mirror of
git://sourceware.org/git/lvm2.git
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5731d06bc5
Some minor indent changes to more easily read code.
1298 lines
27 KiB
C
1298 lines
27 KiB
C
// Copyright (C) 2018 Red Hat, Inc. All rights reserved.
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//
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// This file is part of LVM2.
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//
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// This copyrighted material is made available to anyone wishing to use,
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// modify, copy, or redistribute it subject to the terms and conditions
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// of the GNU Lesser General Public License v.2.1.
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//
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// You should have received a copy of the GNU Lesser General Public License
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// along with this program; if not, write to the Free Software Foundation,
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// Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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#include "radix-tree.h"
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#include "base/memory/container_of.h"
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#include "base/memory/zalloc.h"
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#include <assert.h>
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#include <stdlib.h>
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#include <stdio.h>
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#include <string.h>
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//----------------------------------------------------------------
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enum node_type {
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UNSET = 0,
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VALUE,
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VALUE_CHAIN,
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PREFIX_CHAIN,
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NODE4,
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NODE16,
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NODE48,
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NODE256
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};
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struct value {
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enum node_type type;
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union radix_value value;
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};
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// This is used for entries that have a key which is a prefix of another key.
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struct value_chain {
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union radix_value value;
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struct value child;
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};
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struct prefix_chain {
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struct value child;
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unsigned len;
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uint8_t prefix[];
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};
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struct node4 {
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uint32_t nr_entries;
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uint8_t keys[4];
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struct value values[4];
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};
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struct node16 {
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uint32_t nr_entries;
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uint8_t keys[16];
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struct value values[16];
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};
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struct node48 {
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uint32_t nr_entries;
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uint8_t keys[256];
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struct value values[48];
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};
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struct node256 {
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uint32_t nr_entries;
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struct value values[256];
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};
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struct radix_tree {
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unsigned nr_entries;
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struct value root;
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radix_value_dtr dtr;
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void *dtr_context;
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};
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//----------------------------------------------------------------
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struct radix_tree *radix_tree_create(radix_value_dtr dtr, void *dtr_context)
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{
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struct radix_tree *rt = malloc(sizeof(*rt));
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if (rt) {
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rt->nr_entries = 0;
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rt->root.type = UNSET;
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rt->dtr = dtr;
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rt->dtr_context = dtr_context;
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}
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return rt;
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}
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static inline void _dtr(struct radix_tree *rt, union radix_value v)
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{
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if (rt->dtr)
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rt->dtr(rt->dtr_context, v);
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}
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// Returns the number of values removed
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static unsigned _free_node(struct radix_tree *rt, struct value v)
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{
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unsigned i, nr = 0;
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struct value_chain *vc;
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struct prefix_chain *pc;
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struct node4 *n4;
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struct node16 *n16;
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struct node48 *n48;
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struct node256 *n256;
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switch (v.type) {
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case UNSET:
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break;
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case VALUE:
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_dtr(rt, v.value);
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nr = 1;
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break;
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case VALUE_CHAIN:
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vc = v.value.ptr;
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_dtr(rt, vc->value);
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nr = 1 + _free_node(rt, vc->child);
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free(vc);
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break;
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case PREFIX_CHAIN:
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pc = v.value.ptr;
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nr = _free_node(rt, pc->child);
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free(pc);
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break;
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case NODE4:
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n4 = (struct node4 *) v.value.ptr;
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for (i = 0; i < n4->nr_entries; i++)
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nr += _free_node(rt, n4->values[i]);
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free(n4);
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break;
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case NODE16:
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n16 = (struct node16 *) v.value.ptr;
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for (i = 0; i < n16->nr_entries; i++)
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nr += _free_node(rt, n16->values[i]);
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free(n16);
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break;
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case NODE48:
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n48 = (struct node48 *) v.value.ptr;
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for (i = 0; i < n48->nr_entries; i++)
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nr += _free_node(rt, n48->values[i]);
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free(n48);
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break;
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case NODE256:
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n256 = (struct node256 *) v.value.ptr;
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for (i = 0; i < 256; i++)
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nr += _free_node(rt, n256->values[i]);
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free(n256);
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break;
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}
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return nr;
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}
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void radix_tree_destroy(struct radix_tree *rt)
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{
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_free_node(rt, rt->root);
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free(rt);
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}
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unsigned radix_tree_size(struct radix_tree *rt)
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{
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return rt->nr_entries;
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}
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static bool _insert(struct radix_tree *rt, struct value *v, uint8_t *kb, uint8_t *ke, union radix_value rv);
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static bool _insert_unset(struct radix_tree *rt, struct value *v, uint8_t *kb, uint8_t *ke, union radix_value rv)
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{
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unsigned len = ke - kb;
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if (!len) {
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// value
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v->type = VALUE;
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v->value = rv;
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rt->nr_entries++;
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} else {
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// prefix -> value
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struct prefix_chain *pc = zalloc(sizeof(*pc) + len);
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if (!pc)
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return false;
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pc->child.type = VALUE;
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pc->child.value = rv;
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pc->len = len;
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memcpy(pc->prefix, kb, len);
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v->type = PREFIX_CHAIN;
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v->value.ptr = pc;
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rt->nr_entries++;
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}
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return true;
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}
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static bool _insert_value(struct radix_tree *rt, struct value *v, uint8_t *kb, uint8_t *ke, union radix_value rv)
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{
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unsigned len = ke - kb;
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if (!len)
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// overwrite
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v->value = rv;
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else {
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// value_chain -> value
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struct value_chain *vc = zalloc(sizeof(*vc));
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if (!vc)
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return false;
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vc->value = v->value;
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if (!_insert(rt, &vc->child, kb, ke, rv)) {
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free(vc);
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return false;
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}
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v->type = VALUE_CHAIN;
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v->value.ptr = vc;
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}
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return true;
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}
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static bool _insert_value_chain(struct radix_tree *rt, struct value *v, uint8_t *kb, uint8_t *ke, union radix_value rv)
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{
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struct value_chain *vc = v->value.ptr;
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return _insert(rt, &vc->child, kb, ke, rv);
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}
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static unsigned min(unsigned lhs, unsigned rhs)
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{
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if (lhs <= rhs)
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return lhs;
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else
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return rhs;
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}
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static bool _insert_prefix_chain(struct radix_tree *rt, struct value *v, uint8_t *kb, uint8_t *ke, union radix_value rv)
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{
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struct prefix_chain *pc = v->value.ptr;
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if (!pc->len) {
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v->type = VALUE;
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v->value = rv;
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} else if (*kb == pc->prefix[0]) {
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// There's a common prefix let's split the chain into two and
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// recurse.
