Package org.eclipse.jgit.internal.storage.file

Class GC

  • public class GC
extends Object
    A garbage collector for git FileRepository. Instances of this class are not thread-safe. Don't use the same instance from multiple threads. This class started as a copy of DfsGarbageCollector from Shawn O. Pearce adapted to FileRepositories.

    • Constructor Detail

      • GC

        public GC​(FileRepository repo)
        Creates a new garbage collector with default values. An expirationTime of two weeks and null as progress monitor will be used.
        Parameters:
        repo - the repo to work on

    • Method Detail

      • setExecutor

        public static void setExecutor​(ExecutorService e)
        Set the executor for running auto-gc in the background. If no executor is set JGit's own WorkQueue will be used.
        Parameters:
        e - the executor to be used for running auto-gc

      • gc

        public CompletableFuture<Collection<Pack>> gc()
                                       throws IOException,
                                              ParseException
        Runs a garbage collector on a FileRepository. It will
        • pack loose references into packed-refs
        • repack all reachable objects into new pack files and delete the old pack files
        • prune all loose objects which are now reachable by packs
        If setAuto(boolean) was set to true gc will first check whether any housekeeping is required; if not, it exits without performing any work. If setBackground(boolean) was set to true collectGarbage will start the gc in the background, and then return immediately. In this case, errors will not be reported except in gc.log.
        Returns:
        the collection of Pack's which are newly created
        Throws:
        IOException
        ParseException - If the configuration parameter "gc.pruneexpire" couldn't be parsed

      • prunePacked

        public void prunePacked()
                 throws IOException
        Like "git prune-packed" this method tries to prune all loose objects which can be found in packs. If certain objects can't be pruned (e.g. because the filesystem delete operation fails) this is silently ignored.
        Throws:
        IOException

      • prune

        public void prune​(Set<ObjectId> objectsToKeep)
           throws IOException,
                  ParseException
        Like "git prune" this method tries to prune all loose objects which are unreferenced. If certain objects can't be pruned (e.g. because the filesystem delete operation fails) this is silently ignored.
        Parameters:
        objectsToKeep - a set of objects which should explicitly not be pruned
        Throws:
        IOException
        ParseException - If the configuration parameter "gc.pruneexpire" couldn't be parsed

      • packRefs

        public void packRefs()
              throws IOException
        Pack ref storage. For a RefDirectory database, this packs all non-symbolic, loose refs into packed-refs. For Reftable, all of the data is compacted into a single table.
        Throws:
        IOException

      • repack

        public Collection<Pack> repack()
                        throws IOException
        Packs all objects which reachable from any of the heads into one pack file. Additionally all objects which are not reachable from any head but which are reachable from any of the other refs (e.g. tags), special refs (e.g. FETCH_HEAD) or index are packed into a separate pack file. Objects included in pack files which have a .keep file associated are never repacked. All old pack files which existed before are deleted.
        Returns:
        a collection of the newly created pack files
        Throws:
        IOException - when during reading of refs, index, packfiles, objects, reflog-entries or during writing to the packfiles IOException occurs

      • getStatistics

        public GC.RepoStatistics getStatistics()
                                throws IOException
        Returns information about objects and pack files for a FileRepository.
        Returns:
        information about objects and pack files for a FileRepository
        Throws:
        IOException

      • setProgressMonitor

        public GC setProgressMonitor​(ProgressMonitor pm)
        Set the progress monitor used for garbage collection methods.
        Parameters:
        pm - a ProgressMonitor object.
        Returns:
        this

      • setExpireAgeMillis

        public void setExpireAgeMillis​(long expireAgeMillis)
        During gc() or prune() each unreferenced, loose object which has been created or modified in the last expireAgeMillis milliseconds will not be pruned. Only older objects may be pruned. If set to 0 then every object is a candidate for pruning.
        Parameters:
        expireAgeMillis - minimal age of objects to be pruned in milliseconds.

      • setPackExpireAgeMillis

        public void setPackExpireAgeMillis​(long packExpireAgeMillis)
        During gc() or prune() packfiles which are created or modified in the last packExpireAgeMillis milliseconds will not be deleted. Only older packfiles may be deleted. If set to 0 then every packfile is a candidate for deletion.
        Parameters:
        packExpireAgeMillis - minimal age of packfiles to be deleted in milliseconds.

      • setPackConfig

        public void setPackConfig​(@NonNull
                          PackConfig pconfig)
        Set the PackConfig used when (re-)writing packfiles. This allows to influence how packs are written and to implement something similar to "git gc --aggressive"
        Parameters:
        pconfig - the PackConfig used when writing packs

      • setExpire

        public void setExpire​(Date expire)
        During gc() or prune() each unreferenced, loose object which has been created or modified after or at expire will not be pruned. Only older objects may be pruned. If set to null then every object is a candidate for pruning.
        Parameters:
        expire - instant in time which defines object expiration objects with modification time before this instant are expired objects with modification time newer or equal to this instant are not expired

      • setPackExpire

        public void setPackExpire​(Date packExpire)
        During gc() or prune() packfiles which are created or modified after or at packExpire will not be deleted. Only older packfiles may be deleted. If set to null then every packfile is a candidate for deletion.
        Parameters:
        packExpire - instant in time which defines packfile expiration

      • setAuto

        public void setAuto​(boolean auto)
        Set the gc --auto option. With this option, gc checks whether any housekeeping is required; if not, it exits without performing any work. Some JGit commands run gc --auto after performing operations that could create many loose objects.

        Housekeeping is required if there are too many loose objects or too many packs in the repository. If the number of loose objects exceeds the value of the gc.auto option JGit GC consolidates all existing packs into a single pack (equivalent to -A option), whereas git-core would combine all loose objects into a single pack using repack -d -l. Setting the value of gc.auto to 0 disables automatic packing of loose objects.

        If the number of packs exceeds the value of gc.autoPackLimit, then existing packs (except those marked with a .keep file) are consolidated into a single pack by using the -A option of repack. Setting gc.autoPackLimit to 0 disables automatic consolidation of packs.

        Like git the following jgit commands run auto gc:

        • fetch
        • merge
        • rebase
        • receive-pack
        The auto gc for receive-pack can be suppressed by setting the config option receive.autogc = false
        Parameters:
        auto - defines whether gc should do automatic housekeeping