* Fix and simplify the garbage collector (it's still not concurrent,

though).  In particular it's now much easier to register a GC root.
  Just place a symlink to whatever store path it is that you want to
  keep in /nix/var/nix/gcroots.
This commit is contained in:
Eelco Dolstra 2005-01-27 15:21:29 +00:00
parent 59682e6188
commit c505702265
10 changed files with 124 additions and 109 deletions

View file

@ -3,24 +3,15 @@
#include "util.hh"
/* Garbage collector operation. */
typedef enum { gcReturnLive, gcReturnDead, gcDeleteDead } GCAction;
/* 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). The value `minAge' specifies the minimum age in seconds
for an unreachable file to be considered dead (0 meaning that any
unreachable file is dead). */
PathSet findDeadPaths(const PathSet & live, time_t minAge);
/* If `action' is set to `soReturnLive', return the set of paths
reachable from (i.e. in the closure of) the specified roots. If
`action' is `soReturnDead', return the set of paths not reachable
from the roots. If `action' is `soDeleteDead', actually delete the
latter set. */
void collectGarbage(const PathSet & roots, GCAction action,
PathSet & result);
#endif /* !__GC_H */