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struct prefix_chain *pc2;
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unsigned i, len = min(pc->len, ke - kb);
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for (i = 0; i < len; i++)
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if (kb[i] != pc->prefix[i])
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break;
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if (!(pc2 = zalloc(sizeof(*pc2) + pc->len - i)))
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return false;
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pc2->len = pc->len - i;
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memmove(pc2->prefix, pc->prefix + i, pc2->len);
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pc2->child = pc->child;
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// FIXME: this trashes pc so we can't back out
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pc->child.type = PREFIX_CHAIN;
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pc->child.value.ptr = pc2;
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pc->len = i;
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if (!_insert(rt, &pc->child, kb + i, ke, rv)) {
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free(pc2);
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return false;
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}
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} else {
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// Stick an n4 in front.
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struct node4 *n4 = zalloc(sizeof(*n4));
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if (!n4)
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return false;
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n4->keys[0] = pc->prefix[0];
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if (pc->len == 1) {
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n4->values[0] = pc->child;
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free(pc);
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} else {
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memmove(pc->prefix, pc->prefix + 1, pc->len - 1);
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pc->len--;
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n4->values[0] = *v;
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}
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n4->keys[1] = *kb;
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if (!_insert(rt, n4->values + 1, kb + 1, ke, rv)) {
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free(n4);
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return false;
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}
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n4->nr_entries = 2;
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v->type = NODE4;
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v->value.ptr = n4;
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}
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return true;
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}
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static bool _insert_node4(struct radix_tree *rt, struct value *v, uint8_t *kb, uint8_t *ke, union radix_value rv)
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{
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struct node4 *n4 = v->value.ptr;
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if (n4->nr_entries == 4) {
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struct node16 *n16 = zalloc(sizeof(*n16));
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if (!n16)
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return false;
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n16->nr_entries = 5;
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memcpy(n16->keys, n4->keys, sizeof(n4->keys));
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memcpy(n16->values, n4->values, sizeof(n4->values));
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n16->keys[4] = *kb;
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if (!_insert(rt, n16->values + 4, kb + 1, ke, rv)) {
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free(n16);
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return false;
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}
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free(n4);
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v->type = NODE16;
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v->value.ptr = n16;
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} else {
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if (!_insert(rt, n4->values + n4->nr_entries, kb + 1, ke, rv))
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return false;
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n4->keys[n4->nr_entries] = *kb;
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n4->nr_entries++;
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}
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return true;
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}
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static bool _insert_node16(struct radix_tree *rt, struct value *v, uint8_t *kb, uint8_t *ke, union radix_value rv)
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{
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struct node16 *n16 = v->value.ptr;
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if (n16->nr_entries == 16) {
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unsigned i;
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struct node48 *n48 = zalloc(sizeof(*n48));
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if (!n48)
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return false;
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n48->nr_entries = 17;
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/* coverity[bad_memset] intentional use of '0' */
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memset(n48->keys, 48, sizeof(n48->keys));
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for (i = 0; i < 16; i++) {
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n48->keys[n16->keys[i]] = i;
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n48->values[i] = n16->values[i];
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}
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n48->keys[*kb] = 16;
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if (!_insert(rt, n48->values + 16, kb + 1, ke, rv)) {
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free(n48);
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return false;
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}
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free(n16);
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v->type = NODE48;
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v->value.ptr = n48;
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} else {
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if (!_insert(rt, n16->values + n16->nr_entries, kb + 1, ke, rv))
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return false;
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n16->keys[n16->nr_entries] = *kb;
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n16->nr_entries++;
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}
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return true;
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}
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static bool _insert_node48(struct radix_tree *rt, struct value *v, uint8_t *kb, uint8_t *ke, union radix_value rv)
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{
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struct node48 *n48 = v->value.ptr;
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if (n48->nr_entries == 48) {
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unsigned i;
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struct node256 *n256 = zalloc(sizeof(*n256));
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if (!n256)
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return false;
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n256->nr_entries = 49;
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for (i = 0; i < 256; i++) {
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if (n48->keys[i] < 48)
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n256->values[i] = n48->values[n48->keys[i]];
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}
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if (!_insert(rt, n256->values + *kb, kb + 1, ke, rv)) {
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free(n256);
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return false;
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}
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free(n48);
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v->type = NODE256;
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v->value.ptr = n256;
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} else {
