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authorJunio C Hamano <gitster@pobox.com>2008-09-03 00:47:13 (GMT)
committerJunio C Hamano <gitster@pobox.com>2008-09-03 00:47:13 (GMT)
commit01914577ed42498d9e268684949d699e0272e964 (patch)
treea0405b854b76eeb5b90b7f13ebd3607a655fb2cf
parent53b543ab8218cede7fb9383298c00dcef663692c (diff)
parente910ce30e41ae4ddc20a64661e8cf2702433e5db (diff)
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Merge branch 'tr/filter-branch'
* tr/filter-branch: revision --simplify-merges: make it a no-op without pathspec revision --simplify-merges: do not leave commits unprocessed revision --simplify-merges: use decoration instead of commit->util field Documentation: rev-list-options: move --simplify-merges documentation filter-branch: use --simplify-merges filter-branch: fix ref rewriting with --subdirectory-filter filter-branch: Extend test to show rewriting bug Topo-sort before --simplify-merges revision traversal: show full history with merge simplification revision.c: whitespace fix
-rw-r--r--Documentation/rev-list-options.txt42
-rwxr-xr-xgit-filter-branch.sh32
-rw-r--r--revision.c202
-rw-r--r--revision.h2
-rwxr-xr-xt/t6012-rev-list-simplify.sh93
-rwxr-xr-xt/t7003-filter-branch.sh8
6 files changed, 338 insertions, 41 deletions
diff --git a/Documentation/rev-list-options.txt b/Documentation/rev-list-options.txt
index 735cf07..0ce916a 100644
--- a/Documentation/rev-list-options.txt
+++ b/Documentation/rev-list-options.txt
@@ -409,6 +409,48 @@ Note that without '\--full-history', this still simplifies merges: if
one of the parents is TREESAME, we follow only that one, so the other
sides of the merge are never walked.
+Finally, there is a fourth simplification mode available:
+
+--simplify-merges::
+
+ First, build a history graph in the same way that
+ '\--full-history' with parent rewriting does (see above).
++
+Then simplify each commit `C` to its replacement `C'` in the final
+history according to the following rules:
++
+--
+* Set `C'` to `C`.
++
+* Replace each parent `P` of `C'` with its simplification `P'`. In
+ the process, drop parents that are ancestors of other parents, and
+ remove duplicates.
++
+* If after this parent rewriting, `C'` is a root or merge commit (has
+ zero or >1 parents), a boundary commit, or !TREESAME, it remains.
+ Otherwise, it is replaced with its only parent.
+--
++
+The effect of this is best shown by way of comparing to
+'\--full-history' with parent rewriting. The example turns into:
++
+-----------------------------------------------------------------------
+ .-A---M---N---O
+ / / /
+ I B D
+ \ / /
+ `---------'
+-----------------------------------------------------------------------
++
+Note the major differences in `N` and `P` over '\--full-history':
++
+--
+* `N`'s parent list had `I` removed, because it is an ancestor of the
+ other parent `M`. Still, `N` remained because it is !TREESAME.
++
+* `P`'s parent list similarly had `I` removed. `P` was then
+ removed completely, because it had one parent and is TREESAME.
+--
ifdef::git-rev-list[]
Bisection Helpers
diff --git a/git-filter-branch.sh b/git-filter-branch.sh
index 2871a59..81392ad 100755
--- a/git-filter-branch.sh
+++ b/git-filter-branch.sh
@@ -232,11 +232,11 @@ mkdir ../map || die "Could not create map/ directory"
case "$filter_subdir" in
"")
git rev-list --reverse --topo-order --default HEAD \
- --parents "$@"
+ --parents --simplify-merges "$@"
;;
*)
git rev-list --reverse --topo-order --default HEAD \
- --parents "$@" -- "$filter_subdir"
+ --parents --simplify-merges "$@" -- "$filter_subdir"
esac > ../revs || die "Could not get the commits"
commits=$(wc -l <../revs | tr -d " ")
@@ -317,24 +317,20 @@ done <../revs
# In case of a subdirectory filter, it is possible that a specified head
# is not in the set of rewritten commits, because it was pruned by the
-# revision walker. Fix it by mapping these heads to the next rewritten
-# ancestor(s), i.e. the boundaries in the set of rewritten commits.
+# revision walker. Fix it by mapping these heads to the unique nearest
+# ancestor that survived the pruning.
