From cab8fcc3a6ec1fc514b42cf43f5dfed91755d5a3 Mon Sep 17 00:00:00 2001
From: adumbidiot <nathaniel.daniel23@outlook.com>
Date: Fri, 30 Oct 2020 20:58:28 -0700
Subject: [PATCH] Remove use of global node.lib cache

---
 build/src/windows.rs | 71 ++++++++++++++++++++------------------------
 1 file changed, 33 insertions(+), 38 deletions(-)

diff --git a/build/src/windows.rs b/build/src/windows.rs
index 1deb581a..d493eea8 100644
--- a/build/src/windows.rs
+++ b/build/src/windows.rs
@@ -1,5 +1,7 @@
 use crate::*;
-use std::fs::{create_dir, metadata, write};
+use std::collections::hash_map::DefaultHasher;
+use std::fs::{metadata, write};
+use std::hash::{Hash, Hasher};
 use std::io::Read;
 use std::path::PathBuf;
 
@@ -33,8 +35,11 @@ fn download_node_lib(dist_url: &str, version: &str, arch: &str) -> Vec<u8> {
 }
 
 pub fn setup() {
+  let out_dir = std::env::var("OUT_DIR").expect("OUT_DIR is not set");
+
   // Assume nodejs if not specified.
-  let dist_url = std::env::var("NPM_CONFIG_DISTURL").unwrap_or("https://nodejs.org/dist".into());
+  let dist_url =
+    std::env::var("NPM_CONFIG_DISTURL").unwrap_or_else(|_| "https://nodejs.org/dist".to_string());
 
   // Try to get local nodejs version if not specified.
   let node_version = std::env::var("NPM_CONFIG_TARGET")
@@ -62,55 +67,45 @@ pub fn setup() {
   println!("cargo:rerun-if-env-changed=NPM_CONFIG_DISTURL");
   println!("cargo:rerun-if-env-changed=NPM_CONFIG_TARGET");
 
-  let mut node_lib_file_dir = PathBuf::from(
-    String::from_utf8(
-      Command::new("node")
-        .arg("-e")
-        .arg("console.log(require('os').homedir())")
-        .output()
-        .unwrap()
-        .stdout,
-    )
-    .unwrap()
-    .trim_end()
-    .to_owned(),
+  let mut node_lib_file_path = PathBuf::from(out_dir);
+  let link_search_dir = node_lib_file_path.clone();
+
+  // Hash the dist_url and store it in the node lib file name.
+  let dist_url_hash = {
+    let mut hasher = DefaultHasher::new();
+    dist_url.hash(&mut hasher);
+    hasher.finish()
+  };
+
+  // Encode version, arch, and dist_url to detect and reaquire node.lib when these 3 change.
+  let node_lib_file_name = format!(
+    "node-{version}-{arch}-{dist_url_hash}.lib",
+    version = node_version,
+    arch = arch,
+    dist_url_hash = dist_url_hash
   );
+  node_lib_file_path.push(&node_lib_file_name);
 
-  node_lib_file_dir.push(".napi-rs");
-
-  match create_dir(&node_lib_file_dir) {
-    Ok(_) => {}
-    Err(err) => {
-      if err.kind() != std::io::ErrorKind::AlreadyExists {
-        panic!(
-          "create {} folder failed: {}",
-          node_lib_file_dir.to_str().unwrap(),
-          err
-        )
-      }
-    }
-  }
-
-  let link_search_dir = node_lib_file_dir.clone();
-
-  node_lib_file_dir.push(format!("node-{}.lib", node_version));
-
-  if let Err(_) = metadata(&node_lib_file_dir) {
+  // If file does not exist, download it.
+  if metadata(&node_lib_file_path).is_err() {
     let node_lib = download_node_lib(&dist_url, &node_version, &arch);
-    write(&node_lib_file_dir, &node_lib).expect(&format!(
+
+    write(&node_lib_file_path, &node_lib).expect(&format!(
       "Could not save file to {}",
-      node_lib_file_dir.to_str().unwrap()
+      node_lib_file_path.to_str().unwrap()
     ));
   }
+
   println!(
     "cargo:rustc-link-lib={}",
-    &node_lib_file_dir.file_stem().unwrap().to_str().unwrap()
+    node_lib_file_path.file_stem().unwrap().to_str().unwrap()
   );
   println!(
     "cargo:rustc-link-search=native={}",
-    link_search_dir.to_str().unwrap()
+    link_search_dir.display()
   );
   println!("cargo:rustc-cdylib-link-arg=delayimp.lib");
   println!("cargo:rustc-cdylib-link-arg=/DELAYLOAD:node.exe");
+
   setup_napi_feature();
 }