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if (!_insert(rt, n48->values + n48->nr_entries, kb + 1, ke, rv))
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return false;
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n48->keys[*kb] = n48->nr_entries;
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n48->nr_entries++;
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}
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return true;
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}
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static bool _insert_node256(struct radix_tree *rt, struct value *v, uint8_t *kb, uint8_t *ke, union radix_value rv)
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{
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struct node256 *n256 = v->value.ptr;
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bool r, was_unset = n256->values[*kb].type == UNSET;
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r = _insert(rt, n256->values + *kb, kb + 1, ke, rv);
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if (r && was_unset)
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n256->nr_entries++;
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return r;
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}
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// FIXME: the tree should not be touched if insert fails (eg, OOM)
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static bool _insert(struct radix_tree *rt, struct value *v, uint8_t *kb, uint8_t *ke, union radix_value rv)
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{
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if (kb == ke) {
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if (v->type == UNSET) {
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v->type = VALUE;
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v->value = rv;
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rt->nr_entries++;
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} else if (v->type == VALUE) {
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v->value = rv;
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} else {
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struct value_chain *vc = zalloc(sizeof(*vc));
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if (!vc)
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return false;
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vc->value = rv;
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vc->child = *v;
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v->type = VALUE_CHAIN;
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v->value.ptr = vc;
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rt->nr_entries++;
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}
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return true;
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}
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switch (v->type) {
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case UNSET:
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return _insert_unset(rt, v, kb, ke, rv);
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case VALUE:
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return _insert_value(rt, v, kb, ke, rv);
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case VALUE_CHAIN:
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return _insert_value_chain(rt, v, kb, ke, rv);
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case PREFIX_CHAIN:
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return _insert_prefix_chain(rt, v, kb, ke, rv);
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case NODE4:
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return _insert_node4(rt, v, kb, ke, rv);
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case NODE16:
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return _insert_node16(rt, v, kb, ke, rv);
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case NODE48:
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return _insert_node48(rt, v, kb, ke, rv);
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case NODE256:
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return _insert_node256(rt, v, kb, ke, rv);
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}
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// can't get here
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return false;
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}
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struct lookup_result {
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struct value *v;
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uint8_t *kb;
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};
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static struct lookup_result _lookup_prefix(struct value *v, uint8_t *kb, uint8_t *ke)
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{
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unsigned i;
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struct value_chain *vc;
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struct prefix_chain *pc;
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struct node4 *n4;
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struct node16 *n16;
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struct node48 *n48;
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struct node256 *n256;
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if (kb == ke)
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return (struct lookup_result) {.v = v, .kb = kb};
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switch (v->type) {
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case UNSET:
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case VALUE:
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break;
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case VALUE_CHAIN:
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vc = v->value.ptr;
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return _lookup_prefix(&vc->child, kb, ke);
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case PREFIX_CHAIN:
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pc = v->value.ptr;
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if (ke - kb < pc->len)
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return (struct lookup_result) {.v = v, .kb = kb};
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for (i = 0; i < pc->len; i++)
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if (kb[i] != pc->prefix[i])
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return (struct lookup_result) {.v = v, .kb = kb};
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return _lookup_prefix(&pc->child, kb + pc->len, ke);
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case NODE4:
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n4 = v->value.ptr;
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for (i = 0; i < n4->nr_entries; i++)
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if (n4->keys[i] == *kb)
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return _lookup_prefix(n4->values + i, kb + 1, ke);
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break;
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case NODE16:
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// FIXME: use binary search or simd?
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n16 = v->value.ptr;
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for (i = 0; i < n16->nr_entries; i++)
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if (n16->keys[i] == *kb)
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return _lookup_prefix(n16->values + i, kb + 1, ke);
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break;
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case NODE48:
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n48 = v->value.ptr;
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i = n48->keys[*kb];
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if (i < 48)
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return _lookup_prefix(n48->values + i, kb + 1, ke);
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break;
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case NODE256:
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n256 = v->value.ptr;
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if (n256->values[*kb].type != UNSET)
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return _lookup_prefix(n256->values + *kb, kb + 1, ke);
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break;
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}
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return (struct lookup_result) {.v = v, .kb = kb};
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}
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|
|
bool radix_tree_insert(struct radix_tree *rt, uint8_t *kb, uint8_t *ke, union radix_value rv)
|
|
{
|
|
struct lookup_result lr = _lookup_prefix(&rt->root, kb, ke);
|
|
return _insert(rt, lr.v, lr.kb, ke, rv);
|
|
}
|
|
|
|
// Note the degrade functions also free the original node.
