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-rw-r--r--src/libstore/gc.cc210
-rw-r--r--src/libstore/local-store.hh5
-rw-r--r--src/libutil/util.hh11
3 files changed, 115 insertions, 111 deletions
diff --git a/src/libstore/gc.cc b/src/libstore/gc.cc
index 4123a90be..8a34f0c9b 100644
--- a/src/libstore/gc.cc
+++ b/src/libstore/gc.cc
@@ -499,75 +499,6 @@ void LocalStore::deleteFromStore(GCState & state, std::string_view baseName)
}
-bool LocalStore::canReachRoot(
- GCState & state,
- StorePathSet & visited,
- const StorePath & path)
-{
- checkInterrupt();
-
- //Activity act(*logger, lvlDebug, format("considering whether to delete '%1%'") % path);
-
- if (state.options.action == GCOptions::gcDeleteSpecific
- && !state.options.pathsToDelete.count(path))
- return true;
-
- if (!visited.insert(path).second) return false;
-
- if (state.alive.count(path)) return true;
-
- if (state.dead.count(path)) return false;
-
- if (state.roots.count(path)) {
- debug("cannot delete '%s' because it's a root", printStorePath(path));
- state.alive.insert(path);
- return true;
- }
-
- if (isValidPath(path)) {
- StorePathSet incoming;
-
- /* Don't delete this path if any of its referrers are alive. */
- queryReferrers(path, incoming);
-
- /* If keep-derivations is set and this is a derivation, then
- don't delete the derivation if any of the outputs are
- alive. */
- if (state.gcKeepDerivations && path.isDerivation()) {
- for (auto & [name, maybeOutPath] : queryPartialDerivationOutputMap(path))
- if (maybeOutPath &&
- isValidPath(*maybeOutPath) &&
- queryPathInfo(*maybeOutPath)->deriver == path)
- incoming.insert(*maybeOutPath);
- }
-
- /* If keep-outputs is set, then don't delete this path if
- there are derivers of this path that are not garbage. */
- if (state.gcKeepOutputs) {
- auto derivers = queryValidDerivers(path);
- for (auto & i : derivers)
- incoming.insert(i);
- }
-
- for (auto & i : incoming)
- if (i != path && canReachRoot(state, visited, i)) {
- state.alive.insert(path);
- return true;
- }
- }
-
- {
- auto hashPart = std::string(path.hashPart());
- auto shared(state.shared.lock());
- if (shared->tempRoots.count(hashPart))
- return true;
- shared->pending = hashPart;
- }
-
- return false;
-}
-
-
/* Unlink all files in /nix/store/.links that have a link count of 1,
which indicates that there are no other links and so they can be
safely deleted. FIXME: race condition with optimisePath(): we
@@ -746,28 +677,115 @@ void LocalStore::collectGarbage(const GCOptions & options, GCResults & results)
state.roots.insert(root.first);
}
- /* Now either delete all garbage paths, or just the specified
- paths (for gcDeleteSpecific). */
+ /* Helper function that visits all paths reachable from `start`
+ via the referrers edges and optionally derivers and derivation
+ output edges. If any of those paths is a root, then we cannot
+ delete this path. */
+ auto deleteReferrersClosure = [&](const StorePath & start) {
+ StorePathSet visited;
+ std::queue<StorePath> todo;
+
+ /* Wake up any GC client waiting for deletion of the paths in
+ 'visited' to finish. */
+ Finally releasePending([&]() {
+ auto shared(state.shared.lock());
+ shared->pending.reset();
+ state.wakeup.notify_all();
+ });
+
+ auto enqueue = [&](const StorePath & path) {
+ if (visited.insert(path).second)
+ todo.push(path);
+ };
+
+ enqueue(start);
+
+ while (auto path = pop(todo)) {
+ checkInterrupt();
+
+ /* Bail out if we've previously discovered that this path
+ is alive. */
+ if (state.alive.count(*path)) {
+ state.alive.insert(start);
+ return;
+ }
+
+ /* If we've previously deleted this path, we don't have to
+ handle it again. */
+ if (state.dead.count(*path)) continue;
+
+ /* If this is a root, bail out. */
+ if (state.roots.count(*path)) {
+ debug("cannot delete '%s' because it's a root", printStorePath(*path));
+ state.alive.insert(*path);
+ state.alive.insert(start);
+ return;
+ }
+ if (state.options.action == GCOptions::gcDeleteSpecific
+ && !state.options.pathsToDelete.count(*path))
