/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
* All rights reserved.
*
* This package is an SSL implementation written
* by Eric Young (eay@cryptsoft.com).
* The implementation was written so as to conform with Netscapes SSL.
*
* This library is free for commercial and non-commercial use as long as
* the following conditions are aheared to. The following conditions
* apply to all code found in this distribution, be it the RC4, RSA,
* lhash, DES, etc., code; not just the SSL code. The SSL documentation
* included with this distribution is covered by the same copyright terms
* except that the holder is Tim Hudson (tjh@cryptsoft.com).
*
* Copyright remains Eric Young's, and as such any Copyright notices in
* the code are not to be removed.
* If this package is used in a product, Eric Young should be given attribution
* as the author of the parts of the library used.
* This can be in the form of a textual message at program startup or
* in documentation (online or textual) provided with the package.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* "This product includes cryptographic software written by
* Eric Young (eay@cryptsoft.com)"
* The word 'cryptographic' can be left out if the rouines from the library
* being used are not cryptographic related :-).
* 4. If you include any Windows specific code (or a derivative thereof) from
* the apps directory (application code) you must include an acknowledgement:
* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
*
* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* The licence and distribution terms for any publically available version or
* derivative of this code cannot be changed. i.e. this code cannot simply be
* copied and put under another distribution licence
* [including the GNU Public Licence.] */
#ifndef OPENSSL_HEADER_LHASH_H
#define OPENSSL_HEADER_LHASH_H
#include <openssl/base.h>
#include <openssl/type_check.h>
#if defined(__cplusplus)
extern "C" {
#endif
// lhash is a traditional, chaining hash table that automatically expands and
// contracts as needed. One should not use the lh_* functions directly, rather
// use the type-safe macro wrappers:
//
// A hash table of a specific type of object has type |LHASH_OF(type)|. This
// can be defined (once) with |DEFINE_LHASH_OF(type)| and declared where needed
// with |DECLARE_LHASH_OF(type)|. For example:
//
// struct foo {
// int bar;
// };
//
// DEFINE_LHASH_OF(struct foo)
//
// Although note that the hash table will contain /pointers/ to |foo|.
//
// A macro will be defined for each of the lh_* functions below. For
// LHASH_OF(foo), the macros would be lh_foo_new, lh_foo_num_items etc.
#define LHASH_OF(type) struct lhash_st_##type
#define DECLARE_LHASH_OF(type) LHASH_OF(type);
// lhash_item_st is an element of a hash chain. It points to the opaque data
// for this element and to the next item in the chain. The linked-list is NULL
// terminated.
typedef struct lhash_item_st {
void *data;
struct lhash_item_st *next;
// hash contains the cached, hash value of |data|.
uint32_t hash;
} LHASH_ITEM;
// lhash_cmp_func is a comparison function that returns a value equal, or not
// equal, to zero depending on whether |*a| is equal, or not equal to |*b|,
// respectively. Note the difference between this and |stack_cmp_func| in that
// this takes pointers to the objects directly.
//
// This function's actual type signature is int (*)(const T*, const T*). The
// low-level |lh_*| functions will be passed a type-specific wrapper to call it
// correctly.
typedef int (*lhash_cmp_func)(const void *a, const void *b);
typedef int (*lhash_cmp_func_helper)(lhash_cmp_func func, const void *a,
const void *b);
// lhash_hash_func is a function that maps an object to a uniformly distributed
// uint32_t.
//
// This function's actual type signature is uint32_t (*)(const T*). The
// low-level |lh_*| functions will be passed a type-specific wrapper to call it
// correctly.
typedef uint32_t (*lhash_hash_func)(const void *a);
typedef uint32_t (*lhash_hash_func_helper)(lhash_hash_func func, const void *a);
typedef struct lhash_st _LHASH;
// lh_new returns a new, empty hash table or NULL on error.
OPENSSL_EXPORT _LHASH *lh_new(lhash_hash_func hash, lhash_cmp_func comp);
// lh_free frees the hash table itself but none of the elements. See
// |lh_doall|.
OPENSSL_EXPORT void lh_free(_LHASH *lh);
// lh_num_items returns the number of items in |lh|.
OPENSSL_EXPORT size_t lh_num_items(const _LHASH *lh);
// lh_retrieve finds an element equal to |data| in the hash table and returns
// it. If no such element exists, it returns NULL.
OPENSSL_EXPORT void *lh_retrieve(const _LHASH *lh, const void *data,
lhash_hash_func_helper call_hash_func,
lhash_cmp_func_helper call_cmp_func);
// lh_retrieve_key finds an element matching |key|, given the specified hash and
// comparison function. This differs from |lh_retrieve| in that the key may be a
// different type than the values stored in |lh|. |key_hash| and |cmp_key| must
// be compatible with the functions passed into |lh_new|.
OPENSSL_EXPORT void *lh_retrieve_key(const _LHASH *lh, const void *key,
uint32_t key_hash,
int (*cmp_key)(const void *key,
const void *value));
// lh_insert inserts |data| into the hash table. If an existing element is
// equal to |data| (with respect to the comparison function) then |*old_data|
// will be set to that value and it will be replaced. Otherwise, or in the
// event of an error, |*old_data| will be set to NULL. It returns one on
// success or zero in the case of an allocation error.