|
|
static void _degrade_to_n4(struct node16 *n16, struct value *result)
|
|
{
|
|
struct node4 *n4 = zalloc(sizeof(*n4));
|
|
|
|
assert(n4 != NULL);
|
|
|
|
n4->nr_entries = n16->nr_entries;
|
|
memcpy(n4->keys, n16->keys, n16->nr_entries * sizeof(*n4->keys));
|
|
memcpy(n4->values, n16->values, n16->nr_entries * sizeof(*n4->values));
|
|
free(n16);
|
|
|
|
result->type = NODE4;
|
|
result->value.ptr = n4;
|
|
}
|
|
|
|
static void _degrade_to_n16(struct node48 *n48, struct value *result)
|
|
{
|
|
unsigned i, count = 0;
|
|
struct node16 *n16 = zalloc(sizeof(*n16));
|
|
|
|
assert(n16 != NULL);
|
|
|
|
n16->nr_entries = n48->nr_entries;
|
|
for (i = 0; i < 256; i++) {
|
|
if (n48->keys[i] < 48) {
|
|
n16->keys[count] = i;
|
|
n16->values[count] = n48->values[n48->keys[i]];
|
|
count++;
|
|
}
|
|
}
|
|
|
|
free(n48);
|
|
|
|
result->type = NODE16;
|
|
result->value.ptr = n16;
|
|
}
|
|
|
|
static void _degrade_to_n48(struct node256 *n256, struct value *result)
|
|
{
|
|
unsigned i, count = 0;
|
|
struct node48 *n48 = zalloc(sizeof(*n48));
|
|
|
|
assert(n48 != NULL);
|
|
|
|
n48->nr_entries = n256->nr_entries;
|
|
for (i = 0; i < 256; i++) {
|
|
if (n256->values[i].type == UNSET)
|
|
n48->keys[i] = 48;
|
|
|
|
else {
|
|
n48->keys[i] = count;
|
|
n48->values[count] = n256->values[i];
|
|
count++;
|
|
}
|
|
}
|
|
|
|
free(n256);
|
|
|
|
result->type = NODE48;
|
|
result->value.ptr = n48;
|
|
}
|
|
|
|
// Removes an entry in an array by sliding the values above it down.
|
|
static void _erase_elt(void *array, size_t obj_size, unsigned count, unsigned idx)
|
|
{
|
|
if (idx == (count - 1))
|
|
// The simple case
|
|
return;
|
|
|
|
memmove(((uint8_t *) array) + (obj_size * idx),
|
|
((uint8_t *) array) + (obj_size * (idx + 1)),
|
|
obj_size * (count - idx - 1));
|
|
|
|
// Zero the now unused last elt (set's v.type to UNSET)
|
|
memset(((uint8_t *) array) + (count - 1) * obj_size, 0, obj_size);
|
|
}
|
|
|
|
static bool _remove(struct radix_tree *rt, struct value *root, uint8_t *kb, uint8_t *ke)
|
|
{
|
|
bool r;
|
|
unsigned i, j;
|
|
struct value_chain *vc;
|
|
struct prefix_chain *pc;
|
|
struct node4 *n4;
|
|
struct node16 *n16;
|
|
struct node48 *n48;
|
|
struct node256 *n256;
|
|
|
|
if (kb == ke) {
|
|
if (root->type == VALUE) {
|
|
root->type = UNSET;
|
|
_dtr(rt, root->value);
|
|
return true;
|
|
|
|
} else if (root->type == VALUE_CHAIN) {
|
|
vc = root->value.ptr;
|
|
_dtr(rt, vc->value);
|
|
memcpy(root, &vc->child, sizeof(*root));
|
|
free(vc);
|
|
return true;
|
|
|
|
} else
|
|
return false;
|
|
}
|
|
|
|
switch (root->type) {
|
|
case UNSET:
|
|
case VALUE:
|
|
// this is a value for a prefix of the key
|
|
return false;
|
|
|
|
case VALUE_CHAIN:
|
|
vc = root->value.ptr;
|
|
r = _remove(rt, &vc->child, kb, ke);
|
|
if (r && (vc->child.type == UNSET)) {
|
|
root->type = VALUE;
|
|
root->value = vc->value;
|
|
free(vc);
|
|
}
|
|
return r;
|
|
|
|
case PREFIX_CHAIN:
|
|
pc = root->value.ptr;
|
|
if (ke - kb < pc->len)
|
|
return false;
|
|
|
|
for (i = 0; i < pc->len; i++)
|
|
if (kb[i] != pc->prefix[i])
|
|
return false;
|
|
|
|
r = _remove(rt, &pc->child, kb + pc->len, ke);
|
|
if (r && pc->child.type == UNSET) {
|
|
root->type = UNSET;
|
|
free(pc);
|
|
}
|
|
return r;
|
|
|
|
case NODE4:
|
|
n4 = root->value.ptr;
|
|
for (i = 0; i < n4->nr_entries; i++) {
|
|
if (n4->keys[i] == *kb) {
|
|
r = _remove(rt, n4->values + i, kb + 1, ke);
|
|
if (r && n4->values[i].type == UNSET) {
|
|
if (i < n4->nr_entries) {
|
|
_erase_elt(n4->keys, sizeof(*n4->keys), n4->nr_entries, i);
|
|
