Factor a general remote FS accessor out of BinaryCacheStore

This commit is contained in:
Shea Levy 2016-09-02 14:24:34 -04:00
parent 0f39633290
commit a705e8ce0a
3 changed files with 88 additions and 64 deletions

View file

@ -6,8 +6,7 @@
#include "globals.hh" #include "globals.hh"
#include "nar-info.hh" #include "nar-info.hh"
#include "sync.hh" #include "sync.hh"
#include "worker-protocol.hh" #include "remote-fs-accessor.hh"
#include "nar-accessor.hh"
#include "nar-info-disk-cache.hh" #include "nar-info-disk-cache.hh"
#include <chrono> #include <chrono>
@ -232,70 +231,9 @@ Path BinaryCacheStore::addTextToStore(const string & name, const string & s,
return info.path; return info.path;
} }
/* Given requests for a path /nix/store/<x>/<y>, this accessor will
first download the NAR for /nix/store/<x> from the binary cache,
build a NAR accessor for that NAR, and use that to access <y>. */
struct BinaryCacheStoreAccessor : public FSAccessor
{
ref<BinaryCacheStore> store;
std::map<Path, ref<FSAccessor>> nars;
BinaryCacheStoreAccessor(ref<BinaryCacheStore> store)
: store(store)
{
}
std::pair<ref<FSAccessor>, Path> fetch(const Path & path_)
{
auto path = canonPath(path_);
auto storePath = store->toStorePath(path);
std::string restPath = std::string(path, storePath.size());
if (!store->isValidPath(storePath))
throw InvalidPath(format("path %1% is not a valid store path") % storePath);
auto i = nars.find(storePath);
if (i != nars.end()) return {i->second, restPath};
StringSink sink;
store->narFromPath(storePath, sink);
auto accessor = makeNarAccessor(sink.s);
nars.emplace(storePath, accessor);
return {accessor, restPath};
}
Stat stat(const Path & path) override
{
auto res = fetch(path);
return res.first->stat(res.second);
}
StringSet readDirectory(const Path & path) override
{
auto res = fetch(path);
return res.first->readDirectory(res.second);
}
std::string readFile(const Path & path) override
{
auto res = fetch(path);
return res.first->readFile(res.second);
}
std::string readLink(const Path & path) override
{
auto res = fetch(path);
return res.first->readLink(res.second);
}
};
ref<FSAccessor> BinaryCacheStore::getFSAccessor() ref<FSAccessor> BinaryCacheStore::getFSAccessor()
{ {
return make_ref<BinaryCacheStoreAccessor>(ref<BinaryCacheStore>( return make_ref<RemoteFSAccessor>(ref<Store>(shared_from_this()));
std::dynamic_pointer_cast<BinaryCacheStore>(shared_from_this())));
} }
} }

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@ -0,0 +1,57 @@
#include "remote-fs-accessor.hh"
#include "nar-accessor.hh"
namespace nix {
RemoteFSAccessor::RemoteFSAccessor(ref<Store> store)
: store(store)
{
}
std::pair<ref<FSAccessor>, Path> RemoteFSAccessor::fetch(const Path & path_)
{
auto path = canonPath(path_);
auto storePath = store->toStorePath(path);
std::string restPath = std::string(path, storePath.size());
if (!store->isValidPath(storePath))
throw InvalidPath(format("path %1% is not a valid store path") % storePath);
auto i = nars.find(storePath);
if (i != nars.end()) return {i->second, restPath};
StringSink sink;
store->narFromPath(storePath, sink);
auto accessor = makeNarAccessor(sink.s);
nars.emplace(storePath, accessor);
return {accessor, restPath};
}
FSAccessor::Stat RemoteFSAccessor::stat(const Path & path)
{
auto res = fetch(path);
return res.first->stat(res.second);
}
StringSet RemoteFSAccessor::readDirectory(const Path & path)
{
auto res = fetch(path);
return res.first->readDirectory(res.second);
}
std::string RemoteFSAccessor::readFile(const Path & path)
{
auto res = fetch(path);
return res.first->readFile(res.second);
}
std::string RemoteFSAccessor::readLink(const Path & path)
{
auto res = fetch(path);
return res.first->readLink(res.second);
}
}

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@ -0,0 +1,29 @@
#pragma once
#include "fs-accessor.hh"
#include "ref.hh"
#include "store-api.hh"
namespace nix {
class RemoteFSAccessor : public FSAccessor
{
ref<Store> store;
std::map<Path, ref<FSAccessor>> nars;
std::pair<ref<FSAccessor>, Path> fetch(const Path & path_);
public:
RemoteFSAccessor(ref<Store> store);
Stat stat(const Path & path) override;
StringSet readDirectory(const Path & path) override;
std::string readFile(const Path & path) override;
std::string readLink(const Path & path) override;
};
}