diff --git a/src/libstore/binary-cache-store.cc b/src/libstore/binary-cache-store.cc index 68af85bf..ab971dd8 100644 --- a/src/libstore/binary-cache-store.cc +++ b/src/libstore/binary-cache-store.cc @@ -129,10 +129,8 @@ void BinaryCacheStore::addToStore(const ValidPathInfo & info, const refnars.emplace(info.path, narAccessor); - accessor_->addToCache(info.path, *nar); - } + if (accessor_) + accessor_->addToCache(info.path, *nar, narAccessor); { auto res = jsonRoot.placeholder("root"); @@ -144,10 +142,8 @@ void BinaryCacheStore::addToStore(const ValidPathInfo & info, const refnars.emplace(info.path, makeNarAccessor(nar)); - accessor_->addToCache(info.path, *nar); - } + if (accessor_) + accessor_->addToCache(info.path, *nar, makeNarAccessor(nar)); } /* Compress the NAR. */ diff --git a/src/libstore/nar-accessor.cc b/src/libstore/nar-accessor.cc index d6e9757c..b7448068 100644 --- a/src/libstore/nar-accessor.cc +++ b/src/libstore/nar-accessor.cc @@ -6,6 +6,8 @@ #include #include +#include + namespace nix { struct NarMember @@ -24,83 +26,127 @@ struct NarMember std::map children; }; -struct NarIndexer : ParseSink, StringSource +struct NarAccessor : public FSAccessor { + std::shared_ptr nar; + + GetNarBytes getNarBytes; + NarMember root; - std::stack parents; - std::string currentStart; - bool isExec = false; - - NarIndexer(const std::string & nar) : StringSource(nar) + struct NarIndexer : ParseSink, StringSource { - } + NarAccessor & acc; - void createMember(const Path & path, NarMember member) { - size_t level = std::count(path.begin(), path.end(), '/'); - while(parents.size() > level) { - parents.pop(); - } + std::stack parents; - if(parents.empty()) { - root = std::move(member); - parents.push(&root); - } else { - if(parents.top()->type != FSAccessor::Type::tDirectory) { - throw Error(format("NAR file missing parent directory of path '%1%'") % path); + std::string currentStart; + bool isExec = false; + + NarIndexer(NarAccessor & acc, const std::string & nar) + : StringSource(nar), acc(acc) + { } + + void createMember(const Path & path, NarMember member) { + size_t level = std::count(path.begin(), path.end(), '/'); + while (parents.size() > level) parents.pop(); + + if (parents.empty()) { + acc.root = std::move(member); + parents.push(&acc.root); + } else { + if (parents.top()->type != FSAccessor::Type::tDirectory) + throw Error("NAR file missing parent directory of path '%s'", path); + auto result = parents.top()->children.emplace(baseNameOf(path), std::move(member)); + parents.push(&result.first->second); } - auto result = parents.top()->children.emplace(baseNameOf(path), std::move(member)); - parents.push(&result.first->second); } - } - void createDirectory(const Path & path) override - { - createMember(path, {FSAccessor::Type::tDirectory, false, 0, 0 }); - } - - void createRegularFile(const Path & path) override - { - createMember(path, {FSAccessor::Type::tRegular, false, 0, 0 }); - } - - void isExecutable() override - { - parents.top()->isExecutable = true; - } - - void preallocateContents(unsigned long long size) override - { - currentStart = string(s, pos, 16); - assert(size <= std::numeric_limits::max()); - parents.top()->size = (size_t)size; - parents.top()->start = pos; - } - - void receiveContents(unsigned char * data, unsigned int len) override - { - // Sanity check - if (!currentStart.empty()) { - assert(len < 16 || currentStart == string((char *) data, 16)); - currentStart.clear(); + void createDirectory(const Path & path) override + { + createMember(path, {FSAccessor::Type::tDirectory, false, 0, 0}); } - } - void createSymlink(const Path & path, const string & target) override + void createRegularFile(const Path & path) override + { + createMember(path, {FSAccessor::Type::tRegular, false, 0, 0}); + } + + void isExecutable() override + { + parents.top()->isExecutable = true; + } + + void preallocateContents(unsigned long long size) override + { + currentStart = string(s, pos, 16); + assert(size <= std::numeric_limits::max()); + parents.top()->size = (size_t)size; + parents.top()->start = pos; + } + + void receiveContents(unsigned char * data, unsigned int len) override + { + // Sanity check + if (!currentStart.empty()) { + assert(len < 16 || currentStart == string((char *) data, 16)); + currentStart.clear(); + } + } + + void