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81 lines
3.3 KiB
C
81 lines
3.3 KiB
C
/* Copyright (C) 2000 MySQL AB
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; version 2 of the License.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
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/* Defines used by filesort and uniques */
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#define MERGEBUFF 7
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#define MERGEBUFF2 15
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/*
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The structure SORT_ADDON_FIELD describes a fixed layout
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for field values appended to sorted values in records to be sorted
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in the sort buffer.
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Only fixed layout is supported now.
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Null bit maps for the appended values is placed before the values
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themselves. Offsets are from the last sorted field, that is from the
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record referefence, which is still last component of sorted records.
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It is preserved for backward compatiblility.
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The structure is used tp store values of the additional fields
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in the sort buffer. It is used also when these values are read
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from a temporary file/buffer. As the reading procedures are beyond the
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scope of the 'filesort' code the values have to be retrieved via
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the callback function 'unpack_addon_fields'.
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*/
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typedef struct st_sort_addon_field { /* Sort addon packed field */
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Field *field; /* Original field */
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uint offset; /* Offset from the last sorted field */
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uint null_offset; /* Offset to to null bit from the last sorted field */
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uint length; /* Length in the sort buffer */
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uint8 null_bit; /* Null bit mask for the field */
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} SORT_ADDON_FIELD;
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typedef struct st_buffpek { /* Struktur om sorteringsbuffrarna */
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my_off_t file_pos; /* Where we are in the sort file */
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uchar *base,*key; /* key pointers */
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ha_rows count; /* Number of rows in table */
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ulong mem_count; /* numbers of keys in memory */
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ulong max_keys; /* Max keys in buffert */
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} BUFFPEK;
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typedef struct st_sort_param {
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uint rec_length; /* Length of sorted records */
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uint sort_length; /* Length of sorted columns */
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uint ref_length; /* Length of record ref. */
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uint addon_length; /* Length of added packed fields */
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uint res_length; /* Length of records in final sorted file/buffer */
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uint keys; /* Max keys / buffer */
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ha_rows max_rows,examined_rows;
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TABLE *sort_form; /* For quicker make_sortkey */
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SORT_FIELD *local_sortorder;
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SORT_FIELD *end;
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SORT_ADDON_FIELD *addon_field; /* Descriptors for companion fields */
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uchar *unique_buff;
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bool not_killable;
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char* tmp_buffer;
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} SORTPARAM;
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int merge_many_buff(SORTPARAM *param, uchar *sort_buffer,
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BUFFPEK *buffpek,
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uint *maxbuffer, IO_CACHE *t_file);
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uint read_to_buffer(IO_CACHE *fromfile,BUFFPEK *buffpek,
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uint sort_length);
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int merge_buffers(SORTPARAM *param,IO_CACHE *from_file,
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IO_CACHE *to_file, uchar *sort_buffer,
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BUFFPEK *lastbuff,BUFFPEK *Fb,
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BUFFPEK *Tb,int flag);
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void reuse_freed_buff(QUEUE *queue, BUFFPEK *reuse, uint key_length);
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