/*
* Copyright (C) 2011 Red Hat, Inc.
*
* Author: Angus Salkeld <asalkeld@redhat.com>
*
* This file is part of libqb.
*
* libqb is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 2.1 of the License, or
* (at your option) any later version.
*
* libqb is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with libqb. If not, see <http://www.gnu.org/licenses/>.
*/
#include <os_base.h>
#include <assert.h>
#include <qb/qbdefs.h>
#include <qb/qblist.h>
#include <qb/qbmap.h>
#include "map_int.h"
struct trie_iter {
struct qb_map_iter i;
const char *prefix;
struct trie_node *n;
struct trie_node *root;
};
struct trie_node {
uint32_t idx;
char *segment;
uint32_t num_segments;
char *key;
void *value;
struct trie_node **children;
uint32_t num_children;
uint32_t refcount;
struct trie_node *parent;
struct qb_list_head *notifier_head;
};
struct trie {
struct qb_map map;
size_t length;
uint32_t num_nodes;
uint32_t mem_used;
struct trie_node *header;
};
static void trie_notify(struct trie_node *n, uint32_t event, const char *key,
void *old_value, void *value);
static struct trie_node *trie_new_node(struct trie *t, struct trie_node *parent);
static void trie_destroy_node(struct trie_node *node);
/*
* characters are stored in reverse to make accessing the
* more common case (non-control chars) more space efficient.
*/
#define TRIE_CHAR2INDEX(ch) (126 - ch)
#define TRIE_INDEX2CHAR(idx) (126 - idx)
static int32_t
trie_node_alive(struct trie_node *node)
{
if (node->value == NULL ||
node->refcount <= 0) {
return QB_FALSE;
}
return QB_TRUE;
}
static struct trie_node *
trie_node_next(struct trie_node *node, struct trie_node *root, int all)
{
struct trie_node *c = node;
struct trie_node *n;
struct trie_node *p;
int i;
keep_going:
n = NULL;
/* child/outward
*/
for (i = c->num_children - 1; i >= 0; i--) {
if (c->children[i]) {
n = c->children[i];
break;
}
}
if (n) {
if (all || trie_node_alive(n)) {
return n;
} else {
c = n;
goto keep_going;
}
}
/* sibling/parent
*/
if (c == root) {
return NULL;
}
p = c;
do {
for (i = p->idx - 1; i >= 0; i--) {
if (p->parent->children[i]) {
n = p->parent->children[i];
break;
}
}
if (n == NULL) {
p = p->parent;
}
} while (n == NULL && p != root);
if (n) {
if (all || trie_node_alive(n)) {
return n;
}
if (n == root) {
return NULL;
}
c = n;
goto keep_going;
}
return n;
}
static struct trie_node *
new_child_node(struct trie *t, struct trie_node * parent, char ch)
{
struct trie_node *new_node;
int old_max_idx;
int i;
int idx = TRIE_CHAR2INDEX(ch);
if (idx >= parent->num_children) {
old_max_idx = parent->num_children;
parent->num_children = QB_MAX(idx + 1, 30);
t->mem_used += (sizeof(struct trie_node*) * (parent->num_children - old_max_idx));
parent->children = realloc(parent->children,
(parent->num_children * sizeof(struct trie_node*)));
if (parent->children == NULL) {
return NULL;
}
for (i = old_max_idx; i < parent->num_children; i++) {
parent->children[i] = NULL;
}
}
new_node = trie_new_node(t, parent);
if (new_node == NULL) {
return NULL;
}
new_node->idx = idx;
parent->children[idx] = new_node;
return new_node;
}
static struct trie_node *
trie_node_split(struct trie *t, struct trie_node *cur_node, int seg_cnt)
{
struct trie_node *split_node;
struct trie_node ** children = cur_node->children;
