From d60f0439d70153f822dedbeedf4712af8f315122 Mon Sep 17 00:00:00 2001
From: Kristoffer K <merceyz@users.noreply.github.com>
Date: Mon, 1 Jun 2020 10:35:38 +0200
Subject: [PATCH] perf(core): skip await if response has already resolved
 (#1422)

* perf(core): avoid unnecessary await when get response is in cache

* chore: versions
---
 .yarn/versions/8c6a6df8.yml                | 30 ++++++++++++++++++++++
 packages/yarnpkg-core/sources/httpUtils.ts | 14 ++++++----
 2 files changed, 39 insertions(+), 5 deletions(-)
 create mode 100644 .yarn/versions/8c6a6df8.yml

diff --git a/.yarn/versions/8c6a6df8.yml b/.yarn/versions/8c6a6df8.yml
new file mode 100644
index 000000000000..8812efe8c3c6
--- /dev/null
+++ b/.yarn/versions/8c6a6df8.yml
@@ -0,0 +1,30 @@
+releases:
+  "@yarnpkg/cli": prerelease
+  "@yarnpkg/core": prerelease
+
+declined:
+  - "@yarnpkg/plugin-compat"
+  - "@yarnpkg/plugin-constraints"
+  - "@yarnpkg/plugin-dlx"
+  - "@yarnpkg/plugin-essentials"
+  - "@yarnpkg/plugin-exec"
+  - "@yarnpkg/plugin-file"
+  - "@yarnpkg/plugin-git"
+  - "@yarnpkg/plugin-github"
+  - "@yarnpkg/plugin-http"
+  - "@yarnpkg/plugin-init"
+  - "@yarnpkg/plugin-interactive-tools"
+  - "@yarnpkg/plugin-link"
+  - "@yarnpkg/plugin-node-modules"
+  - "@yarnpkg/plugin-npm"
+  - "@yarnpkg/plugin-npm-cli"
+  - "@yarnpkg/plugin-pack"
+  - "@yarnpkg/plugin-patch"
+  - "@yarnpkg/plugin-pnp"
+  - "@yarnpkg/plugin-stage"
+  - "@yarnpkg/plugin-typescript"
+  - "@yarnpkg/plugin-version"
+  - "@yarnpkg/plugin-workspace-tools"
+  - "@yarnpkg/builder"
+  - "@yarnpkg/doctor"
+  - "@yarnpkg/pnpify"
diff --git a/packages/yarnpkg-core/sources/httpUtils.ts b/packages/yarnpkg-core/sources/httpUtils.ts
index b9626829b0b7..2226dca63a41 100644
--- a/packages/yarnpkg-core/sources/httpUtils.ts
+++ b/packages/yarnpkg-core/sources/httpUtils.ts
@@ -12,7 +12,7 @@ const NETWORK_CONCURRENCY = 8;
 
 const limit = plimit(NETWORK_CONCURRENCY);
 
-const cache = new Map<string, Promise<Response<Buffer>>>();
+const cache = new Map<string, Promise<Buffer> | Buffer>();
 
 const globalHttpAgent = new HttpAgent({keepAlive: true});
 const globalHttpsAgent = new HttpsAgent({keepAlive: true});
@@ -97,16 +97,20 @@ export async function get(target: string, {configuration, json, ...rest}: Option
   let entry = cache.get(target);
 
   if (!entry) {
-    entry = request(target, null, {configuration, ...rest});
+    entry = request(target, null, {configuration, ...rest}).then(response => {
+      cache.set(target, response.body);
+      return response.body;
+    });
     cache.set(target, entry);
   }
 
-  const response = await entry;
+  if (Buffer.isBuffer(entry) === false)
+    entry = await entry;
 
   if (json) {
-    return JSON.parse(response.body.toString());
+    return JSON.parse(entry.toString());
   } else {
-    return response.body;
+    return entry;
   }
 }