_erase_elt(n4->values, sizeof(*n4->values), n4->nr_entries, i);
|
|
}
|
|
|
|
n4->nr_entries--;
|
|
if (!n4->nr_entries) {
|
|
free(n4);
|
|
root->type = UNSET;
|
|
}
|
|
}
|
|
return r;
|
|
}
|
|
}
|
|
return false;
|
|
|
|
case NODE16:
|
|
n16 = root->value.ptr;
|
|
for (i = 0; i < n16->nr_entries; i++) {
|
|
if (n16->keys[i] == *kb) {
|
|
r = _remove(rt, n16->values + i, kb + 1, ke);
|
|
if (r && n16->values[i].type == UNSET) {
|
|
if (i < n16->nr_entries) {
|
|
_erase_elt(n16->keys, sizeof(*n16->keys), n16->nr_entries, i);
|
|
_erase_elt(n16->values, sizeof(*n16->values), n16->nr_entries, i);
|
|
}
|
|
|
|
n16->nr_entries--;
|
|
if (n16->nr_entries <= 4) {
|
|
_degrade_to_n4(n16, root);
|
|
}
|
|
}
|
|
return r;
|
|
}
|
|
}
|
|
return false;
|
|
|
|
case NODE48:
|
|
n48 = root->value.ptr;
|
|
i = n48->keys[*kb];
|
|
if (i < 48) {
|
|
r = _remove(rt, n48->values + i, kb + 1, ke);
|
|
if (r && n48->values[i].type == UNSET) {
|
|
n48->keys[*kb] = 48;
|
|
for (j = 0; j < 256; j++)
|
|
if (n48->keys[j] < 48 && n48->keys[j] > i)
|
|
n48->keys[j]--;
|
|
_erase_elt(n48->values, sizeof(*n48->values), n48->nr_entries, i);
|
|
n48->nr_entries--;
|
|
if (n48->nr_entries <= 16)
|
|
_degrade_to_n16(n48, root);
|
|
}
|
|
return r;
|
|
}
|
|
return false;
|
|
|
|
case NODE256:
|
|
n256 = root->value.ptr;
|
|
r = _remove(rt, n256->values + (*kb), kb + 1, ke);
|
|
if (r && n256->values[*kb].type == UNSET) {
|
|
n256->nr_entries--;
|
|
if (n256->nr_entries <= 48)
|
|
_degrade_to_n48(n256, root);
|
|
}
|
|
return r;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
bool radix_tree_remove(struct radix_tree *rt, uint8_t *key_begin, uint8_t *key_end)
|
|
{
|
|
if (_remove(rt, &rt->root, key_begin, key_end)) {
|
|
rt->nr_entries--;
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
//----------------------------------------------------------------
|
|
|
|
static bool _prefix_chain_matches(struct lookup_result *lr, uint8_t *ke)
|
|
{
|
|
// It's possible the top node is a prefix chain, and
|
|
// the remaining key matches part of it.
|
|
if (lr->v->type == PREFIX_CHAIN) {
|
|
unsigned i, rlen = ke - lr->kb;
|
|
struct prefix_chain *pc = lr->v->value.ptr;
|
|
if (rlen < pc->len) {
|
|
for (i = 0; i < rlen; i++)
|
|
if (pc->prefix[i] != lr->kb[i])
|
|
return false;
|
|
return true;
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
static bool _remove_subtree(struct radix_tree *rt, struct value *root, uint8_t *kb, uint8_t *ke, unsigned *count)
|
|
{
|
|
bool r;
|
|
unsigned i, j, len;
|
|
struct value_chain *vc;
|
|
struct prefix_chain *pc;
|
|
struct node4 *n4;
|
|
struct node16 *n16;
|
|
struct node48 *n48;
|
|
struct node256 *n256;
|
|
|
|
if (kb == ke) {
|
|
*count += _free_node(rt, *root);
|
|
root->type = UNSET;
|
|
return true;
|
|
}
|
|
|
|
switch (root->type) {
|
|
case UNSET:
|
|
case VALUE:
|
|
// No entries with the given prefix
|
|
return true;
|
|
|
|
case VALUE_CHAIN:
|
|
vc = root->value.ptr;
|
|
r = _remove_subtree(rt, &vc->child, kb, ke, count);
|
|
if (r && (vc->child.type == UNSET)) {
|
|
root->type = VALUE;
|
|
root->value = vc->value;
|
|
free(vc);
|
|
}
|
|
return r;
|
|
|
|
case PREFIX_CHAIN:
|
|
pc = root->value.ptr;
|
|
len = min(pc->len, ke - kb);
|
|
for (i = 0; i < len; i++)
|
|
if (kb[i] != pc->prefix[i])
|
|
return true;
|
|
|
|
r = _remove_subtree(rt, &pc->child, len < pc->len ? ke : (kb + pc->len), ke, count);
|
|
if (r && pc->child.type == UNSET) {
|
|
root->type = UNSET;
|
|
free(pc);
|
|
}
|
|
return r;
|
|
|
|
case NODE4:
|
|
n4 = root->value.ptr;
|
|
for (i = 0; i < n4->nr_entries; i++) {
|