OPENSSL_EXPORT int lh_insert(_LHASH *lh, void **old_data, void *data,
lhash_hash_func_helper call_hash_func,
lhash_cmp_func_helper call_cmp_func);
// lh_delete removes an element equal to |data| from the hash table and returns
// it. If no such element is found, it returns NULL.
OPENSSL_EXPORT void *lh_delete(_LHASH *lh, const void *data,
lhash_hash_func_helper call_hash_func,
lhash_cmp_func_helper call_cmp_func);
// lh_doall_arg calls |func| on each element of the hash table and also passes
// |arg| as the second argument.
// TODO(fork): rename this
OPENSSL_EXPORT void lh_doall_arg(_LHASH *lh, void (*func)(void *, void *),
void *arg);
// lh_strhash is the default hash function which processes NUL-terminated
// strings.
OPENSSL_EXPORT uint32_t lh_strhash(const char *c);
#define DEFINE_LHASH_OF(type) \
DECLARE_LHASH_OF(type) \
\
typedef int (*lhash_##type##_cmp_func)(const type *, const type *); \
typedef uint32_t (*lhash_##type##_hash_func)(const type *); \
\
OPENSSL_INLINE int lh_##type##_call_cmp_func(lhash_cmp_func func, \
const void *a, const void *b) { \
return ((lhash_##type##_cmp_func)func)((const type *)a, (const type *)b); \
} \
\
OPENSSL_INLINE uint32_t lh_##type##_call_hash_func(lhash_hash_func func, \
const void *a) { \
return ((lhash_##type##_hash_func)func)((const type *)a); \
} \
\
OPENSSL_INLINE LHASH_OF(type) * \
lh_##type##_new(lhash_##type##_hash_func hash, \
lhash_##type##_cmp_func comp) { \
return (LHASH_OF(type) *)lh_new((lhash_hash_func)hash, \
(lhash_cmp_func)comp); \
} \
\
OPENSSL_INLINE void lh_##type##_free(LHASH_OF(type) *lh) { \
lh_free((_LHASH *)lh); \
} \
\
OPENSSL_INLINE size_t lh_##type##_num_items(const LHASH_OF(type) *lh) { \
return lh_num_items((const _LHASH *)lh); \
} \
\
OPENSSL_INLINE type *lh_##type##_retrieve(const LHASH_OF(type) *lh, \
const type *data) { \
return (type *)lh_retrieve((const _LHASH *)lh, data, \
lh_##type##_call_hash_func, \
lh_##type##_call_cmp_func); \
} \
\
typedef struct { \
int (*cmp_key)(const void *key, const type *value); \
const void *key; \
} LHASH_CMP_KEY_##type; \
\
OPENSSL_INLINE int lh_##type##_call_cmp_key(const void *key, \
const void *value) { \
const LHASH_CMP_KEY_##type *cb = (const LHASH_CMP_KEY_##type *)key; \
return cb->cmp_key(cb->key, (const type *)value); \
} \
\
OPENSSL_INLINE type *lh_##type##_retrieve_key( \
const LHASH_OF(type) *lh, const void *key, uint32_t key_hash, \
int (*cmp_key)(const void *key, const type *value)) { \
LHASH_CMP_KEY_##type cb = {cmp_key, key}; \
return (type *)lh_retrieve_key((const _LHASH *)lh, &cb, key_hash, \
lh_##type##_call_cmp_key); \
} \
\
OPENSSL_INLINE int lh_##type##_insert(LHASH_OF(type) *lh, type **old_data, \
type *data) { \
void *old_data_void = NULL; \
int ret = \
lh_insert((_LHASH *)lh, &old_data_void, data, \
lh_##type##_call_hash_func, lh_##type##_call_cmp_func); \
*old_data = (type *)old_data_void; \
return ret; \
} \
\
OPENSSL_INLINE type *lh_##type##_delete(LHASH_OF(type) *lh, \
const type *data) { \
return (type *)lh_delete((_LHASH *)lh, data, lh_##type##_call_hash_func, \
lh_##type##_call_cmp_func); \
} \
\
typedef struct { \
void (*doall)(type *); \
void (*doall_arg)(type *, void *); \
void *arg; \
} LHASH_DOALL_##type; \
\
OPENSSL_INLINE void lh_##type##_call_doall(void *value, void *arg) { \
const LHASH_DOALL_##type *cb = (const LHASH_DOALL_##type *)arg; \
cb->doall((type *)value); \
} \
\
OPENSSL_INLINE void lh_##type##_call_doall_arg(void *value, void *arg) { \
const LHASH_DOALL_##type *cb = (const LHASH_DOALL_##type *)arg; \
cb->doall_arg((type *)value, cb->arg); \
} \
\
OPENSSL_INLINE void lh_##type##_doall(LHASH_OF(type) *lh, \
void (*func)(type *)) { \
LHASH_DOALL_##type cb = {func, NULL, NULL}; \
lh_doall_arg((_LHASH *)lh, lh_##type##_call_doall, &cb); \
} \
\
OPENSSL_INLINE void lh_##type##_doall_arg( \
LHASH_OF(type) *lh, void (*func)(type *, void *), void *arg) { \
LHASH_DOALL_##type cb = {NULL, func, arg}; \
lh_doall_arg((_LHASH *)lh, lh_##type##_call_doall_arg, &cb); \
}
#if defined(__cplusplus)
} // extern C
#endif
#endif // OPENSSL_HEADER_LHASH_H