| // Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // https://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| #ifndef OPENSSL_HEADER_LHASH_INTERNAL_H |
| #define OPENSSL_HEADER_LHASH_INTERNAL_H |
| |
| #include <openssl/lhash.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 |OPENSSL_lh_*| functions below. For |
| // |LHASH_OF(foo)|, the macros would be |lh_foo_new|, |lh_foo_num_items| etc. |
| |
| |
| // 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; |
| |
| // OPENSSL_lh_new returns a new, empty hash table or NULL on error. |
| OPENSSL_EXPORT _LHASH *OPENSSL_lh_new(lhash_hash_func hash, |
| lhash_cmp_func comp); |
| |
| // OPENSSL_lh_free frees the hash table itself but none of the elements. See |
| // |OPENSSL_lh_doall|. |
| OPENSSL_EXPORT void OPENSSL_lh_free(_LHASH *lh); |
| |
| // OPENSSL_lh_num_items returns the number of items in |lh|. |
| OPENSSL_EXPORT size_t OPENSSL_lh_num_items(const _LHASH *lh); |
| |
| // OPENSSL_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 *OPENSSL_lh_retrieve(const _LHASH *lh, const void *data, |
| lhash_hash_func_helper call_hash_func, |
| lhash_cmp_func_helper call_cmp_func); |
| |
| // OPENSSL_lh_retrieve_key finds an element matching |key|, given the specified |
| // hash and comparison function. This differs from |OPENSSL_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 |
| // |OPENSSL_lh_new|. |
| OPENSSL_EXPORT void *OPENSSL_lh_retrieve_key(const _LHASH *lh, const void *key, |
| uint32_t key_hash, |
| int (*cmp_key)(const void *key, |
| const void *value)); |
| |
| // OPENSSL_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 OPENSSL_lh_insert(_LHASH *lh, void **old_data, void *data, |
| lhash_hash_func_helper call_hash_func, |
| lhash_cmp_func_helper call_cmp_func); |
| |
| // OPENSSL_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 *OPENSSL_lh_delete(_LHASH *lh, const void *data, |
| lhash_hash_func_helper call_hash_func, |
| lhash_cmp_func_helper call_cmp_func); |
| |
| // OPENSSL_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 OPENSSL_lh_doall_arg(_LHASH *lh, |
| void (*func)(void *, void *), |
| void *arg); |
| |
| #define DEFINE_LHASH_OF(type) \ |
| /* We disable MSVC C4191 in this macro, which warns when pointers are cast \ |
| * to the wrong type. While the cast itself is valid, it is often a bug \ |
| * because calling it through the cast is UB. However, we never actually \ |
| * call functions as |lhash_cmp_func|. The type is just a type-erased \ |
| * function pointer. (C does not guarantee function pointers fit in \ |
| * |void*|, and GCC will warn on this.) Thus we just disable the false \ |
| * positive warning. */ \ |
| OPENSSL_MSVC_PRAGMA(warning(push)) \ |
| OPENSSL_MSVC_PRAGMA(warning(disable : 4191)) \ |
| \ |
| DECLARE_LHASH_OF(type) \ |
| \ |
| typedef int (*lhash_##type##_cmp_func)(const type *, const type *); \ |
| typedef uint32_t (*lhash_##type##_hash_func)(const type *); \ |
| \ |
| 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); \ |
| } \ |
| \ |
| inline uint32_t lh_##type##_call_hash_func(lhash_hash_func func, \ |
| const void *a) { \ |
| return ((lhash_##type##_hash_func)func)((const type *)a); \ |
| } \ |
| \ |
| inline LHASH_OF(type) *lh_##type##_new(lhash_##type##_hash_func hash, \ |
| lhash_##type##_cmp_func comp) { \ |
| return (LHASH_OF(type) *)OPENSSL_lh_new((lhash_hash_func)hash, \ |
| (lhash_cmp_func)comp); \ |
| } \ |
| \ |
| inline void lh_##type##_free(LHASH_OF(type) *lh) { \ |
| OPENSSL_lh_free((_LHASH *)lh); \ |
| } \ |
| \ |
| inline size_t lh_##type##_num_items(const LHASH_OF(type) *lh) { \ |
| return OPENSSL_lh_num_items((const _LHASH *)lh); \ |
| } \ |
| \ |
| inline type *lh_##type##_retrieve(const LHASH_OF(type) *lh, \ |
| const type *data) { \ |
| return (type *)OPENSSL_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; \ |
| \ |
| 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); \ |
| } \ |
| \ |
| 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 *)OPENSSL_lh_retrieve_key((const _LHASH *)lh, &cb, key_hash, \ |
| lh_##type##_call_cmp_key); \ |
| } \ |
| \ |
| inline int lh_##type##_insert(LHASH_OF(type) *lh, type **old_data, \ |
| type *data) { \ |
| void *old_data_void = NULL; \ |
| int ret = OPENSSL_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; \ |
| } \ |
| \ |
| inline type *lh_##type##_delete(LHASH_OF(type) *lh, const type *data) { \ |
| return (type *)OPENSSL_lh_delete((_LHASH *)lh, data, \ |
| lh_##type##_call_hash_func, \ |
| lh_##type##_call_cmp_func); \ |
| } \ |
| \ |
| typedef struct { \ |
| void (*doall_arg)(type *, void *); \ |
| void *arg; \ |
| } LHASH_DOALL_##type; \ |
| \ |
| 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); \ |
| } \ |
| \ |
| inline void lh_##type##_doall_arg(LHASH_OF(type) *lh, \ |
| void (*func)(type *, void *), void *arg) { \ |
| LHASH_DOALL_##type cb = {func, arg}; \ |
| OPENSSL_lh_doall_arg((_LHASH *)lh, lh_##type##_call_doall_arg, &cb); \ |
| } \ |
| \ |
| OPENSSL_MSVC_PRAGMA(warning(pop)) |
| |
| |
| #if defined(__cplusplus) |
| } // extern C |
| #endif |
| |
| #endif // OPENSSL_HEADER_LHASH_INTERNAL_H |
