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Diffstat (limited to 'third_party/nix/src/libstore/local-store.hh')
| -rw-r--r-- | third_party/nix/src/libstore/local-store.hh | 319 |
1 files changed, 319 insertions, 0 deletions
diff --git a/third_party/nix/src/libstore/local-store.hh b/third_party/nix/src/libstore/local-store.hh new file mode 100644 index 0000000000..a7c49079d2 --- /dev/null +++ b/third_party/nix/src/libstore/local-store.hh @@ -0,0 +1,319 @@ +#pragma once + +#include <chrono> +#include <future> +#include <string> +#include <unordered_set> + +#include <absl/status/status.h> +#include <absl/strings/str_split.h> + +#include "libstore/pathlocks.hh" +#include "libstore/sqlite.hh" +#include "libstore/store-api.hh" +#include "libutil/sync.hh" +#include "libutil/util.hh" + +namespace nix { + +/* Nix store and database schema version. Version 1 (or 0) was Nix <= + 0.7. Version 2 was Nix 0.8 and 0.9. Version 3 is Nix 0.10. + Version 4 is Nix 0.11. Version 5 is Nix 0.12-0.16. Version 6 is + Nix 1.0. Version 7 is Nix 1.3. Version 10 is 2.0. */ +const int nixSchemaVersion = 10; + +struct Derivation; + +struct OptimiseStats { + unsigned long filesLinked = 0; + unsigned long long bytesFreed = 0; + unsigned long long blocksFreed = 0; +}; + +class LocalStore : public LocalFSStore { + private: + /* Lock file used for upgrading. */ + AutoCloseFD globalLock; + + struct State { + /* The SQLite database object. */ + SQLite db; + + /* Some precompiled SQLite statements. */ + SQLiteStmt stmtRegisterValidPath; + SQLiteStmt stmtUpdatePathInfo; + SQLiteStmt stmtAddReference; + SQLiteStmt stmtQueryPathInfo; + SQLiteStmt stmtQueryReferences; + SQLiteStmt stmtQueryReferrers; + SQLiteStmt stmtInvalidatePath; + SQLiteStmt stmtAddDerivationOutput; + SQLiteStmt stmtQueryValidDerivers; + SQLiteStmt stmtQueryDerivationOutputs; + SQLiteStmt stmtQueryPathFromHashPart; + SQLiteStmt stmtQueryValidPaths; + + /* The file to which we write our temporary roots. */ + AutoCloseFD fdTempRoots; + + /* The last time we checked whether to do an auto-GC, or an + auto-GC finished. */ + std::chrono::time_point<std::chrono::steady_clock> lastGCCheck; + + /* Whether auto-GC is running. If so, get gcFuture to wait for + the GC to finish. */ + bool gcRunning = false; + std::shared_future<void> gcFuture; + + /* How much disk space was available after the previous + auto-GC. If the current available disk space is below + minFree but not much below availAfterGC, then there is no + point in starting a new GC. */ + uint64_t availAfterGC = std::numeric_limits<uint64_t>::max(); + + std::unique_ptr<PublicKeys> publicKeys; + }; + + Sync<State, std::recursive_mutex> _state; + + public: + PathSetting realStoreDir_; + + const Path realStoreDir; + const Path dbDir; + const Path linksDir; + const Path reservedPath; + const Path schemaPath; + const Path trashDir; + const Path tempRootsDir; + const Path fnTempRoots; + + private: + Setting<bool> requireSigs{ + (Store*)this, settings.requireSigs, "require-sigs", + "whether store paths should have a trusted signature on import"}; + + const PublicKeys& getPublicKeys(); + + public: + // Hack for build-remote.cc. + // TODO(tazjin): remove this when we've got gRPC + PathSet locksHeld = + absl::StrSplit(getEnv("NIX_HELD_LOCKS").value_or(""), + absl::ByAnyChar(" \t\n\r"), absl::SkipEmpty()); + + /* Initialise the local store, upgrading the schema if + necessary. */ + LocalStore(const Params& params); + + ~LocalStore(); + + /* Implementations of abstract store API methods. */ + + std::string getUri() override; + + bool isValidPathUncached(const Path& path) override; + + PathSet queryValidPaths(const PathSet& paths, SubstituteFlag maybeSubstitute = + NoSubstitute) override; + + PathSet queryAllValidPaths() override; + + void queryPathInfoUncached( + const Path& path, + Callback<std::shared_ptr<ValidPathInfo>> callback) noexcept override; + + void queryReferrers(const Path& path, PathSet& referrers) override; + + PathSet queryValidDerivers(const Path& path) override; + + PathSet queryDerivationOutputs(const Path& path) override; + + StringSet queryDerivationOutputNames(const Path& path) override; + + Path queryPathFromHashPart(const std::string& hashPart) override; + + PathSet querySubstitutablePaths(const PathSet& paths) override; + + void querySubstitutablePathInfos(const PathSet& paths, + SubstitutablePathInfos& infos) override; + + void addToStore(const ValidPathInfo& info, Source& source, RepairFlag repair, + CheckSigsFlag checkSigs, + std::shared_ptr<FSAccessor> accessor) override; + + Path addToStore(const std::string& name, const Path& srcPath, bool recursive, + HashType hashAlgo, PathFilter& filter, + RepairFlag repair) override; + + /* Like addToStore(), but the contents of the path are contained + in `dump', which is either a NAR serialisation (if recursive == + true) or simply the contents of a regular file (if recursive == + false). */ + Path addToStoreFromDump(const std::string& dump, const std::string& name, + bool recursive = true, HashType hashAlgo = htSHA256, + RepairFlag repair = NoRepair); + + Path addTextToStore(const std::string& name, const