|
if (n4->keys[i] == *kb) {
|
|
r = _remove_subtree(rt, n4->values + i, kb + 1, ke, count);
|
|
if (r && n4->values[i].type == UNSET) {
|
|
if (i < n4->nr_entries) {
|
|
_erase_elt(n4->keys, sizeof(*n4->keys), n4->nr_entries, i);
|
|
_erase_elt(n4->values, sizeof(*n4->values), n4->nr_entries, i);
|
|
}
|
|
|
|
n4->nr_entries--;
|
|
if (!n4->nr_entries) {
|
|
free(n4);
|
|
root->type = UNSET;
|
|
}
|
|
}
|
|
return r;
|
|
}
|
|
}
|
|
return true;
|
|
|
|
case NODE16:
|
|
n16 = root->value.ptr;
|
|
for (i = 0; i < n16->nr_entries; i++) {
|
|
if (n16->keys[i] == *kb) {
|
|
r = _remove_subtree(rt, n16->values + i, kb + 1, ke, count);
|
|
if (r && n16->values[i].type == UNSET) {
|
|
if (i < n16->nr_entries) {
|
|
_erase_elt(n16->keys, sizeof(*n16->keys), n16->nr_entries, i);
|
|
_erase_elt(n16->values, sizeof(*n16->values), n16->nr_entries, i);
|
|
}
|
|
|
|
n16->nr_entries--;
|
|
if (n16->nr_entries <= 4)
|
|
_degrade_to_n4(n16, root);
|
|
}
|
|
return r;
|
|
}
|
|
}
|
|
return true;
|
|
|
|
case NODE48:
|
|
n48 = root->value.ptr;
|
|
i = n48->keys[*kb];
|
|
if (i < 48) {
|
|
r = _remove_subtree(rt, n48->values + i, kb + 1, ke, count);
|
|
if (r && n48->values[i].type == UNSET) {
|
|
n48->keys[*kb] = 48;
|
|
for (j = 0; j < 256; j++)
|
|
if (n48->keys[j] < 48 && n48->keys[j] > i)
|
|
n48->keys[j]--;
|
|
_erase_elt(n48->values, sizeof(*n48->values), n48->nr_entries, i);
|
|
n48->nr_entries--;
|
|
if (n48->nr_entries <= 16)
|
|
_degrade_to_n16(n48, root);
|
|
}
|
|
return r;
|
|
}
|
|
return true;
|
|
|
|
case NODE256:
|
|
n256 = root->value.ptr;
|
|
if (n256->values[*kb].type == UNSET)
|
|
return true; // No entries
|
|
|
|
r = _remove_subtree(rt, n256->values + (*kb), kb + 1, ke, count);
|
|
if (r && n256->values[*kb].type == UNSET) {
|
|
n256->nr_entries--;
|
|
if (n256->nr_entries <= 48)
|
|
_degrade_to_n48(n256, root);
|
|
}
|
|
return r;
|
|
}
|
|
|
|
// Shouldn't get here
|
|
return false;
|
|
}
|
|
|
|
unsigned radix_tree_remove_prefix(struct radix_tree *rt, uint8_t *kb, uint8_t *ke)
|
|
{
|
|
unsigned count = 0;
|
|
|
|
if (_remove_subtree(rt, &rt->root, kb, ke, &count))
|
|
rt->nr_entries -= count;
|
|
|
|
return count;
|
|
}
|
|
|
|
//----------------------------------------------------------------
|
|
|
|
bool radix_tree_lookup(struct radix_tree *rt,
|
|
uint8_t *kb, uint8_t *ke, union radix_value *result)
|
|
{
|
|
struct value_chain *vc;
|
|
struct lookup_result lr = _lookup_prefix(&rt->root, kb, ke);
|
|
if (lr.kb == ke) {
|
|
switch (lr.v->type) {
|
|
case VALUE:
|
|
*result = lr.v->value;
|
|
return true;
|
|
|
|
case VALUE_CHAIN:
|
|
vc = lr.v->value.ptr;
|
|
*result = vc->value;
|
|
return true;
|
|
|
|
default:
|
|
return false;
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
// FIXME: build up the keys too
|
|
static bool _iterate(struct value *v, struct radix_tree_iterator *it)
|
|
{
|
|
unsigned i;
|
|
struct value_chain *vc;
|
|
struct prefix_chain *pc;
|
|
struct node4 *n4;
|
|
struct node16 *n16;
|
|
struct node48 *n48;
|
|
struct node256 *n256;
|
|
|
|
switch (v->type) {
|
|
case UNSET:
|
|
// can't happen
|
|
break;
|
|
|
|
case VALUE:
|
|
return it->visit(it, NULL, NULL, v->value);
|
|
|
|
case VALUE_CHAIN:
|
|
vc = v->value.ptr;
|
|
return it->visit(it, NULL, NULL, vc->value) && _iterate(&vc->child, it);
|
|
|
|
case PREFIX_CHAIN:
|
|
pc = v->value.ptr;
|
|
return _iterate(&pc->child, it);
|
|
|
|
case NODE4:
|
|
n4 = (struct node4 *) v->value.ptr;
|
|
for (i = 0; i < n4->nr_entries; i++)
|
|
if (!_iterate(n4->values + i, it))
|
|
return false;
|
|
return true;
|
|
|
|
