Class CachedPack

  extended by
Direct Known Subclasses:

public abstract class CachedPack
extends Object

Describes a pack file ObjectReuseAsIs can append onto a stream.

Constructor Summary
Method Summary
 long getDeltaCount()
          Get the number of delta objects stored in this pack.
abstract  long getObjectCount()
          Get the number of objects in this pack.
abstract  Set<ObjectId> getTips()
          Objects that start this pack.
abstract  boolean hasObject(ObjectToPack obj, StoredObjectRepresentation rep)
          Determine if this pack contains the object representation given.
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail


public CachedPack()
Method Detail


public abstract Set<ObjectId> getTips()
Objects that start this pack.

All objects reachable from the tips are contained within this pack. If PackWriter is going to include everything reachable from all of these objects, this cached pack is eligible to be appended directly onto the output pack stream.

the tip objects that describe this pack.


public abstract long getObjectCount()
                             throws IOException
Get the number of objects in this pack.

the total object count for the pack.
IOException - if the object count cannot be read.


public long getDeltaCount()
                   throws IOException
Get the number of delta objects stored in this pack.

This is an optional method, not every cached pack storage system knows the precise number of deltas stored within the pack. This number must be smaller than getObjectCount() as deltas are not supposed to span across pack files.

This method must be fast, if the only way to determine delta counts is to scan the pack file's contents one object at a time, implementors should return 0 and avoid the high cost of the scan.

the number of deltas; 0 if the number is not known or there are no deltas.
IOException - if the delta count cannot be read.


public abstract boolean hasObject(ObjectToPack obj,
                                  StoredObjectRepresentation rep)
Determine if this pack contains the object representation given.

PackWriter uses this method during the finding sources phase to prune away any objects from the leading thin-pack that already appear within this pack and should not be sent twice.

Implementors are strongly encouraged to rely on looking at rep only and using its internal state to decide if this object is within this pack. Implementors should ensure a representation from this cached pack is tested as part of ObjectReuseAsIs.selectObjectRepresentation(PackWriter, org.eclipse.jgit.lib.ProgressMonitor, Iterable) , ensuring this method would eventually return true if the object would be included by this cached pack.

obj - the object being packed. Can be used as an ObjectId.
rep - representation from the ObjectReuseAsIs instance that originally supplied this CachedPack.
true if this pack contains this object.

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