mi_dynrec.c
上传用户:romrleung
上传日期:2022-05-23
资源大小:18897k
文件大小:43k
- /* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult AB
- 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; either version 2 of the License, or
- (at your option) any later version.
- 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
- /*
- Functions to handle space-packed-records and blobs
-
- A row may be stored in one or more linked blocks.
- The block size is between MI_MIN_BLOCK_LENGTH and MI_MAX_BLOCK_LENGTH.
- Each block is aligned on MI_DYN_ALIGN_SIZE.
- The reson for the max block size is to not have too many different types
- of blocks. For the differnet block types, look at _mi_get_block_info()
- */
- #include "myisamdef.h"
- /* Enough for comparing if number is zero */
- static char zero_string[]={0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
- static int write_dynamic_record(MI_INFO *info,const byte *record,
- ulong reclength);
- static int _mi_find_writepos(MI_INFO *info,ulong reclength,my_off_t *filepos,
- ulong *length);
- static int update_dynamic_record(MI_INFO *info,my_off_t filepos,byte *record,
- ulong reclength);
- static int delete_dynamic_record(MI_INFO *info,my_off_t filepos,
- uint second_read);
- static int _mi_cmp_buffer(File file, const byte *buff, my_off_t filepos,
- uint length);
- #ifdef THREAD
- /* Play it safe; We have a small stack when using threads */
- #undef my_alloca
- #undef my_afree
- #define my_alloca(A) my_malloc((A),MYF(0))
- #define my_afree(A) my_free((A),MYF(0))
- #endif
- /* Interface function from MI_INFO */
- int _mi_write_dynamic_record(MI_INFO *info, const byte *record)
- {
- ulong reclength=_mi_rec_pack(info,info->rec_buff,record);
- return (write_dynamic_record(info,info->rec_buff,reclength));
- }
- int _mi_update_dynamic_record(MI_INFO *info, my_off_t pos, const byte *record)
- {
- uint length=_mi_rec_pack(info,info->rec_buff,record);
- return (update_dynamic_record(info,pos,info->rec_buff,length));
- }
- int _mi_write_blob_record(MI_INFO *info, const byte *record)
- {
- byte *rec_buff;
- int error;
- ulong reclength,reclength2,extra;
- extra= (ALIGN_SIZE(MI_MAX_DYN_BLOCK_HEADER)+MI_SPLIT_LENGTH+
- MI_DYN_DELETE_BLOCK_HEADER+1);
- reclength= (info->s->base.pack_reclength +
- _my_calc_total_blob_length(info,record)+ extra);
- #ifdef NOT_USED /* We now support big rows */
- if (reclength > MI_DYN_MAX_ROW_LENGTH)
- {
- my_errno=HA_ERR_TO_BIG_ROW;
- return -1;
- }
- #endif
- if (!(rec_buff=(byte*) my_alloca(reclength)))
- {
- my_errno=ENOMEM;
- return(-1);
- }
- reclength2= _mi_rec_pack(info,rec_buff+ALIGN_SIZE(MI_MAX_DYN_BLOCK_HEADER),
- record);
- DBUG_PRINT("info",("reclength: %lu reclength2: %lu",
- reclength, reclength2));
- DBUG_ASSERT(reclength2 <= reclength);
- error=write_dynamic_record(info,rec_buff+ALIGN_SIZE(MI_MAX_DYN_BLOCK_HEADER),
- reclength2);
- my_afree(rec_buff);
- return(error);
- }
- int _mi_update_blob_record(MI_INFO *info, my_off_t pos, const byte *record)
- {
- byte *rec_buff;
- int error;
- ulong reclength,extra;
- extra= (ALIGN_SIZE(MI_MAX_DYN_BLOCK_HEADER)+MI_SPLIT_LENGTH+
- MI_DYN_DELETE_BLOCK_HEADER);
- reclength= (info->s->base.pack_reclength+
- _my_calc_total_blob_length(info,record)+ extra);
- #ifdef NOT_USED /* We now support big rows */
- if (reclength > MI_DYN_MAX_ROW_LENGTH)
- {
- my_errno=HA_ERR_TO_BIG_ROW;
- return -1;
- }
- #endif
- if (!(rec_buff=(byte*) my_alloca(reclength)))
- {
- my_errno=ENOMEM;
- return(-1);
- }
- reclength=_mi_rec_pack(info,rec_buff+ALIGN_SIZE(MI_MAX_DYN_BLOCK_HEADER),
- record);
- error=update_dynamic_record(info,pos,
- rec_buff+ALIGN_SIZE(MI_MAX_DYN_BLOCK_HEADER),
- reclength);
- my_afree(rec_buff);
- return(error);
- }
- int _mi_delete_dynamic_record(MI_INFO *info)
- {
- return delete_dynamic_record(info,info->lastpos,0);
- }
- /* Write record to data-file */
- static int write_dynamic_record(MI_INFO *info, const byte *record,
- ulong reclength)
- {
- int flag;
- ulong length;
- my_off_t filepos;
- DBUG_ENTER("write_dynamic_record");
- flag=0;
- do
- {
- if (_mi_find_writepos(info,reclength,&filepos,&length))
- goto err;
- if (_mi_write_part_record(info,filepos,length,info->s->state.dellink,
- (byte**) &record,&reclength,&flag))
- goto err;
- } while (reclength);
- DBUG_RETURN(0);
- err:
- DBUG_RETURN(1);
- }
- /* Get a block for data ; The given data-area must be used !! */
- static int _mi_find_writepos(MI_INFO *info,
- ulong reclength, /* record length */
- my_off_t *filepos, /* Return file pos */
- ulong *length) /* length of block at filepos */
- {
- MI_BLOCK_INFO block_info;
- ulong tmp;
- DBUG_ENTER("_mi_find_writepos");
- if (info->s->state.dellink != HA_OFFSET_ERROR)
- {
- /* Deleted blocks exists; Get last used block */
- *filepos=info->s->state.dellink;
- block_info.second_read=0;
- info->rec_cache.seek_not_done=1;
- if (!(_mi_get_block_info(&block_info,info->dfile,info->s->state.dellink) &
- BLOCK_DELETED))
- {
- DBUG_PRINT("error",("Delete link crashed"));
- my_errno=HA_ERR_WRONG_IN_RECORD;
- DBUG_RETURN(-1);
- }
- info->s->state.dellink=block_info.next_filepos;
- info->state->del--;
- info->state->empty-= block_info.block_len;
- *length= block_info.block_len;
- }
- else
- {
- /* No deleted blocks; Allocate a new block */
- *filepos=info->state->data_file_length;
- if ((tmp=reclength+3 + test(reclength >= (65520-3))) <
- info->s->base.min_block_length)
- tmp= info->s->base.min_block_length;
- else
- tmp= ((tmp+MI_DYN_ALIGN_SIZE-1) &
- (~ (ulong) (MI_DYN_ALIGN_SIZE-1)));
- if (info->state->data_file_length >
- (info->s->base.max_data_file_length - tmp))
- {
- my_errno=HA_ERR_RECORD_FILE_FULL;
- DBUG_RETURN(-1);
- }
- if (tmp > MI_MAX_BLOCK_LENGTH)
- tmp=MI_MAX_BLOCK_LENGTH;
- *length= tmp;
- info->state->data_file_length+= tmp;
- info->s->state.split++;
- info->update|=HA_STATE_WRITE_AT_END;
- }
- DBUG_RETURN(0);
- } /* _mi_find_writepos */
- /*
- Unlink a deleted block from the deleted list.
