Fix memory leak in response.clone(), further reduce memory usage of Request & Response (#3902)

* Atomize respsone.url & response.statusText

* Fix warning

* Atomize Request & Response URLs when possible

* Fix memory leak in response.clone()

bun/bench/snippets on  jarred/atomize
❯ mem bun --smol request-response-clone.mjs
cpu: Apple M1 Max
runtime: bun 0.7.2 (arm64-darwin)

benchmark             time (avg)             (min … max)       p75       p99      p995
-------------------------------------------------------- -----------------------------
req.clone().url     77.3 ns/iter  (40.35 ns … 222.64 ns)  91.53 ns 128.11 ns 172.78 ns
resp.clone().url  162.43 ns/iter    (116 ns … 337.77 ns)  177.4 ns 232.38 ns 262.65 ns

Peak memory usage: 60 MB

bun/bench/snippets on  jarred/atomize
❯ mem bun-0.7.1 --smol request-response-clone.mjs
cpu: Apple M1 Max
runtime: bun 0.7.1 (arm64-darwin)

benchmark             time (avg)             (min … max)       p75       p99      p995
-------------------------------------------------------- -----------------------------
req.clone().url   115.85 ns/iter  (80.35 ns … 247.39 ns) 128.19 ns 181.93 ns 207.23 ns
resp.clone().url  252.32 ns/iter  (202.6 ns … 351.07 ns) 266.56 ns 325.88 ns 334.73 ns

Peak memory usage: 1179 MB

* Update tests

* Update js_ast.zig

* Update test

---------

Co-authored-by: Jarred Sumner <709451+Jarred-Sumner@users.noreply.github.com>

1 files changed, 6 insertions, 3 deletions

diff --git a/src/bun.js/api/filesystem_router.zig b/src/bun.js/api/filesystem_router.zig
index 216f66b7f..edb666040 100644
--- a/src/bun.js/api/filesystem_router.zig
+++ b/src/bun.js/api/filesystem_router.zig
@@ -75,6 +75,8 @@ const DeprecatedGlobalRouter = struct {
         };
 
         var path_: ?ZigString.Slice = null;
+        var req_url_slice: ZigString.Slice = .{};
+        defer req_url_slice.deinit();
         var pathname: string = "";
         defer {
             if (path_) |path| {
@@ -88,7 +90,8 @@ const DeprecatedGlobalRouter = struct {
             var url = URL.parse(path_.?.slice());
             pathname = url.pathname;
         } else if (arg.as(Request)) |req| {
-            var url = URL.parse(req.url);
+            req_url_slice = req.url.toUTF8(bun.default_allocator);
+            var url = URL.parse(req_url_slice.slice());
             pathname = url.pathname;
         }
 
@@ -389,11 +392,11 @@ pub const FileSystemRouter = struct {
             if (argument.isCell()) {
                 if (argument.as(JSC.WebCore.Request)) |req| {
                     req.ensureURL() catch unreachable;
-                    break :brk ZigString.Slice.fromUTF8NeverFree(req.url).clone(globalThis.allocator()) catch unreachable;
+                    break :brk req.url.toUTF8(globalThis.allocator());
                 }
 
                 if (argument.as(JSC.WebCore.Response)) |resp| {
-                    break :brk ZigString.Slice.fromUTF8NeverFree(resp.url).clone(globalThis.allocator()) catch unreachable;
+                    break :brk resp.url.toUTF8(globalThis.allocator());
                 }
             }