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137 lines
5.2 KiB
C
137 lines
5.2 KiB
C
/*****************************************************************************
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Copyright (c) 2007, 2016, 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 as published by the Free Software
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Foundation; version 2 of the License.
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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 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 Street, Fifth Floor, Boston, MA 02110-1335 USA
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*****************************************************************************/
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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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/*******************************************************************//**
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Creates a hash storage. If any of the parameters is 0, then a default
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value is used.
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@return own: hash storage */
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UNIV_INLINE
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ha_storage_t*
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ha_storage_create(
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/*==============*/
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ulint initial_heap_bytes, /*!< in: initial heap's size */
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ulint initial_hash_cells); /*!< in: initial number of cells
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in the hash table */
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/*******************************************************************//**
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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*
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ha_storage_put_memlim(
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/*==================*/
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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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/*******************************************************************//**
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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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/*******************************************************************//**
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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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/*******************************************************************//**
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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), \
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strlen(str) + 1, (memlim)))
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/*******************************************************************//**
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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
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ha_storage_empty(
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/*=============*/
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ha_storage_t** storage); /*!< in/out: hash storage */
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/*******************************************************************//**
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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
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ha_storage_free(
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/*============*/
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ha_storage_t* storage); /*!< in, own: hash storage */
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/*******************************************************************//**
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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
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ha_storage_get_size(
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/*================*/
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const ha_storage_t* storage); /*!< in: hash storage */
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#include "ha0storage.inl"
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#endif /* ha0storage_h */
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