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  • Committer: Monty Taylor
  • Date: 2009-09-30 07:01:32 UTC
  • mto: This revision was merged to the branch mainline in revision 1184.
  • Revision ID: mordred@inaugust.com-20090930070132-b1ol1xu1rpajdddy
Small namespace cleanup.

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drizzled/join_cache.cc
 
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/* - mode: c; c-basic-offset: 2; indent-tabs-mode: nil; -*-
 
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 *  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
 
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 *
 
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 *  Copyright (C) 2008-2009 Sun Microsystems
 
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 *
 
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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; either version 2 of the License, or
 
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 *  (at your option) any later version.
 
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 *
 
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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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 *
 
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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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 
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 */
 
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/**
 
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 * @file
 
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 *
 
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 * Implementation of the JOIN cache
 
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 * 
 
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 * @defgroup Query_Optimizer  Query Optimizer
 
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 * @{
 
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 */
 
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#include "drizzled/server_includes.h"
 
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#include "drizzled/sql_select.h" /* include join.h */
 
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#include "drizzled/field/blob.h"
 
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#include <algorithm>
 
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using namespace std;
 
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static uint32_t used_blob_length(CACHE_FIELD **ptr);
 
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static uint32_t used_blob_length(CACHE_FIELD **ptr)
 
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{
 
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  uint32_t length,blob_length;
 
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  for (length=0 ; *ptr ; ptr++)
 
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  {
 
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    (*ptr)->blob_length=blob_length=(*ptr)->blob_field->get_length();
 
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    length+=blob_length;
 
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    (*ptr)->blob_field->get_ptr(&(*ptr)->str);
 
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  }
 
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  return length;
 
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}
 
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/*****************************************************************************
 
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  Fill join cache with packed records
 
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  Records are stored in tab->cache.buffer and last record in
 
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  last record is stored with pointers to blobs to support very big
 
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  records
 
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******************************************************************************/
 
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int join_init_cache(Session *session, JoinTable *tables, uint32_t table_count)
 
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{
 
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  register unsigned int i;
 
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  unsigned int length, blobs;
 
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  size_t size;
 
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  CACHE_FIELD *copy,**blob_ptr;
 
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  JOIN_CACHE  *cache;
 
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  JoinTable *join_tab;
 
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  cache= &tables[table_count].cache;
 
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  cache->fields=blobs=0;
 
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  join_tab= tables;
 
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  for (i=0 ; i < table_count ; i++,join_tab++)
 
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  {
 
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    if (!join_tab->used_fieldlength)            /* Not calced yet */
 
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      calc_used_field_length(session, join_tab);
 
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    cache->fields+=join_tab->used_fields;
 
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    blobs+=join_tab->used_blobs;
 
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    /* SemiJoinDuplicateElimination: reserve space for rowid */
 
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    if (join_tab->rowid_keep_flags & JoinTable::KEEP_ROWID)
 
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    {
 
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      cache->fields++;
 
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      join_tab->used_fieldlength += join_tab->table->file->ref_length;
 
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    }
 
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  }
 
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  if (!(cache->field=(CACHE_FIELD*)
 
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        sql_alloc(sizeof(CACHE_FIELD)*(cache->fields+table_count*2)+(blobs+1)*
 
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                  sizeof(CACHE_FIELD*))))
 
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  {
 
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    free((unsigned char*) cache->buff);
 
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    cache->buff=0;
 
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    return(1);
 
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  }
 
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  copy=cache->field;
 
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  blob_ptr=cache->blob_ptr=(CACHE_FIELD**)
 
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    (cache->field+cache->fields+table_count*2);
 
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  length=0;
 
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  for (i=0 ; i < table_count ; i++)
 
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  {
 
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    uint32_t null_fields=0, used_fields;
 
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    Field **f_ptr,*field;
 
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    for (f_ptr= tables[i].table->field,used_fields= tables[i].used_fields; used_fields; f_ptr++)
 
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    {
 
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      field= *f_ptr;
 
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      if (field->isReadSet())
 
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      {
 
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        used_fields--;
 
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        length+=field->fill_cache_field(copy);
 
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        if (copy->blob_field)
 
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          (*blob_ptr++)=copy;
 
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        if (field->maybe_null())
 
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          null_fields++;
 
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        copy->get_rowid= NULL;
 
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        copy++;
 
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      }
 
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    }
 
118
    /* Copy null bits from table */
 
119
    if (null_fields && tables[i].table->getNullFields())
 
120
    {                                           /* must copy null bits */
 
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      copy->str= tables[i].table->null_flags;
 
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      copy->length= tables[i].table->s->null_bytes;
 
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      copy->strip=0;
 
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      copy->blob_field=0;
 
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      copy->get_rowid= NULL;
 
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      length+=copy->length;
 
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      copy++;
 
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      cache->fields++;
 
129
    }
 
130
    /* If outer join table, copy null_row flag */
 
131
    if (tables[i].table->maybe_null)
 
