lix/src/libstore/binary-cache-store.hh
Eelco Dolstra 75989bdca7 Make computeFSClosure() single-threaded again
The fact that queryPathInfo() is synchronous meant that we needed a
thread for every concurrent binary cache lookup, even though they end
up being handled by the same download thread. Requiring hundreds of
threads is not a good idea. So now there is an asynchronous version of
queryPathInfo() that takes a callback function to process the
result. Similarly, enqueueDownload() now takes a callback rather than
returning a future.

Thus, a command like

  nix path-info --store https://cache.nixos.org/ -r /nix/store/slljrzwmpygy1daay14kjszsr9xix063-nixos-16.09beta231.dccf8c5

that returns 4941 paths now takes 1.87s using only 2 threads (the main
thread and the downloader thread). (This is with a prewarmed
CloudFront.)
2016-09-16 18:54:14 +02:00

143 lines
3.5 KiB
C++

#pragma once
#include "crypto.hh"
#include "store-api.hh"
#include "pool.hh"
#include <atomic>
namespace nix {
struct NarInfo;
class BinaryCacheStore : public Store
{
private:
std::unique_ptr<SecretKey> secretKey;
std::string compression;
protected:
BinaryCacheStore(const Params & params);
[[noreturn]] void notImpl();
virtual bool fileExists(const std::string & path) = 0;
virtual void upsertFile(const std::string & path, const std::string & data) = 0;
/* Return the contents of the specified file, or null if it
doesn't exist. */
virtual void getFile(const std::string & path,
std::function<void(std::shared_ptr<std::string>)> success,
std::function<void(std::exception_ptr exc)> failure) = 0;
std::shared_ptr<std::string> getFile(const std::string & path);
bool wantMassQuery_ = false;
int priority = 50;
public:
virtual void init();
private:
std::string narMagic;
std::string narInfoFileFor(const Path & storePath);
public:
bool isValidPathUncached(const Path & path) override;
PathSet queryValidPaths(const PathSet & paths) override
{ notImpl(); }
PathSet queryAllValidPaths() override
{ notImpl(); }
void queryPathInfoUncached(const Path & path,
std::function<void(std::shared_ptr<ValidPathInfo>)> success,
std::function<void(std::exception_ptr exc)> failure) override;
void queryReferrers(const Path & path,
PathSet & referrers) override
{ notImpl(); }
PathSet queryValidDerivers(const Path & path) override
{ return {}; }
PathSet queryDerivationOutputs(const Path & path) override
{ notImpl(); }
StringSet queryDerivationOutputNames(const Path & path) override
{ notImpl(); }
Path queryPathFromHashPart(const string & hashPart) override
{ notImpl(); }
PathSet querySubstitutablePaths(const PathSet & paths) override
{ return {}; }
void querySubstitutablePathInfos(const PathSet & paths,
SubstitutablePathInfos & infos) override
{ }
bool wantMassQuery() override { return wantMassQuery_; }
void addToStore(const ValidPathInfo & info, const std::string & nar,
bool repair = false, bool dontCheckSigs = false) override;
Path addToStore(const string & name, const Path & srcPath,
bool recursive = true, HashType hashAlgo = htSHA256,
PathFilter & filter = defaultPathFilter, bool repair = false) override;
Path addTextToStore(const string & name, const string & s,
const PathSet & references, bool repair = false) override;
void narFromPath(const Path & path, Sink & sink) override;
void buildPaths(const PathSet & paths, BuildMode buildMode = bmNormal) override
{ notImpl(); }
BuildResult buildDerivation(const Path & drvPath, const BasicDerivation & drv,
BuildMode buildMode = bmNormal) override
{ notImpl(); }
void ensurePath(const Path & path) override
{ notImpl(); }
void addTempRoot(const Path & path) override
{ notImpl(); }
void addIndirectRoot(const Path & path) override
{ notImpl(); }
void syncWithGC() override
{ }
Roots findRoots() override
{ notImpl(); }
void collectGarbage(const GCOptions & options, GCResults & results) override
{ notImpl(); }
void optimiseStore() override
{ }
bool verifyStore(bool checkContents, bool repair) override
{ return true; }
ref<FSAccessor> getFSAccessor() override;
void addSignatures(const Path & storePath, const StringSet & sigs) override
{ notImpl(); }
};
}