uint32_t num_children = cur_node->num_children;
struct qb_list_head *tmp;
int i;
int s;
cur_node->children = NULL;
cur_node->num_children = 0;
split_node = new_child_node(t, cur_node, cur_node->segment[seg_cnt]);
if (split_node == NULL) {
return NULL;
}
split_node->children = children;
split_node->num_children = num_children;
for (i = 0; i < split_node->num_children; i++) {
if (split_node->children[i]) {
split_node->children[i]->parent = split_node;
}
}
split_node->value = cur_node->value;
split_node->key = cur_node->key;
split_node->refcount = cur_node->refcount;
cur_node->value = NULL;
cur_node->key = NULL;
cur_node->refcount = 0;
/* move notifier list to split */
tmp = split_node->notifier_head;
split_node->notifier_head = cur_node->notifier_head;
cur_node->notifier_head = tmp;
qb_list_init(cur_node->notifier_head);
if (seg_cnt < cur_node->num_segments) {
split_node->num_segments = cur_node->num_segments - seg_cnt - 1;
split_node->segment = malloc(split_node->num_segments * sizeof(char));
if (split_node->segment == NULL) {
trie_destroy_node(split_node);
return NULL;
}
for (i = (seg_cnt + 1); i < cur_node->num_segments; i++) {
s = i - seg_cnt - 1;
split_node->segment[s] = cur_node->segment[i];
cur_node->segment[i] = '\0';
}
cur_node->num_segments = seg_cnt;
}
return cur_node;
}
static struct trie_node *
trie_insert(struct trie *t, const char *key)
{
struct trie_node *cur_node = t->header;
struct trie_node *new_node;
char *cur = (char *)key;
int idx = TRIE_CHAR2INDEX(key[0]);
int seg_cnt = 0;
do {
new_node = NULL;
if (cur_node->num_segments > 0 &&
seg_cnt < cur_node->num_segments) {
if (cur_node->segment[seg_cnt] == *cur) {
/* we found the char in the segment */
seg_cnt++;
} else {
cur_node = trie_node_split(t, cur_node, seg_cnt);
if (cur_node == NULL) {
return NULL;
}
new_node = new_child_node(t, cur_node, *cur);
if (new_node == NULL) {
return NULL;
}
}
} else if (idx < cur_node->num_children &&
cur_node->children[idx]) {
/* the char can be found on the next node */
new_node = cur_node->children[idx];
} else if (cur_node == t->header) {
/* the root node is empty so make it on the next node */
new_node = new_child_node(t, cur_node, *cur);
if (new_node == NULL) {
return NULL;
}
} else if (cur_node->value == NULL &&
qb_list_empty(cur_node->notifier_head) &&
cur_node->num_children == 0 &&
seg_cnt == cur_node->num_segments) {
/* we are on a leaf (with no value) so just add it as a segment */
cur_node->segment = realloc(cur_node->segment, cur_node->num_segments + 1);
cur_node->segment[cur_node->num_segments] = *cur;
t->mem_used += sizeof(char);
cur_node->num_segments++;
seg_cnt++;
} else if (seg_cnt == cur_node->num_segments) {
/* on the last segment need to make a new node */
new_node = new_child_node(t, cur_node, *cur);
if (new_node == NULL) {
return NULL;
}
} else /* need_to_split */ {
cur_node = trie_node_split(t, cur_node, seg_cnt);
if (cur_node == NULL) {
return NULL;
}
new_node = new_child_node(t, cur_node, *cur);
if (new_node == NULL) {
return NULL;
}
}
if (new_node) {
seg_cnt = 0;
cur_node = new_node;
}
cur++;
idx = TRIE_CHAR2INDEX(*cur);
} while (*cur != '\0');
if (cur_node->num_segments > 0 &&
seg_cnt < cur_node->num_segments) {
/* we need to split */
cur_node = trie_node_split(t, cur_node, seg_cnt);
