Merge branch 'ps/odb-generic-object-name-handling'

Object name handling (disambiguation and abbreviation) has been
refactored to be backend-generic, moving logic into the respective
object database backends.

* ps/odb-generic-object-name-handling:
  odb: introduce generic `odb_find_abbrev_len()`
  object-file: move logic to compute packed abbreviation length
  object-name: move logic to compute loose abbreviation length
  object-name: simplify computing common prefixes
  object-name: abbreviate loose object names without `disambiguate_state`
  object-name: merge `update_candidates()` and `match_prefix()`
  object-name: backend-generic `get_short_oid()`
  object-name: backend-generic `repo_collect_ambiguous()`
  object-name: extract function to parse object ID prefixes
  object-name: move logic to iterate through packed prefixed objects
  object-name: move logic to iterate through loose prefixed objects
  odb: introduce `struct odb_for_each_object_options`
  oidtree: extend iteration to allow for arbitrary return codes
  oidtree: modernize the code a bit
  object-file: fix sparse 'plain integer as NULL pointer' error

1 files changed, 41 insertions, 7 deletions

diff --git a/oidtree.h b/oidtree.h
index 77898f510a..2b7bad2e60 100644
--- a/oidtree.h
+++ b/oidtree.h
@@ -5,18 +5,52 @@
 #include "hash.h"
 #include "mem-pool.h"
 
+/*
+ * OID trees are an efficient storage for object IDs that use a critbit tree
+ * internally. Common prefixes are duplicated and object IDs are stored in a
+ * way that allow easy iteration over the objects in lexicographic order. As a
+ * consequence, operations that want to enumerate all object IDs that match a
+ * given prefix can be answered efficiently.
+ *
+ * Note that it is not (yet) possible to store data other than the object IDs
+ * themselves in this tree.
+ */
 struct oidtree {
 	struct cb_tree tree;
 	struct mem_pool mem_pool;
 };
 
-void oidtree_init(struct oidtree *);
-void oidtree_clear(struct oidtree *);
-void oidtree_insert(struct oidtree *, const struct object_id *);
-int oidtree_contains(struct oidtree *, const struct object_id *);
+/* Initialize the oidtree so that it is ready for use. */
+void oidtree_init(struct oidtree *ot);
 
-typedef enum cb_next (*oidtree_iter)(const struct object_id *, void *data);
-void oidtree_each(struct oidtree *, const struct object_id *,
-			size_t oidhexsz, oidtree_iter, void *data);
+/*
+ * Release all memory associated with the oidtree and reinitialize it for
+ * subsequent use.
+ */
+void oidtree_clear(struct oidtree *ot);
+
+/* Insert the object ID into the tree. */
+void oidtree_insert(struct oidtree *ot, const struct object_id *oid);
+
+/* Check whether the tree contains the given object ID. */
+bool oidtree_contains(struct oidtree *ot, const struct object_id *oid);
+
+/*
+ * Callback function used for `oidtree_each()`. Returning a non-zero exit code
+ * will cause iteration to stop. The exit code will be propagated to the caller
+ * of `oidtree_each()`.
+ */
+typedef int (*oidtree_each_cb)(const struct object_id *oid,
+			       void *cb_data);
+
+/*
+ * Iterate through all object IDs in the tree whose prefix matches the given
+ * object ID prefix and invoke the callback function on each of them.
+ *
+ * Returns any non-zero exit code from the provided callback function.
+ */
+int oidtree_each(struct oidtree *ot,
+		 const struct object_id *prefix, size_t prefix_hex_len,
+		 oidtree_each_cb cb, void *cb_data);
 
 #endif /* OIDTREE_H */