[11/22] pack-bitmap.c: introduce 'bitmap_is_preferred_refname()'

Commit Message

Taylor Blau April 9, 2021, 6:11 p.m. UTC

In a recent commit, pack-objects learned support for the
'pack.preferBitmapTips' configuration. This patch prepares the
multi-pack bitmap code to respect this configuration, too.

Since the multi-pack bitmap code already does a traversal of all
references (in order to discover the set of reachable commits in the
multi-pack index), it is more efficient to check whether or not each
reference is a suffix of any value of 'pack.preferBitmapTips' rather
than do an additional traversal.

Implement a function 'bitmap_is_preferred_refname()' which does just
that. The caller will be added in a subsequent patch.

Signed-off-by: Taylor Blau <[e-mail]>
---
 pack-bitmap.c | 16 ++++++++++++++++
 pack-bitmap.h |  1 +
 2 files changed, 17 insertions(+)

Patch

diff --git a/pack-bitmap.c b/pack-bitmap.c
index 97ee2d331d..be52570b0f 100644
--- a/pack-bitmap.c
+++ b/pack-bitmap.c
@@ -1594,3 +1594,19 @@  const struct string_list *bitmap_preferred_tips(struct repository *r)
 {
 	return repo_config_get_value_multi(r, "pack.preferbitmaptips");
 }
+
+int bitmap_is_preferred_refname(struct repository *r, const char *refname)
+{
+	const struct string_list *preferred_tips = bitmap_preferred_tips(r);
+	struct string_list_item *item;
+
+	if (!preferred_tips)
+		return 0;
+
+	for_each_string_list_item(item, preferred_tips) {
+		if (starts_with(refname, item->string))
+			return 1;
+	}
+
+	return 0;
+}
diff --git a/pack-bitmap.h b/pack-bitmap.h
index 988ed3a30d..0bf75ff2a7 100644
--- a/pack-bitmap.h
+++ b/pack-bitmap.h
@@ -93,5 +93,6 @@  void bitmap_writer_finish(struct pack_idx_entry **index,
 			  uint16_t options);
 
 const struct string_list *bitmap_preferred_tips(struct repository *r);
+int bitmap_is_preferred_refname(struct repository *r, const char *refname);
 
 #endif