- This block will be combined with the preceding or next block to form
- a big block.
- */
- static bool unlink_deleted_block(MI_INFO *info, MI_BLOCK_INFO *block_info)
- {
- DBUG_ENTER("unlink_deleted_block");
- if (block_info->filepos == info->s->state.dellink)
- {
- /* First deleted block; We can just use this ! */
- info->s->state.dellink=block_info->next_filepos;
- }
- else
- {
- MI_BLOCK_INFO tmp;
- tmp.second_read=0;
- /* Unlink block from the previous block */
- if (!(_mi_get_block_info(&tmp,info->dfile,block_info->prev_filepos)
- & BLOCK_DELETED))
- DBUG_RETURN(1); /* Something is wrong */
- mi_sizestore(tmp.header+4,block_info->next_filepos);
- if (my_pwrite(info->dfile,(char*) tmp.header+4,8,
- block_info->prev_filepos+4, MYF(MY_NABP)))
- DBUG_RETURN(1);
- /* Unlink block from next block */
- if (block_info->next_filepos != HA_OFFSET_ERROR)
- {
- if (!(_mi_get_block_info(&tmp,info->dfile,block_info->next_filepos)
- & BLOCK_DELETED))
- DBUG_RETURN(1); /* Something is wrong */
- mi_sizestore(tmp.header+12,block_info->prev_filepos);
- if (my_pwrite(info->dfile,(char*) tmp.header+12,8,
- block_info->next_filepos+12,
- MYF(MY_NABP)))
- DBUG_RETURN(1);
- }
- }
- /* We now have one less deleted block */
- info->state->del--;
- info->state->empty-= block_info->block_len;
- info->s->state.split--;
- /*
- If this was a block that we where accessing through table scan
- (mi_rrnd() or mi_scan(), then ensure that we skip over this block
- when doing next mi_rrnd() or mi_scan().
- */
- if (info->nextpos == block_info->filepos)
- info->nextpos+=block_info->block_len;
- DBUG_RETURN(0);
- }
- /*
- Add a backward link to delete block
- SYNOPSIS
- update_backward_delete_link()
- info MyISAM handler
- delete_block Position to delete block to update.
- If this is 'HA_OFFSET_ERROR', nothing will be done
- filepos Position to block that 'delete_block' should point to
- RETURN
- 0 ok
- 1 error. In this case my_error is set.
- */
- static int update_backward_delete_link(MI_INFO *info, my_off_t delete_block,
- my_off_t filepos)
- {
- MI_BLOCK_INFO block_info;
- DBUG_ENTER("update_backward_delete_link");
- if (delete_block != HA_OFFSET_ERROR)
- {
- block_info.second_read=0;
- if (_mi_get_block_info(&block_info,info->dfile,delete_block)
- & BLOCK_DELETED)
- {
- char buff[8];
- mi_sizestore(buff,filepos);
- if (my_pwrite(info->dfile,buff, 8, delete_block+12, MYF(MY_NABP)))
- DBUG_RETURN(1); /* Error on write */
- }
- else
- {
- my_errno=HA_ERR_WRONG_IN_RECORD;
- DBUG_RETURN(1); /* Wrong delete link */
- }
- }
- DBUG_RETURN(0);
- }
- /* Delete datarecord from database */
- /* info->rec_cache.seek_not_done is updated in cmp_record */
- static int delete_dynamic_record(MI_INFO *info, my_off_t filepos,
- uint second_read)
- {
- uint length,b_type;
- MI_BLOCK_INFO block_info,del_block;
- int error;
- my_bool remove_next_block;
- DBUG_ENTER("delete_dynamic_record");
- /* First add a link from the last block to the new one */
- error= update_backward_delete_link(info, info->s->state.dellink, filepos);
- block_info.second_read=second_read;
- do
- {
- /* Remove block at 'filepos' */
- if ((b_type=_mi_get_block_info(&block_info,info->dfile,filepos))
- & (BLOCK_DELETED | BLOCK_ERROR | BLOCK_SYNC_ERROR |
- BLOCK_FATAL_ERROR) ||
- (length=(uint) (block_info.filepos-filepos) +block_info.block_len) <
- MI_MIN_BLOCK_LENGTH)
- {
- my_errno=HA_ERR_WRONG_IN_RECORD;
- DBUG_RETURN(1);
- }
- /* Check if next block is a delete block */
- del_block.second_read=0;
- remove_next_block=0;
- if (_mi_get_block_info(&del_block,info->dfile,filepos+length) &
- BLOCK_DELETED && del_block.block_len+length < MI_DYN_MAX_BLOCK_LENGTH)
- {
- /* We can't remove this yet as this block may be the head block */
- remove_next_block=1;
- length+=del_block.block_len;
- }
- block_info.header[0]=0;
- mi_int3store(block_info.header+1,length);
- mi_sizestore(block_info.header+4,info->s->state.dellink);
- if (b_type & BLOCK_LAST)
- bfill(block_info.header+12,8,255);
- else
- mi_sizestore(block_info.header+12,block_info.next_filepos);
- if (my_pwrite(info->dfile,(byte*) block_info.header,20,filepos,
- MYF(MY_NABP)))
- DBUG_RETURN(1);
- info->s->state.dellink = filepos;
- info->state->del++;
- info->state->empty+=length;
- filepos=block_info.next_filepos;
- /* Now it's safe to unlink the deleted block directly after this one */
- if (remove_next_block && unlink_deleted_block(info,&del_block))
- error=1;
- } while (!(b_type & BLOCK_LAST));
- DBUG_RETURN(error);
- }
- /* Write a block to datafile */
- int _mi_write_part_record(MI_INFO *info,
- my_off_t filepos, /* points at empty block */
- ulong length, /* length of block */
- my_off_t next_filepos,/* Next empty block */
- byte **record, /* pointer to record ptr */
- ulong *reclength, /* length of *record */
- int *flag) /* *flag == 0 if header */
- {
- ulong head_length,res_length,extra_length,long_block,del_length;
- byte *pos,*record_end;
- my_off_t next_delete_block;
- uchar temp[MI_SPLIT_LENGTH+MI_DYN_DELETE_BLOCK_HEADER];
- DBUG_ENTER("_mi_write_part_record");
- next_delete_block=HA_OFFSET_ERROR;
- res_length=extra_length=0;
- if (length > *reclength + MI_SPLIT_LENGTH)
- { /* Splitt big block */
- res_length=MY_ALIGN(length- *reclength - MI_EXTEND_BLOCK_LENGTH,
- MI_DYN_ALIGN_SIZE);
- length-= res_length; /* Use this for first part */
- }
- long_block= (length < 65520L && *reclength < 65520L) ? 0 : 1;
- if (length == *reclength+ 3 + long_block)
- {
- /* Block is exactly of the right length */
- temp[0]=(uchar) (1+ *flag)+(uchar) long_block; /* Flag is 0 or 6 */
- if (long_block)
- {
- mi_int3store(temp+1,*reclength);
- head_length=4;
- }
- else
- {
- mi_int2store(temp+1,*reclength);
- head_length=3;
- }
- }
- else if (length-long_block < *reclength+4)
- { /* To short block */
- if (next_filepos == HA_OFFSET_ERROR)
- next_filepos=info->s->state.dellink != HA_OFFSET_ERROR ?