-# NEEDSWORK: we should sort the unmapped refs topologically first
-while read ref
-do
- sha1=$(git rev-parse "$ref"^0)
- test -f "$workdir"/../map/$sha1 && continue
- # Assign the boundarie(s) in the set of rewritten commits
- # as the replacement commit(s).
- # (This would look a bit nicer if --not --stdin worked.)
- for p in $( (cd "$workdir"/../map; ls | sed "s/^/^/") |
- git rev-list $ref --boundary --stdin |
- sed -n "s/^-//p")
+if test "$filter_subdir"
+then
+ while read ref
do
- map $p >> "$workdir"/../map/$sha1
- done
-done < "$tempdir"/heads
+ sha1=$(git rev-parse "$ref"^0)
+ test -f "$workdir"/../map/$sha1 && continue
+ ancestor=$(git rev-list --simplify-merges -1 \
+ $ref -- "$filter_subdir")
+ test "$ancestor" && echo $(map $ancestor) >> "$workdir"/../map/$sha1
+ done < "$tempdir"/heads
+fi
# Finally update the refs
diff --git a/revision.c b/revision.c
index 36291b6..bcbc7bd 100644
--- a/revision.c
+++ b/revision.c
@@ -489,7 +489,7 @@ static int add_parents_to_list(struct rev_info *revs, struct commit *commit,
p->object.flags |= SEEN;
insert_by_date_cached(p, list, cached_base, cache_ptr);
}
- if(revs->first_parent_only)
+ if (revs->first_parent_only)
break;
}
return 0;
@@ -1041,6 +1041,11 @@ static int handle_revision_opt(struct rev_info *revs, int argc, const char **arg
} else if (!strcmp(arg, "--topo-order")) {
revs->lifo = 1;
revs->topo_order = 1;
+ } else if (!strcmp(arg, "--simplify-merges")) {
+ revs->simplify_merges = 1;
+ revs->rewrite_parents = 1;
+ revs->simplify_history = 0;
+ revs->limited = 1;
} else if (!strcmp(arg, "--date-order")) {
revs->lifo = 0;
revs->topo_order = 1;
@@ -1368,6 +1373,179 @@ static void add_child(struct rev_info *revs, struct commit *parent, struct commi
l->next = add_decoration(&revs->children, &parent->object, l);
}
+static int remove_duplicate_parents(struct commit *commit)
+{
+ struct commit_list **pp, *p;
+ int surviving_parents;
+
+ /* Examine existing parents while marking ones we have seen... */
+ pp = &commit->parents;
+ while ((p = *pp) != NULL) {
+ struct commit *parent = p->item;
+ if (parent->object.flags & TMP_MARK) {
+ *pp = p->next;
+ continue;
+ }
+ parent->object.flags |= TMP_MARK;
+ pp = &p->next;
+ }
+ /* count them while clearing the temporary mark */
+ surviving_parents = 0;
+ for (p = commit->parents; p; p = p->next) {
+ p->item->object.flags &= ~TMP_MARK;
+ surviving_parents++;
+ }
+ return surviving_parents;
+}
+
+struct merge_simplify_state {
+ struct commit *simplified;
+};
+
+static struct merge_simplify_state *locate_simplify_state(struct rev_info *revs, struct commit *commit)
+{
+ struct merge_simplify_state *st;
+
+ st = lookup_decoration(&revs->merge_simplification, &commit->object);
+ if (!st) {
+ st = xcalloc(1, sizeof(*st));
+ add_decoration(&revs->merge_simplification, &commit->object, st);
+ }
+ return st;
+}
+
+static struct commit_list **simplify_one(struct rev_info *revs, struct commit *commit, struct commit_list **tail)
+{
+ struct commit_list *p;
+ struct merge_simplify_state *st, *pst;
+ int cnt;
+
+ st = locate_simplify_state(revs, commit);
+
+ /*
+ * Have we handled this one?
+ */
+ if (st->simplified)
+ return tail;
+
+ /*
+ * An UNINTERESTING commit simplifies to itself, so does a
+ * root commit. We do not rewrite parents of such commit
+ * anyway.
+ */
+ if ((commit->object.flags & UNINTERESTING) || !commit->parents) {
+ st->simplified = commit;
+ return tail;
+ }
+
+ /*
+ * Do we know what commit all of our parents should be rewritten to?
+ * Otherwise we are not ready to rewrite this one yet.
