nix/libstore/local-store.hh

   1 #pragma once
   2
   3 #include "sqlite.hh"
   4 #include <string>
   5 #include <unordered_set>
   6
   7 #include "pathlocks.hh"
   8 #include "store-api.hh"
   9 #include "util.hh"
  10
  11
  12 namespace nix {
  13
  14
  15 /* Nix store and database schema version.  Version 1 (or 0) was Nix <=
  16    0.7.  Version 2 was Nix 0.8 and 0.9.  Version 3 is Nix 0.10.
  17    Version 4 is Nix 0.11.  Version 5 is Nix 0.12-0.16.  Version 6 is
  18    Nix 1.0.  Version 7 is Nix 1.3.  Guix has always used version 7.  */
  19 const int nixSchemaVersion = 7;
  20
  21
  22 extern string drvsLogDir;
  23
  24
  25 struct Derivation;
  26
  27
  28 struct OptimiseStats
  29 {
  30     unsigned long filesLinked;
  31     unsigned long long bytesFreed;
  32     unsigned long long blocksFreed;
  33     OptimiseStats()
  34     {
  35         filesLinked = 0;
  36         bytesFreed = blocksFreed = 0;
  37     }
  38 };
  39
  40
  41 class LocalStore : public StoreAPI
  42 {
  43 private:
  44     /* The currently running substituter or empty.  */
  45     std::shared_ptr<Agent> runningSubstituter;
  46
  47     /* Ensure the substituter is running and return it.  */
  48     std::shared_ptr<Agent> substituter();
  49
  50     Path linksDir;
  51
  52 public:
  53
  54     /* Initialise the local store, upgrading the schema if
  55        necessary. */
  56     LocalStore(bool reserveSpace = true);
  57
  58     ~LocalStore();
  59
  60     /* Implementations of abstract store API methods. */
  61
  62     bool isValidPath(const Path & path);
  63
  64     PathSet queryValidPaths(const PathSet & paths);
  65
  66     PathSet queryAllValidPaths();
  67
  68     ValidPathInfo queryPathInfo(const Path & path);
  69
  70     Hash queryPathHash(const Path & path);
  71
  72     void queryReferences(const Path & path, PathSet & references);
  73
  74     void queryReferrers(const Path & path, PathSet & referrers);
  75
  76     Path queryDeriver(const Path & path);
  77
  78     PathSet queryValidDerivers(const Path & path);
  79
  80     PathSet queryDerivationOutputs(const Path & path);
  81
  82     StringSet queryDerivationOutputNames(const Path & path);
  83
  84     Path queryPathFromHashPart(const string & hashPart);
  85
  86     PathSet querySubstitutablePaths(const PathSet & paths);
  87
  88     void querySubstitutablePathInfos(PathSet & paths,
  89         SubstitutablePathInfos & infos);
  90
  91     void querySubstitutablePathInfos(const PathSet & paths,
  92         SubstitutablePathInfos & infos);
  93
  94     Path addToStore(const string & name, const Path & srcPath,
  95         bool recursive = true, HashType hashAlgo = htSHA256,
  96         PathFilter & filter = defaultPathFilter, bool repair = false);
  97
  98     /* Like addToStore(), but the contents of the path are contained
  99        in `dump', which is either a NAR serialisation (if recursive ==
 100        true) or simply the contents of a regular file (if recursive ==
 101        false). */
 102     Path addToStoreFromDump(const string & dump, const string & name,
 103         bool recursive = true, HashType hashAlgo = htSHA256, bool repair = false);
 104
 105     Path addTextToStore(const string & name, const string & s,
 106         const PathSet & references, bool repair = false);
 107
 108     void exportPath(const Path & path, bool sign,
 109         Sink & sink);
 110
 111     Paths importPaths(bool requireSignature, Source & source);
 112
 113     void buildPaths(const PathSet & paths, BuildMode buildMode);
 114
 115     void ensurePath(const Path & path);
 116
 117     void addTempRoot(const Path & path);
 118
 119     void addIndirectRoot(const Path & path);
 120
 121     void syncWithGC();
 122
 123     Roots findRoots();
 124
 125     void collectGarbage(const GCOptions & options, GCResults & results);
 126
 127     /* Optimise the disk space usage of the Nix store by hard-linking
 128        files with the same contents. */
 129     void optimiseStore(OptimiseStats & stats);
 130
 131     /* Generic variant of the above method.  */
 132     void optimiseStore();
 133
 134     /* Optimise a single store path. */
 135     void optimisePath(const Path & path);
 136
 137     /* Check the integrity of the Nix store.  Returns true if errors
 138        remain. */
 139     bool verifyStore(bool checkContents, bool repair);
 140
 141     /* Register the validity of a path, i.e., that `path' exists, that
 142        the paths referenced by it exists, and in the case of an output
 143        path of a derivation, that it has been produced by a successful
 144        execution of the derivation (or something equivalent).  Also
 145        register the hash of the file system contents of the path.  The
 146        hash must be a SHA-256 hash. */
 147     void registerValidPath(const ValidPathInfo & info);
 148
 149     void registerValidPaths(const ValidPathInfos & infos);
 150
 151     /* Register that the build of a derivation with output `path' has