if (cur_node == NULL) {
return NULL;
}
new_node = new_child_node(t, cur_node, *cur);
if (new_node == NULL) {
return NULL;
}
}
return cur_node;
}
static struct trie_node *
trie_lookup(struct trie *t, const char *key, int exact_match)
{
struct trie_node *cur_node = t->header;
char *cur = (char *)key;
int idx = TRIE_CHAR2INDEX(key[0]);
int seg_cnt = 0;
do {
if (cur_node->num_segments > 0 &&
seg_cnt < cur_node->num_segments) {
if (cur_node->segment[seg_cnt] == *cur) {
/* we found the char in the segment */
seg_cnt++;
} else {
return NULL;
}
} else if (idx < cur_node->num_children &&
cur_node->children[idx]) {
/* the char can be found on the next node */
cur_node = cur_node->children[idx];
seg_cnt = 0;
} else {
return NULL;
}
cur++;
idx = TRIE_CHAR2INDEX(*cur);
} while (*cur != '\0');
if (exact_match &&
cur_node->num_segments > 0 &&
seg_cnt < cur_node->num_segments) {
return NULL;
}
return cur_node;
}
static void
trie_node_release(struct trie *t, struct trie_node *node)
{
int i;
int empty = QB_FALSE;
if (node->key == NULL &&
node->parent != NULL &&
qb_list_empty(node->notifier_head)) {
struct trie_node *p = node->parent;
if (node->num_children == 0) {
empty = QB_TRUE;
} else {
empty = QB_TRUE;
for (i = node->num_children - 1; i >= 0; i--) {
if (node->children[i]) {
empty = QB_FALSE;
break;
}
}
}
if (!empty) {
return;
}
/*
* unlink the node from the parent
*/
p->children[node->idx] = NULL;
trie_destroy_node(node);
t->num_nodes--;
t->mem_used -= sizeof(struct trie_node);
trie_node_release(t, p);
}
}
static void
trie_node_destroy(struct trie *t, struct trie_node *n)
{
if (n->value == NULL) {
return;
}
trie_notify(n, QB_MAP_NOTIFY_DELETED, n->key, n->value, NULL);
n->key = NULL;
n->value = NULL;
trie_node_release(t, n);
}
static void
trie_print_node(struct trie_node *n, struct trie_node *r, const char *suffix)
{
int i;
if (n->parent) {
trie_print_node(n->parent, n, suffix);
}
if (n->idx == 0) {
return;
}
printf("[%c", (char) TRIE_INDEX2CHAR(n->idx));
for (i = 0; i < n->num_segments; i++) {
printf("%c", n->segment[i]);
}
if (n == r) {
#ifndef S_SPLINT_S
printf("] (%" PRIu32 ") %s\n", n->refcount, suffix);
#endif /* S_SPLINT_S */
} else {
printf("] ");
}
}
static void
trie_node_ref(struct trie *t, struct trie_node *node)
{
if (t->header == node) {
return;
}
node->refcount++;
}
static void
trie_node_deref(struct trie *t, struct trie_node *node)
{
if (!trie_node_alive(node)) {
return;
}
node->refcount--;
if (node->refcount > 0) {
return;
}
trie_node_destroy(t, node);
}
static void
trie_destroy(struct qb_map *map)
{
struct trie *t = (struct trie *)map;
struct trie_node *cur_node = t->header;
struct trie_node *fwd_node;
do {
fwd_node = trie_node_next(cur_node, t->header, QB_FALSE);
trie_node_destroy(t, cur_node);
} while ((cur_node = fwd_node));
free(t);
}
static void
trie_destroy_node(struct trie_node *node)
{
free(node->segment);
free(node->children);
free(node->notifier_head);
free(node);
}
static struct trie_node *
trie_new_node(struct trie *t, struct trie_node *parent)
{
struct trie_node *new_node = calloc(1, sizeof(struct trie_node));
if (new_node == NULL) {
return NULL;
}
new_node->notifier_head = calloc(1, sizeof(struct qb_list_head));
if (new_node->notifier_head == NULL) {
free(new_node);