+ */
+ for (cnt = 0, p = commit->parents; p; p = p->next) {
+ pst = locate_simplify_state(revs, p->item);
+ if (!pst->simplified) {
+ tail = &commit_list_insert(p->item, tail)->next;
+ cnt++;
+ }
+ }
+ if (cnt) {
+ tail = &commit_list_insert(commit, tail)->next;
+ return tail;
+ }
+
+ /*
+ * Rewrite our list of parents.
+ */
+ for (p = commit->parents; p; p = p->next) {
+ pst = locate_simplify_state(revs, p->item);
+ p->item = pst->simplified;
+ }
+ cnt = remove_duplicate_parents(commit);
+
+ /*
+ * It is possible that we are a merge and one side branch
+ * does not have any commit that touches the given paths;
+ * in such a case, the immediate parents will be rewritten
+ * to different commits.
+ *
+ * o----X X: the commit we are looking at;
+ * / / o: a commit that touches the paths;
+ * ---o----'
+ *
+ * Further reduce the parents by removing redundant parents.
+ */
+ if (1 < cnt) {
+ struct commit_list *h = reduce_heads(commit->parents);
+ cnt = commit_list_count(h);
+ free_commit_list(commit->parents);
+ commit->parents = h;
+ }
+
+ /*
+ * A commit simplifies to itself if it is a root, if it is
+ * UNINTERESTING, if it touches the given paths, or if it is a
+ * merge and its parents simplifies to more than one commits
+ * (the first two cases are already handled at the beginning of
+ * this function).
+ *
+ * Otherwise, it simplifies to what its sole parent simplifies to.
+ */
+ if (!cnt ||
+ (commit->object.flags & UNINTERESTING) ||
+ !(commit->object.flags & TREESAME) ||
+ (1 < cnt))
+ st->simplified = commit;
+ else {
+ pst = locate_simplify_state(revs, commit->parents->item);
+ st->simplified = pst->simplified;
+ }
+ return tail;
+}
+
+static void simplify_merges(struct rev_info *revs)
+{
+ struct commit_list *list;
+ struct commit_list *yet_to_do, **tail;
+
+ if (!revs->topo_order)
+ sort_in_topological_order(&revs->commits, revs->lifo);
+ if (!revs->prune)
+ return;
+
+ /* feed the list reversed */
+ yet_to_do = NULL;
+ for (list = revs->commits; list; list = list->next)
+ commit_list_insert(list->item, &yet_to_do);
+ while (yet_to_do) {
+ list = yet_to_do;
+ yet_to_do = NULL;
+ tail = &yet_to_do;
+ while (list) {
+ struct commit *commit = list->item;
+ struct commit_list *next = list->next;
+ free(list);
+ list = next;
+ tail = simplify_one(revs, commit, tail);
+ }
+ }
+
+ /* clean up the result, removing the simplified ones */
+ list = revs->commits;
+ revs->commits = NULL;
+ tail = &revs->commits;
+ while (list) {
+ struct commit *commit = list->item;
+ struct commit_list *next = list->next;
+ struct merge_simplify_state *st;
+ free(list);
+ list = next;
+ st = locate_simplify_state(revs, commit);
+ if (st->simplified == commit)
+ tail = &commit_list_insert(commit, tail)->next;
+ }
+}
+
static void set_children(struct rev_info *revs)
{
struct commit_list *l;
@@ -1408,6 +1586,8 @@ int prepare_revision_walk(struct rev_info *revs)
return -1;
if (revs->topo_order)
sort_in_topological_order(&revs->commits, revs->lifo);
+ if (revs->simplify_merges)
+ simplify_merges(revs);
if (revs->children.name)
set_children(revs);
return 0;
@@ -1440,26 +1620,6 @@ static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp
}
}
-static void remove_duplicate_parents(struct commit *commit)
-{
- struct commit_list **pp, *p;
-
- /* Examine existing parents while marking ones we have seen... */
- pp = &commit->parents;
- while ((p = *pp) != NULL) {
- struct commit *parent = p->item;
- if (parent->object.flags & TMP_MARK) {
- *pp = p->next;
- continue;
- }
- parent->object.flags |= TMP_MARK;
- pp = &p->next;
- }
- /* ... and clear the temporary mark */
- for (p = commit->parents; p; p = p->next)
