Fix memory leak in `await new Response(latin1String).arrayBuffer()` and `await Response.json(obj).json()` (#3656)

❯ mem bun --smol response-arrayBuffer.mjs
cpu: Apple M1 Max
runtime: bun 0.6.15 (arm64-darwin)

benchmark                                                        time (avg)             (min … max)       p75       p99      p995
--------------------------------------------------------------------------------------------------- -----------------------------
new Response().arrayBuffer() (new string each call, latin1)    12.9 µs/iter      (625 ns … 4.18 ms)      1 µs 567.17 µs 711.79 µs
new Response().arrayBuffer() (new string each call, utf16)    12.85 µs/iter     (1.67 µs … 1.56 ms)   2.17 µs 462.75 µs 621.13 µs
new Response().arrayBuffer() (existing string, latin1)         6.53 µs/iter     (6.21 µs … 7.07 µs)   6.64 µs   7.07 µs   7.07 µs

Peak memory usage: 49 MB

bun on  jarred/memory-leak-fix took 2s
❯ mem bun response-arrayBuffer.mjs
cpu: Apple M1 Max
runtime: bun 0.6.15 (arm64-darwin)

benchmark                                                        time (avg)             (min … max)       p75       p99      p995
--------------------------------------------------------------------------------------------------- -----------------------------
new Response().arrayBuffer() (new string each call, latin1)     1.2 µs/iter     (1.04 µs … 1.42 µs)   1.22 µs   1.42 µs   1.42 µs
new Response().arrayBuffer() (new string each call, utf16)     2.74 µs/iter     (2.42 µs … 6.37 µs)   2.68 µs   6.37 µs   6.37 µs
new Response().arrayBuffer() (existing string, latin1)       746.37 ns/iter   (643.82 ns … 1.04 µs) 776.11 ns   1.04 µs   1.04 µs

Peak memory usage: 104 MB

bun on  jarred/memory-leak-fix took 2s
❯ mem ~/.bun/bin/bun response-arrayBuffer.mjs
cpu: Apple M1 Max
runtime: bun 0.6.15 (arm64-darwin)

benchmark                                                        time (avg)             (min … max)       p75       p99      p995
--------------------------------------------------------------------------------------------------- -----------------------------
new Response().arrayBuffer() (new string each call, latin1)    1.69 µs/iter      (1.56 µs … 2.1 µs)   1.73 µs    2.1 µs    2.1 µs
new Response().arrayBuffer() (new string each call, utf16)     2.65 µs/iter     (2.47 µs … 3.17 µs)   2.69 µs   3.17 µs   3.17 µs
new Response().arrayBuffer() (existing string, latin1)       667.67 ns/iter   (547.67 ns … 1.28 µs) 694.21 ns   1.28 µs   1.28 µs

Peak memory usage: 2735 MB

bun on  jarred/memory-leak-fix took 2s
❯ mem ~/.bun/bin/bun --smol response-arrayBuffer.mjs
cpu: Apple M1 Max
runtime: bun 0.6.15 (arm64-darwin)

benchmark                                                        time (avg)             (min … max)       p75       p99      p995
--------------------------------------------------------------------------------------------------- -----------------------------
new Response().arrayBuffer() (new string each call, latin1)   13.51 µs/iter       (541 ns … 3.2 ms)   1.92 µs 553.42 µs 709.92 µs
new Response().arrayBuffer() (new string each call, utf16)    13.07 µs/iter     (1.71 µs … 3.43 ms)   2.13 µs 451.21 µs 651.67 µs
new Response().arrayBuffer() (existing string, latin1)         6.25 µs/iter     (5.79 µs … 6.81 µs)    6.4 µs   6.81 µs   6.81 µs

