diff --git a/Makefile b/Makefile
index 461c845..4e0cc39 100644
--- a/Makefile
+++ b/Makefile
@@ -816,6 +816,7 @@ LIB_OBJS += notes-merge.o
LIB_OBJS += notes-utils.o
LIB_OBJS += object.o
LIB_OBJS += oidset.o
+LIB_OBJS += oidset2.o
LIB_OBJS += pack-bitmap.o
LIB_OBJS += pack-bitmap-write.o
LIB_OBJS += pack-check.o
diff --git a/oidset2.c b/oidset2.c
new file mode 100644
index 0000000..43bc9ee
--- /dev/null
+++ b/oidset2.c
@@ -0,0 +1,104 @@
+#include "cache.h"
+#include "oidset2.h"
+
+static int oidset2_hashcmp(const void *unused_cmp_data,
+ const void *va, const void *vb,
+ const void *vkey)
+{
+ const struct oidset2_entry *a = va, *b = vb;
+ const struct object_id *key = vkey;
+ return oidcmp(&a->oid, key ? key : &b->oid);
+}
+
+struct oidset2_entry *oidset2_get(const struct oidset2 *set, const struct object_id *oid)
+{
+ struct hashmap_entry key;
+ struct oidset2_entry *value;
+
+ if (!set->map.cmpfn)
+ return NULL;
+
+ hashmap_entry_init(&key, sha1hash(oid->hash));
+ value = hashmap_get(&set->map, &key, oid);
+
+ return value;
+}
+
+int oidset2_contains(const struct oidset2 *set, const struct object_id *oid)
+{
+ return !!oidset2_get(set, oid);
+}
+
+int oidset2_insert(struct oidset2 *set, const struct object_id *oid,
+ enum object_type type, int64_t object_length,
+ const char *pathname)
+{
+ struct oidset2_entry *entry;
+
+ if (!set->map.cmpfn)
+ hashmap_init(&set->map, oidset2_hashcmp, NULL, 0);
+
+ if (oidset2_contains(set, oid))
+ return 1;
+
+ entry = xcalloc(1, sizeof(*entry));
+ hashmap_entry_init(&entry->hash, sha1hash(oid->hash));
+ oidcpy(&entry->oid, oid);
+
+ entry->type = type;
+ entry->object_length = object_length;
+ if (pathname)
+ entry->pathname = strdup(pathname);
+
+ hashmap_add(&set->map, entry);
+ return 0;
+}
+
+void oidset2_remove(struct oidset2 *set, const struct object_id *oid)
+{
+ struct hashmap_entry key;
+ struct oidset2_entry *e;
+
+ hashmap_entry_init(&key, sha1hash(oid->hash));
+ e = hashmap_remove(&set->map, &key, oid);
+
+ free(e->pathname);
+ free(e);
+}
+
+void oidset2_clear(struct oidset2 *set)
+{
+ hashmap_free(&set->map, 1);
+}
+
+static int oidset2_cmp(const void *a, const void *b)
+{
+ const struct oidset2_entry *ae = *((const struct oidset2_entry **)a);
+ const struct oidset2_entry *be = *((const struct oidset2_entry **)b);
+
+ return oidcmp(&ae->oid, &be->oid);
+}
+
+void oidset2_foreach(struct oidset2 *set, oidset2_foreach_cb cb, void *cb_data)
+{
+ struct hashmap_iter iter;
+ struct oidset2_entry **array;
+ struct oidset2_entry *e;
+ int j, k;
+
+ array = xcalloc(set->map.size, sizeof(*e));
+
+ hashmap_iter_init(&set->map, &iter);
+ k = 0;
+ while ((e = hashmap_iter_next(&iter)))
+ array[k++] = e;
+
+ QSORT(array, k, oidset2_cmp);
+
+ for (j = 0; j < k; j++) {
+ e = array[j];
+ cb(j, k, e, cb_data);
+ }
+
+ free(array);
+}diff --git a/oidset2.h b/oidset2.h
new file mode 100644
index 0000000..67d8a5a
--- /dev/null
+++ b/oidset2.h
@@ -0,0 +1,58 @@
+#ifndef OIDSET2_H
+#define OIDSET2_H
+
+/**
+ * oidset2 is a variant of oidset, but allows additional fields for each object.
+ */
+
+/**
+ * A single oidset2; should be zero-initialized (or use OIDSET2_INIT).
+ */
+struct oidset2 {
+ struct hashmap map;
+};
+
+#define OIDSET2_INIT { { NULL } }
+
+struct oidset2_entry {
+ struct hashmap_entry hash;
+ struct object_id oid;
+
+ enum object_type type;
+ int64_t object_length; /* This is SIGNED. Use -1 when unknown. */
+ char *pathname;
+};
+
+struct oidset2_entry *oidset2_get(const struct oidset2 *set, const struct object_id *oid);
+
+/**
+ * Returns true iff `set` contains `oid`.
+ */
+int oidset2_contains(const struct oidset2 *set, const struct object_id *oid);
+
+/**
+ * Insert the oid into the set; a copy is made, so "oid" does not need
+ * to persist after this function is called.
+ *
+ * Returns 1 if the oid was already in the set, 0 otherwise. This can be used
+ * to perform an efficient check-and-add.
+ */
+int oidset2_insert(struct oidset2 *set, const struct object_id *oid,
+ enum object_type type, int64_t object_length,
+ const char *pathname);
+
+void oidset2_remove(struct oidset2 *set, const struct object_id *oid);
+
+typedef void (*oidset2_foreach_cb)(
+ int i, int i_limit,
+ struct oidset2_entry *e, void *cb_data);
+
+void oidset2_foreach(struct oidset2 *set, oidset2_foreach_cb cb, void *cb_data);
+
+/**
+ * Remove all entries from the oidset2, freeing any resources associated with
+ * it.
+ */
+void oidset2_clear(struct oidset2 *set);
+
+#endif /* OIDSET2_H */--
2.9.3