From 069643465f1d34eceb7923a3e7f12da352ef98c7 Mon Sep 17 00:00:00 2001
From: Hannes Mehnert <hannes@mehnert.org>
Date: Sun, 25 Sep 2022 23:13:52 +0200
Subject: [PATCH] allow to specify the number of parallel downloads as boot
 parameter

---
 mirage/config.ml    | 10 +++++++++-
 mirage/unikernel.ml |  2 +-
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/mirage/config.ml b/mirage/config.ml
index 0937bd4..2104f9d 100644
--- a/mirage/config.ml
+++ b/mirage/config.ml
@@ -20,6 +20,14 @@ let remote =
   in
   Key.(create "remote" Arg.(opt string "https://github.com/ocaml/opam-repository.git#master" doc))
 
+let parallel_downloads =
+  let doc =
+    Key.Arg.info
+      ~doc:"Amount of parallel HTTP downloads"
+      ["parallel-downloads"]
+  in
+  Key.(create "parallel-downloads" Arg.(opt int 20 doc))
+
 let hook_url =
   let doc =
     Key.Arg.info
@@ -40,7 +48,7 @@ let tls_authenticator =
 
 let mirror =
   foreign "Unikernel.Make"
-    ~keys:[ Key.v check ; Key.v remote ; Key.v hook_url ; Key.v tls_authenticator ; Key.v port ]
+    ~keys:[ Key.v check ; Key.v remote ; Key.v parallel_downloads ; Key.v hook_url ; Key.v tls_authenticator ; Key.v port ]
     ~packages:[
       package ~min:"0.1.0" ~sublibs:[ "mirage" ] "paf" ;
       package "h2" ;
diff --git a/mirage/unikernel.ml b/mirage/unikernel.ml
index d69680c..42e11cd 100644
--- a/mirage/unikernel.ml
+++ b/mirage/unikernel.ml
@@ -629,7 +629,7 @@ stamp: %S
                "https://github.com/Opsian/opsian-ocaml/releases/download/0.1/0.1.tar.gz"
                k)) urls
     in
-    let pool = Lwt_pool.create 20 (Fun.const Lwt.return_unit) in
+    let pool = Lwt_pool.create (Key_gen.parallel_downloads ()) (Fun.const Lwt.return_unit) in
     Lwt_list.iter_p (fun (url, csums) ->
         Lwt_pool.use pool @@ fun () ->
         HM.fold (fun h v r ->