 152        failed. */
 153     void registerFailedPath(const Path & path);
 154
 155     /* Query whether `path' previously failed to build. */
 156     bool hasPathFailed(const Path & path);
 157
 158     PathSet queryFailedPaths();
 159
 160     void clearFailedPaths(const PathSet & paths);
 161
 162     void vacuumDB();
 163
 164     /* Repair the contents of the given path by redownloading it using
 165        a substituter (if available). */
 166     void repairPath(const Path & path);
 167
 168     /* Check whether the given valid path exists and has the right
 169        contents. */
 170     bool pathContentsGood(const Path & path);
 171
 172     void markContentsGood(const Path & path);
 173
 174     void createUser(const std::string & userName, uid_t userId);
 175
 176 private:
 177
 178     Path schemaPath;
 179
 180     /* Lock file used for upgrading. */
 181     AutoCloseFD globalLock;
 182
 183     /* The SQLite database object. */
 184     SQLite db;
 185
 186     /* Some precompiled SQLite statements. */
 187     SQLiteStmt stmtRegisterValidPath;
 188     SQLiteStmt stmtUpdatePathInfo;
 189     SQLiteStmt stmtAddReference;
 190     SQLiteStmt stmtQueryPathInfo;
 191     SQLiteStmt stmtQueryReferences;
 192     SQLiteStmt stmtQueryReferrers;
 193     SQLiteStmt stmtInvalidatePath;
 194     SQLiteStmt stmtRegisterFailedPath;
 195     SQLiteStmt stmtHasPathFailed;
 196     SQLiteStmt stmtQueryFailedPaths;
 197     SQLiteStmt stmtClearFailedPath;
 198     SQLiteStmt stmtAddDerivationOutput;
 199     SQLiteStmt stmtQueryValidDerivers;
 200     SQLiteStmt stmtQueryDerivationOutputs;
 201     SQLiteStmt stmtQueryPathFromHashPart;
 202     SQLiteStmt stmtQueryValidPaths;
 203
 204     /* Cache for pathContentsGood(). */
 205     std::map<Path, bool> pathContentsGoodCache;
 206
 207     /* The file to which we write our temporary roots. */
 208     Path fnTempRoots;
 209     AutoCloseFD fdTempRoots;
 210
 211     int getSchema();
 212
 213     void openDB(bool create);
 214
 215     void makeStoreWritable();
 216
 217     uint64_t queryValidPathId(const Path & path);
 218
 219     uint64_t addValidPath(const ValidPathInfo & info, bool checkOutputs = true);
 220
 221     void addReference(uint64_t referrer, uint64_t reference);
 222
 223     void appendReferrer(const Path & from, const Path & to, bool lock);
 224
 225     void rewriteReferrers(const Path & path, bool purge, PathSet referrers);
 226
 227     void invalidatePath(const Path & path);
 228
 229     /* Delete a path from the Nix store. */
 230     void invalidatePathChecked(const Path & path);
 231
 232     void verifyPath(const Path & path, const PathSet & store,
 233         PathSet & done, PathSet & validPaths, bool repair, bool & errors);
 234
 235     void updatePathInfo(const ValidPathInfo & info);
 236
 237     struct GCState;
 238
 239     void deleteGarbage(GCState & state, const Path & path);
 240
 241     void tryToDelete(GCState & state, const Path & path);
 242
 243     bool canReachRoot(GCState & state, PathSet & visited, const Path & path);
 244
 245     void deletePathRecursive(GCState & state, const Path & path);
 246
 247     bool isActiveTempFile(const GCState & state,
 248         const Path & path, const string & suffix);
 249
 250     int openGCLock(LockType lockType);
 251
 252     void removeUnusedLinks(const GCState & state);
 253
 254     string getLineFromSubstituter(Agent & run);
 255
 256     template<class T> T getIntLineFromSubstituter(Agent & run);
 257
 258     Path createTempDirInStore();
 259
 260     Path importPath(bool requireSignature, Source & source);
 261
 262     void checkDerivationOutputs(const Path & drvPath, const Derivation & drv);
 263
 264     typedef std::unordered_set<ino_t> InodeHash;
 265
 266     InodeHash loadInodeHash();
 267     Strings readDirectoryIgnoringInodes(const Path & path, const InodeHash & inodeHash);
 268     void optimisePath_(OptimiseStats & stats, const Path & path, InodeHash & inodeHash);
 269
 270     // Internal versions that are not wrapped in retry_sqlite.
 271     bool isValidPath_(const Path & path);
 272     void queryReferrers_(const Path & path, PathSet & referrers);
 273 };
 274
 275
 276 typedef std::pair<dev_t, ino_t> Inode;
 277 typedef set<Inode> InodesSeen;
 278
 279
 280 /* "Fix", or canonicalise, the meta-data of the files in a store path
 281    after it has been built.  In particular:
 282    - the last modification date on each file is set to 1 (i.e.,
 283      00:00:01 1/1/1970 UTC)
 284    - the permissions are set of 444 or 555 (i.e., read-only with or
 285      without execute permission; setuid bits etc. are cleared)
 286    - the owner and group are set to the Nix user and group, if we're
 287      running as root. */
 288 void canonicalisePathMetaData(const Path & path, uid_t fromUid, InodesSeen & inodesSeen);
 289 void canonicalisePathMetaData(const Path & path, uid_t fromUid);
 290
 291 void canonicaliseTimestampAndPermissions(const Path & path);
 292
 293 MakeError(PathInUse, Error);
 294
 295 }