From 19a75d99f828c12602c30d45e9bef80d027795ab Mon Sep 17 00:00:00 2001
From: Maximilian Marx <mmarx@wh2.tu-dresden.de>
Date: Sun, 27 Oct 2024 16:30:43 +0100
Subject: [PATCH] feat: increase NOFILES runtime limit

Before actually getting rate limited, we simply run out of free
sockets with the default limit of just 1024. Bumping this to 16384
helps considerably with derivations that have many
prerequisites (e.g., nixpkgs#texliveFull).

Signed-off-by: Maximilian Marx <mmarx@wh2.tu-dresden.de>
---
 Cargo.lock                     | 10 ++++++++++
 crates/nix-weather/Cargo.toml  |  1 +
 crates/nix-weather/src/main.rs | 11 +++++++++++
 3 files changed, 22 insertions(+)

diff --git a/Cargo.lock b/Cargo.lock
index 8a0ab98..9ccd545 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1249,6 +1249,7 @@ dependencies = [
  "pretty_env_logger",
  "rayon",
  "reqwest",
+ "rlimit",
  "scraper",
  "serde",
  "serde_json",
@@ -1740,6 +1741,15 @@ dependencies = [
  "windows-sys 0.52.0",
 ]
 
+[[package]]
+name = "rlimit"
+version = "0.10.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7043b63bd0cd1aaa628e476b80e6d4023a3b50eb32789f2728908107bd0c793a"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "roff"
 version = "0.2.2"
diff --git a/crates/nix-weather/Cargo.toml b/crates/nix-weather/Cargo.toml
index 325ef70..86a9382 100644
--- a/crates/nix-weather/Cargo.toml
+++ b/crates/nix-weather/Cargo.toml
@@ -28,6 +28,7 @@ openssl = { version = "0.10.63" }
 pretty_env_logger = "0.5.0"
 rayon = "1.9.0"
 reqwest = { version = "0.12", features = ["blocking"] }
+rlimit = "0.10.2"
 scraper = "0.18.1"
 serde = "1.0.197"
 serde_json = "1.0.114"
diff --git a/crates/nix-weather/src/main.rs b/crates/nix-weather/src/main.rs
index ff850e9..97e9381 100644
--- a/crates/nix-weather/src/main.rs
+++ b/crates/nix-weather/src/main.rs
@@ -22,6 +22,9 @@ mod nix;
 /// The initial time to wait on http 104, in milliseconds
 const SLIDE: u64 = 100;
 
+// Open files limit to try to set
+const NOFILES_LIMIT: u64 = 16384;
+
 const DEFAULT_CACHE: &str = "cache.nixos.org";
 const DEFAULT_CONFIG_DIR: &str = "/etc/nixos";
 
@@ -109,6 +112,14 @@ async fn main() -> io::Result<()> {
 
   log::debug!("{:#?}", &ips);
 
+  // try to increase NOFILES runtime limit
+  if rlimit::increase_nofile_limit(NOFILES_LIMIT).is_err() {
+    log::warn!(
+      "Failed to increase NOFILES limit, still at {:#?}",
+      rlimit::Resource::NOFILE.get().unwrap_or_default()
+    );
+  }
+
   let domain_addr = SocketAddr::new(ips[0], 443);
 
   let client = reqwest::Client::builder()