- info->s->state.dellink : info->state->data_file_length;
- if (*flag == 0) /* First block */
- {
- if (*reclength > MI_MAX_BLOCK_LENGTH)
- {
- head_length= 16;
- temp[0]=13;
- mi_int4store(temp+1,*reclength);
- mi_int3store(temp+5,length-head_length);
- mi_sizestore((byte*) temp+8,next_filepos);
- }
- else
- {
- head_length=5+8+long_block*2;
- temp[0]=5+(uchar) long_block;
- if (long_block)
- {
- mi_int3store(temp+1,*reclength);
- mi_int3store(temp+4,length-head_length);
- mi_sizestore((byte*) temp+7,next_filepos);
- }
- else
- {
- mi_int2store(temp+1,*reclength);
- mi_int2store(temp+3,length-head_length);
- mi_sizestore((byte*) temp+5,next_filepos);
- }
- }
- }
- else
- {
- head_length=3+8+long_block;
- temp[0]=11+(uchar) long_block;
- if (long_block)
- {
- mi_int3store(temp+1,length-head_length);
- mi_sizestore((byte*) temp+4,next_filepos);
- }
- else
- {
- mi_int2store(temp+1,length-head_length);
- mi_sizestore((byte*) temp+3,next_filepos);
- }
- }
- }
- else
- { /* Block with empty info last */
- head_length=4+long_block;
- extra_length= length- *reclength-head_length;
- temp[0]= (uchar) (3+ *flag)+(uchar) long_block; /* 3,4 or 9,10 */
- if (long_block)
- {
- mi_int3store(temp+1,*reclength);
- temp[4]= (uchar) (extra_length);
- }
- else
- {
- mi_int2store(temp+1,*reclength);
- temp[3]= (uchar) (extra_length);
- }
- length= *reclength+head_length; /* Write only what is needed */
- }
- DBUG_DUMP("header",(byte*) temp,head_length);
- /* Make a long block for one write */
- record_end= *record+length-head_length;
- del_length=(res_length ? MI_DYN_DELETE_BLOCK_HEADER : 0);
- bmove((byte*) (*record-head_length),(byte*) temp,head_length);
- memcpy(temp,record_end,(size_t) (extra_length+del_length));
- bzero((byte*) record_end,extra_length);
- if (res_length)
- {
- /* Check first if we can join this block with the next one */
- MI_BLOCK_INFO del_block;
- my_off_t next_block=filepos+length+extra_length+res_length;
- del_block.second_read=0;
- if (next_block < info->state->data_file_length &&
- info->s->state.dellink != HA_OFFSET_ERROR)
- {
- if ((_mi_get_block_info(&del_block,info->dfile,next_block)
- & BLOCK_DELETED) &&
- res_length + del_block.block_len < MI_DYN_MAX_BLOCK_LENGTH)
- {
- if (unlink_deleted_block(info,&del_block))
- goto err;
- res_length+=del_block.block_len;
- }
- }
- /* Create a delete link of the last part of the block */
- pos=record_end+extra_length;
- pos[0]= ' ';
- mi_int3store(pos+1,res_length);
- mi_sizestore(pos+4,info->s->state.dellink);
- bfill(pos+12,8,255); /* End link */
- next_delete_block=info->s->state.dellink;
- info->s->state.dellink= filepos+length+extra_length;
- info->state->del++;
- info->state->empty+=res_length;
- info->s->state.split++;
- }
- if (info->opt_flag & WRITE_CACHE_USED &&
- info->update & HA_STATE_WRITE_AT_END)
- {
- if (info->update & HA_STATE_EXTEND_BLOCK)
- {
- info->update&= ~HA_STATE_EXTEND_BLOCK;
- if (my_block_write(&info->rec_cache,(byte*) *record-head_length,
- length+extra_length+del_length,filepos))
- goto err;
- }
- else if (my_b_write(&info->rec_cache,(byte*) *record-head_length,
- length+extra_length+del_length))
- goto err;
- }
- else
- {
- info->rec_cache.seek_not_done=1;
- if (my_pwrite(info->dfile,(byte*) *record-head_length,length+extra_length+
- del_length,filepos,info->s->write_flag))
- goto err;
- }
- memcpy(record_end,temp,(size_t) (extra_length+del_length));
- *record=record_end;
- *reclength-=(length-head_length);
- *flag=6;
- if (del_length)
- {
- /* link the next delete block to this */
- if (update_backward_delete_link(info, next_delete_block,
- info->s->state.dellink))
- goto err;
- }
- DBUG_RETURN(0);
- err:
- DBUG_PRINT("exit",("errno: %d",my_errno));
- DBUG_RETURN(1);
- } /*_mi_write_part_record */
- /* update record from datafile */
- static int update_dynamic_record(MI_INFO *info, my_off_t filepos, byte *record,
- ulong reclength)
- {
- int flag;
- uint error;
- ulong length;
- MI_BLOCK_INFO block_info;
- DBUG_ENTER("update_dynamic_record");
- flag=block_info.second_read=0;
- while (reclength > 0)
- {
- if (filepos != info->s->state.dellink)
- {
- block_info.next_filepos= HA_OFFSET_ERROR;
- if ((error=_mi_get_block_info(&block_info,info->dfile,filepos))
- & (BLOCK_DELETED | BLOCK_ERROR | BLOCK_SYNC_ERROR |
- BLOCK_FATAL_ERROR))
- {
- DBUG_PRINT("error",("Got wrong block info"));
- if (!(error & BLOCK_FATAL_ERROR))
- my_errno=HA_ERR_WRONG_IN_RECORD;
- goto err;
- }
- length=(ulong) (block_info.filepos-filepos) + block_info.block_len;
- if (length < reclength)
- {
- uint tmp=MY_ALIGN(reclength - length + 3 +
- test(reclength >= 65520L),MI_DYN_ALIGN_SIZE);
- /* Don't create a block bigger than MI_MAX_BLOCK_LENGTH */
- tmp= min(length+tmp, MI_MAX_BLOCK_LENGTH)-length;
- /* Check if we can extend this block */
- if (block_info.filepos + block_info.block_len ==
- info->state->data_file_length &&
- info->state->data_file_length <
- info->s->base.max_data_file_length-tmp)
