/*      $OpenBSD: tree.c,v 1.8 2021/06/14 17:58:16 eric Exp $   */

/*
 * Copyright (c) 2012 Eric Faurot <eric@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/tree.h>

#include <inttypes.h>
#include <stdlib.h>

#include "tree.h"
#include "log.h"

struct treeentry {
        SPLAY_ENTRY(treeentry)   entry;
        uint64_t                 id;
        void                    *data;
};

static int treeentry_cmp(struct treeentry *, struct treeentry *);

SPLAY_PROTOTYPE(_tree, treeentry, entry, treeentry_cmp);

int
tree_check(struct tree *t, uint64_t id)
{
        struct treeentry        key;

        key.id = id;
        return (SPLAY_FIND(_tree, &t->tree, &key) != NULL);
}

void *
tree_set(struct tree *t, uint64_t id, void *data)
{
        struct treeentry        *entry, key;
        char                    *old;

        key.id = id;
        if ((entry = SPLAY_FIND(_tree, &t->tree, &key)) == NULL) {
                if ((entry = malloc(sizeof *entry)) == NULL)
                        fatal("tree_set: malloc");
                entry->id = id;
                SPLAY_INSERT(_tree, &t->tree, entry);
                old = NULL;
                t->count += 1;
        } else
                old = entry->data;

        entry->data = data;

        return (old);
}

void
tree_xset(struct tree *t, uint64_t id, void *data)
{
        struct treeentry        *entry;

        if ((entry = malloc(sizeof *entry)) == NULL)
                fatal("tree_xset: malloc");
        entry->id = id;
        entry->data = data;
        if (SPLAY_INSERT(_tree, &t->tree, entry))
                fatalx("tree_xset(%p, 0x%016"PRIx64 ")", t, id);
        t->count += 1;
}

void *
tree_get(struct tree *t, uint64_t id)
{
        struct treeentry        key, *entry;

        key.id = id;
        if ((entry = SPLAY_FIND(_tree, &t->tree, &key)) == NULL)
                return (NULL);

        return (entry->data);
}

void *
tree_xget(struct tree *t, uint64_t id)
{
        struct treeentry        key, *entry;

        key.id = id;
        if ((entry = SPLAY_FIND(_tree, &t->tree, &key)) == NULL)
                fatalx("tree_get(%p, 0x%016"PRIx64 ")", t, id);

        return (entry->data);
}

void *
tree_pop(struct tree *t, uint64_t id)
{
        struct treeentry        key, *entry;
        void                    *data;

        key.id = id;
        if ((entry = SPLAY_FIND(_tree, &t->tree, &key)) == NULL)
                return (NULL);

        data = entry->data;
        SPLAY_REMOVE(_tree, &t->tree, entry);
        free(entry);
        t->count -= 1;

        return (data);
}

void *
tree_xpop(struct tree *t, uint64_t id)
{
        struct treeentry        key, *entry;
        void                    *data;

        key.id = id;
        if ((entry = SPLAY_FIND(_tree, &t->tree, &key)) == NULL)
                fatalx("tree_xpop(%p, 0x%016" PRIx64 ")", t, id);

        data = entry->data;
        SPLAY_REMOVE(_tree, &t->tree, entry);
        free(entry);
        t->count -= 1;

        return (data);
}

int
tree_poproot(struct tree *t, uint64_t *id, void **data)
{
        struct treeentry        *entry;

        entry = SPLAY_ROOT(&t->tree);
        if (entry == NULL)
                return (0);
        if (id)
                *id = entry->id;
        if (data)
                *data = entry->data;
        SPLAY_REMOVE(_tree, &t->tree, entry);
        free(entry);
        t->count -= 1;

        return (1);
}

int
tree_root(struct tree *t, uint64_t *id, void **data)
{
        struct treeentry        *entry;

        entry = SPLAY_ROOT(&t->tree);
        if (entry == NULL)
                return (0);
        if (id)
                *id = entry->id;
        if (data)
                *data = entry->data;
        return (1);
}

int
tree_iter(struct tree *t, void **hdl, uint64_t *id, void **data)
{
        struct treeentry *curr = *hdl;

        if (curr == NULL)
                curr = SPLAY_MIN(_tree, &t->tree);
        else
                curr = SPLAY_NEXT(_tree, &t->tree, curr);

        if (curr) {
                *hdl = curr;
                if (id)
                        *id = curr->id;
                if (data)
                        *data = curr->data;
                return (1);
        }

        return (0);
}

int
tree_iterfrom(struct tree *t, void **hdl, uint64_t k, uint64_t *id, void **data)
{
        struct treeentry *curr = *hdl, key;

        if (curr == NULL) {
                if (k == 0)
                        curr = SPLAY_MIN(_tree, &t->tree);
                else {
                        key.id = k;
                        curr = SPLAY_FIND(_tree, &t->tree, &key);
                        if (curr == NULL) {
                                SPLAY_INSERT(_tree, &t->tree, &key);
                                curr = SPLAY_NEXT(_tree, &t->tree, &key);
                                SPLAY_REMOVE(_tree, &t->tree, &key);
                        }
                }
        } else
                curr = SPLAY_NEXT(_tree, &t->tree, curr);

        if (curr) {
                *hdl = curr;
                if (id)
                        *id = curr->id;
                if (data)
                        *data = curr->data;
                return (1);
        }

        return (0);
}

void
tree_merge(struct tree *dst, struct tree *src)
{
        struct treeentry        *entry;

        while (!SPLAY_EMPTY(&src->tree)) {
                entry = SPLAY_ROOT(&src->tree);
                SPLAY_REMOVE(_tree, &src->tree, entry);
                if (SPLAY_INSERT(_tree, &dst->tree, entry))
                        fatalx("tree_merge: duplicate");
        }
        dst->count += src->count;
        src->count = 0;
}

static int
treeentry_cmp(struct treeentry *a, struct treeentry *b)
{
        if (a->id < b->id)
                return (-1);
        if (a->id > b->id)
                return (1);
        return (0);
}

SPLAY_GENERATE(_tree, treeentry, entry, treeentry_cmp);