_dynrec.c
上传用户:romrleung
上传日期:2022-05-23
资源大小:18897k
文件大小:33k
- /* 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 */
- #include "isamdef.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(N_INFO *info,const byte *record,
- uint reclength);
- static int _nisam_find_writepos(N_INFO *info,uint reclength,ulong *filepos,
- uint *length);
- static int update_dynamic_record(N_INFO *info,ulong filepos,byte *record,
- uint reclength);
- static int delete_dynamic_record(N_INFO *info,ulong filepos,
- uint second_read);
- static int _nisam_cmp_buffer(File file, const byte *buff, ulong 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 N_INFO */
- int _nisam_write_dynamic_record(N_INFO *info, const byte *record)
- {
- uint reclength=_nisam_rec_pack(info,info->rec_buff,record);
- return (write_dynamic_record(info,info->rec_buff,reclength));
- }
- int _nisam_update_dynamic_record(N_INFO *info, ulong pos, const byte *record)
- {
- uint length=_nisam_rec_pack(info,info->rec_buff,record);
- return (update_dynamic_record(info,pos,info->rec_buff,length));
- }
- int _nisam_write_blob_record(N_INFO *info, const byte *record)
- {
- byte *rec_buff;
- int error;
- uint reclength,extra;
- extra=ALIGN_SIZE(MAX_DYN_BLOCK_HEADER)+N_SPLITT_LENGTH+
- DYN_DELETE_BLOCK_HEADER;
- if (!(rec_buff=(byte*) my_alloca(info->s->base.pack_reclength+
- _calc_total_blob_length(info,record)+
- extra)))
- return(-1);
- reclength=_nisam_rec_pack(info,rec_buff+ALIGN_SIZE(MAX_DYN_BLOCK_HEADER),
- record);
- error=write_dynamic_record(info,rec_buff+ALIGN_SIZE(MAX_DYN_BLOCK_HEADER),
- reclength);
- my_afree(rec_buff);
- return(error);
- }
- int _nisam_update_blob_record(N_INFO *info, ulong pos, const byte *record)
- {
- byte *rec_buff;
- int error;
- uint reclength,extra;
- extra=ALIGN_SIZE(MAX_DYN_BLOCK_HEADER)+N_SPLITT_LENGTH+
- DYN_DELETE_BLOCK_HEADER;
- if (!(rec_buff=(byte*) my_alloca(info->s->base.pack_reclength+
- _calc_total_blob_length(info,record)+
- extra)))
- return(-1);
- reclength=_nisam_rec_pack(info,rec_buff+ALIGN_SIZE(MAX_DYN_BLOCK_HEADER),
- record);
- error=update_dynamic_record(info,pos,
- rec_buff+ALIGN_SIZE(MAX_DYN_BLOCK_HEADER),
- reclength);
- my_afree(rec_buff);
- return(error);
- }
- int _nisam_delete_dynamic_record(N_INFO *info)
- {
- return delete_dynamic_record(info,info->lastpos,0);
- }
- /* Write record to data-file */
- static int write_dynamic_record(N_INFO *info, const byte *record,
- uint reclength)
- {
- int flag;
- uint length;
- ulong filepos;
- DBUG_ENTER("write_dynamic_record");
- flag=0;
- while (reclength)
- {
- if (_nisam_find_writepos(info,reclength,&filepos,&length))
- goto err;
- if (_nisam_write_part_record(info,filepos,length,info->s->state.dellink,
- (byte**) &record,&reclength,&flag))
- goto err;
- }
- DBUG_RETURN(0);
- err:
- DBUG_RETURN(1);
- }
- /* Get a block for data ; The given data-area must be used !! */
- static int _nisam_find_writepos(N_INFO *info,
- uint reclength, /* record length */
- ulong *filepos, /* Return file pos */
- uint *length) /* length of block at filepos */
- {
- BLOCK_INFO block_info;
- DBUG_ENTER("_nisam_find_writepos");
- if (info->s->state.dellink != NI_POS_ERROR)
- {
- *filepos=info->s->state.dellink;
- block_info.second_read=0;
- info->rec_cache.seek_not_done=1;