Peak memory usage: 292 MB

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

1 files changed, 136 insertions, 0 deletions

diff --git a/bench/snippets/response-arrayBuffer.mjs b/bench/snippets/response-arrayBuffer.mjs
new file mode 100644
index 000000000..a3b1f0a73
--- /dev/null
+++ b/bench/snippets/response-arrayBuffer.mjs
@@ -0,0 +1,136 @@
+// This snippet mostly exists to reproduce a memory leak
+//
+import { bench, run } from "mitata";
+
+const obj = {
+  "id": 1296269,
+  "node_id": "MDEwOlJlcG9zaXRvcnkxMjk2MjY5",
+  "name": "Hello-World",
+  "full_name": "octocat/Hello-World",
+  "owner": {
+    "login": "octocat",
+    "id": 1,
+    "node_id": "MDQ6VXNlcjE=",
+    "avatar_url": "https://github.com/images/error/octocat_happy.gif",
+    "gravatar_id": "",
+    "url": "https://api.github.com/users/octocat",
+    "html_url": "https://github.com/octocat",
+    "followers_url": "https://api.github.com/users/octocat/followers",
+    "following_url": "https://api.github.com/users/octocat/following{/other_user}",
+    "gists_url": "https://api.github.com/users/octocat/gists{/gist_id}",
+    "starred_url": "https://api.github.com/users/octocat/starred{/owner}{/repo}",
+    "subscriptions_url": "https://api.github.com/users/octocat/subscriptions",
+    "organizations_url": "https://api.github.com/users/octocat/orgs",
+    "repos_url": "https://api.github.com/users/octocat/repos",
+    "events_url": "https://api.github.com/users/octocat/events{/privacy}",
+    "received_events_url": "https://api.github.com/users/octocat/received_events",
+    "type": "User",
+    "site_admin": false,
+  },
+  "private": false,
+  "html_url": "https://github.com/octocat/Hello-World",
+  "description": "This your first repo!",
+  "fork": false,
+  "url": "https://api.github.com/repos/octocat/Hello-World",
+  "archive_url": "https://api.github.com/repos/octocat/Hello-World/{archive_format}{/ref}",
+  "assignees_url": "https://api.github.com/repos/octocat/Hello-World/assignees{/user}",
+  "blobs_url": "https://api.github.com/repos/octocat/Hello-World/git/blobs{/sha}",
+  "branches_url": "https://api.github.com/repos/octocat/Hello-World/branches{/branch}",
+  "collaborators_url": "https://api.github.com/repos/octocat/Hello-World/collaborators{/collaborator}",
+  "comments_url": "https://api.github.com/repos/octocat/Hello-World/comments{/number}",
+  "commits_url": "https://api.github.com/repos/octocat/Hello-World/commits{/sha}",
+  "compare_url": "https://api.github.com/repos/octocat/Hello-World/compare/{base}...{head}",
+  "contents_url": "https://api.github.com/repos/octocat/Hello-World/contents/{+path}",
+  "contributors_url": "https://api.github.com/repos/octocat/Hello-World/contributors",
+  "deployments_url": "https://api.github.com/repos/octocat/Hello-World/deployments",
+  "downloads_url": "https://api.github.com/repos/octocat/Hello-World/downloads",
+  "events_url": "https://api.github.com/repos/octocat/Hello-World/events",
+  "forks_url": "https://api.github.com/repos/octocat/Hello-World/forks",
+  "git_commits_url": "https://api.github.com/repos/octocat/Hello-World/git/commits{/sha}",
+  "git_refs_url": "https://api.github.com/repos/octocat/Hello-World/git/refs{/sha}",
+  "git_tags_url": "https://api.github.com/repos/octocat/Hello-World/git/tags{/sha}",
+  "git_url": "git:github.com/octocat/Hello-World.git",
+  "issue_comment_url": "https://api.github.com/repos/octocat/Hello-World/issues/comments{/number}",
+  "issue_events_url": "https://api.github.com/repos/octocat/Hello-World/issues/events{/number}",
+  "issues_url": "https://api.github.com/repos/octocat/Hello-World/issues{/number}",
+  "keys_url": "https://api.github.com/repos/octocat/Hello-World/keys{/key_id}",
+  "labels_url": "https://api.github.com/repos/octocat/Hello-World/labels{/name}",
+  "languages_url": "https://api.github.com/repos/octocat/Hello-World/languages",
+  "merges_url": "https://api.github.com/repos/octocat/Hello-World/merges",
+  "milestones_url": "https://api.github.com/repos/octocat/Hello-World/milestones{/number}",
+  "notifications_url": "https://api.github.com/repos/octocat/Hello-World/notifications{?since,all,participating}",
+  "pulls_url": "https://api.github.com/repos/octocat/Hello-World/pulls{/number}",
+  "releases_url": "https://api.github.com/repos/octocat/Hello-World/releases{/id}",
+  "ssh_url": "git@github.com:octocat/Hello-World.git",
+  "stargazers_url": "https://api.github.com/repos/octocat/Hello-World/stargazers",
+  "statuses_url": "https://api.github.com/repos/octocat/Hello-World/statuses/{sha}",
+  "subscribers_url": "https://api.github.com/repos/octocat/Hello-World/subscribers",
+  "subscription_url": "https://api.github.com/repos/octocat/Hello-World/subscription",
+  "tags_url": "https://api.github.com/repos/octocat/Hello-World/tags",
+  "teams_url": "https://api.github.com/repos/octocat/Hello-World/teams",
+  "trees_url": "https://api.github.com/repos/octocat/Hello-World/git/trees{/sha}",
+  "clone_url": "https://github.com/octocat/Hello-World.git",
+  "mirror_url": "git:git.example.com/octocat/Hello-World",
+  "hooks_url": "https://api.github.com/repos/octocat/Hello-World/hooks",
+  "svn_url": "https://svn.github.com/octocat/Hello-World",
+  "homepage": "https://github.com",
+  "language": null,
+  "forks_count": 9,
+  "stargazers_count": 80,
+  "watchers_count": 80,
+  "size": 108,
+  "default_branch": "master",
+  "open_issues_count": 0,
+  "is_template": false,
+  "topics": ["octocat", "atom", "electron", "api"],
+  "has_issues": true,
+  "has_projects": true,
+  "has_wiki": true,
+  "has_pages": false,
+  "has_downloads": true,
+  "has_discussions": false,
+  "archived": false,
+  "disabled": false,
+  "visibility": "public",
+  "pushed_at": "2011-01-26T19:06:43Z",
+  "created_at": "2011-01-26T19:01:12Z",
+  "updated_at": "2011-01-26T19:14:43Z",
+  "permissions": {
+    "admin": false,
+    "push": false,
+    "pull": true,
+  },
+  "security_and_analysis": {
+    "advanced_security": {
+      "status": "enabled",
+    },
+    "secret_scanning": {
+      "status": "enabled",
+    },
+    "secret_scanning_push_protection": {
+      "status": "disabled",
+    },
+  },
+};
+
+// Force the string to be 8bit
+const str = String.fromCharCode(
+  ...JSON.stringify(obj)
+    .split("")
+    .map(a => a.charCodeAt(0)),
+);
+var i = 0;
+
+bench("new Response().arrayBuffer() (new string each call, latin1)", async () => {
+  return await new Response(str + i++).arrayBuffer();
+});
+
+bench("new Response().arrayBuffer() (new string each call, utf16)", async () => {
+  return await new Response(str + i++ + "😊").arrayBuffer();
+});
+
+bench("new Response().arrayBuffer() (existing string, latin1)", async () => {
+  return await new Response(str).arrayBuffer();
+});
+
+await run();