case NODE16:
|
|
n16 = (struct node16 *) v->value.ptr;
|
|
for (i = 0; i < n16->nr_entries; i++)
|
|
if (!_iterate(n16->values + i, it))
|
|
return false;
|
|
return true;
|
|
|
|
case NODE48:
|
|
n48 = (struct node48 *) v->value.ptr;
|
|
for (i = 0; i < n48->nr_entries; i++)
|
|
if (!_iterate(n48->values + i, it))
|
|
return false;
|
|
return true;
|
|
|
|
case NODE256:
|
|
n256 = (struct node256 *) v->value.ptr;
|
|
for (i = 0; i < 256; i++)
|
|
if (n256->values[i].type != UNSET && !_iterate(n256->values + i, it))
|
|
return false;
|
|
return true;
|
|
}
|
|
|
|
// can't get here
|
|
return false;
|
|
}
|
|
|
|
void radix_tree_iterate(struct radix_tree *rt, uint8_t *kb, uint8_t *ke,
|
|
struct radix_tree_iterator *it)
|
|
{
|
|
struct lookup_result lr = _lookup_prefix(&rt->root, kb, ke);
|
|
if (lr.kb == ke || _prefix_chain_matches(&lr, ke))
|
|
(void) _iterate(lr.v, it);
|
|
}
|
|
|
|
//----------------------------------------------------------------
|
|
// Checks:
|
|
// 1) The number of entries matches rt->nr_entries
|
|
// 2) The number of entries is correct in each node
|
|
// 3) prefix chain len > 0
|
|
// 4) all unused values are UNSET
|
|
|
|
static bool _check_nodes(struct value *v, unsigned *count)
|
|
{
|
|
uint64_t bits;
|
|
unsigned i, ncount;
|
|
struct value_chain *vc;
|
|
struct prefix_chain *pc;
|
|
struct node4 *n4;
|
|
struct node16 *n16;
|
|
struct node48 *n48;
|
|
struct node256 *n256;
|
|
|
|
switch (v->type) {
|
|
case UNSET:
|
|
return true;
|
|
|
|
case VALUE:
|
|
(*count)++;
|
|
return true;
|
|
|
|
case VALUE_CHAIN:
|
|
(*count)++;
|
|
vc = v->value.ptr;
|
|
return _check_nodes(&vc->child, count);
|
|
|
|
case PREFIX_CHAIN:
|
|
pc = v->value.ptr;
|
|
return _check_nodes(&pc->child, count);
|
|
|
|
case NODE4:
|
|
n4 = v->value.ptr;
|
|
for (i = 0; i < n4->nr_entries; i++)
|
|
if (!_check_nodes(n4->values + i, count))
|
|
return false;
|
|
|
|
for (i = n4->nr_entries; i < 4; i++)
|
|
if (n4->values[i].type != UNSET) {
|
|
fprintf(stderr, "unused value is not UNSET (n4)\n");
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
|
|
case NODE16:
|
|
n16 = v->value.ptr;
|
|
for (i = 0; i < n16->nr_entries; i++)
|
|
if (!_check_nodes(n16->values + i, count))
|
|
return false;
|
|
|
|
for (i = n16->nr_entries; i < 16; i++)
|
|
if (n16->values[i].type != UNSET) {
|
|
fprintf(stderr, "unused value is not UNSET (n16)\n");
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
|
|
case NODE48:
|
|
bits = 0;
|
|
n48 = v->value.ptr;
|
|
ncount = 0;
|
|
for (i = 0; i < 256; i++) {
|
|
if (n48->keys[i] < 48) {
|
|
if (n48->keys[i] >= n48->nr_entries) {
|
|
fprintf(stderr, "referencing value past nr_entries (n48)\n");
|
|
return false;
|
|
}
|
|
|
|
if (bits & (1ull << n48->keys[i])) {
|
|
fprintf(stderr, "duplicate entry (n48) %u\n", (unsigned) n48->keys[i]);
|
|
return false;
|
|
}
|
|
bits = bits | (1ull << n48->keys[i]);
|
|
ncount++;
|
|
|
|
if (!_check_nodes(n48->values + n48->keys[i], count))
|
|
return false;
|
|
}
|
|
}
|
|
|
|
for (i = 0; i < n48->nr_entries; i++) {
|
|
if (!(bits & (1ull << i))) {
|
|
fprintf(stderr, "not all values are referenced (n48)\n");
|
|
return false;
|
|
}
|
|
}
|
|
|
|
if (ncount != n48->nr_entries) {
|
|
fprintf(stderr, "incorrect number of entries in n48, n48->nr_entries = %u, actual = %u\n",
|
|
n48->nr_entries, ncount);
|
|
return false;
|
|
}
|
|
|
|
for (i = 0; i < n48->nr_entries; i++)
|
|
if (n48->values[i].type == UNSET) {
|
|
fprintf(stderr, "value in UNSET (n48)\n");
|
|
return false;
|
|
}
|
|
|
|
for (i = n48->nr_entries; i < 48; i++)
|
|
