoReader } from "./textproto.ts";
 import { STATUS_TEXT } from "./http_status";
@@ -96,16 +96,23 @@ export async function listenAndServe(
 export interface Response {
   status?: number;
   headers?: Headers;
-  body?: Uint8Array;
+  body?: Uint8Array | Reader;
 }
 
 export function setContentLength(r: Response): void {
   if (!r.headers) {
     r.headers = new Headers();
   }
-  if (!r.headers.has("content-length")) {
-    const bodyLength = r.body ? r.body.byteLength : 0;
-    r.headers.append("Content-Length", bodyLength.toString());
+
+  if (r.body) {
+    if (!r.headers.has("content-length")) {
+      if (r.body instanceof Uint8Array) {
+        const bodyLength = r.body.byteLength;
+        r.headers.append("Content-Length", bodyLength.toString());
+      } else {
+        r.headers.append("Transfer-Encoding", "chunked");
+      }
+    }
   }
 }
 
@@ -116,6 +123,26 @@ export class ServerRequest {
   headers: Headers;
   w: BufWriter;
 
+  private async _streamBody(body: Reader, bodyLength: number) {
+    const n = await copy(this.w, body);
+    assert(n == bodyLength);
+  }
+
+  private async _streamChunkedBody(body: Reader) {
+    const encoder = new TextEncoder();
+
+    for await (const chunk of toAsyncIterator(body)) {
+      const start = encoder.encode(`${chunk.byteLength.toString(16)}\r\n`);
+      const end = encoder.encode("\r\n");
+      await this.w.write(start);
+      await this.w.write(chunk);
+      await this.w.write(end);
+    }
+
+    const endChunk = encoder.encode("0\r\n\r\n");
+    await this.w.write(endChunk);
+  }
+
   async respond(r: Response): Promise<void> {
     const protoMajor = 1;
     const protoMinor = 1;
@@ -139,9 +166,21 @@ export class ServerRequest {
     const header = new TextEncoder().encode(out);
     let n = await this.w.write(header);
     assert(header.byteLength == n);
+
     if (r.body) {
-      n = await this.w.write(r.body);
-      assert(r.body.byteLength == n);
+      if (r.body instanceof Uint8Array) {
+        n = await this.w.write(r.body);
+        assert(r.body.byteLength == n);
+      } else {
+        if (r.headers.has("content-length")) {
+          await this._streamBody(
+            r.body,
+            parseInt(r.headers.get("content-length"))
+          );
+        } else {
+          await this._streamChunkedBody(r.body);
+        }
+      }
     }
 
     await this.w.flush();