forked from lix-project/lix
90ad02bf62
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.
64 lines
1.9 KiB
C++
64 lines
1.9 KiB
C++
#include "builtins.hh"
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#include "download.hh"
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#include "store-api.hh"
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#include "archive.hh"
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#include "compression.hh"
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namespace nix {
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void builtinFetchurl(const BasicDerivation & drv)
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{
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auto getAttr = [&](const string & name) {
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auto i = drv.env.find(name);
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if (i == drv.env.end()) throw Error(format("attribute ‘%s’ missing") % name);
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return i->second;
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};
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auto fetch = [&](const string & url) {
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/* No need to do TLS verification, because we check the hash of
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the result anyway. */
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DownloadRequest request(url);
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request.verifyTLS = false;
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/* Show a progress indicator, even though stderr is not a tty. */
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request.showProgress = DownloadRequest::yes;
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/* Note: have to use a fresh downloader here because we're in
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a forked process. */
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auto data = makeDownloader()->download(request);
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assert(data.data);
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return data.data;
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};
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std::shared_ptr<std::string> data;
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try {
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if (getAttr("outputHashMode") == "flat")
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data = fetch("http://tarballs.nixos.org/" + getAttr("outputHashAlgo") + "/" + getAttr("outputHash"));
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} catch (Error & e) {
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debug(e.what());
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}
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if (!data) data = fetch(getAttr("url"));
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Path storePath = getAttr("out");
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auto unpack = drv.env.find("unpack");
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if (unpack != drv.env.end() && unpack->second == "1") {
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if (string(*data, 0, 6) == string("\xfd" "7zXZ\0", 6))
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data = decompress("xz", *data);
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StringSource source(*data);
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restorePath(storePath, source);
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} else
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writeFile(storePath, *data);
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auto executable = drv.env.find("executable");
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if (executable != drv.env.end() && executable->second == "1") {
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if (chmod(storePath.c_str(), 0755) == -1)
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throw SysError(format("making ‘%1%’ executable") % storePath);
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}
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}
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}
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