createSymlink(const Path & path, const string & target) override + { + createMember(path, + NarMember{FSAccessor::Type::tSymlink, false, 0, 0, target}); + } + }; + + NarAccessor(ref nar) : nar(nar) { - createMember(path, - NarMember{FSAccessor::Type::tSymlink, false, 0, 0, target}); + NarIndexer indexer(*this, *nar); + parseDump(indexer, indexer); } - NarMember* find(const Path & path) + NarAccessor(const std::string & listing, GetNarBytes getNarBytes) + : getNarBytes(getNarBytes) + { + using json = nlohmann::json; + + std::function recurse; + + recurse = [&](NarMember & member, json & v) { + std::string type = v["type"]; + + if (type == "directory") { + member.type = FSAccessor::Type::tDirectory; + for (auto i = v["entries"].begin(); i != v["entries"].end(); ++i) { + std::string name = i.key(); + recurse(member.children[name], i.value()); + } + } else if (type == "regular") { + member.type = FSAccessor::Type::tRegular; + member.size = v["size"]; + member.isExecutable = v.value("executable", false); + member.start = v["narOffset"]; + } else if (type == "symlink") { + member.type = FSAccessor::Type::tSymlink; + member.target = v.value("target", ""); + } else return; + }; + + json v = json::parse(listing); + recurse(root, v); + } + + NarMember * find(const Path & path) { Path canon = path == "" ? "" : canonPath(path); - NarMember* current = &root; + NarMember * current = &root; auto end = path.end(); - for(auto it = path.begin(); it != end; ) { + for (auto it = path.begin(); it != end; ) { // because it != end, the remaining component is non-empty so we need // a directory - if(current->type != FSAccessor::Type::tDirectory) return nullptr; + if (current->type != FSAccessor::Type::tDirectory) return nullptr; // skip slash (canonPath above ensures that this is always a slash) assert(*it == '/'); @@ -109,7 +155,7 @@ struct NarIndexer : ParseSink, StringSource // lookup current component auto next = std::find(it, end, '/'); auto child = current->children.find(std::string(it, next)); - if(child == current->children.end()) return nullptr; + if (child == current->children.end()) return nullptr; current = &child->second; it = next; @@ -118,28 +164,16 @@ struct NarIndexer : ParseSink, StringSource return current; } - NarMember& at(const Path & path) { + NarMember & get(const Path & path) { auto result = find(path); - if(result == nullptr) { - throw Error(format("NAR file does not contain path '%1%'") % path); - } + if (result == nullptr) + throw Error("NAR file does not contain path '%1%'", path); return *result; } -}; - -struct NarAccessor : public FSAccessor -{ - ref nar; - NarIndexer indexer; - - NarAccessor(ref nar) : nar(nar), indexer(*nar) - { - parseDump(indexer, indexer); - } Stat stat(const Path & path) override { - auto i = indexer.find(path); + auto i = find(path); if (i == nullptr) return {FSAccessor::Type::tMissing, 0, false}; return {i->type, i->size, i->isExecutable, i->start}; @@ -147,30 +181,33 @@ struct NarAccessor : public FSAccessor StringSet readDirectory(const Path & path) override { - auto i = indexer.at(path); + auto i = get(path); if (i.type != FSAccessor::Type::tDirectory) throw Error(format("path '%1%' inside NAR file is not a directory") % path); StringSet res; - for(auto&& child : i.children) { + for (auto & child : i.children) res.insert(child.first); - } return res; } std::string readFile(const Path & path) override { - auto i = indexer.at(path); + auto i = get(path); if (i.type != FSAccessor::Type::tRegular) throw Error(format("path '%1%' inside NAR file is not a regular file") % path); + + if (getNarBytes) return getNarBytes(i.start, i.size); + + assert(nar); return std::string(*nar, i.start, i.size); } std::string readLink(const Path & path) override { - auto i = indexer.at(path); + auto i = get(path); if (i.type != FSAccessor::Type::tSymlink) throw Error(format("path '%1%' inside NAR file is not a symlink") % path); return i.target; @@ -182,6 +219,12 @@ ref makeNarAccessor(ref nar) return make_ref(nar); } +ref makeLazyNarAccessor(const std::string & listing, + GetNarBytes getNarBytes) +{ + return make_ref(listing, getNarBytes); +} + void listNar(JSONPlaceholder & res, ref accessor, const Path & path, bool recurse) { diff --git a/src/libstore/nar-accessor.hh b/src/libstore/nar-accessor.hh index ed8fe15c..1903355a 