From 103cfee056cbc8f002929fd5958e305c1a75fe45 Mon Sep 17 00:00:00 2001 From: Eelco Dolstra Date: Mon, 22 Feb 2010 11:44:17 +0000 Subject: [PATCH] * Revert r19650 (implement gc-keep-outputs by looking for derivations with the same name as the output) and instead use the DerivationOutputs table in the database, which is the correct way to to do things. --- src/libstore/gc.cc | 56 ++----------------------------------- src/libstore/local-store.cc | 24 ++++++++++++++++ src/libstore/local-store.hh | 9 ++++-- src/libstore/store-api.cc | 13 --------- src/libstore/store-api.hh | 6 ---- 5 files changed, 34 insertions(+), 74 deletions(-) diff --git a/src/libstore/gc.cc b/src/libstore/gc.cc index f58f691c99..659c636e3d 100644 --- a/src/libstore/gc.cc +++ b/src/libstore/gc.cc @@ -416,12 +416,7 @@ struct LocalStore::GCState PathSet busy; bool gcKeepOutputs; bool gcKeepDerivations; - - bool drvsIndexed; - typedef std::multimap DrvsByName; - DrvsByName drvsByName; // derivation paths hashed by name attribute - - GCState(GCResults & results_) : results(results_), drvsIndexed(false) + GCState(GCResults & results_) : results(results_) { } }; @@ -441,42 +436,6 @@ bool LocalStore::isActiveTempFile(const GCState & state, && state.tempRoots.find(string(path, 0, path.size() - suffix.size())) != state.tempRoots.end(); } - -/* Return all the derivations in the Nix store that have `path' as an - output. This function assumes that derivations have the same name - as their outputs. */ -PathSet LocalStore::findDerivers(GCState & state, const Path & path) -{ - PathSet derivers; - - Path deriver = queryDeriver(path); - if (deriver != "") derivers.insert(deriver); - - if (!state.drvsIndexed) { - Paths entries = readDirectory(nixStore); - foreach (Paths::iterator, i, entries) - if (isDerivation(*i)) - state.drvsByName.insert(std::pair( - getNameOfStorePath(*i), nixStore + "/" + *i)); - state.drvsIndexed = true; - } - - string name = getNameOfStorePath(path); - - // Urgh, I should have used Haskell... - std::pair range = - state.drvsByName.equal_range(name); - - for (GCState::DrvsByName::iterator i = range.first; i != range.second; ++i) - if (isValidPath(i->second)) { - Derivation drv = derivationFromPath(i->second); - foreach (DerivationOutputs::iterator, j, drv.outputs) - if (j->second.path == path) derivers.insert(i->second); - } - - return derivers; -} - bool LocalStore::tryToDelete(GCState & state, const Path & path) { @@ -522,18 +481,9 @@ bool LocalStore::tryToDelete(GCState & state, const Path & path) if (!pathExists(path)) return true; /* If gc-keep-outputs is set, then don't delete this path if - its deriver is not garbage. !!! Nix does not reliably - store derivers, so we have to look at all derivations to - determine which of them derive `path'. Since this makes - the garbage collector very slow to start on large Nix - stores, here we just look for all derivations that have the - same name as `path' (where the name is the part of the - filename after the hash, i.e. the `name' attribute of the - derivation). This is somewhat hacky: currently, the - deriver of a path always has the same name as the output, - but this might change in the future. */ + there are derivers of this path that are not garbage. */ if (state.gcKeepOutputs) { - PathSet derivers = findDerivers(state, path); + PathSet derivers = queryValidDerivers(path); foreach (PathSet::iterator, deriver, derivers) { /* Break an infinite recursion if gc-keep-derivations and gc-keep-outputs are both set by tentatively diff --git a/src/libstore/local-store.cc b/src/libstore/local-store.cc