125 lines
5.1 KiB
C
125 lines
5.1 KiB
C
/*****************************************************************************
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Copyright (c) 2007, 2018, Oracle and/or its affiliates. All Rights Reserved.
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This program is free software; you can redistribute it and/or modify it under
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the terms of the GNU General Public License, version 2.0, as published by the
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Free Software Foundation.
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This program is also distributed with certain software (including but not
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limited to OpenSSL) that is licensed under separate terms, as designated in a
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particular file or component or in included license documentation. The authors
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of MySQL hereby grant you an additional permission to link the program and
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your derivative works with the separately licensed software that they have
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included with MySQL.
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This program is distributed in the hope that it will be useful, but WITHOUT
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ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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FOR A PARTICULAR PURPOSE. See the GNU General Public License, version 2.0,
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for more details.
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You should have received a copy of the GNU General Public License along with
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this program; if not, write to the Free Software Foundation, Inc.,
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51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*****************************************************************************/
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/** @file include/ha0storage.h
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Hash storage.
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Provides a data structure that stores chunks of data in
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its own storage, avoiding duplicates.
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Created September 22, 2007 Vasil Dimov
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*******************************************************/
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#ifndef ha0storage_h
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#define ha0storage_h
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#include "univ.i"
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/** This value is used by default by ha_storage_create(). More memory
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is allocated later when/if it is needed. */
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#define HA_STORAGE_DEFAULT_HEAP_BYTES 1024
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/** This value is used by default by ha_storage_create(). It is a
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constant per ha_storage's lifetime. */
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#define HA_STORAGE_DEFAULT_HASH_CELLS 4096
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/** Hash storage */
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struct ha_storage_t;
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/** Creates a hash storage. If any of the parameters is 0, then a default value
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is used.
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@param[in] initial_hash_cells initial number of cells in the hash
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table
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@param[in] initial_heap_bytes initial heap's size
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@return own: hash storage */
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UNIV_INLINE
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ha_storage_t *ha_storage_create(ulint initial_heap_bytes,
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ulint initial_hash_cells);
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/** Copies data into the storage and returns a pointer to the copy. If the
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same data chunk is already present, then pointer to it is returned.
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Data chunks are considered to be equal if len1 == len2 and
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memcmp(data1, data2, len1) == 0. If "data" is not present (and thus
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data_len bytes need to be allocated) and the size of storage is going to
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become more than "memlim" then "data" is not added and NULL is returned.
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To disable this behavior "memlim" can be set to 0, which stands for
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"no limit".
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@return pointer to the copy */
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const void *ha_storage_put_memlim(
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ha_storage_t *storage, /*!< in/out: hash storage */
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const void *data, /*!< in: data to store */
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ulint data_len, /*!< in: data length */
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ulint memlim); /*!< in: memory limit to obey */
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/** Same as ha_storage_put_memlim() but without memory limit.
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@param storage in/out: hash storage
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@param data in: data to store
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@param data_len in: data length
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@return pointer to the copy of the string */
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#define ha_storage_put(storage, data, data_len) \
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ha_storage_put_memlim((storage), (data), (data_len), 0)
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/** Copies string into the storage and returns a pointer to the copy. If the
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same string is already present, then pointer to it is returned.
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Strings are considered to be equal if strcmp(str1, str2) == 0.
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@param storage in/out: hash storage
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@param str in: string to put
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@return pointer to the copy of the string */
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#define ha_storage_put_str(storage, str) \
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((const char *)ha_storage_put((storage), (str), strlen(str) + 1))
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/** Copies string into the storage and returns a pointer to the copy obeying
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a memory limit.
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If the same string is already present, then pointer to it is returned.
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Strings are considered to be equal if strcmp(str1, str2) == 0.
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@param storage in/out: hash storage
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@param str in: string to put
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@param memlim in: memory limit to obey
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@return pointer to the copy of the string */
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#define ha_storage_put_str_memlim(storage, str, memlim) \
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((const char *)ha_storage_put_memlim((storage), (str), strlen(str) + 1, \
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(memlim)))
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/** Empties a hash storage, freeing memory occupied by data chunks.
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This invalidates any pointers previously returned by ha_storage_put().
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The hash storage is not invalidated itself and can be used again. */
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UNIV_INLINE
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void ha_storage_empty(ha_storage_t **storage); /*!< in/out: hash storage */
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/** Frees a hash storage and everything it contains, it cannot be used after
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this call.
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This invalidates any pointers previously returned by ha_storage_put(). */
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UNIV_INLINE
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void ha_storage_free(ha_storage_t *storage); /*!< in, own: hash storage */
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/** Gets the size of the memory used by a storage.
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@return bytes used */
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UNIV_INLINE
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ulint ha_storage_get_size(const ha_storage_t *storage); /*!< in: hash storage */
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#include "ha0storage.ic"
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#endif /* ha0storage_h */
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