From 6656ef7b5b798200cf8bf0c7534dbad1e964444d Mon Sep 17 00:00:00 2001 From: Eelco Dolstra Date: Wed, 14 Sep 2016 16:34:37 +0200 Subject: [PATCH] Revive binary-caches-parallel-connections It's a slight misnomer now because it actually limits *all* downloads, not just binary cache lookups. Also add a "enable-http2" option to allow disabling use of HTTP/2 (enabled by default). --- doc/manual/command-ref/conf-file.xml | 7 +++---- src/libstore/download.cc | 10 ++++++++-- 2 files changed, 11 insertions(+), 6 deletions(-) diff --git a/doc/manual/command-ref/conf-file.xml b/doc/manual/command-ref/conf-file.xml index fb7bdf573..8b7640e58 100644 --- a/doc/manual/command-ref/conf-file.xml +++ b/doc/manual/command-ref/conf-file.xml @@ -408,10 +408,9 @@ flag, e.g. --option gc-keep-outputs false. binary-caches-parallel-connections - The maximum number of parallel HTTP connections - used by the binary cache substituter to get NAR info files. This - number should be high to minimise latency. It defaults to - 25. + The maximum number of parallel TCP connections + used to fetch files from binary caches and by other downloads. It + defaults to 25. 0 means no limit. diff --git a/src/libstore/download.cc b/src/libstore/download.cc index 2aca0a975..b2d223da9 100644 --- a/src/libstore/download.cc +++ b/src/libstore/download.cc @@ -40,6 +40,8 @@ struct CurlDownloader : public Downloader std::random_device rd; std::mt19937 mt19937; + bool enableHttp2; + struct DownloadItem : public std::enable_shared_from_this { CurlDownloader & downloader; @@ -185,7 +187,8 @@ struct CurlDownloader : public Downloader curl_easy_setopt(req, CURLOPT_NOSIGNAL, 1); curl_easy_setopt(req, CURLOPT_USERAGENT, ("Nix/" + nixVersion).c_str()); curl_easy_setopt(req, CURLOPT_PIPEWAIT, 1); - curl_easy_setopt(req, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_2TLS); + if (downloader.enableHttp2) + curl_easy_setopt(req, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_2TLS); curl_easy_setopt(req, CURLOPT_WRITEFUNCTION, DownloadItem::writeCallbackWrapper); curl_easy_setopt(req, CURLOPT_WRITEDATA, this); curl_easy_setopt(req, CURLOPT_HEADERFUNCTION, DownloadItem::headerCallbackWrapper); @@ -291,7 +294,10 @@ struct CurlDownloader : public Downloader curlm = curl_multi_init(); curl_multi_setopt(curlm, CURLMOPT_PIPELINING, CURLPIPE_MULTIPLEX); - curl_multi_setopt(curlm, CURLMOPT_MAX_TOTAL_CONNECTIONS, 25); // FIXME: configurable + curl_multi_setopt(curlm, CURLMOPT_MAX_TOTAL_CONNECTIONS, + settings.get("binary-caches-parallel-connections", 25)); + + enableHttp2 = settings.get("enable-http2", true); wakeupPipe.create(); fcntl(wakeupPipe.readSide.get(), F_SETFL, O_NONBLOCK);