100644 --- a/src/libstore/nar-accessor.hh +++ b/src/libstore/nar-accessor.hh @@ -8,6 +8,16 @@ namespace nix { file. */ ref makeNarAccessor(ref nar); +/* Create a NAR accessor from a NAR listing (in the format produced by + listNar()). The callback getNarBytes(offset, length) is used by the + readFile() method of the accessor to get the contents of files + inside the NAR. */ +typedef std::function GetNarBytes; + +ref makeLazyNarAccessor( + const std::string & listing, + GetNarBytes getNarBytes); + class JSONPlaceholder; /* Write a JSON representation of the contents of a NAR (except file diff --git a/src/libstore/remote-fs-accessor.cc b/src/libstore/remote-fs-accessor.cc index ba9620a1..5233fb2c 100644 --- a/src/libstore/remote-fs-accessor.cc +++ b/src/libstore/remote-fs-accessor.cc @@ -1,5 +1,10 @@ #include "remote-fs-accessor.hh" #include "nar-accessor.hh" +#include "json.hh" + +#include +#include +#include namespace nix { @@ -11,20 +16,30 @@ RemoteFSAccessor::RemoteFSAccessor(ref store, const Path & cacheDir) createDirs(cacheDir); } -Path RemoteFSAccessor::makeCacheFile(const Path & storePath) +Path RemoteFSAccessor::makeCacheFile(const Path & storePath, const std::string & ext) { assert(cacheDir != ""); - return fmt("%s/%s.nar", cacheDir, storePathToHash(storePath)); + return fmt("%s/%s.%s", cacheDir, storePathToHash(storePath), ext); } -void RemoteFSAccessor::addToCache(const Path & storePath, const std::string & nar) +void RemoteFSAccessor::addToCache(const Path & storePath, const std::string & nar, + ref narAccessor) { - try { - if (cacheDir == "") return; - /* FIXME: do this asynchronously. */ - writeFile(makeCacheFile(storePath), nar); - } catch (...) { - ignoreException(); + nars.emplace(storePath, narAccessor); + + if (cacheDir != "") { + try { + std::ostringstream str; + JSONPlaceholder jsonRoot(str); + listNar(jsonRoot, narAccessor, "", true); + writeFile(makeCacheFile(storePath, "ls"), str.str()); + + /* FIXME: do this asynchronously. */ + writeFile(makeCacheFile(storePath, "nar"), nar); + + } catch (...) { + ignoreException(); + } } } @@ -42,20 +57,49 @@ std::pair, Path> RemoteFSAccessor::fetch(const Path & path_) if (i != nars.end()) return {i->second, restPath}; StringSink sink; + std::string listing; + Path cacheFile; - try { - if (cacheDir != "") - *sink.s = nix::readFile(makeCacheFile(storePath)); - } catch (SysError &) { } + if (cacheDir != "" && pathExists(cacheFile = makeCacheFile(storePath, "nar"))) { - if (sink.s->empty()) { - store->narFromPath(storePath, sink); - addToCache(storePath, *sink.s); + try { + listing = nix::readFile(makeCacheFile(storePath, "ls")); + + auto narAccessor = makeLazyNarAccessor(listing, + [cacheFile](uint64_t offset, uint64_t length) { + + AutoCloseFD fd = open(cacheFile.c_str(), O_RDONLY | O_CLOEXEC); + if (!fd) + throw SysError("opening NAR cache file '%s'", cacheFile); + + if (lseek(fd.get(), offset, SEEK_SET) != (off_t) offset) + throw SysError("seeking in '%s'", cacheFile); + + std::string buf(length, 0); + readFull(fd.get(), (unsigned char *) buf.data(), length); + + return buf; + }); + + nars.emplace(storePath, narAccessor); + return {narAccessor, restPath}; + + } catch (SysError &) { } + + try { + *sink.s = nix::readFile(cacheFile); + + auto narAccessor = makeNarAccessor(sink.s); + nars.emplace(storePath, narAccessor); + return {narAccessor, restPath}; + + } catch (SysError &) { } } - auto accessor = makeNarAccessor(sink.s); - nars.emplace(storePath, accessor); - return {accessor, restPath}; + store->narFromPath(storePath, sink); + auto narAccessor = makeNarAccessor(sink.s); + addToCache(storePath, *sink.s, narAccessor); + return {narAccessor, restPath}; } FSAccessor::Stat RemoteFSAccessor::stat(const Path & path) diff --git a/src/libstore/remote-fs-accessor.hh b/src/libstore/remote-fs-accessor.hh index 2a3fc01e..4afb3be9 100644 --- a/src/libstore/remote-fs-accessor.hh +++ b/src/libstore/remote-fs-accessor.hh @@ -18,9 +18,10 @@ class RemoteFSAccessor : public FSAccessor friend class BinaryCacheStore; - Path makeCacheFile(const Path & storePath); + Path makeCacheFile(const Path & storePath, const std::string & ext); - void addToCache(const Path & storePath, const std::string & nar); + void addToCache(const Path & storePath, const std::string & nar, + ref narAccessor); public: