rblist.c

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/*
 * Based on strlist.c by:
 * (c) 2009 Arnaldo Carvalho de Melo <acme@redhat.com>
 *
 * Licensed under the GPLv2.
 */

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>

#include "rblist.h"

int rblist__add_node(struct rblist *rblist, const void *new_entry)
{
    struct rb_node **p = &rblist->entries.rb_node;
    struct rb_node *parent = NULL, *new_node;

    while (*p != NULL) {
        int rc;

        parent = *p;

        rc = rblist->node_cmp(parent, new_entry);
        if (rc > 0)
            p = &(*p)->rb_left;
        else if (rc < 0)
            p = &(*p)->rb_right;
        else
            return -EEXIST;
    }

    new_node = rblist->node_new(rblist, new_entry);
    if (new_node == NULL)
        return -ENOMEM;

    rb_link_node(new_node, parent, p);
    rb_insert_color(new_node, &rblist->entries);
    ++rblist->nr_entries;

    return 0;
}

void rblist__remove_node(struct rblist *rblist, struct rb_node *rb_node)
{
    rb_erase(rb_node, &rblist->entries);
    --rblist->nr_entries;
    rblist->node_delete(rblist, rb_node);
}

static struct rb_node *__rblist__findnew(struct rblist *rblist,
                     const void *entry,
                     bool create)
{
    struct rb_node **p = &rblist->entries.rb_node;
    struct rb_node *parent = NULL, *new_node = NULL;

    while (*p != NULL) {
        int rc;

        parent = *p;

        rc = rblist->node_cmp(parent, entry);
        if (rc > 0)
            p = &(*p)->rb_left;
        else if (rc < 0)
            p = &(*p)->rb_right;
        else
            return parent;
    }

    if (create) {
        new_node = rblist->node_new(rblist, entry);
        if (new_node) {
            rb_link_node(new_node, parent, p);
            rb_insert_color(new_node, &rblist->entries);
            ++rblist->nr_entries;
        }
    }

    return new_node;
}

struct rb_node *rblist__find(struct rblist *rblist, const void *entry)
{
    return __rblist__findnew(rblist, entry, false);
}

struct rb_node *rblist__findnew(struct rblist *rblist, const void *entry)
{
    return __rblist__findnew(rblist, entry, true);
}

void rblist__init(struct rblist *rblist)
{
    if (rblist != NULL) {
        rblist->entries  = RB_ROOT;
        rblist->nr_entries = 0;
    }

    return;
}

void rblist__exit(struct rblist *rblist)
{
    struct rb_node *pos, *next = rb_first(&rblist->entries);

    while (next) {
        pos = next;
        next = rb_next(pos);
        rblist__remove_node(rblist, pos);
    }
}

void rblist__delete(struct rblist *rblist)
{
    if (rblist != NULL) {
        rblist__exit(rblist);
        free(rblist);
    }
}

struct rb_node *rblist__entry(const struct rblist *rblist, unsigned int idx)
{
    struct rb_node *node;

    for (node = rb_first(&rblist->entries); node; node = rb_next(node)) {
        if (!idx--)
            return node;
    }

    return NULL;
}