From 90ad02bf626b885a5dd8967894e2eafc953bdf92 Mon Sep 17 00:00:00 2001 From: Eelco Dolstra Date: Wed, 14 Sep 2016 16:00:40 +0200 Subject: Enable HTTP/2 support The binary cache store can now use HTTP/2 to do lookups. This is much more efficient than HTTP/1.1 due to multiplexing: we can issue many requests in parallel over a single TCP connection. Thus it's no longer necessary to use a bunch of concurrent TCP connections (25 by default). For example, downloading 802 .narinfo files from https://cache.nixos.org/, using a single TCP connection, takes 11.8s with HTTP/1.1, but only 0.61s with HTTP/2. This did require a fairly substantial rewrite of the Downloader class to use the curl multi interface, because otherwise curl wouldn't be able to do multiplexing for us. As a bonus, we get connection reuse even with HTTP/1.1. All downloads are now handled by a single worker thread. Clients call Downloader::enqueueDownload() to tell the worker thread to start the download, getting a std::future to the result. --- src/libexpr/parser.y | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'src/libexpr/parser.y') diff --git a/src/libexpr/parser.y b/src/libexpr/parser.y index 776e5cb39b81..3f7eed16f0f4 100644 --- a/src/libexpr/parser.y +++ b/src/libexpr/parser.y @@ -662,7 +662,7 @@ std::pair EvalState::resolveSearchPathElem(const SearchPathEl // FIXME: support specifying revision/branch res = { true, exportGit(store, elem.second, "master") }; else - res = { true, makeDownloader()->downloadCached(store, elem.second, true) }; + res = { true, getDownloader()->downloadCached(store, elem.second, true) }; } catch (DownloadError & e) { printMsg(lvlError, format("warning: Nix search path entry ‘%1%’ cannot be downloaded, ignoring") % elem.second); res = { false, "" }; -- cgit 1.4.1