From 354bb40e75d94466e91fe6960523612c9d17ccfb Mon Sep 17 00:00:00 2001 From: Karen Arutyunov Date: Thu, 2 Nov 2017 23:11:29 +0300 Subject: Add implementation --- mysql/hash.h | 125 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 125 insertions(+) create mode 100644 mysql/hash.h (limited to 'mysql/hash.h') diff --git a/mysql/hash.h b/mysql/hash.h new file mode 100644 index 0000000..7bc97a7 --- /dev/null +++ b/mysql/hash.h @@ -0,0 +1,125 @@ +/* Copyright (c) 2000, 2015, Oracle and/or its affiliates. All rights reserved. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; version 2 of the License. + + This program 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 General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ + +/* Dynamic hashing of record with different key-length */ + +#ifndef _hash_h +#define _hash_h + +#include "my_global.h" /* uchar */ +#include "my_sys.h" /* DYNAMIC_ARRAY */ + +/* + This forward declaration is used from C files where the real + definition is included before. Since C does not allow repeated + typedef declarations, even when identical, the definition may not be + repeated. +*/ +#ifndef CHARSET_INFO_DEFINED +#define CHARSET_INFO_DEFINED +typedef struct charset_info_st CHARSET_INFO; +#endif /* CHARSET_INFO_DEFINED */ + +#ifdef __cplusplus +extern "C" { +#endif + +/* + Overhead to store an element in hash + Can be used to approximate memory consumption for a hash + */ +#define HASH_OVERHEAD (sizeof(char*)*2) + +/* flags for hash_init */ +#define HASH_UNIQUE 1 /* hash_insert fails on duplicate key */ + +struct st_hash; +typedef uint my_hash_value_type; +typedef uchar *(*my_hash_get_key)(const uchar *,size_t*,my_bool); +typedef void (*my_hash_free_key)(void *); +/** + Function type representing a hash function to be used with the HASH + container. + Should accept pointer to HASH, pointer to key buffer and key length + as parameters. +*/ +typedef my_hash_value_type (*my_hash_function)(const struct st_hash *, + const uchar *, + size_t); + +typedef struct st_hash { + size_t key_offset,key_length; /* Length of key if const length */ + size_t blength; + ulong records; + uint flags; + DYNAMIC_ARRAY array; /* Place for hash_keys */ + my_hash_get_key get_key; + void (*free)(void *); + CHARSET_INFO *charset; + my_hash_function hash_function; + PSI_memory_key m_psi_key; +} HASH; + +/* A search iterator state */ +typedef uint HASH_SEARCH_STATE; + +#define my_hash_init(A,B,C,D,E,F,G,H,I) \ + _my_hash_init(A,0,B,NULL,C,D,E,F,G,H,I) +#define my_hash_init2(A,B,C,D,E,F,G,H,I,J) \ + _my_hash_init(A,B,C,NULL,D,E,F,G,H,I,J) +#define my_hash_init3(A,B,C,D,E,F,G,H,I,J,K) \ + _my_hash_init(A,B,C,D,E,F,G,H,I,J,K) +my_bool _my_hash_init(HASH *hash, uint growth_size, CHARSET_INFO *charset, + my_hash_function hash_function, + ulong default_array_elements, size_t key_offset, + size_t key_length, my_hash_get_key get_key, + void (*free_element)(void*), + uint flags, + PSI_memory_key psi_key); +void my_hash_claim(HASH *tree); +void my_hash_free(HASH *tree); +void my_hash_reset(HASH *hash); +uchar *my_hash_element(HASH *hash, ulong idx); +uchar *my_hash_search(const HASH *info, const uchar *key, size_t length); +uchar *my_hash_search_using_hash_value(const HASH *info, + my_hash_value_type hash_value, + const uchar *key, size_t length); +my_hash_value_type my_calc_hash(const HASH *info, + const uchar *key, size_t length); +uchar *my_hash_first(const HASH *info, const uchar *key, size_t length, + HASH_SEARCH_STATE *state); +uchar *my_hash_first_from_hash_value(const HASH *info, + my_hash_value_type hash_value, + const uchar *key, + size_t length, + HASH_SEARCH_STATE *state); +uchar *my_hash_next(const HASH *info, const uchar *key, size_t length, + HASH_SEARCH_STATE *state); +my_bool my_hash_insert(HASH *info, const uchar *data); +my_bool my_hash_delete(HASH *hash, uchar *record); +my_bool my_hash_update(HASH *hash, uchar *record, uchar *old_key, + size_t old_key_length); +void my_hash_replace(HASH *hash, HASH_SEARCH_STATE *state, uchar *new_row); +my_bool my_hash_check(HASH *hash); /* Only in debug library */ + +#define my_hash_clear(H) memset((H), 0, sizeof(*(H))) +#define my_hash_inited(H) ((H)->blength != 0) +#define my_hash_init_opt(A,B,C,D,E,F,G,H,I) \ + (!my_hash_inited(A) && _my_hash_init(A,0,B,NULL,C,D,E,F,G,H,I)) + +#ifdef __cplusplus +} +#endif +#endif -- cgit v1.1