forked from lix-project/lix
6636202356
Starts progress on #5729. The idea is that we should not have these default methods throwing "unimplemented". This is a small step in that direction. I kept `addTempRoot` because it is a no-op, rather than failure. Also, as a practical matter, it is called all over the place, while doing other tasks, so the downcasting would be annoying. Maybe in the future I could move the "real" `addTempRoot` to `GcStore`, and the existing usecases use a `tryAddTempRoot` wrapper to downcast or do nothing, but I wasn't sure whether that was a good idea so with a bias to less churn I didn't do it yet.
85 lines
2.4 KiB
C++
85 lines
2.4 KiB
C++
#pragma once
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#include "store-api.hh"
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namespace nix {
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typedef std::unordered_map<StorePath, std::unordered_set<std::string>> Roots;
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struct GCOptions
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{
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/* Garbage collector operation:
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- `gcReturnLive': return the set of paths reachable from
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(i.e. in the closure of) the roots.
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- `gcReturnDead': return the set of paths not reachable from
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the roots.
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- `gcDeleteDead': actually delete the latter set.
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- `gcDeleteSpecific': delete the paths listed in
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`pathsToDelete', insofar as they are not reachable.
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*/
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typedef enum {
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gcReturnLive,
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gcReturnDead,
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gcDeleteDead,
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gcDeleteSpecific,
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} GCAction;
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GCAction action{gcDeleteDead};
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/* If `ignoreLiveness' is set, then reachability from the roots is
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ignored (dangerous!). However, the paths must still be
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unreferenced *within* the store (i.e., there can be no other
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store paths that depend on them). */
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bool ignoreLiveness{false};
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/* For `gcDeleteSpecific', the paths to delete. */
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StorePathSet pathsToDelete;
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/* Stop after at least `maxFreed' bytes have been freed. */
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uint64_t maxFreed{std::numeric_limits<uint64_t>::max()};
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};
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struct GCResults
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{
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/* Depending on the action, the GC roots, or the paths that would
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be or have been deleted. */
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PathSet paths;
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/* For `gcReturnDead', `gcDeleteDead' and `gcDeleteSpecific', the
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number of bytes that would be or was freed. */
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uint64_t bytesFreed = 0;
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};
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struct GcStore : public virtual Store
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{
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/* Add an indirect root, which is merely a symlink to `path' from
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/nix/var/nix/gcroots/auto/<hash of `path'>. `path' is supposed
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to be a symlink to a store path. The garbage collector will
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automatically remove the indirect root when it finds that
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`path' has disappeared. */
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virtual void addIndirectRoot(const Path & path) = 0;
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/* Find the roots of the garbage collector. Each root is a pair
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(link, storepath) where `link' is the path of the symlink
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outside of the Nix store that point to `storePath'. If
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'censor' is true, privacy-sensitive information about roots
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found in /proc is censored. */
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virtual Roots findRoots(bool censor) = 0;
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/* Perform a garbage collection. */
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virtual void collectGarbage(const GCOptions & options, GCResults & results) = 0;
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};
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GcStore & requireGcStore(Store & store);
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}
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