Re: [ANNOUNCE] Stacked GIT 0.7
From: Catalin Marinas <hidden>
Date: 2016-06-15 22:42:07
Subsystem:
the rest · Maintainer:
Linus Torvalds
Possibly related (same subject, not in this thread)
- 2016-06-15 · [ANNOUNCE] Stacked GIT 0.7 · Catalin Marinas <hidden>
- 2016-06-15 · Re: [ANNOUNCE] Stacked GIT 0.7 · Ingo Molnar <hidden>
- 2016-06-15 · Re: [ANNOUNCE] Stacked GIT 0.7 · Catalin Marinas <hidden>
- 2016-06-15 · Re: [ANNOUNCE] Stacked GIT 0.7 · Catalin Marinas <hidden>
Catalin Marinas [off-list ref] wrote:
After some tests, it looks like 'git-diff-tree -p ... | git-apply --index' is about 3 times faster than 'git-read-tree -m' (in the best case for git-read-tree with minor modifications of the base). It now takes ~0.5s to push a single patch (compared to ~1.5s).
And that's the patch for whoever wants to try. I will also add it to the repository tonight: Optimise 'push' to use git-apply instead of git-read-tree With this patch, 'push' will use 'git-diff-tree | git-apply' first. If this operation fails, it will fall back to the three-way merge with git-read-tree. Signed-off-by: Catalin Marinas <redacted> --- stgit/git.py | 9 +++++++++ stgit/stack.py | 19 +++++++++++-------- 2 files changed, 20 insertions(+), 8 deletions(-)
diff --git a/stgit/git.py b/stgit/git.py
--- a/stgit/git.py
+++ b/stgit/git.py@@ -355,6 +355,15 @@ def commit(message, files = [], parents return commit_id +def apply_diff(rev1, rev2): + """Apply the diff between rev1 and rev2 onto the current + index. This function doesn't need to raise an exception since it + is only used for fast-pushing a patch. If this operation fails, + the pushing would fall back to the three-way merge. + """ + return os.system('git-diff-tree -p %s %s | git-apply --index 2> /dev/null' + % (rev1, rev2)) == 0 + def merge(base, head1, head2): """Perform a 3-way merge between base, head1 and head2 into the local tree
diff --git a/stgit/stack.py b/stgit/stack.py
--- a/stgit/stack.py
+++ b/stgit/stack.py@@ -598,14 +598,17 @@ class Series: # The current patch is empty after merge. patch.set_bottom(head, backup = True) patch.set_top(head, backup = True) - # merge/refresh can fail but the patch needs to be pushed - try: - git.merge(bottom, head, top) - except git.GitException, ex: - print >> sys.stderr, \ - 'The merge failed during "push". ' \ - 'Use "refresh" after fixing the conflicts' - pass + + # Try the fast applying first. If this fails, fall back to the + # three-way merge + if not git.apply_diff(bottom, top): + # merge can fail but the patch needs to be pushed + try: + git.merge(bottom, head, top) + except git.GitException, ex: + print >> sys.stderr, \ + 'The merge failed during "push". ' \ + 'Use "refresh" after fixing the conflicts' append_string(self.__applied_file, name)
--
Catalin