Pack better represents the purpose of the object and paves the way to
add a PackFile object that extends File.

Change-Id: I39b4f697902d395e9b6df5e8ce53078ce72fcea3
Signed-off-by: Nasser Grainawi <quic_nasserg@quicinc.com>

This is the format given by the Eclipse legal doc generator [1].

[1] https://www.eclipse.org/projects/tools/documentation.php?id=technology.jgit

Bug: 548298
Change-Id: I8d8cabc998ba1b083e3f0906a8d558d391ffb6c4
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

Change-Id: Ieb2f66aef2cab7e2a6d8e35c5f5047da881994dd
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

This breaks all existing callers once. Applications are not supposed
to build against the internal storage API unless they can accept API
churn and make necessary updates as versions change.

Change-Id: I2ab1327c202ef2003565e1b0770a583970e432e9

Similar to what we did with the file code, move the pack writer
into its own package so the related classes and their package
private methods are hidden from the rest of the library.

Change-Id: Ic1b5c7c8c8d266e90c910d8d68dfc8e93586854f
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

Rather than making a loader, and then using that to fill the object
representation, parse the header and set up our data directly.
This saves some time, as we don't waste cycles on information we
won't use right now.

The weight computed for a representation is now its actual stored
size in the pack file, rather than its inflated size.  This accounts
for changes made when the compression level is modified on the
repository.  It is however more costly to determine the weight of
the object, since we have to find its length in the pack.  To try and
recover that cost we now cache the length as part of our ObjectToPack
record, so it doesn't have to be found during the output phase.

A LocalObjectToPack now costs us (assuming 32 bit pointers):

                   (32 bit)     (64 bit)
  vm header:         8 bytes      8 bytes
  ObjectId:         20 bytes     20 bytes
  PackedObjectInfo: 12 bytes     12 bytes
  ObjectToPack:      8 bytes     12 bytes
  LocalOTP:         20 bytes     24 bytes
                 -----------    ---------
                    68 bytes     74 bytes

Change-Id: I923d2736186eb2ac8ab498d3eb137e17930fcb50
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

This move isolates all of the local file specific implementation code
into a single package, where their package-private methods and support
classes are properly hidden away from the rest of the core library.

Because of the sheer number of files impacted, I have limited this
change to only the renames and the updated imports.

Change-Id: Icca4884e1a418f83f8b617d0c4c78b73d8a4bd17
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

The new selection implementation uses a public API on the
ObjectReader, allowing the storage library to enumerate its
candidates and select the best one for this packer without
needing to build a temporary list of the candidates first.

Change-Id: Ie01496434f7d3581d6d3bbb9e33c8f9fa649b6cd
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

Replace the old crude event listener system with a much more generic
implementation, patterned after the event dispatch techniques used
in Google Web Toolkit 1.5 and later.

Each event delivers to an interface that defines a single method,
and the event itself is what performs the delivery in a type-safe
way through its own dispatch method.

Listeners are registered in a generic listener list, indexed by
the interface they implement and wish to receive an event for.
Delivery of events is performed by looping through all listeners
implementing the event's corresponding listener interface, and using
the event's own dispatch method to deliver the event.  This is the
classical "double dispatch" pattern for event delivery.

Listeners can be unregistered by invoking remove() on their
registration handle.  This change therefore requires application
code to track the handle if it wishes to remove the listener at a
later point in time.

Event delivery is now exposed as a generic public method on the
Repository class, making it easier for any type of message to
be sent out to any type of listener that has registered, without
needing to pre-arrange for type-safe fireFoo() methods.

New event types can be added in the future simply by defining a
new RepositoryEvent subclass and a corresponding RepositoryListener
interface that it dispatches to.  By always adding new events through
a new interface, we never need to worry about defining an Adapter
to provide default no-op implementations of new event methods.

Change-Id: I651417b3098b9afc93d91085e9f0b2265df8fc81
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

Per CQ 3448 this is the initial contribution of the JGit project
to eclipse.org.  It is derived from the historical JGit repository
at commit 3a2dd9921c.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>