- {
- /* extend file */
- DBUG_PRINT("info",("Extending file with %d bytes",tmp));
- if (info->nextpos == info->state->data_file_length)
- info->nextpos+= tmp;
- info->state->data_file_length+= tmp;
- info->update|= HA_STATE_WRITE_AT_END | HA_STATE_EXTEND_BLOCK;
- length+=tmp;
- }
- else if (length < MI_MAX_BLOCK_LENGTH - MI_MIN_BLOCK_LENGTH)
- {
- /*
- Check if next block is a deleted block
- Above we have MI_MIN_BLOCK_LENGTH to avoid the problem where
- the next block is so small it can't be splited which could
- casue problems
- */
- MI_BLOCK_INFO del_block;
- del_block.second_read=0;
- if (_mi_get_block_info(&del_block,info->dfile,
- block_info.filepos + block_info.block_len) &
- BLOCK_DELETED)
- {
- /* Use; Unlink it and extend the current block */
- DBUG_PRINT("info",("Extending current block"));
- if (unlink_deleted_block(info,&del_block))
- goto err;
- if ((length+=del_block.block_len) > MI_MAX_BLOCK_LENGTH)
- {
- /*
- New block was too big, link overflow part back to
- delete list
- */
- my_off_t next_pos;
- ulong rest_length= length-MI_MAX_BLOCK_LENGTH;
- set_if_bigger(rest_length, MI_MIN_BLOCK_LENGTH);
- next_pos= del_block.filepos+ del_block.block_len - rest_length;
- if (update_backward_delete_link(info, info->s->state.dellink,
- next_pos))
- DBUG_RETURN(1);
- /* create delete link for data that didn't fit into the page */
- del_block.header[0]=0;
- mi_int3store(del_block.header+1, rest_length);
- mi_sizestore(del_block.header+4,info->s->state.dellink);
- bfill(del_block.header+12,8,255);
- if (my_pwrite(info->dfile,(byte*) del_block.header,20, next_pos,
- MYF(MY_NABP)))
- DBUG_RETURN(1);
- info->s->state.dellink= next_pos;
- info->s->state.split++;
- info->state->del++;
- info->state->empty+= rest_length;
- length-= rest_length;
- }
- }
- }
- }
- }
- else
- {
- if (_mi_find_writepos(info,reclength,&filepos,&length))
- goto err;
- }
- if (_mi_write_part_record(info,filepos,length,block_info.next_filepos,
- &record,&reclength,&flag))
- goto err;
- if ((filepos=block_info.next_filepos) == HA_OFFSET_ERROR)
- {
- /* Start writing data on deleted blocks */
- filepos=info->s->state.dellink;
- }
- }
- if (block_info.next_filepos != HA_OFFSET_ERROR)
- if (delete_dynamic_record(info,block_info.next_filepos,1))
- goto err;
- DBUG_RETURN(0);
- err:
- DBUG_RETURN(1);
- }
- /* Pack a record. Return new reclength */
- uint _mi_rec_pack(MI_INFO *info, register byte *to, register const byte *from)
- {
- uint length,new_length,flag,bit,i;
- char *pos,*end,*startpos,*packpos;
- enum en_fieldtype type;
- reg3 MI_COLUMNDEF *rec;
- MI_BLOB *blob;
- DBUG_ENTER("_mi_rec_pack");
- flag=0 ; bit=1;
- startpos=packpos=to; to+= info->s->base.pack_bits; blob=info->blobs;
- rec=info->s->rec;
- for (i=info->s->base.fields ; i-- > 0; from+= length,rec++)
- {
- length=(uint) rec->length;
- if ((type = (enum en_fieldtype) rec->type) != FIELD_NORMAL)
- {
- if (type == FIELD_BLOB)
- {
- if (!blob->length)
- flag|=bit;
- else
- {
- char *temp_pos;
- size_t tmp_length=length-mi_portable_sizeof_char_ptr;
- memcpy((byte*) to,from,tmp_length);
- memcpy_fixed(&temp_pos,from+tmp_length,sizeof(char*));
- memcpy(to+tmp_length,temp_pos,(size_t) blob->length);
- to+=tmp_length+blob->length;
- }
- blob++;
- }
- else if (type == FIELD_SKIP_ZERO)
- {
- if (memcmp((byte*) from,zero_string,length) == 0)
- flag|=bit;
- else
- {
- memcpy((byte*) to,from,(size_t) length); to+=length;
- }
- }
- else if (type == FIELD_SKIP_ENDSPACE ||
- type == FIELD_SKIP_PRESPACE)
- {
- pos= (byte*) from; end= (byte*) from + length;
- if (type == FIELD_SKIP_ENDSPACE)
- { /* Pack trailing spaces */
- while (end > from && *(end-1) == ' ')
- end--;
- }
- else
- { /* Pack pref-spaces */
- while (pos < end && *pos == ' ')
- pos++;
- }
- new_length=(uint) (end-pos);
- if (new_length +1 + test(rec->length > 255 && new_length > 127)
- < length)
- {
- if (rec->length > 255 && new_length > 127)
- {
- to[0]=(char) ((new_length & 127)+128);
- to[1]=(char) (new_length >> 7);
- to+=2;
- }
- else
- *to++= (char) new_length;
- memcpy((byte*) to,pos,(size_t) new_length); to+=new_length;
- flag|=bit;
- }
- else
- {
- memcpy(to,from,(size_t) length); to+=length;
- }
- }
- else if (type == FIELD_VARCHAR)
- {
- uint tmp_length=uint2korr(from);
- store_key_length_inc(to,tmp_length);
- memcpy(to,from+2,tmp_length);
- to+=tmp_length;
- continue;
- }
- else
- {
- memcpy(to,from,(size_t) length); to+=length;
- continue; /* Normal field */
- }
- if ((bit= bit << 1) >= 256)
- {
- *packpos++ = (char) (uchar) flag;
- bit=1; flag=0;
- }
- }
- else
- {
- memcpy(to,from,(size_t) length); to+=length;
- }
- }
- if (bit != 1)
- *packpos= (char) (uchar) flag;
- if (info->s->calc_checksum)
- *to++=(char) info->checksum;
- DBUG_PRINT("exit",("packed length: %d",(int) (to-startpos)));
- DBUG_RETURN((uint) (to-startpos));
- } /* _mi_rec_pack */
- /*
- Check if a record was correctly packed. Used only by myisamchk
- Returns 0 if record is ok.
