[JGIT PATCH 2/2] Micro-optimize the merge base generator
- From
Shawn O. Pearce <spearce@spearce.org>
- Date
- Mar 18, 2009, 18:01 UTC
- Message-ID
- <1237399309-29493-2-git-send-email-spearce@spearce.org>
- In-Reply-To
- <1237399309-29493-1-git-send-email-spearce@spearce.org>
Instead of doing 3 bit-wise and operations followed by 3 compares and two boolean and conditions on every commit we evaluate in the history, we can fold all of the tests into a pair of fields and do one bit mask and compare.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org> --- .../spearce/jgit/revwalk/MergeBaseGenerator.java | 13 +++++++++++-- 1 files changed, 11 insertions(+), 2 deletions(-)
diff --git a/org.spearce.jgit/src/org/spearce/jgit/revwalk/MergeBaseGenerator.java b/org.spearce.jgit/src/org/spearce/jgit/revwalk/MergeBaseGenerator.java index 2eb9688..8694e4c 100644 --- a/org.spearce.jgit/src/org/spearce/jgit/revwalk/MergeBaseGenerator.java +++ b/org.spearce.jgit/src/org/spearce/jgit/revwalk/MergeBaseGenerator.java @@ -73,6 +73,10 @@ private int branchMask; + private int recarryTest; + + private int recarryMask; + MergeBaseGenerator(final RevWalk w) { walker = w; pending = new DateRevQueue(); @@ -91,6 +95,12 @@ void init(final AbstractRevQueue p) { // will be available for reuse when the walk resets. // walker.freeFlag(branchMask); + + // Setup the condition used by carryOntoOne to detect a late + // merge base and produce it on the next round. + // + recarryTest = branchMask | POPPED; + recarryMask = branchMask | POPPED | MERGE_BASE; } } @@ -187,8 +197,7 @@ private boolean carryOntoOne(final RevCommit p, final int carry) { final boolean haveAll = (p.flags & carry) == carry; p.flags |= carry; - if ((p.flags & POPPED) != 0 && (carry & MERGE_BASE) == 0 - && (p.flags & branchMask) == branchMask) { + if ((p.flags & recarryMask) == recarryTest) { // We were popped without being a merge base, but we just got // voted to be one. Inject ourselves back at the front of the // pending queue and tell all of our ancestors they are within
-- 1.6.2.1.337.g6270ba