- p->item->object.flags &= ~TMP_MARK;
-}
-
static int rewrite_parents(struct rev_info *revs, struct commit *commit)
{
struct commit_list **pp = &commit->parents;
diff --git a/revision.h b/revision.h
index 91f1944..fc23522 100644
--- a/revision.h
+++ b/revision.h
@@ -42,6 +42,7 @@ struct rev_info {
simplify_history:1,
lifo:1,
topo_order:1,
+ simplify_merges:1,
tag_objects:1,
tree_objects:1,
blob_objects:1,
@@ -110,6 +111,7 @@ struct rev_info {
struct reflog_walk_info *reflog_info;
struct decoration children;
+ struct decoration merge_simplification;
};
#define REV_TREE_SAME 0
diff --git a/t/t6012-rev-list-simplify.sh b/t/t6012-rev-list-simplify.sh
new file mode 100755
index 0000000..510bb96
--- /dev/null
+++ b/t/t6012-rev-list-simplify.sh
@@ -0,0 +1,93 @@
+#!/bin/sh
+
+test_description='merge simplification'
+
+. ./test-lib.sh
+
+note () {
+ git tag "$1"
+}
+
+_x40='[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]'
+_x40="$_x40$_x40$_x40$_x40$_x40$_x40$_x40$_x40"
+
+unnote () {
+ git name-rev --tags --stdin | sed -e "s|$_x40 (tags/\([^)]*\)) |\1 |g"
+}
+
+test_expect_success setup '
+ echo "Hi there" >file &&
+ git add file &&
+ test_tick && git commit -m "Initial file" &&
+ note A &&
+
+ git branch other-branch &&
+
+ echo "Hello" >file &&
+ git add file &&
+ test_tick && git commit -m "Modified file" &&
+ note B &&
+
+ git checkout other-branch &&
+
+ echo "Hello" >file &&
+ git add file &&
+ test_tick && git commit -m "Modified the file identically" &&
+ note C &&
+
+ echo "This is a stupid example" >another-file &&
+ git add another-file &&
+ test_tick && git commit -m "Add another file" &&
+ note D &&
+
+ test_tick && git merge -m "merge" master &&
+ note E &&
+
+ echo "Yet another" >elif &&
+ git add elif &&
+ test_tick && git commit -m "Irrelevant change" &&
+ note F &&
+
+ git checkout master &&
+ echo "Yet another" >elif &&
+ git add elif &&
+ test_tick && git commit -m "Another irrelevant change" &&
+ note G &&
+
+ test_tick && git merge -m "merge" other-branch &&
+ note H &&
+
+ echo "Final change" >file &&
+ test_tick && git commit -a -m "Final change" &&
+ note I
+'
+
+FMT='tformat:%P %H | %s'
+
+check_result () {
+ for c in $1
+ do
+ echo "$c"
+ done >expect &&
+ shift &&
+ param="$*" &&
+ test_expect_success "log $param" '
+ git log --pretty="$FMT" --parents $param |
+ unnote >actual &&
+ sed -e "s/^.* \([^ ]*\) .*/\1/" >check <actual &&
+ test_cmp expect check || {
+ cat actual
+ false
+ }
+ '
+}
+
+check_result 'I H G F E D C B A' --full-history
+check_result 'I H E C B A' --full-history -- file
+check_result 'I H E C B A' --full-history --topo-order -- file
+check_result 'I H E C B A' --full-history --date-order -- file
+check_result 'I E C B A' --simplify-merges -- file
+check_result 'I B A' -- file
+check_result 'I B A' --topo-order -- file
+
+test_done
diff --git a/t/t7003-filter-branch.sh b/t/t7003-filter-branch.sh
index f92d414..95f13a8 100755
--- a/t/t7003-filter-branch.sh
+++ b/t/t7003-filter-branch.sh
@@ -96,13 +96,17 @@ test_expect_success 'filter subdirectory only' '
test_tick &&
git commit -m "again not subdir" &&
git branch sub &&
- git-filter-branch -f --subdirectory-filter subdir refs/heads/sub
+ git branch sub-earlier HEAD~2 &&
+ git-filter-branch -f --subdirectory-filter subdir \
+ refs/heads/sub refs/heads/sub-earlier
'
test_expect_success 'subdirectory filter result looks okay' '
test 2 = $(git rev-list sub | wc -l) &&
git show sub:new &&
- test_must_fail git show sub:subdir
+ test_must_fail git show sub:subdir &&
+ git show sub-earlier:new &&
+ test_must_fail git show sub-earlier:subdir
'
test_expect_success 'more setup' '