hash.h

/*
 * Copyright (C) 2008 Philippe Gerum <rpm@xenomai.org>.
 *
 * This library 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 of the License, or (at your option) any later version.
 *
 * This library 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 this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA.
 */

#ifndef _BOILERPLATE_HASH_H
#define _BOILERPLATE_HASH_H

#include <pthread.h>
#include <boilerplate/list.h>

#define HASHSLOTS  (1<<8)

struct hashobj {
        dref_type(const void *) key;
#ifdef CONFIG_XENO_PSHARED
        char static_key[16];
#endif
        size_t len;
        struct holder link;
};

struct hash_bucket {
        struct listobj obj_list;
};

struct hash_table {
        struct hash_bucket table[HASHSLOTS];
        pthread_mutex_t lock;
};

struct hash_operations {
        int (*compare)(const void *l,
                       const void *r,
                       size_t len);
#ifdef CONFIG_XENO_PSHARED
        int (*probe)(struct hashobj *oldobj);
        void *(*alloc)(size_t len);
        void (*free)(void *key);
#endif
};

typedef int (*hash_walk_op)(struct hash_table *t,
                            struct hashobj *obj,
                            void *arg);
        
#ifdef CONFIG_XENO_PSHARED

/* Private version - h-table is not shareable between processes. */

struct pvhashobj {
        const void *key;
        size_t len;
        struct pvholder link;
};

struct pvhash_bucket {
        struct pvlistobj obj_list;
};

struct pvhash_table {
        struct pvhash_bucket table[HASHSLOTS];
        pthread_mutex_t lock;
};

struct pvhash_operations {
        int (*compare)(const void *l,
                       const void *r,
                       size_t len);
};

typedef int (*pvhash_walk_op)(struct pvhash_table *t,
                              struct pvhashobj *obj,
                              void *arg);
        
#else /* !CONFIG_XENO_PSHARED */
#define pvhashobj               hashobj
#define pvhash_bucket           hash_bucket
#define pvhash_table            hash_table
#define pvhash_walk_op          hash_walk_op
#endif /* !CONFIG_XENO_PSHARED */

#ifdef __cplusplus
extern "C" {
#endif

unsigned int __hash_key(const void *key,
                        size_t length, unsigned int c);

void __hash_init(void *heap, struct hash_table *t);

int __hash_enter(struct hash_table *t,
                 const void *key, size_t len,
                 struct hashobj *newobj,
                 const struct hash_operations *hops,
                 int nodup);

static inline void hash_init(struct hash_table *t)
{
        __hash_init(__main_heap, t);
}

void hash_destroy(struct hash_table *t);

static inline int hash_enter(struct hash_table *t,
                             const void *key, size_t len,
                             struct hashobj *newobj,
                             const struct hash_operations *hops)
{
        return __hash_enter(t, key, len, newobj, hops, 1);
}

static inline int hash_enter_dup(struct hash_table *t,
                                 const void *key, size_t len,
                                 struct hashobj *newobj,
                                 const struct hash_operations *hops)
{
        return __hash_enter(t, key, len, newobj, hops, 0);
}

int hash_remove(struct hash_table *t, struct hashobj *delobj,
                const struct hash_operations *hops);

struct hashobj *hash_search(struct hash_table *t,
                            const void *key, size_t len,
                            const struct hash_operations *hops);

int hash_walk(struct hash_table *t,
              hash_walk_op walk, void *arg);

#ifdef CONFIG_XENO_PSHARED

int __hash_enter_probe(struct hash_table *t,
                       const void *key, size_t len,
                       struct hashobj *newobj,
                       const struct hash_operations *hops,
                       int nodup);

int __pvhash_enter(struct pvhash_table *t,
                   const void *key, size_t len,
                   struct pvhashobj *newobj,
                   const struct pvhash_operations *hops,
                   int nodup);

static inline
int hash_enter_probe(struct hash_table *t,
                     const void *key, size_t len,
                     struct hashobj *newobj,
                     const struct hash_operations *hops)
{
        return __hash_enter_probe(t, key, len, newobj, hops, 1);
}

static inline
int hash_enter_probe_dup(struct hash_table *t,
                         const void *key, size_t len,
                         struct hashobj *newobj,
                         const struct hash_operations *hops)
{
        return __hash_enter_probe(t, key, len, newobj, hops, 0);
}

struct hashobj *hash_search_probe(struct hash_table *t,
                                  const void *key, size_t len,
                                  const struct hash_operations *hops);

void pvhash_init(struct pvhash_table *t);

static inline
int pvhash_enter(struct pvhash_table *t,
                 const void *key, size_t len,
                 struct pvhashobj *newobj,
                 const struct pvhash_operations *hops)
{
        return __pvhash_enter(t, key, len, newobj, hops, 1);
}

static inline
int pvhash_enter_dup(struct pvhash_table *t,
                     const void *key, size_t len,
                     struct pvhashobj *newobj,
                     const struct pvhash_operations *hops)
{
        return __pvhash_enter(t, key, len, newobj, hops, 0);
}

int pvhash_remove(struct pvhash_table *t, struct pvhashobj *delobj,
                  const struct pvhash_operations *hops);

struct pvhashobj *pvhash_search(struct pvhash_table *t,
                                const void *key, size_t len,
                                const struct pvhash_operations *hops);

int pvhash_walk(struct pvhash_table *t,
                pvhash_walk_op walk, void *arg);

#else /* !CONFIG_XENO_PSHARED */
#define pvhash_init             hash_init
#define pvhash_enter            hash_enter
#define pvhash_enter_dup        hash_enter_dup
#define pvhash_remove           hash_remove
#define pvhash_search           hash_search
#define pvhash_walk             hash_walk
#define pvhash_operations       hash_operations
#endif /* !CONFIG_XENO_PSHARED */

#ifdef __cplusplus
}
#endif

#endif /* _BOILERPLATE_HASH_H */