132
    {
 
133
      copy->str= (unsigned char*) &tables[i].table->null_row;
 
134
      copy->length=sizeof(tables[i].table->null_row);
 
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      copy->strip=0;
 
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      copy->blob_field=0;
 
137
      copy->get_rowid= NULL;
 
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      length+=copy->length;
 
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      copy++;
 
140
      cache->fields++;
 
141
    }
 
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    /* SemiJoinDuplicateElimination: Allocate space for rowid if needed */
 
143
    if (tables[i].rowid_keep_flags & JoinTable::KEEP_ROWID)
 
144
    {
 
145
      copy->str= tables[i].table->file->ref;
 
146
      copy->length= tables[i].table->file->ref_length;
 
147
      copy->strip=0;
 
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      copy->blob_field=0;
 
149
      copy->get_rowid= NULL;
 
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      if (tables[i].rowid_keep_flags & JoinTable::CALL_POSITION)
 
151
      {
 
152
        /* We will need to call h->position(): */
 
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        copy->get_rowid= tables[i].table;
 
154
        /* And those after us won't have to: */
 
155
        tables[i].rowid_keep_flags&=  ~((int)JoinTable::CALL_POSITION);
 
156
      }
 
157
      copy++;
 
158
    }
 
159
  }
 
160
 
 
161
  cache->length= length+blobs*sizeof(char*);
 
162
  cache->blobs= blobs;
 
163
  *blob_ptr= NULL;                                      /* End sequentel */
 
164
  size= max((size_t) session->variables.join_buff_size, (size_t)cache->length);
 
165
  if (!(cache->buff= (unsigned char*) malloc(size)))
 
166
    return 1;
 
167
  cache->end= cache->buff+size;
 
168
  reset_cache_write(cache);
 
169
  return 0;
 
170
}
 
171
 
 
172
bool store_record_in_cache(JOIN_CACHE *cache)
 
173
{
 
174
  uint32_t length;
 
175
  unsigned char *pos;
 
176
  CACHE_FIELD *copy,*end_field;
 
177
  bool last_record;
 
178
 
 
179
  pos= cache->pos;
 
180
  end_field= cache->field+cache->fields;
 
181
 
 
182
  length= cache->length;
 
183
  if (cache->blobs)
 
184
    length+= used_blob_length(cache->blob_ptr);
 
185
  if ((last_record= (length + cache->length > (size_t) (cache->end - pos))))
 
186
    cache->ptr_record= cache->records;
 
187
  /*
 
188
    There is room in cache. Put record there
 
189
  */
 
190
  cache->records++;
 
191
  for (copy= cache->field; copy < end_field; copy++)
 
192
  {
 
193
    if (copy->blob_field)
 
194
    {
 
195
      if (last_record)
 
196
      {
 
197
        copy->blob_field->get_image(pos, copy->length+sizeof(char*), copy->blob_field->charset());
 
198
        pos+= copy->length+sizeof(char*);
 
199
      }
 
200
      else
 
201
      {
 
202
        copy->blob_field->get_image(pos, copy->length, // blob length
 
203
                                    copy->blob_field->charset());
 
204
        memcpy(pos+copy->length,copy->str,copy->blob_length);  // Blob data
 
205
        pos+= copy->length+copy->blob_length;
 
206
      }
 
207
    }
 
208
    else
 
209
    {
 
210
      // SemiJoinDuplicateElimination: Get the rowid into table->ref:
 
211
      if (copy->get_rowid)
 
212
        copy->get_rowid->file->position(copy->get_rowid->record[0]);
 
213
 
 
214
      if (copy->strip)
 
215
      {
 
216
        unsigned char *str,*end;
 
217
        for (str= copy->str,end= str+copy->length; end > str && end[-1] == ' '; end--)
 
218
        {}
 
219
        length= (uint32_t) (end-str);
 
220
        memcpy(pos+2, str, length);
 
221
        int2store(pos, length);
 
222
        pos+= length+2;
 
223
      }
 
224
      else
 
225
      {
 
226
        memcpy(pos,copy->str,copy->length);
 
227
        pos+= copy->length;
 
228
      }
 
229
    }
 
230
  }
 
231
  cache->pos= pos;
 
232
  return last_record || (size_t) (cache->end - pos) < cache->length;
 
233
}
 
234
 
 
235
void reset_cache_read(JOIN_CACHE *cache)
 
236
{
 
237
  cache->record_nr= 0;
 
238
  cache->pos= cache->buff;
 
239
}
 
240
 
 
241
void reset_cache_write(JOIN_CACHE *cache)
 
242
{
 
243
  reset_cache_read(cache);
 
244
  cache->records= 0;
 
245
  cache->ptr_record= UINT32_MAX;
 
246
}
 
247
 
 
248
/**
 
249
  @} (end of group Query_Optimizer)
 
250
*/