diff options
Diffstat (limited to 'src/include/openssl/lhash.h')
-rw-r--r-- | src/include/openssl/lhash.h | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/src/include/openssl/lhash.h b/src/include/openssl/lhash.h new file mode 100644 index 0000000..c8628d1 --- /dev/null +++ b/src/include/openssl/lhash.h @@ -0,0 +1,194 @@ +/* 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 DEFINE_LHASH_OF(type) LHASH_OF(type) { int dummy; } + +#define DECLARE_LHASH_OF(type) LHASH_OF(type); + +/* The make_macros.sh script in this directory parses the following lines and + * generates the lhash_macros.h file that contains macros for the following + * types of stacks: + * + * LHASH_OF:ASN1_OBJECT + * LHASH_OF:CONF_VALUE + * LHASH_OF:ERR_STATE + * LHASH_OF:ERR_STRING_DATA + * LHASH_OF:EX_CLASS_ITEM + * LHASH_OF:SSL_SESSION */ + +#define IN_LHASH_H +#include <openssl/lhash_macros.h> +#undef IN_LHASH_H + + +/* 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. */ +typedef int (*lhash_cmp_func)(const void *a, const void *b); + +/* lhash_hash_func is a function that maps an object to a uniformly distributed + * uint32_t. */ +typedef uint32_t (*lhash_hash_func)(const void *a); + +typedef struct lhash_st { + /* num_items contains the total number of items in the hash table. */ + size_t num_items; + /* buckets is an array of |num_buckets| pointers. Each points to the head of + * a chain of LHASH_ITEM objects that have the same hash value, mod + * |num_buckets|. */ + LHASH_ITEM **buckets; + /* num_buckets contains the length of |buckets|. This value is always >= + * kMinNumBuckets. */ + size_t num_buckets; + /* callback_depth contains the current depth of |lh_doall| or |lh_doall_arg| + * calls. If non-zero then this suppresses resizing of the |buckets| array, + * which would otherwise disrupt the iteration. */ + unsigned callback_depth; + + lhash_cmp_func comp; + lhash_hash_func hash; +} _LHASH; + +/* lh_new returns a new, empty hash table or NULL on error. If |comp| is NULL, + * |strcmp| will be used. If |hash| is NULL, a generic hash function will be + * used. */ +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); + +/* 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); + +/* 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); + +/* lh_doall calls |func| on each element of the hash table. + * TODO(fork): rename this */ +OPENSSL_EXPORT void lh_doall(_LHASH *lh, void (*func)(void *)); + +/* 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); + + +#if defined(__cplusplus) +} /* extern C */ +#endif + +#endif /* OPENSSL_HEADER_STACK_H */ |