return NULL;
}
new_node->parent = parent;
new_node->num_children = 0;
new_node->children = NULL;
new_node->num_segments = 0;
new_node->segment = NULL;
t->num_nodes++;
t->mem_used += sizeof(struct trie_node);
qb_list_init(new_node->notifier_head);
return new_node;
}
void
qb_trie_dump(qb_map_t* m)
{
struct trie * t = (struct trie*)m;
struct trie_node *n;
if (t == NULL) {
return;
}
#ifndef S_SPLINT_S
printf("nodes: %" PRIu32 ", bytes: %" PRIu32 "\n", t->num_nodes, t->mem_used);
#endif /* S_SPLINT_S */
n = t->header;
do {
if (n->num_children == 0) {
trie_print_node(n, n, " ");
}
n = trie_node_next(n, t->header, QB_FALSE);
} while (n);
}
static void
trie_put(struct qb_map *map, const char *key, const void *value)
{
struct trie *t = (struct trie *)map;
struct trie_node *n = trie_insert(t, key);
if (n) {
const char *old_value = n->value;
const char *old_key = n->key;
n->key = (char *)key;
n->value = (void *)value;
if (old_value == NULL) {
trie_node_ref(t, n);
t->length++;
trie_notify(n, QB_MAP_NOTIFY_INSERTED,
n->key, NULL, n->value);
} else {
trie_notify(n, QB_MAP_NOTIFY_REPLACED,
(char *)old_key, (void *)old_value,
(void *)value);
}
}
}
static int32_t
trie_rm(struct qb_map *map, const char *key)
{
struct trie *t = (struct trie *)map;
struct trie_node *n = trie_lookup(t, key, QB_TRUE);
if (n) {
trie_node_deref(t, n);
t->length--;
return QB_TRUE;
} else {
return QB_FALSE;
}
}
static void *
trie_get(struct qb_map *map, const char *key)
{
struct trie *t = (struct trie *)map;
struct trie_node *n = trie_lookup(t, key, QB_TRUE);
if (n) {
return n->value;
}
return NULL;
}
static void
trie_notify_deref(struct qb_map_notifier *f)
{
f->refcount--;
if (f->refcount == 0) {
qb_list_del(&f->list);
free(f);
}
}
static void
trie_notify_ref(struct qb_map_notifier *f)
{
f->refcount++;
}
static void
trie_notify(struct trie_node *n,
uint32_t event, const char *key, void *old_value, void *value)
{
struct trie_node *c = n;
struct qb_list_head *list;
struct qb_list_head *next;
struct qb_list_head *head;
struct qb_map_notifier *tn;
do {
head = c->notifier_head;
qb_list_for_each_safe(list, next, head) {
tn = qb_list_entry(list, struct qb_map_notifier, list);
trie_notify_ref(tn);
if ((tn->events & event) &&
((tn->events & QB_MAP_NOTIFY_RECURSIVE) ||
(n == c))) {
tn->callback(event, (char *)key, old_value,
value, tn->user_data);
}
if (((event & QB_MAP_NOTIFY_DELETED) ||
(event & QB_MAP_NOTIFY_REPLACED)) &&
(tn->events & QB_MAP_NOTIFY_FREE)) {
tn->callback(QB_MAP_NOTIFY_FREE, (char *)key,
old_value, value, tn->user_data);
}
trie_notify_deref(tn);
}
c = c->parent;
} while (c);
}
static int32_t
trie_notify_add(qb_map_t * m, const char *key,
qb_map_notify_fn fn, int32_t events, void *user_data)
{
struct trie *t = (struct trie *)m;
struct qb_map_notifier *f;
struct trie_node *n;
struct qb_list_head *list;
int add_to_tail = QB_FALSE;
if (key) {
n = trie_lookup(t, key, QB_TRUE);
if (n == NULL) {
n = trie_insert(t, key);
}
} else {
n = t->header;
}
if (n) {
qb_list_for_each(list, n->notifier_head) {
f = qb_list_entry(list, struct qb_map_notifier, list);
if (events & QB_MAP_NOTIFY_FREE &&
f->events == events) {
/* only one free notifier */
return -EEXIST;
}
if (f->events == events &&
f->callback == fn &&
f->user_data == user_data) {
