[PATCH 2/9] sha1-array: provide oid_array_filter

[Stefan Beller <sbeller@google.com>]

Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
---
 sha1-array.c | 18 ++++++++++++++++++
 sha1-array.h |  5 +++++
 2 files changed, 23 insertions(+)

diff --git a/sha1-array.c b/sha1-array.c
index 265941fbf40..76323935dd7 100644
--- a/sha1-array.c
+++ b/sha1-array.c
@@ -77,3 +77,21 @@ int oid_array_for_each_unique(struct oid_array *array,
 	}
 	return 0;
 }
+
+int oid_array_filter(struct oid_array *array,
+		     for_each_oid_fn fn,
+		     void *cbdata)
+{
+	int src, dst;
+
+	for (src = dst = 0; src < array->nr; src++) {
+		if (fn(&array->oid[src], cbdata)) {
+			if (dst < src)
+				oidcpy(&array->oid[dst], &array->oid[src]);
+			dst++;
+		}
+	}
+	array->nr = dst;
+
+	return 0;
+}
diff --git a/sha1-array.h b/sha1-array.h
index 232bf950172..a2d7c210835 100644
--- a/sha1-array.h
+++ b/sha1-array.h
@@ -23,4 +23,9 @@ int oid_array_for_each_unique(struct oid_array *array,
 			      for_each_oid_fn fn,
 			      void *data);
 
+/* Call fn for each oid, and remove it if fn returns 0, retain it otherwise */
+int oid_array_filter(struct oid_array *array,
+		     for_each_oid_fn fn,
+		     void *cbdata);
+
 #endif /* SHA1_ARRAY_H */
-- 
2.19.0.397.gdd90340f6a-goog