diff options
| -rw-r--r-- | src/libstore/Makefile.am | 3 | ||||
| -rw-r--r-- | src/libstore/gc.cc | 83 | ||||
| -rw-r--r-- | src/libstore/gc.hh | 24 | ||||
| -rw-r--r-- | src/libstore/normalise.hh | 4 | ||||
| -rw-r--r-- | src/libstore/store.cc | 2 | ||||
| -rw-r--r-- | src/nix-store/main.cc | 70 |
6 files changed, 167 insertions, 19 deletions
diff --git a/src/libstore/Makefile.am b/src/libstore/Makefile.am index 8c61b36f4..31735e893 100644 --- a/src/libstore/Makefile.am +++ b/src/libstore/Makefile.am @@ -4,7 +4,8 @@ libstore_a_SOURCES = \ store.cc store.hh storeexpr.cc storeexpr.hh \ normalise.cc misc.cc normalise.hh \ globals.cc globals.hh db.cc db.hh \ - references.cc references.hh pathlocks.cc pathlocks.hh + references.cc references.hh pathlocks.cc pathlocks.hh \ + gc.cc gc.hh AM_CXXFLAGS = -Wall \ -I.. ${bdb_include} ${aterm_include} -I../libutil diff --git a/src/libstore/gc.cc b/src/libstore/gc.cc new file mode 100644 index 000000000..aed7c2294 --- /dev/null +++ b/src/libstore/gc.cc @@ -0,0 +1,83 @@ +#include "normalise.hh" +#include "globals.hh" + + +void followLivePaths(Path nePath, PathSet & live) +{ + /* Just to be sure, canonicalise the path. It is important to do + this here and in findDeadPath() to ensure that a live path is + not mistaken for a dead path due to some non-canonical + representation. */ + nePath = canonPath(nePath); + + if (live.find(nePath) != live.end()) return; + live.insert(nePath); + + startNest(nest, lvlDebug, format("following `%1%'") % nePath); + assertStorePath(nePath); + + if (isValidPath(nePath)) { + + /* !!! should make sure that no substitutes are used */ + StoreExpr ne = storeExprFromPath(nePath); + + /* !!! painfully similar to requisitesWorker() */ + if (ne.type == StoreExpr::neClosure) + for (ClosureElems::iterator i = ne.closure.elems.begin(); + i != ne.closure.elems.end(); ++i) + { + Path p = canonPath(i->first); + if (live.find(p) == live.end()) { + debug(format("found live `%1%'") % p); + assertStorePath(p); + live.insert(p); + } + } + + else if (ne.type == StoreExpr::neDerivation) + for (PathSet::iterator i = ne.derivation.inputs.begin(); + i != ne.derivation.inputs.end(); ++i) + followLivePaths(*i, live); + + else abort(); + + } + + Path nfPath; + if (querySuccessor(nePath, nfPath)) + followLivePaths(nfPath, live); +} + + +PathSet findLivePaths(const Paths & roots) +{ + PathSet live; + + startNest(nest, lvlDebug, "finding live paths"); + + for (Paths::const_iterator i = roots.begin(); i != roots.end(); ++i) + followLivePaths(*i, live); + + return live; +} + + +PathSet findDeadPaths(const PathSet & live) +{ + PathSet dead; + + startNest(nest, lvlDebug, "finding dead paths"); + + Strings storeNames = readDirectory(nixStore); + + for (Strings::iterator i = storeNames.begin(); i != storeNames.end(); ++i) { + Path p = canonPath(nixStore + "/" + *i); + if (live.find(p) == live.end()) { + debug(format("dead path `%1%'") % p); + dead.insert(p); + } else + debug(format("live path `%1%'") % p); + } + + return dead; +} diff --git a/src/libstore/gc.hh b/src/libstore/gc.hh new file mode 100644 index 000000000..997057ba9 --- /dev/null +++ b/src/libstore/gc.hh @@ -0,0 +1,24 @@ +#ifndef __GC_H +#define __GC_H + +#include "storeexpr.hh" + + +/* Determine the set of "live" store paths, given a set of root store + expressions. The live store paths are those that are reachable + from the roots. The roots are reachable by definition. Any path + mentioned in a reachable store expression is also reachable. If a + derivation store expression is reachable, then its successor (if it + exists) if also reachable. It is not an error for store + expressions not to exist (since this can happen on derivation store + expressions, for instance, due to the substitute mechanism), but + successor links are followed even for non-existant derivations. */ +PathSet findLivePaths(const Paths & roots); + +/* Given a set of "live" store paths, determine the set of "dead" + store paths (which are simply all store paths that are not in the + live set). */ +PathSet findDeadPaths(const PathSet & live); + + +#endif /* !