- */
- my_bool _mi_rec_check(MI_INFO *info,const char *record, byte *rec_buff,
- ulong packed_length, my_bool with_checksum)
- {
- uint length,new_length,flag,bit,i;
- char *pos,*end,*packpos,*to;
- enum en_fieldtype type;
- reg3 MI_COLUMNDEF *rec;
- DBUG_ENTER("_mi_rec_check");
- packpos=rec_buff; to= rec_buff+info->s->base.pack_bits;
- rec=info->s->rec;
- flag= *packpos; bit=1;
- for (i=info->s->base.fields ; i-- > 0; record+= length, rec++)
- {
- length=(uint) rec->length;
- if ((type = (enum en_fieldtype) rec->type) != FIELD_NORMAL)
- {
- if (type == FIELD_BLOB)
- {
- uint blob_length=
- _mi_calc_blob_length(length-mi_portable_sizeof_char_ptr,record);
- if (!blob_length && !(flag & bit))
- goto err;
- if (blob_length)
- to+=length - mi_portable_sizeof_char_ptr+ blob_length;
- }
- else if (type == FIELD_SKIP_ZERO)
- {
- if (memcmp((byte*) record,zero_string,length) == 0)
- {
- if (!(flag & bit))
- goto err;
- }
- else
- to+=length;
- }
- else if (type == FIELD_SKIP_ENDSPACE ||
- type == FIELD_SKIP_PRESPACE)
- {
- pos= (byte*) record; end= (byte*) record + length;
- if (type == FIELD_SKIP_ENDSPACE)
- { /* Pack trailing spaces */
- while (end > record && *(end-1) == ' ')
- end--;
- }
- else
- { /* Pack pre-spaces */
- while (pos < end && *pos == ' ')
- pos++;
- }
- new_length=(uint) (end-pos);
- if (new_length +1 + test(rec->length > 255 && new_length > 127)
- < length)
- {
- if (!(flag & bit))
- goto err;
- if (rec->length > 255 && new_length > 127)
- {
- if (to[0] != (char) ((new_length & 127)+128) ||
- to[1] != (char) (new_length >> 7))
- goto err;
- to+=2;
- }
- else if (*to++ != (char) new_length)
- goto err;
- to+=new_length;
- }
- else
- to+=length;
- }
- else if (type == FIELD_VARCHAR)
- {
- uint tmp_length=uint2korr(record);
- to+=get_pack_length(tmp_length)+tmp_length;
- continue;
- }
- else
- {
- to+=length;
- continue; /* Normal field */
- }
- if ((bit= bit << 1) >= 256)
- {
- flag= *++packpos;
- bit=1;
- }
- }
- else
- {
- to+=length;
- }
- }
- if (packed_length != (uint) (to - rec_buff) + test(info->s->calc_checksum) ||
- (bit != 1 && (flag & ~(bit - 1))))
- goto err;
- if (with_checksum && ((uchar) info->checksum != (uchar) *to))
- {
- DBUG_PRINT("error",("wrong checksum for row"));
- goto err;
- }
- DBUG_RETURN(0);
- err:
- DBUG_RETURN(1);
- }
- /* Unpacks a record */
- /* Returns -1 and my_errno =HA_ERR_RECORD_DELETED if reclength isn't */
- /* right. Returns reclength (>0) if ok */
- ulong _mi_rec_unpack(register MI_INFO *info, register byte *to, byte *from,
- ulong found_length)
- {
- uint flag,bit,length,rec_length,min_pack_length;
- enum en_fieldtype type;
- byte *from_end,*to_end,*packpos;
- reg3 MI_COLUMNDEF *rec,*end_field;
- DBUG_ENTER("_mi_rec_unpack");
- to_end=to + info->s->base.reclength;
- from_end=from+found_length;
- flag= (uchar) *from; bit=1; packpos=from;
- if (found_length < info->s->base.min_pack_length)
- goto err;
- from+= info->s->base.pack_bits;
- min_pack_length=info->s->base.min_pack_length - info->s->base.pack_bits;
- for (rec=info->s->rec , end_field=rec+info->s->base.fields ;
- rec < end_field ; to+= rec_length, rec++)
- {
- rec_length=rec->length;
- if ((type = (enum en_fieldtype) rec->type) != FIELD_NORMAL &&
- (type != FIELD_CHECK))
- {
- if (type == FIELD_VARCHAR)
- {
- get_key_length(length,from);
- if (length > rec_length-2)
- goto err;
- int2store(to,length);
- memcpy(to+2,from,length);
- from+=length;
- continue;
- }
- if (flag & bit)
- {
- if (type == FIELD_BLOB || type == FIELD_SKIP_ZERO)
- bzero((byte*) to,rec_length);
- else if (type == FIELD_SKIP_ENDSPACE ||
- type == FIELD_SKIP_PRESPACE)
- {
- if (rec->length > 255 && *from & 128)
- {
- if (from + 1 >= from_end)
- goto err;
- length= (*from & 127)+ ((uint) (uchar) *(from+1) << 7); from+=2;
- }
- else
- {
- if (from == from_end)
- goto err;
- length= (uchar) *from++;
- }
- min_pack_length--;
- if (length >= rec_length ||
- min_pack_length + length > (uint) (from_end - from))
- goto err;
- if (type == FIELD_SKIP_ENDSPACE)
- {
- memcpy(to,(byte*) from,(size_t) length);
- bfill((byte*) to+length,rec_length-length,' ');
- }
- else
- {
- bfill((byte*) to,rec_length-length,' ');
- memcpy(to+rec_length-length,(byte*) from,(size_t) length);
- }
- from+=length;
- }
- }
- else if (type == FIELD_BLOB)
- {
- uint size_length=rec_length- mi_portable_sizeof_char_ptr;
- ulong blob_length=_mi_calc_blob_length(size_length,from);
- if ((ulong) (from_end-from) - size_length < blob_length ||
- min_pack_length > (uint) (from_end -(from+size_length+blob_length)))
- goto err;
- memcpy((byte*) to,(byte*) from,(size_t) size_length);
- from+=size_length;
- memcpy_fixed((byte*) to+size_length,(byte*) &from,sizeof(char*));
- from+=blob_length;
- }
- else
- {
- if (type == FIELD_SKIP_ENDSPACE || type == FIELD_SKIP_PRESPACE)
- min_pack_length--;
- if (min_pack_length + rec_length > (uint) (from_end - from))
- goto err;
- memcpy(to,(byte*) from,(size_t) rec_length); from+=rec_length;
- }
- if ((bit= bit << 1) >= 256)
