From 2c68f577fc8a400f4d354f4700e4809c1bfd6470 Mon Sep 17 00:00:00 2001 From: Eric Wong Date: Tue, 7 Dec 2021 18:38:10 +0000 Subject: [PATCH] cbtree: remove broken and unused cb_unlink cb_unlink is broken once a node is no longer self-referential due to subsequent insertions. This is a consequence of an intrusive implementation and I'm not sure if it's easily fixable while retaining our cache-friendly intrusive property (I've tried for several hours in another project). In any case, we're not using cb_unlink anywhere in our codebase, just get rid of it to avoid misleading future readers. Signed-off-by: Eric Wong Signed-off-by: Junio C Hamano --- cbtree.c | 32 -------------------------------- cbtree.h | 1 - 2 files changed, 33 deletions(-) diff --git a/cbtree.c b/cbtree.c index b0c65d810f..336e46dbba 100644 --- a/cbtree.c +++ b/cbtree.c @@ -95,38 +95,6 @@ struct cb_node *cb_lookup(struct cb_tree *t, const uint8_t *k, size_t klen) return p && !memcmp(p->k, k, klen) ? p : NULL; } -struct cb_node *cb_unlink(struct cb_tree *t, const uint8_t *k, size_t klen) -{ - struct cb_node **wherep = &t->root; - struct cb_node **whereq = NULL; - struct cb_node *q = NULL; - size_t direction = 0; - uint8_t c; - struct cb_node *p = t->root; - - if (!p) return NULL; /* empty tree, nothing to delete */ - - /* traverse to find best match, keeping link to parent */ - while (1 & (uintptr_t)p) { - whereq = wherep; - q = cb_node_of(p); - c = q->byte < klen ? k[q->byte] : 0; - direction = (1 + (q->otherbits | c)) >> 8; - wherep = q->child + direction; - p = *wherep; - } - - if (memcmp(p->k, k, klen)) - return NULL; /* no match, nothing unlinked */ - - /* found an exact match */ - if (whereq) /* update parent */ - *whereq = q->child[1 - direction]; - else - t->root = NULL; - return p; -} - static enum cb_next cb_descend(struct cb_node *p, cb_iter fn, void *arg) { if (1 & (uintptr_t)p) { diff --git a/cbtree.h b/cbtree.h index dedbb8e2a4..0be14fb7ee 100644 --- a/cbtree.h +++ b/cbtree.h @@ -47,7 +47,6 @@ static inline void cb_init(struct cb_tree *t) struct cb_node *cb_lookup(struct cb_tree *, const uint8_t *k, size_t klen); struct cb_node *cb_insert(struct cb_tree *, struct cb_node *, size_t klen); -struct cb_node *cb_unlink(struct cb_tree *t, const uint8_t *k, size_t klen); typedef enum cb_next (*cb_iter)(struct cb_node *, void *arg);