Copying flags through a graph with deep side branches can cause
StackOverflowError. The recursive step to visit the 2nd parent of
a merge commit can overflow the stack if these are themselves very
deep histories with many branches.

Rewrite the loop to iterate up to 500 recursive steps deep before
unwinding the stack and running the remaining parts of the graph
using a dynamically allocated FIFORevQueue.

This approach still allows simple graphs that mostly merge short
lived topic branches into master to copy flags with no dynamic
memory allocation, relying only on temporary stack extensions.
Larger more complex graphs only pay the allocation penalities
if copying has to extend outwards "very far" in the graph, which
is unlikely for many coloring based algorithms.

Change-Id: I1882e6832c916e27dd5f6b7602d9caf66fb39c84

Bug: 400707
Change-Id: I9b09bb88528af465018fc0278f5441f7e6b75986

Bug: 400707
Change-Id: I9b09bb88528af465018fc0278f5441f7e6b75986

A few classes such as Constanrs are marked with @SuppressWarnings, as are
toString() methods with many liternal, but otherwise $NLS-n$ is used for
string containing text that should not be translated. A few literals may
fall into the gray zone, but mostly I've tried to only tag the obvious
ones.

Change-Id: I22e50a77e2bf9e0b842a66bdf674e8fa1692f590

StartGenerator now processes .git/shallow to have the
RevWalk stop for shallow commits.

See RevWalkShallowTest for tests.

Bug: 394543
CQ: 6908
Change-Id: Ia5af1dab3fe9c7888f44eeecab1e1bcf2e8e48fe
Signed-off-by: Chris Aniszczyk <zx@twitter.com>

Parsing is rewritten to use the size limited form of getCachedBytes,
thus freeing the revwalk infrastructure from needing to care about
a large object vs. a small object when it gets an ObjectLoader.

Right now we hardcode our upper bound for a commit or annotated
tag to be 15 MiB.  I don't know of any that is more than 1 MiB in
the wild, so going 15x that should give us some reasonable headroom.

Change-Id: If296c211d8b257d76e44908504e71dd9ba70ffa8
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

Callers might have a canonical commit encoding on hand that they
wish to convert into a clean structure for presentation purposes,
and the object may not be available in a repository.  (E.g. maybe
its a "draft" commit being written in an editor.)

Change-Id: I21759cff337cbbb34dbdde91aec5aa4448a1ef37
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 don't actually need a Repository object here, just an ObjectReader
that can load content for us.  So change the API to depend on that.

However, this breaks the asCommit and asTag legacy translation methods
on RevCommit and RevTag, so we still have to keep the Repository
inside of RevWalk for those two types.  Hopefully we can drop those in
the future, and then drop the Repository off the RevWalk.

Change-Id: Iba983e48b663790061c43ae9ffbb77dfe6f4818e
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

As discussed on the egit-dev mailing list, we prefer not to have
trailing whitespace in our source code.  Correct all currently
offending lines by trimming them.

Change-Id: I002b1d1980071084c0bc53242c8f5900970e6845
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>