- {
- flag= (uchar) *++packpos; bit=1;
- }
- }
- else
- {
- if (min_pack_length > (uint) (from_end - from))
- goto err;
- min_pack_length-=rec_length;
- memcpy(to,(byte*) from,(size_t) rec_length); from+=rec_length;
- }
- }
- if (info->s->calc_checksum)
- from++;
- if (to == to_end && from == from_end && (bit == 1 || !(flag & ~(bit-1))))
- DBUG_RETURN(found_length);
- err:
- my_errno=HA_ERR_RECORD_DELETED;
- DBUG_PRINT("error",("to_end: %lx -> %lx from_end: %lx -> %lx",
- to,to_end,from,from_end));
- DBUG_DUMP("from",(byte*) info->rec_buff,info->s->base.min_pack_length);
- DBUG_RETURN(MY_FILE_ERROR);
- } /* _mi_rec_unpack */
- /* Calc length of blob. Update info in blobs->length */
- ulong _my_calc_total_blob_length(MI_INFO *info, const byte *record)
- {
- ulong length;
- MI_BLOB *blob,*end;
- for (length=0, blob= info->blobs, end=blob+info->s->base.blobs ;
- blob != end;
- blob++)
- {
- blob->length=_mi_calc_blob_length(blob->pack_length,record + blob->offset);
- length+=blob->length;
- }
- return length;
- }
- ulong _mi_calc_blob_length(uint length, const byte *pos)
- {
- switch (length) {
- case 1:
- return (uint) (uchar) *pos;
- case 2:
- return (uint) uint2korr(pos);
- case 3:
- return uint3korr(pos);
- case 4:
- return uint4korr(pos);
- default:
- break;
- }
- return 0; /* Impossible */
- }
- void _my_store_blob_length(byte *pos,uint pack_length,uint length)
- {
- switch (pack_length) {
- case 1:
- *pos= (uchar) length;
- break;
- case 2:
- int2store(pos,length);
- break;
- case 3:
- int3store(pos,length);
- break;
- case 4:
- int4store(pos,length);
- default:
- break;
- }
- return;
- }
- /* Read record from datafile */
- /* Returns 0 if ok, -1 if error */
- int _mi_read_dynamic_record(MI_INFO *info, my_off_t filepos, byte *buf)
- {
- int flag;
- uint b_type,left_length;
- byte *to;
- MI_BLOCK_INFO block_info;
- File file;
- DBUG_ENTER("mi_read_dynamic_record");
- if (filepos != HA_OFFSET_ERROR)
- {
- LINT_INIT(to);
- LINT_INIT(left_length);
- file=info->dfile;
- block_info.next_filepos=filepos; /* for easyer loop */
- flag=block_info.second_read=0;
- do
- {
- if (info->opt_flag & WRITE_CACHE_USED &&
- info->rec_cache.pos_in_file <= block_info.next_filepos &&
- flush_io_cache(&info->rec_cache))
- goto err;
- info->rec_cache.seek_not_done=1;
- if ((b_type=_mi_get_block_info(&block_info,file,
- block_info.next_filepos))
- & (BLOCK_DELETED | BLOCK_ERROR | BLOCK_SYNC_ERROR |
- BLOCK_FATAL_ERROR))
- {
- if (b_type & (BLOCK_SYNC_ERROR | BLOCK_DELETED))
- my_errno=HA_ERR_RECORD_DELETED;
- goto err;
- }
- if (flag == 0) /* First block */
- {
- flag=1;
- if (block_info.rec_len > (uint) info->s->base.max_pack_length)
- goto panic;
- if (info->s->base.blobs)
- {
- if (!(to=mi_alloc_rec_buff(info, block_info.rec_len,
- &info->rec_buff)))
- goto err;
- }
- else
- to= info->rec_buff;
- left_length=block_info.rec_len;
- }
- if (left_length < block_info.data_len || ! block_info.data_len)
- goto panic; /* Wrong linked record */
- if (my_pread(file,(byte*) to,block_info.data_len,block_info.filepos,
- MYF(MY_NABP)))
- goto panic;
- left_length-=block_info.data_len;
- to+=block_info.data_len;
- } while (left_length);
- info->update|= HA_STATE_AKTIV; /* We have a aktive record */
- fast_mi_writeinfo(info);
- DBUG_RETURN(_mi_rec_unpack(info,buf,info->rec_buff,block_info.rec_len) !=
- MY_FILE_ERROR ? 0 : -1);
- }
- fast_mi_writeinfo(info);
- DBUG_RETURN(-1); /* Wrong data to read */
- panic:
- my_errno=HA_ERR_WRONG_IN_RECORD;
- err:
- VOID(_mi_writeinfo(info,0));
- DBUG_RETURN(-1);
- }
- /* compare unique constraint between stored rows */
- int _mi_cmp_dynamic_unique(MI_INFO *info, MI_UNIQUEDEF *def,
- const byte *record, my_off_t pos)
- {
- byte *rec_buff,*old_record;
- int error;
- DBUG_ENTER("_mi_cmp_dynamic_unique");
- if (!(old_record=my_alloca(info->s->base.reclength)))
- DBUG_RETURN(1);
- /* Don't let the compare destroy blobs that may be in use */
- rec_buff=info->rec_buff;
- if (info->s->base.blobs)
- info->rec_buff=0;
- error=_mi_read_dynamic_record(info,pos,old_record);
- if (!error)
- error=mi_unique_comp(def, record, old_record, def->null_are_equal);
- if (info->s->base.blobs)
- {
- my_free(mi_get_rec_buff_ptr(info, info->rec_buff), MYF(MY_ALLOW_ZERO_PTR));
- info->rec_buff=rec_buff;
- }
- my_afree(old_record);
- DBUG_RETURN(error);
- }
- /* Compare of record one disk with packed record in memory */
- int _mi_cmp_dynamic_record(register MI_INFO *info, register const byte *record)
- {
- uint flag,reclength,b_type;
- my_off_t filepos;
- byte *buffer;
- MI_BLOCK_INFO block_info;
- DBUG_ENTER("_mi_cmp_dynamic_record");
- /* We are going to do changes; dont let anybody disturb */
- dont_break(); /* Dont allow SIGHUP or SIGINT */
- if (info->opt_flag & WRITE_CACHE_USED)
- {
- info->update&= ~(HA_STATE_WRITE_AT_END | HA_STATE_EXTEND_BLOCK);
- if (flush_io_cache(&info->rec_cache))
- DBUG_RETURN(-1);
- }
- info->rec_cache.seek_not_done=1;
- /* If nobody have touched the database we don't have to test rec */
