sha1-array: provide oid_array_filter

Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/technical/api-oid-array.txt b/Documentation/technical/api-oid-array.txt
index 9febfb1d528b2764d6d603ea25eae0ac6b048f68..c97428c2c3495e3f575ed944027740e882128482 100644 (file)
--- a/Documentation/technical/api-oid-array.txt
+++ b/Documentation/technical/api-oid-array.txt
@@ -48,6 +48,11 @@ Functions
        is not sorted, this function has the side effect of sorting
        it.
 
+`oid_array_filter`::
+       Apply the callback function `want` to each entry in the array,
+       retaining only the entries for which the function returns true.
+       Preserve the order of the entries that are retained.
+
 Examples
 --------
 

diff --git a/sha1-array.c b/sha1-array.c
index b94e0ec0f5e45fa56e1748bbb611a904ab81de67..d922e94e3fc58488402ac0095075bf5ef0e4d17b 100644 (file)
--- 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->oid;
+
+       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 232bf9501729696846f514e13ce5f23c425d9d27..55d016c4bf7bf56936f034b7550996d1b7ca6473 100644 (file)
--- a/sha1-array.h
+++ b/sha1-array.h
@@ -22,5 +22,8 @@ int oid_array_for_each(struct oid_array *array,
 int oid_array_for_each_unique(struct oid_array *array,
                              for_each_oid_fn fn,
                              void *data);
+void oid_array_filter(struct oid_array *array,
+                     for_each_oid_fn want,
+                     void *cbdata);
 
 #endif /* SHA1_ARRAY_H */