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+/* 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 */