- buffer=info->rec_buff;
- if ((info->opt_flag & READ_CHECK_USED))
- { /* If check isn't disabled */
- if (info->s->base.blobs)
- {
- if (!(buffer=(byte*) my_alloca(info->s->base.pack_reclength+
- _my_calc_total_blob_length(info,record))))
- DBUG_RETURN(-1);
- }
- reclength=_mi_rec_pack(info,buffer,record);
- record= buffer;
- filepos=info->lastpos;
- flag=block_info.second_read=0;
- block_info.next_filepos=filepos;
- while (reclength > 0)
- {
- if ((b_type=_mi_get_block_info(&block_info,info->dfile,
- block_info.next_filepos))
- & (BLOCK_DELETED | BLOCK_ERROR | BLOCK_SYNC_ERROR |
- BLOCK_FATAL_ERROR))
- {
- if (b_type & (BLOCK_SYNC_ERROR | BLOCK_DELETED))
- my_errno=HA_ERR_RECORD_CHANGED;
- goto err;
- }
- if (flag == 0) /* First block */
- {
- flag=1;
- if (reclength != block_info.rec_len)
- {
- my_errno=HA_ERR_RECORD_CHANGED;
- goto err;
- }
- } else if (reclength < block_info.data_len)
- {
- my_errno=HA_ERR_WRONG_IN_RECORD;
- goto err;
- }
- reclength-=block_info.data_len;
- if (_mi_cmp_buffer(info->dfile,record,block_info.filepos,
- block_info.data_len))
- {
- my_errno=HA_ERR_RECORD_CHANGED;
- goto err;
- }
- flag=1;
- record+=block_info.data_len;
- }
- }
- my_errno=0;
- err:
- if (buffer != info->rec_buff)
- my_afree((gptr) buffer);
- DBUG_RETURN(my_errno);
- }
- /* Compare file to buffert */
- static int _mi_cmp_buffer(File file, const byte *buff, my_off_t filepos,
- uint length)
- {
- uint next_length;
- char temp_buff[IO_SIZE*2];
- DBUG_ENTER("_mi_cmp_buffer");
- next_length= IO_SIZE*2 - (uint) (filepos & (IO_SIZE-1));
- while (length > IO_SIZE*2)
- {
- if (my_pread(file,temp_buff,next_length,filepos, MYF(MY_NABP)) ||
- memcmp((byte*) buff,temp_buff,next_length))
- goto err;
- filepos+=next_length;
- buff+=next_length;
- length-= next_length;
- next_length=IO_SIZE*2;
- }
- if (my_pread(file,temp_buff,length,filepos,MYF(MY_NABP)))
- goto err;
- DBUG_RETURN(memcmp((byte*) buff,temp_buff,length));
- err:
- DBUG_RETURN(1);
- }
- int _mi_read_rnd_dynamic_record(MI_INFO *info, byte *buf,
- register my_off_t filepos,
- my_bool skip_deleted_blocks)
- {
- int flag,info_read,save_errno;
- uint left_len,b_type;
- byte *to;
- MI_BLOCK_INFO block_info;
- MYISAM_SHARE *share=info->s;
- DBUG_ENTER("_mi_read_rnd_dynamic_record");
- info_read=0;
- LINT_INIT(to);
- if (info->lock_type == F_UNLCK)
- {
- #ifndef UNSAFE_LOCKING
- if (share->tot_locks == 0)
- {
- if (my_lock(share->kfile,F_RDLCK,0L,F_TO_EOF,
- MYF(MY_SEEK_NOT_DONE) | info->lock_wait))
- DBUG_RETURN(my_errno);
- }
- #else
- info->tmp_lock_type=F_RDLCK;
- #endif
- }
- else
- info_read=1; /* memory-keyinfoblock is ok */
- flag=block_info.second_read=0;
- left_len=1;
- do
- {
- if (filepos >= info->state->data_file_length)
- {
- if (!info_read)
- { /* Check if changed */
- info_read=1;
- info->rec_cache.seek_not_done=1;
- if (mi_state_info_read_dsk(share->kfile,&share->state,1))
- goto panic;
- }
- if (filepos >= info->state->data_file_length)
- {
- my_errno= HA_ERR_END_OF_FILE;
- goto err;
- }
- }
- if (info->opt_flag & READ_CACHE_USED)
- {
- if (_mi_read_cache(&info->rec_cache,(byte*) block_info.header,filepos,
- sizeof(block_info.header),
- (!flag && skip_deleted_blocks ? READING_NEXT : 0) |
- READING_HEADER))
- goto panic;
- b_type=_mi_get_block_info(&block_info,-1,filepos);
- }
- else
- {
- if (info->opt_flag & WRITE_CACHE_USED &&
- info->rec_cache.pos_in_file <= filepos &&
- flush_io_cache(&info->rec_cache))
- DBUG_RETURN(my_errno);
- info->rec_cache.seek_not_done=1;
- b_type=_mi_get_block_info(&block_info,info->dfile,filepos);
- }
- if (b_type & (BLOCK_DELETED | BLOCK_ERROR | BLOCK_SYNC_ERROR |
- BLOCK_FATAL_ERROR))
- {
- if ((b_type & (BLOCK_DELETED | BLOCK_SYNC_ERROR))
- && skip_deleted_blocks)
- {
- filepos=block_info.filepos+block_info.block_len;
- block_info.second_read=0;
- continue; /* Search after next_record */
- }
- if (b_type & (BLOCK_DELETED | BLOCK_SYNC_ERROR))
- {
- my_errno=HA_ERR_RECORD_DELETED;
- info->lastpos=block_info.filepos;
- info->nextpos=block_info.filepos+block_info.block_len;
- }
- goto err;
- }
- if (flag == 0) /* First block */
- {
- if (block_info.rec_len > (uint) share->base.max_pack_length)
- goto panic;
- info->lastpos=filepos;
- if (share->base.blobs)
- {
- if (!(to= mi_alloc_rec_buff(info, block_info.rec_len,
- &info->rec_buff)))
- goto err;
- }
- else
- to= info->rec_buff;
- left_len=block_info.rec_len;
- }
- if (left_len < block_info.data_len)
- goto panic; /* Wrong linked record */
- /* copy information that is already read */
- {
- uint offset=(uint) (block_info.filepos - filepos);
- uint tmp_length= (sizeof(block_info.header) - offset);
- filepos=block_info.filepos;
- if (tmp_length > block_info.data_len)
- tmp_length= block_info.data_len;
- if (tmp_length)
- {
- memcpy((byte*) to, block_info.header+offset,tmp_length);
- block_info.data_len-=tmp_length;
- left_len-=tmp_length;
- to+=tmp_length;
- filepos+=tmp_length;
- }
- }
- /* read rest of record from file */
