diff options
Diffstat (limited to 'src/libstore/nar-accessor.cc')
| -rw-r--r-- | src/libstore/nar-accessor.cc | 193 |
1 files changed, 118 insertions, 75 deletions
diff --git a/src/libstore/nar-accessor.cc b/src/libstore/nar-accessor.cc index d6e9757c2cbf..b74480684f2a 100644 --- a/src/libstore/nar-accessor.cc +++ b/src/libstore/nar-accessor.cc @@ -6,6 +6,8 @@ #include <stack> #include <algorithm> +#include <nlohmann/json.hpp> + namespace nix { struct NarMember @@ -24,83 +26,127 @@ struct NarMember std::map<std::string, NarMember> children; }; -struct NarIndexer : ParseSink, StringSource +struct NarAccessor : public FSAccessor { - NarMember root; - std::stack<NarMember*> parents; + std::shared_ptr<const std::string> nar; - std::string currentStart; - bool isExec = false; + GetNarBytes getNarBytes; - NarIndexer(const std::string & nar) : StringSource(nar) + NarMember root; + + 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<NarMember *> 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 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 createRegularFile(const Path & path) override + { + createMember(path, {FSAccessor::Type::tRegular, false, 0, 0}); + } - void isExecutable() override - { - parents.top()->isExecutable = true; - } + void isExecutable() override + { + parents.top()->isExecutable = true; + } - void preallocateContents(unsigned long long size) override - { - currentStart = string(s, pos, 16); - assert(size <= std::numeric_limits<size_t>::max()); - parents.top()->size = (size_t)size; - parents.top()->start = pos; - } + void preallocateContents(unsigned long long size) override + { + currentStart = string(s, pos, 16); + assert(size <= std::numeric_limits<size_t>::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 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<const std::string> nar) : nar(nar) + { + NarIndexer indexer(*this, *nar); + parseDump(indexer, indexer); } - void createSymlink(const Path & path, const string & target) override + NarAccessor(const std::string & listing, GetNarBytes getNarBytes) + : getNarBytes(getNarBytes) { - createMember(path, - NarMember{FSAccessor::Type::tSymlink, false, 0, 0, target}); + using json = nlohmann::json; + + std::function<void(NarMember &, json &)> 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) + 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<const std::string> nar; - NarIndexer indexer; - - NarAccessor(ref<const std::string> 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<FSAccessor> makeNarAccessor(ref<const std::string> nar) return make_ref<NarAccessor>(nar); } +ref<FSAccessor> makeLazyNarAccessor(const std::string & listing, + GetNarBytes getNarBytes) +{ + return make_ref<NarAccessor>(listing, getNarBytes); +} + void listNar(JSONPlaceholder & res, ref<FSAccessor> accessor, const Path & path, bool recurse) { |