+ return;
+
+ {
+ auto hashPart = std::string(path->hashPart());
+ auto shared(state.shared.lock());
+ if (shared->tempRoots.count(hashPart)) {
+ debug("cannot delete '%s' because it's a temporary root", printStorePath(*path));
+ state.alive.insert(*path);
+ state.alive.insert(start);
+ return;
+ }
+ shared->pending = hashPart;
+ }
+
+ if (isValidPath(*path)) {
+
+ /* Visit the referrers of this path. */
+ StorePathSet referrers;
+ queryReferrers(*path, referrers);
+ for (auto & p : referrers)
+ enqueue(p);
+
+ /* If keep-derivations is set and this is a
+ derivation, then visit the derivation outputs. */
+ if (state.gcKeepDerivations && path->isDerivation()) {
+ for (auto & [name, maybeOutPath] : queryPartialDerivationOutputMap(*path))
+ if (maybeOutPath &&
+ isValidPath(*maybeOutPath) &&
+ queryPathInfo(*maybeOutPath)->deriver == *path)
+ enqueue(*maybeOutPath);
+ }
+
+ /* If keep-outputs is set, then visit the derivers. */
+ if (state.gcKeepOutputs) {
+ auto derivers = queryValidDerivers(*path);
+ for (auto & i : derivers)
+ enqueue(i);
+ }
+ }
+ }
+
+ for (auto & path : topoSortPaths(visited)) {
+ if (!state.dead.insert(path).second) continue;
+ if (state.shouldDelete) {
+ invalidatePathChecked(path);
+ deleteFromStore(state, path.to_string());
+ }
+ }
+ };
+
+ /* Either delete all garbage paths, or just the specified
+ paths (for gcDeleteSpecific). */
if (options.action == GCOptions::gcDeleteSpecific) {
for (auto & i : options.pathsToDelete) {
- StorePathSet visited;
-
- if (canReachRoot(state, visited, i))
+ deleteReferrersClosure(i);
+ if (!state.dead.count(i))
throw Error(
- "cannot delete path '%1%' since it is still alive. "
+ "Cannot delete path '%1%' since it is still alive. "
"To find out why, use: "
"nix-store --query --roots",
printStorePath(i));
-
- auto sorted = topoSortPaths(visited);
- for (auto & path : sorted) {
- if (state.dead.count(path)) continue;
- invalidatePathChecked(path);
- deleteFromStore(state, path.to_string());
- state.dead.insert(path);
- }
}
} else if (options.maxFreed > 0) {
@@ -792,29 +810,9 @@ void LocalStore::collectGarbage(const GCOptions & options, GCResults & results)
string name = dirent->d_name;
if (name == "." || name == ".." || name == linksName) continue;
- if (auto storePath = maybeParseStorePath(storeDir + "/" + name)) {
- StorePathSet visited;
-
- /* Wake up any GC client waiting for deletion of
- the paths in 'visited' to finish. */
- Finally releasePending([&]() {
- auto shared(state.shared.lock());
- shared->pending.reset();
- state.wakeup.notify_all();
- });
-
- if (!canReachRoot(state, visited, *storePath)) {
- auto sorted = topoSortPaths(visited);
- for (auto & path : sorted) {
- if (state.dead.count(path)) continue;
- if (state.shouldDelete) {
- invalidatePathChecked(path);
- deleteFromStore(state, path.to_string());
- }
- state.dead.insert(path);
- }
- }
- } else
+ if (auto storePath = maybeParseStorePath(storeDir + "/" + name))
+ deleteReferrersClosure(*storePath);
+ else
deleteFromStore(state, name);
}
diff --git a/src/libstore/local-store.hh b/src/libstore/local-store.hh
index 8629e1528..21a4e60cf 100644
--- a/src/libstore/local-store.hh
+++ b/src/libstore/local-store.hh
@@ -240,11 +240,6 @@ private:
struct GCState;
- bool canReachRoot(
- GCState & state,
- StorePathSet & visited,
- const StorePath & path);
-
void deleteFromStore(GCState & state, std::string_view baseName);
void findRoots(const Path & path, unsigned char type, Roots & roots);
diff --git a/src/libutil/util.hh b/src/libutil/util.hh
index 76f80f7a4..485ff4153 100644
--- a/src/libutil/util.hh
+++ b/src/libutil/util.hh
@@ -523,6 +523,17 @@ std::optional<typename T::value_type> remove_begin(T & c)
}
+/* Remove and return the first item from a container. */
+template <class T>
+std::optional<typename T::value_type> pop(T & c)
+{
+ if (c.empty()) return {};
+ auto v = std::move(c.front());
+ c.pop();
+ return v;
+}
+
+
template<typename T>
class Callback;
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-23 00:31:06 +0000