- if (block_info.data_len)
- {
- if (info->opt_flag & READ_CACHE_USED)
- {
- if (_mi_read_cache(&info->rec_cache,(byte*) to,filepos,
- block_info.data_len,
- (!flag && skip_deleted_blocks) ? READING_NEXT :0))
- goto panic;
- }
- else
- {
- /* VOID(my_seek(info->dfile,filepos,MY_SEEK_SET,MYF(0))); */
- if (my_read(info->dfile,(byte*) to,block_info.data_len,MYF(MY_NABP)))
- {
- if (my_errno == -1)
- my_errno= HA_ERR_WRONG_IN_RECORD; /* Unexpected end of file */
- goto err;
- }
- }
- }
- if (flag++ == 0)
- {
- info->nextpos=block_info.filepos+block_info.block_len;
- skip_deleted_blocks=0;
- }
- left_len-=block_info.data_len;
- to+=block_info.data_len;
- filepos=block_info.next_filepos;
- } while (left_len);
- info->update|= HA_STATE_AKTIV | HA_STATE_KEY_CHANGED;
- fast_mi_writeinfo(info);
- if (_mi_rec_unpack(info,buf,info->rec_buff,block_info.rec_len) !=
- MY_FILE_ERROR)
- DBUG_RETURN(0);
- DBUG_RETURN(my_errno); /* Wrong record */
- panic:
- my_errno=HA_ERR_WRONG_IN_RECORD; /* Something is fatal wrong */
- err:
- save_errno=my_errno;
- VOID(_mi_writeinfo(info,0));
- DBUG_RETURN(my_errno=save_errno);
- }
- /* Read and process header from a dynamic-record-file */
- uint _mi_get_block_info(MI_BLOCK_INFO *info, File file, my_off_t filepos)
- {
- uint return_val=0;
- uchar *header=info->header;
- if (file >= 0)
- {
- VOID(my_seek(file,filepos,MY_SEEK_SET,MYF(0)));
- if (my_read(file,(char*) header,sizeof(info->header),MYF(0)) !=
- sizeof(info->header))
- goto err;
- }
- DBUG_DUMP("header",(byte*) header,MI_BLOCK_INFO_HEADER_LENGTH);
- if (info->second_read)
- {
- if (info->header[0] <= 6 || info->header[0] == 13)
- return_val=BLOCK_SYNC_ERROR;
- }
- else
- {
- if (info->header[0] > 6 && info->header[0] != 13)
- return_val=BLOCK_SYNC_ERROR;
- }
- info->next_filepos= HA_OFFSET_ERROR; /* Dummy if no next block */
- switch (info->header[0]) {
- case 0:
- if ((info->block_len=(uint) mi_uint3korr(header+1)) <
- MI_MIN_BLOCK_LENGTH ||
- (info->block_len & (MI_DYN_ALIGN_SIZE -1)))
- goto err;
- info->filepos=filepos;
- info->next_filepos=mi_sizekorr(header+4);
- info->prev_filepos=mi_sizekorr(header+12);
- #if SIZEOF_OFF_T == 4
- if ((mi_uint4korr(header+4) != 0 &&
- (mi_uint4korr(header+4) != (ulong) ~0 ||
- info->next_filepos != (ulong) ~0)) ||
- (mi_uint4korr(header+12) != 0 &&
- (mi_uint4korr(header+12) != (ulong) ~0 ||
- info->prev_filepos != (ulong) ~0)))
- goto err;
- #endif
- return return_val | BLOCK_DELETED; /* Deleted block */
- case 1:
- info->rec_len=info->data_len=info->block_len=mi_uint2korr(header+1);
- info->filepos=filepos+3;
- return return_val | BLOCK_FIRST | BLOCK_LAST;
- case 2:
- info->rec_len=info->data_len=info->block_len=mi_uint3korr(header+1);
- info->filepos=filepos+4;
- return return_val | BLOCK_FIRST | BLOCK_LAST;
- case 13:
- info->rec_len=mi_uint4korr(header+1);
- info->block_len=info->data_len=mi_uint3korr(header+5);
- info->next_filepos=mi_sizekorr(header+8);
- info->second_read=1;
- info->filepos=filepos+16;
- return return_val | BLOCK_FIRST;
- case 3:
- info->rec_len=info->data_len=mi_uint2korr(header+1);
- info->block_len=info->rec_len+ (uint) header[3];
- info->filepos=filepos+4;
- return return_val | BLOCK_FIRST | BLOCK_LAST;
- case 4:
- info->rec_len=info->data_len=mi_uint3korr(header+1);
- info->block_len=info->rec_len+ (uint) header[4];
- info->filepos=filepos+5;
- return return_val | BLOCK_FIRST | BLOCK_LAST;
- case 5:
- info->rec_len=mi_uint2korr(header+1);
- info->block_len=info->data_len=mi_uint2korr(header+3);
- info->next_filepos=mi_sizekorr(header+5);
- info->second_read=1;
- info->filepos=filepos+13;
- return return_val | BLOCK_FIRST;
- case 6:
- info->rec_len=mi_uint3korr(header+1);
- info->block_len=info->data_len=mi_uint3korr(header+4);
- info->next_filepos=mi_sizekorr(header+7);
- info->second_read=1;
- info->filepos=filepos+15;
- return return_val | BLOCK_FIRST;
- /* The following blocks are identical to 1-6 without rec_len */
- case 7:
- info->data_len=info->block_len=mi_uint2korr(header+1);
- info->filepos=filepos+3;
- return return_val | BLOCK_LAST;
- case 8:
- info->data_len=info->block_len=mi_uint3korr(header+1);
- info->filepos=filepos+4;
- return return_val | BLOCK_LAST;
- case 9:
- info->data_len=mi_uint2korr(header+1);
- info->block_len=info->data_len+ (uint) header[3];
- info->filepos=filepos+4;
- return return_val | BLOCK_LAST;
- case 10:
- info->data_len=mi_uint3korr(header+1);
- info->block_len=info->data_len+ (uint) header[4];
- info->filepos=filepos+5;
- return return_val | BLOCK_LAST;
- case 11:
- info->data_len=info->block_len=mi_uint2korr(header+1);
- info->next_filepos=mi_sizekorr(header+3);
- info->second_read=1;
- info->filepos=filepos+11;
- return return_val;
- case 12:
- info->data_len=info->block_len=mi_uint3korr(header+1);
- info->next_filepos=mi_sizekorr(header+4);
- info->second_read=1;
- info->filepos=filepos+12;
- return return_val;
- }
- err:
- my_errno=HA_ERR_WRONG_IN_RECORD; /* Garbage */
- return BLOCK_ERROR;
- }