By moving the logic that parses a pack stream from the network (or
a bundle) into a type that can be constructed by an ObjectInserter,
repository implementations have a chance to inject their own logic
for storing object data received into the destination repository.

The API isn't completely generic yet, there are still quite a few
assumptions that the PackParser subclass is storing the data onto
the local filesystem as a single file.  But its about the simplest
split of IndexPack I can come up with without completely ripping
the code apart.

Change-Id: I5b167c9cc6d7a7c56d0197c62c0fd0036a83ec6c
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Chris Aniszczyk <caniszczyk@gmail.com>

Merging Git notes branches has several differences from merging "normal"
branches. Although Git notes are initially stored as one flat tree the
tree may fanout when the number of notes becomes too large for efficient
access. In this case the first two hex digits of the note name will be
used as a subdirectory name and the rest 38 hex digits as the file name
under that directory. Similarly, when number of notes decreases a fanout
tree may collapse back into a flat tree. The Git notes merge algorithm
must take into account possibly different tree structures in different
note branches and must properly match them against each other.

Any conflict on a Git note is, by default, resolved by concatenating
the two conflicting versions of the note. A delete-edit conflict is, by
default, resolved by keeping the edit version.

The note merge logic is pluggable and the caller may provide custom
note merger that will perform different merging strategy.

Additionally, it is possible to have non-note entries inside a notes
tree. The merge algorithm must also take this fact into account and
will try to merge such non-note entries. However, in case of any merge
conflicts the merge operation will fail. Git notes merge algorithm is
currently not trying to do content merge of non-note entries.

Thanks to Shawn Pearce for patiently answering my questions related to
this topic, giving hints and providing code snippets.

Change-Id: I3b2335c76c766fd7ea25752e54087f9b19d69c88
Signed-off-by: Sasa Zivkov <sasa.zivkov@sap.com>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

This makes usage of a TreeFormatter more similar to a CommitBuilder or
a TagBuilder: populate the formatter and pass to the ObjectInserter.

Change-Id: I5a45ef3a35cc73f4905a34bc6f6228510df8eb2c
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Reviewed-by: Chris Aniszczyk <caniszczyk@gmail.com>

These objects don't need to be updated with the resulting ObjectId of
the formatted content, callers can get that from the ObjectInserter on
their own.

Change-Id: Idc5f097de9f7beafc5e54e597383d82daf9d7db4
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Reviewed-by: Chris Aniszczyk <caniszczyk@gmail.com>

The correct names for these is build(), as that is what a Java
developer will expect given the "builder" pattern.

Bug: 323541
Change-Id: I35042bdc95a955beeaee29e54bde10e4240b2a71
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Reviewed-by: Chris Aniszczyk <caniszczyk@gmail.com>

ObjectWriter is a deprecated API that people shouldn't be using.
So get rid of it in favor of the ObjectInserter API.

Change-Id: I6218bcb26b6b9ffb64e3e470dba5dca2e0a62fd4
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

These objects should be responsible for their own formatting,
rather than delegating it to some obtuse type called ObjectInserter.

While we are at it, simplify the way we insert these into a database.
Passing in the type and calling format in application code turned
out to be a huge mistake in terms of ease-of-use of the insert API.

Change-Id: Id5bb95ee56aa2a002243e9b7853b84ec8df1d7bf
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

Since these types no longer support reading, calling them a Builder
is a better description of what they do.  They help the caller to
build a commit or a tag object.

Change-Id: I53cae5a800a66ea1721b0fe5e702599df31da05d
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

The Tag class now only supports the creation of an annotated tag
object.  To read an annotated tag, applictions should use RevTag.
This permits us to have exactly one implementation, and RevTag's
is faster and more bug-free.

Change-Id: Ib573f7e15f36855112815269385c21dea532e2cf
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

The Commit class now only supports the creation of a commit object.
To read a commit, applictions should use RevCommit.  This permits
us to have exactly one implementation, and RevCommit's is faster
and more bug-free.

Change-Id: Ib573f7e15f36855112815269385c21dea532e2cf
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

We should be more lenient when tagging without an
tagger or message. Currently, we will throw an NPE
which is incorrect behavior.

Change-Id: I04e30ce25a9432e4ca56c3f29658ecb24fb18d24
Signed-off-by: Chris Aniszczyk <caniszczyk@gmail.com>

There was a duplicated getter and setter for tagger in Tag.
There's no needed to have two getters and setters that represent
the same things. The appropriate tests were updated also.

Change-Id: If46dc00c4c0f31ea4234c6d3bda3c03e6ebbafac
Signed-off-by: Chris Aniszczyk <caniszczyk@gmail.com>

The ObjectInserter API permits ObjectDatabase implementations to
control their own object insertion behavior, rather than forcing
it to always be a new loose file created in the local filesystem.
Inserted objects can also be queued and written asynchronously to
the main application, such as by appending into a pack file that
is later closed and added to the repository.

This change also starts to open the door to non-file based object
storage, such as an in-memory HashMap for unit testing, or a more
complex system built on top of a distributed hash table.

To help existing application code port to the newer interface we
are keeping ObjectWriter as a delegation wrapper to the new API.
Each ObjectWriter instances holds a reference to an ObjectInserter
for the Repository's top-level ObjectDatabase, and it flushes and
releases that instance on each object processed.

Change-Id: I413224fb95563e7330c82748deb0aada4e0d6ace
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>