return -EEXIST;
}
}
f = malloc(sizeof(struct qb_map_notifier));
if (f == NULL) {
return -errno;
}
f->events = events;
f->user_data = user_data;
f->callback = fn;
f->refcount = 1;
qb_list_init(&f->list);
if (key) {
if (events & QB_MAP_NOTIFY_RECURSIVE) {
add_to_tail = QB_TRUE;
}
} else {
if (events & QB_MAP_NOTIFY_FREE) {
add_to_tail = QB_TRUE;
}
}
if (add_to_tail) {
qb_list_add_tail(&f->list, n->notifier_head);
} else {
qb_list_add(&f->list, n->notifier_head);
}
return 0;
}
return -EINVAL;
}
static int32_t
trie_notify_del(qb_map_t * m, const char *key,
qb_map_notify_fn fn, int32_t events,
int32_t cmp_userdata, void *user_data)
{
struct trie *t = (struct trie *)m;
struct trie_node *n;
struct qb_list_head *list;
struct qb_list_head *next;
int32_t found = QB_FALSE;
if (key) {
n = trie_lookup(t, key, QB_FALSE);
} else {
n = t->header;
}
if (n == NULL) {
return -ENOENT;
}
qb_list_for_each_safe(list, next, n->notifier_head) {
struct qb_map_notifier *f = qb_list_entry(list, struct qb_map_notifier, list);
if (f->events == events && f->callback == fn) {
if (cmp_userdata && (f->user_data == user_data)) {
trie_notify_deref(f);
found = QB_TRUE;
} else if (!cmp_userdata) {
trie_notify_deref(f);
found = QB_TRUE;
}
}
}
if (found) {
trie_node_release(t, n);
return 0;
} else {
return -ENOENT;
}
}
static qb_map_iter_t *
trie_iter_create(struct qb_map *map, const char *prefix)
{
struct trie_iter *i = malloc(sizeof(struct trie_iter));
struct trie *t = (struct trie *)map;
if (i == NULL) {
return NULL;
}
i->i.m = map;
i->prefix = prefix;
i->n = t->header;
i->root = t->header;
return (qb_map_iter_t *) i;
}
static const char *
trie_iter_next(qb_map_iter_t * i, void **value)
{
struct trie_iter *si = (struct trie_iter *)i;
struct trie_node *p = si->n;
struct trie *t = (struct trie *)(i->m);
if (p == NULL) {
return NULL;
}
if (p->parent == NULL && si->prefix) {
si->root = trie_lookup(t, si->prefix, QB_FALSE);
if (si->root == NULL) {
si->n = NULL;
} else if (si->root->value == NULL) {
si->n = trie_node_next(si->root, si->root, QB_FALSE);
} else {
si->n = si->root;
}
} else {
si->n = trie_node_next(p, si->root, QB_FALSE);
}
if (si->n == NULL) {
trie_node_deref(t, p);
return NULL;
}
trie_node_ref(t, si->n);
trie_node_deref(t, p);
*value = si->n->value;
return si->n->key;
}
static void
trie_iter_free(qb_map_iter_t * i)
{
struct trie_iter *si = (struct trie_iter *)i;
struct trie *t = (struct trie *)(i->m);
if (si->n != NULL) {
/* if free'ing the iterator before getting to the last
* node make sure we de-ref the current node.
*/
trie_node_deref(t, si->n);
}
free(i);
}
static size_t
trie_count_get(struct qb_map *map)
{
struct trie *list = (struct trie *)map;
return list->length;
}
qb_map_t *
qb_trie_create(void)
{
struct trie *t = malloc(sizeof(struct trie));
if (t == NULL) {
return NULL;
}
t->map.put = trie_put;
t->map.get = trie_get;
t->map.rm = trie_rm;
t->map.count_get = trie_count_get;
t->map.iter_create = trie_iter_create;
t->map.iter_next = trie_iter_next;
t->map.iter_free = trie_iter_free;
t->map.destroy = trie_destroy;
t->map.notify_add = trie_notify_add;
t->map.notify_del = trie_notify_del;
t->length = 0;
t->num_nodes = 0;
t->mem_used = sizeof(struct trie);
t->header = trie_new_node(t, NULL);
return (qb_map_t *) t;
}