index 2f12256db0..0590b294ba 100644 --- a/src/libstore/local-store.cc +++ b/src/libstore/local-store.cc @@ -297,6 +297,8 @@ void LocalStore::prepareStatements() "select time from FailedPaths where path = ?;"); stmtAddDerivationOutput.create(db, "insert or replace into DerivationOutputs (drv, id, path) values (?, ?, ?);"); + stmtQueryValidDerivers.create(db, + "select v.id, v.path from DerivationOutputs d join ValidPaths v on d.drv = v.id where d.path = ?;"); } @@ -599,6 +601,28 @@ Path LocalStore::queryDeriver(const Path & path) } +PathSet LocalStore::queryValidDerivers(const Path & path) +{ + assertStorePath(path); + + SQLiteStmtUse use(stmtQueryValidDerivers); + stmtQueryValidDerivers.bind(path); + + PathSet derivers; + int r; + while ((r = sqlite3_step(stmtQueryValidDerivers)) == SQLITE_ROW) { + const char * s = (const char *) sqlite3_column_text(stmtQueryValidDerivers, 1); + assert(s); + derivers.insert(s); + } + + if (r != SQLITE_DONE) + throw SQLiteError(db, format("error getting valid derivers of `%1%'") % path); + + return derivers; +} + + void LocalStore::startSubstituter(const Path & substituter, RunningSubstituter & run) { if (run.pid != -1) return; diff --git a/src/libstore/local-store.hh b/src/libstore/local-store.hh index f10ba18d5a..6bd47b3055 100644 --- a/src/libstore/local-store.hh +++ b/src/libstore/local-store.hh @@ -103,6 +103,12 @@ public: void queryReferrers(const Path & path, PathSet & referrers); Path queryDeriver(const Path & path); + + /* Return all currently valid derivations that have `path' as an + output. (Note that the result of `queryDeriver()' is the + derivation that was actually used to produce `path', which may + not exist anymore.) */ + PathSet queryValidDerivers(const Path & path); PathSet querySubstitutablePaths(); @@ -199,6 +205,7 @@ private: SQLiteStmt stmtRegisterFailedPath; SQLiteStmt stmtHasPathFailed; SQLiteStmt stmtAddDerivationOutput; + SQLiteStmt stmtQueryValidDerivers; int getSchema(); @@ -228,8 +235,6 @@ private: bool tryToDelete(GCState & state, const Path & path); - PathSet findDerivers(GCState & state, const Path & path); - bool isActiveTempFile(const GCState & state, const Path & path, const string & suffix); diff --git a/src/libstore/store-api.cc b/src/libstore/store-api.cc index f0abe61ad1..01dd516216 100644 --- a/src/libstore/store-api.cc +++ b/src/libstore/store-api.cc @@ -1,7 +1,6 @@ #include "store-api.hh" #include "globals.hh" #include "util.hh" -#include "derivations.hh" #include @@ -53,18 +52,6 @@ Path toStorePath(const Path & path) } -string getNameOfStorePath(const Path & path) -{ - Path::size_type slash = path.rfind('/'); - string p = slash == Path::npos ? path : string(path, slash + 1); - Path::size_type dash = p.find('-'); - assert(dash != Path::npos); - string p2 = string(p, dash + 1); - if (isDerivation(p2)) p2 = string(p2, 0, p2.size() - 4); - return p2; -} - - Path followLinksToStore(const Path & _path) { Path path = absPath(_path); diff --git a/src/libstore/store-api.hh b/src/libstore/store-api.hh index 23a3ab25e4..d85ae0c9a1 100644 --- a/src/libstore/store-api.hh +++ b/src/libstore/store-api.hh @@ -243,12 +243,6 @@ void checkStoreName(const string & name); Path toStorePath(const Path & path); -/* Get the "name" part of a store path, that is, the part after the - hash and the dash, and with any ".drv" suffix removed - (e.g. /nix/store/-foo-1.2.3.drv => foo-1.2.3). */ -string getNameOfStorePath(const Path & path); - - /* Follow symlinks until we end up with a path in the Nix store. */ Path followLinksToStore(const Path & path);