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).
This commit is contained in:
Eelco Dolstra 2016-09-14 16:34:37 +02:00
parent 90ad02bf62
commit 6656ef7b5b
2 changed files with 11 additions and 6 deletions

View file

@ -408,10 +408,9 @@ flag, e.g. <literal>--option gc-keep-outputs false</literal>.</para>
<varlistentry><term><literal>binary-caches-parallel-connections</literal></term>
<listitem><para>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.</para></listitem>
<listitem><para>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.</para></listitem>
</varlistentry>

View file

@ -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<DownloadItem>
{
CurlDownloader & downloader;
@ -185,6 +187,7 @@ 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);
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);
@ -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);