if (n48->values[i].type != UNSET) {
|
|
fprintf(stderr, "unused value is not UNSET (n48)\n");
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
|
|
case NODE256:
|
|
n256 = v->value.ptr;
|
|
|
|
ncount = 0;
|
|
for (i = 0; i < 256; i++) {
|
|
struct value *v2 = n256->values + i;
|
|
|
|
if (v2->type == UNSET)
|
|
continue;
|
|
|
|
if (!_check_nodes(v2, count))
|
|
return false;
|
|
|
|
ncount++;
|
|
}
|
|
|
|
if (ncount != n256->nr_entries) {
|
|
fprintf(stderr, "incorrect number of entries in n256, n256->nr_entries = %u, actual = %u\n",
|
|
n256->nr_entries, ncount);
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
|
|
default:
|
|
fprintf(stderr, "unknown value type: %u\n", v->type);
|
|
}
|
|
|
|
fprintf(stderr, "shouldn't get here\n");
|
|
return false;
|
|
}
|
|
|
|
bool radix_tree_is_well_formed(struct radix_tree *rt)
|
|
{
|
|
unsigned count = 0;
|
|
|
|
if (!_check_nodes(&rt->root, &count))
|
|
return false;
|
|
|
|
if (rt->nr_entries != count) {
|
|
fprintf(stderr, "incorrect entry count: rt->nr_entries = %u, actual = %u\n",
|
|
rt->nr_entries, count);
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
//----------------------------------------------------------------
|
|
|
|
static void _dump(FILE *out, struct value v, unsigned indent)
|
|
{
|
|
unsigned i;
|
|
struct value_chain *vc;
|
|
struct prefix_chain *pc;
|
|
struct node4 *n4;
|
|
struct node16 *n16;
|
|
struct node48 *n48;
|
|
struct node256 *n256;
|
|
|
|
if (v.type == UNSET)
|
|
return;
|
|
|
|
for (i = 0; i < 2 * indent; i++)
|
|
fprintf(out, " ");
|
|
|
|
switch (v.type) {
|
|
case UNSET:
|
|
// can't happen
|
|
break;
|
|
|
|
case VALUE:
|
|
fprintf(out, "<val: %llu>\n", (unsigned long long) v.value.n);
|
|
break;
|
|
|
|
case VALUE_CHAIN:
|
|
vc = v.value.ptr;
|
|
fprintf(out, "<val_chain: %llu>\n", (unsigned long long) vc->value.n);
|
|
_dump(out, vc->child, indent + 1);
|
|
break;
|
|
|
|
case PREFIX_CHAIN:
|
|
pc = v.value.ptr;
|
|
fprintf(out, "<prefix: ");
|
|
for (i = 0; i < pc->len; i++)
|
|
fprintf(out, "%x.", (unsigned) *(pc->prefix + i));
|
|
fprintf(out, ">\n");
|
|
_dump(out, pc->child, indent + 1);
|
|
break;
|
|
|
|
case NODE4:
|
|
n4 = v.value.ptr;
|
|
fprintf(out, "<n4: ");
|
|
for (i = 0; i < n4->nr_entries; i++)
|
|
fprintf(out, "%x ", (unsigned) n4->keys[i]);
|
|
fprintf(out, ">\n");
|
|
|
|
for (i = 0; i < n4->nr_entries; i++)
|
|
_dump(out, n4->values[i], indent + 1);
|
|
break;
|
|
|
|
case NODE16:
|
|
n16 = v.value.ptr;
|
|
fprintf(out, "<n16: ");
|
|
for (i = 0; i < n16->nr_entries; i++)
|
|
fprintf(out, "%x ", (unsigned) n16->keys[i]);
|
|
fprintf(out, ">\n");
|
|
|
|
for (i = 0; i < n16->nr_entries; i++)
|
|
_dump(out, n16->values[i], indent + 1);
|
|
break;
|
|
|
|
case NODE48:
|
|
n48 = v.value.ptr;
|
|
fprintf(out, "<n48: ");
|
|
for (i = 0; i < 256; i++)
|
|
if (n48->keys[i] < 48)
|
|
fprintf(out, "%x ", i);
|
|
fprintf(out, ">\n");
|
|
|
|
for (i = 0; i < n48->nr_entries; i++) {
|
|
assert(n48->values[i].type != UNSET);
|
|
_dump(out, n48->values[i], indent + 1);
|
|
}
|
|
break;
|
|
|
|
case NODE256:
|
|
n256 = v.value.ptr;
|
|
fprintf(out, "<n256: ");
|
|
for (i = 0; i < 256; i++)
|
|
if (n256->values[i].type != UNSET)
|
|
fprintf(out, "%x ", i);
|
|
fprintf(out, ">\n");
|
|
|
|
for (i = 0; i < 256; i++)
|
|
if (n256->values[i].type != UNSET)
|
|
_dump(out, n256->values[i], indent + 1);
|
|
break;
|
|
}
|
|
}
|
|
|
|
void radix_tree_dump(struct radix_tree *rt, FILE *out)
|
|
{
|
|
_dump(out, rt->root, 0);
|
|
}
|
|
|
|
//----------------------------------------------------------------
|