__GC_H */ diff --git a/src/libstore/normalise.hh b/src/libstore/normalise.hh index 43be136e5..7b0835b45 100644 --- a/src/libstore/normalise.hh +++ b/src/libstore/normalise.hh @@ -40,9 +40,5 @@ PathSet storeExprRoots(const Path & nePath); PathSet storeExprRequisites(const Path & nePath, bool includeExprs, bool includeSuccessors); -/* Return the list of the paths of all known store expressions whose - output paths are completely contained in the set `outputs'. */ -PathSet findGenerators(const PathSet & outputs); - #endif /* !__NORMALISE_H */ diff --git a/src/libstore/store.cc b/src/libstore/store.cc index 44b3a29e3..fdd22c3b8 100644 --- a/src/libstore/store.cc +++ b/src/libstore/store.cc @@ -388,7 +388,7 @@ static void invalidatePath(const Path & path, Transaction & txn) subs2.push_back(*j); else found = true; - if (!found) throw Error("integrity error in substitutes mapping"); + // !!! if (!found) throw Error("integrity error in substitutes mapping"); writeSubstitutes(txn, *i, subs); /* If path *i now has no substitutes left, and is not valid, diff --git a/src/nix-store/main.cc b/src/nix-store/main.cc index e83f9133f..78599e308 100644 --- a/src/nix-store/main.cc +++ b/src/nix-store/main.cc @@ -3,6 +3,7 @@ #include "globals.hh" #include "normalise.hh" +#include "gc.hh" #include "archive.hh" #include "shared.hh" #include "dotgraph.hh" @@ -32,17 +33,6 @@ static void opRealise(Strings opFlags, Strings opArgs) } -/* Delete a path in the Nix store directory. */ -static void opDelete(Strings opFlags, Strings opArgs) -{ - if (!opFlags.empty()) throw UsageError("unknown flag"); - - for (Strings::iterator it = opArgs.begin(); - it != opArgs.end(); it++) - deleteFromStore(*it); -} - - /* Add paths to the Nix values directory and print the hashes of those paths. */ static void opAdd(Strings opFlags, Strings opArgs) @@ -220,6 +210,60 @@ static void opIsValid(Strings opFlags, Strings opArgs) } +static void opGC(Strings opFlags, Strings opArgs) +{ + if (opFlags.size() != 1) throw UsageError("missing flag"); + if (!opArgs.empty()) + throw UsageError("no arguments expected"); + + /* Do what? */ + string flag = opFlags.front(); + enum { soPrintLive, soPrintDead, soDelete } subOp; + if (flag == "--print-live") subOp = soPrintLive; + else if (flag == "--print-dead") subOp = soPrintDead; + else if (flag == "--delete") subOp = soDelete; + else throw UsageError(format("bad sub-operation `%1% in GC") % flag); + + Paths roots; + while (1) { + Path root; + getline(cin, root); + if (cin.eof()) break; + roots.push_back(root); + } + + PathSet live = findLivePaths(roots); + + if (subOp == soPrintLive) { + for (PathSet::iterator i = live.begin(); i != live.end(); ++i) + cout << *i << endl; + return; + } + + PathSet dead = findDeadPaths(live); + + if (subOp == soPrintDead) { + for (PathSet::iterator i = dead.begin(); i != dead.end(); ++i) + cout << *i << endl; + return; + } + + if (subOp == soDelete) { + + /* !!! What happens if the garbage collector run is aborted + halfway through? In particular, dead paths can always + become live again (through re-instantiation), and might + then refer to deleted paths. => check instantiation + invariants */ + + for (PathSet::iterator i = dead.begin(); i != dead.end(); ++i) { + printMsg(lvlInfo, format("deleting `%1%'") % *i); + deleteFromStore(*i); + } + } +} + + /* A sink that writes dump output to stdout. */ struct StdoutSink : DumpSink { @@ -298,8 +342,6 @@ void run(Strings args) if (arg == "--realise" || arg == "-r") op = opRealise; - else if (arg == "--delete" || arg == "-d") - op = opDelete; else if (arg == "--add" || arg == "-A") op = opAdd; else if (arg == "--query" || arg == "-q") @@ -312,6 +354,8 @@ void run(Strings args) op = opValidPath; else if (arg == "--isvalid") op = opIsValid; + else if (arg == "--gc") + op = opGC; else if (arg == "--dump") op = opDump; else if (arg == "--restore") |