51afc709dc
The tree interfaces of the reftable library handle both insertion and searching of tree nodes with a single function, where the behaviour is altered between the two via an `insert` bit. This makes it quit awkward to handle allocation failures because on inserting we'd have to check for `NULL` pointers and return an error, whereas on searching entries we don't have to handle it as an allocation error. Split up concerns of this function into two separate functions, one for inserting entries and one for searching entries. This makes it easy for us to check for allocation errors as `tree_insert()` should never return a `NULL` pointer now. Adapt callers accordingly. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
46 lines
1.3 KiB
C
46 lines
1.3 KiB
C
/*
|
|
Copyright 2020 Google LLC
|
|
|
|
Use of this source code is governed by a BSD-style
|
|
license that can be found in the LICENSE file or at
|
|
https://developers.google.com/open-source/licenses/bsd
|
|
*/
|
|
|
|
#ifndef TREE_H
|
|
#define TREE_H
|
|
|
|
/* tree_node is a generic binary search tree. */
|
|
struct tree_node {
|
|
void *key;
|
|
struct tree_node *left, *right;
|
|
};
|
|
|
|
/*
|
|
* Search the tree for the node matching the given key using `compare` as
|
|
* comparison function. Returns the node whose key matches or `NULL` in case
|
|
* the key does not exist in the tree.
|
|
*/
|
|
struct tree_node *tree_search(struct tree_node *tree,
|
|
void *key,
|
|
int (*compare)(const void *, const void *));
|
|
|
|
/*
|
|
* Insert a node into the tree. Returns the newly inserted node if the key does
|
|
* not yet exist. Otherwise it returns the preexisting node. Returns `NULL`
|
|
* when allocating the new node fails.
|
|
*/
|
|
struct tree_node *tree_insert(struct tree_node **rootp,
|
|
void *key,
|
|
int (*compare)(const void *, const void *));
|
|
|
|
/* performs an infix walk of the tree. */
|
|
void infix_walk(struct tree_node *t, void (*action)(void *arg, void *key),
|
|
void *arg);
|
|
|
|
/*
|
|
* deallocates the tree nodes recursively. Keys should be deallocated separately
|
|
* by walking over the tree. */
|
|
void tree_free(struct tree_node *t);
|
|
|
|
#endif
|