From 9df8d9d83140beb24a53b0ac52b1eaf2ea34c095 Mon Sep 17 00:00:00 2001
From: David Sherret <dsherret@users.noreply.github.com>
Date: Mon, 17 Oct 2022 12:27:31 -0400
Subject: [PATCH] perf(npm): parallelize caching of npm specifier package infos
 (#16323)

---
 cli/npm/cache.rs            |  6 ++++++
 cli/npm/resolution.rs       | 26 ++++++++++++++++++++++----
 cli/npm/resolvers/common.rs |  7 +------
 cli/npm/resolvers/local.rs  |  2 +-
 4 files changed, 30 insertions(+), 11 deletions(-)

diff --git a/cli/npm/cache.rs b/cli/npm/cache.rs
index 6b841501ac1b07..77ecf12285dba6 100644
--- a/cli/npm/cache.rs
+++ b/cli/npm/cache.rs
@@ -23,6 +23,12 @@ use super::semver::NpmVersion;
 use super::tarball::verify_and_extract_tarball;
 use super::NpmPackageId;
 
+/// For some of the tests, we want downloading of packages
+/// to be deterministic so that the output is always the same
+pub fn should_sync_download() -> bool {
+  std::env::var("DENO_UNSTABLE_NPM_SYNC_DOWNLOAD") == Ok("1".to_string())
+}
+
 pub const NPM_PACKAGE_SYNC_LOCK_FILENAME: &str = ".deno_sync_lock";
 
 #[derive(Clone, Debug)]
diff --git a/cli/npm/resolution.rs b/cli/npm/resolution.rs
index d53b6771428490..2ceaa86ab23533 100644
--- a/cli/npm/resolution.rs
+++ b/cli/npm/resolution.rs
@@ -15,6 +15,7 @@ use deno_core::parking_lot::RwLock;
 use serde::Deserialize;
 use serde::Serialize;
 
+use super::cache::should_sync_download;
 use super::registry::NpmPackageInfo;
 use super::registry::NpmPackageVersionDistInfo;
 use super::registry::NpmPackageVersionInfo;
@@ -386,6 +387,7 @@ impl NpmResolution {
 
     // go over the top level packages first, then down the
     // tree one level at a time through all the branches
+    let mut unresolved_tasks = Vec::with_capacity(package_reqs.len());
     for package_req in package_reqs {
       if snapshot.package_reqs.contains_key(&package_req) {
         // skip analyzing this package, as there's already a matching top level package
@@ -400,7 +402,24 @@ impl NpmResolution {
       }
 
       // no existing best version, so resolve the current packages
-      let info = self.api.package_info(&package_req.name).await?;
+      let api = self.api.clone();
+      let maybe_info = if should_sync_download() {
+        // for deterministic test output
+        Some(api.package_info(&package_req.name).await)
+      } else {
+        None
+      };
+      unresolved_tasks.push(tokio::task::spawn(async move {
+        let info = match maybe_info {
+          Some(info) => info?,
+          None => api.package_info(&package_req.name).await?,
+        };
+        Result::<_, AnyError>::Ok((package_req, info))
+      }));
+    }
+
+    for result in futures::future::join_all(unresolved_tasks).await {
+      let (package_req, info) = result??;
       let version_and_info = get_resolved_package_version_and_info(
         &package_req.name,
         &package_req,
@@ -449,9 +468,8 @@ impl NpmResolution {
         ordering => ordering,
       });
 
-      // cache all the dependencies' registry infos in parallel when this env var isn't set
-      if std::env::var("DENO_UNSTABLE_NPM_SYNC_DOWNLOAD") != Ok("1".to_string())
-      {
+      // cache all the dependencies' registry infos in parallel if should
+      if !should_sync_download() {
         let handles = deps
           .iter()
           .map(|dep| {
diff --git a/cli/npm/resolvers/common.rs b/cli/npm/resolvers/common.rs
index 7769d2322f21ac..b91deae9e6b99e 100644
--- a/cli/npm/resolvers/common.rs
+++ b/cli/npm/resolvers/common.rs
@@ -10,6 +10,7 @@ use deno_core::futures;
 use deno_core::futures::future::BoxFuture;
 use deno_core::url::Url;
 
+use crate::npm::cache::should_sync_download;
 use crate::npm::resolution::NpmResolutionSnapshot;
 use crate::npm::NpmCache;
 use crate::npm::NpmPackageReq;
@@ -79,12 +80,6 @@ pub async fn cache_packages(
   Ok(())
 }
 
-/// For some of the tests, we want downloading of packages
-/// to be deterministic so that the output is always the same
-pub fn should_sync_download() -> bool {
-  std::env::var("DENO_UNSTABLE_NPM_SYNC_DOWNLOAD") == Ok("1".to_string())
-}
-
 pub fn ensure_registry_read_permission(
   registry_path: &Path,
   path: &Path,
diff --git a/cli/npm/resolvers/local.rs b/cli/npm/resolvers/local.rs
index 10ac8abfae44cd..cd79320b798b00 100644
--- a/cli/npm/resolvers/local.rs
+++ b/cli/npm/resolvers/local.rs
@@ -20,9 +20,9 @@ use deno_runtime::deno_core::futures;
 use tokio::task::JoinHandle;
 
 use crate::fs_util;
+use crate::npm::cache::should_sync_download;
 use crate::npm::resolution::NpmResolution;
 use crate::npm::resolution::NpmResolutionSnapshot;
-use crate::npm::resolvers::common::should_sync_download;
 use crate::npm::NpmCache;
 use crate::npm::NpmPackageId;
 use crate::npm::NpmPackageReq;