std::string& s, + const PathSet& references, RepairFlag repair) override; + + absl::Status buildPaths(std::ostream& log_sink, const PathSet& paths, + BuildMode build_mode) override; + + BuildResult buildDerivation(std::ostream& log_sink, const Path& drvPath, + const BasicDerivation& drv, + BuildMode buildMode) override; + + void ensurePath(const Path& path) override; + + void addTempRoot(const Path& path) override; + + void addIndirectRoot(const Path& path) override; + + void syncWithGC() override; + + private: + typedef std::shared_ptr<AutoCloseFD> FDPtr; + using FDs = std::list<FDPtr>; + + void findTempRoots(FDs& fds, Roots& roots, bool censor); + + public: + Roots findRoots(bool censor) override; + + void collectGarbage(const GCOptions& options, GCResults& results) override; + + /* Optimise the disk space usage of the Nix store by hard-linking + files with the same contents. */ + void optimiseStore(OptimiseStats& stats); + + void optimiseStore() override; + + /* Optimise a single store path. */ + void optimisePath(const Path& path); + + bool verifyStore(bool checkContents, RepairFlag repair) override; + + /* Register the validity of a path, i.e., that `path' exists, that + the paths referenced by it exists, and in the case of an output + path of a derivation, that it has been produced by a successful + execution of the derivation (or something equivalent). Also + register the hash of the file system contents of the path. The + hash must be a SHA-256 hash. */ + void registerValidPath(const ValidPathInfo& info); + + void registerValidPaths(const ValidPathInfos& infos); + + unsigned int getProtocol() override; + + void vacuumDB(); + + /* Repair the contents of the given path by redownloading it using + a substituter (if available). */ + void repairPath(const Path& path); + + void addSignatures(const Path& storePath, const StringSet& sigs) override; + + /* If free disk space in /nix/store if below minFree, delete + garbage until it exceeds maxFree. */ + void autoGC(bool sync = true); + + private: + int getSchema(); + + void openDB(State& state, bool create); + + void makeStoreWritable(); + + static uint64_t queryValidPathId(State& state, const Path& path); + + uint64_t addValidPath(State& state, const ValidPathInfo& info, + bool checkOutputs = true); + + void invalidatePath(State& state, const Path& path); + + /* Delete a path from the Nix store. */ + void invalidatePathChecked(const Path& path); + + void verifyPath(const Path& path, const PathSet& store, PathSet& done, + PathSet& validPaths, RepairFlag repair, bool& errors); + + static void updatePathInfo(State& state, const ValidPathInfo& info); + + void upgradeStore6(); + void upgradeStore7(); + PathSet queryValidPathsOld(); + ValidPathInfo queryPathInfoOld(const Path& path); + + struct GCState; + + static void deleteGarbage(GCState& state, const Path& path); + + void tryToDelete(GCState& state, const Path& path); + + bool canReachRoot(GCState& state, PathSet& visited, const Path& path); + + void deletePathRecursive(GCState& state, const Path& path); + + static bool isActiveTempFile(const GCState& state, const Path& path, + const std::string& suffix); + + AutoCloseFD openGCLock(LockType lockType); + + void findRoots(const Path& path, unsigned char type, Roots& roots); + + void findRootsNoTemp(Roots& roots, bool censor); + + void findRuntimeRoots(Roots& roots, bool censor); + + void removeUnusedLinks(const GCState& state); + + Path createTempDirInStore(); + + void checkDerivationOutputs(const Path& drvPath, const Derivation& drv); + + using InodeHash = std::unordered_set<ino_t>; + + InodeHash loadInodeHash(); + static Strings readDirectoryIgnoringInodes(const Path& path, + const InodeHash& inodeHash); + void optimisePath_(OptimiseStats& stats, const Path& path, + InodeHash& inodeHash); + + // Internal versions that are not wrapped in retry_sqlite. + static bool isValidPath_(State& state, const Path& path); + static void queryReferrers(State& state, const Path& path, + PathSet& referrers); + + /* Add signatures to a ValidPathInfo using the secret keys + specified by the ‘secret-key-files’ option. */ + static void signPathInfo(ValidPathInfo& info); + + Path getRealStoreDir() override { return realStoreDir; } + + void createUser(const std::string& userName, uid_t userId) override; + + friend class DerivationGoal; + friend class SubstitutionGoal; +}; + +using Inode = std::pair<dev_t, ino_t>; +using InodesSeen = std::set<Inode>; + +/* "Fix", or canonicalise, the meta-data of the files in a store path + after it has been built. In particular: + - the last modification date on each file is set to 1 (i.e., + 00:00:01 1/1/1970 UTC) + - the permissions are set of 444 or 555 (i.e., read-only with or + without execute permission; setuid bits etc. are cleared) + - the owner and group are set to the Nix user and group, if we're + running as root. */ +void canonicalisePathMetaData(const Path& path, uid_t fromUid, + InodesSeen& inodesSeen); +void canonicalisePathMetaData(const Path& path, uid_t fromUid); + +void canonicaliseTimestampAndPermissions(const Path& path); + +MakeError(PathInUse, Error); + +} // namespace nix |