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

[Stefan Beller]

Helped-by: Junio C Hamano <gits...@pobox.com>
Signed-off-by: Stefan Beller <sbel...@google.com>
---
 sha1-array.c | 17 +++++++++++++++++
 sha1-array.h |  9 +++++++++
 2 files changed, 26 insertions(+)

diff --git a/sha1-array.c b/sha1-array.c
index 265941fbf40..67db5eeec9a 100644
--- a/sha1-array.c
+++ b/sha1-array.c
@@ -77,3 +77,20 @@ int oid_array_for_each_unique(struct oid_array *array,
        }
        return 0;
 }
+
+void oid_array_filter(struct oid_array *array,
+                     for_each_oid_fn want,
+                     void *cb_data)
+{
+       unsigned nr = array->nr, src, dst;
+       struct object_id *oids = array->oids;
+
+       for (src = dst = 0; src < nr; src++) {
+               if (want(&oids[src], cb_data)) {
+                       if (src != dst)
+                               oidcpy(oids[dst], &oids[src]);
+                       dst++;
+               }
+       }
+       array->nr = dst;
+}
diff --git a/sha1-array.h b/sha1-array.h
index 232bf950172..ae059ca0431 100644
--- a/sha1-array.h
+++ b/sha1-array.h
@@ -23,4 +23,13 @@ int oid_array_for_each_unique(struct oid_array *array,
                              for_each_oid_fn fn,
                              void *data);
 
+/*
+ * Apply want to each entry in array, retaining only the entries for
+ * which the function returns true.  Preserve the order of the entries
+ * that are retained.
+ */
+int oid_array_filter(struct oid_array *array,
+                    for_each_oid_fn want,
+                    void *cbdata);
+
 #endif /* SHA1_ARRAY_H */
-- 
2.19.0.397.gdd90340f6a-goog