- if (!(_nisam_get_block_info(&block_info,info->dfile,
- info->s->state.dellink) & BLOCK_DELETED))
- {
- my_errno=HA_ERR_WRONG_IN_RECORD;
- DBUG_RETURN(-1);
- }
- info->s->state.dellink=block_info.next_filepos;
- info->s->state.del--;
- info->s->state.empty-= block_info.block_len;
- *length= block_info.block_len;
- }
- else
- {
- if (info->s->state.data_file_length > info->s->base.max_data_file_length)
- {
- my_errno=HA_ERR_RECORD_FILE_FULL;
- DBUG_RETURN(-1);
- }
- *filepos=info->s->state.data_file_length; /* New block last */
- if ((*length=reclength+3 + test(reclength > 65532)) <
- info->s->base.min_block_length)
- *length=info->s->base.min_block_length;
- info->s->state.data_file_length+= *length;
- info->s->state.splitt++;
- info->update|=HA_STATE_WRITE_AT_END;
- }
- DBUG_RETURN(0);
- } /* _nisam_find_writepos */
- /* Write a block to datafile */
- int _nisam_write_part_record(N_INFO *info,
- ulong filepos, /* points at empty block */
- uint length, /* length of block */
- ulong next_filepos, /* Next empty block */
- byte **record, /* pointer to record ptr */
- uint *reclength, /* length of *record */
- int *flag) /* *flag == 0 if header */
- {
- uint head_length,res_length,extra_length,long_block,del_length;
- byte *pos,*record_end;
- uchar temp[N_SPLITT_LENGTH+DYN_DELETE_BLOCK_HEADER];
- DBUG_ENTER("_nisam_write_part_record");
- res_length=extra_length=0;
- if (length > *reclength + N_SPLITT_LENGTH)
- { /* Splitt big block */
- res_length=length- *reclength - 3 - N_EXTEND_BLOCK_LENGTH;
- length-= res_length; /* Use this for first part */
- }
- long_block= (length < 65535L && *reclength < 65535L) ? 0 : 1;
- if (length-long_block == *reclength+3 || length == *reclength + 4)
- { /* Exact what we need */
- temp[0]=(uchar) (1+ *flag); /* 1, or 9 */
- if (long_block)
- {
- int3store(temp+1,*reclength);
- }
- else
- {
- int2store(temp+1,*reclength);
- }
- head_length=3+long_block;
- if (length-long_block == *reclength+4)
- {
- length--;
- temp[0]++; /* 2 or 10 */
- extra_length++; /* One empty */
- }
- }
- else if (length-long_block*2 < *reclength+5)
- { /* To short block */
- if (next_filepos == NI_POS_ERROR)
- next_filepos=info->s->state.dellink != NI_POS_ERROR ?
- info->s->state.dellink : info->s->state.data_file_length;
- if (*flag == 0) /* First block */
- {
- head_length=5+4+long_block*2;
- temp[0]=4;
- if (long_block)
- {
- int3store(temp+1,*reclength);
- int3store(temp+4,length-head_length);
- int4store((byte*) temp+7,next_filepos);
- }
- else
- {
- int2store(temp+1,*reclength);
- int2store(temp+3,length-head_length);
- int4store((byte*) temp+5,next_filepos);
- }
- }
- else
- {
- head_length=3+4+long_block;
- temp[0]=12;
- if (long_block)
- {
- int3store(temp+1,length-head_length);
- int4store((byte*) temp+4,next_filepos);
- }
- else
- {
- int2store(temp+1,length-head_length);
- int4store((byte*) temp+3,next_filepos);
- }
- }
- }
- else
- { /* Block with empty info last */
- head_length=5+long_block*2;
- temp[0]= (uchar) (3+ *flag); /* 3 or 11 */
- if (long_block)
- {
- int3store(temp+1,*reclength);
- int3store(temp+4,length-7);
- }
- else
- {
- int2store(temp+1,*reclength);
- int2store(temp+3,length-5);
- }
- extra_length= length- *reclength-head_length;
- length= *reclength+head_length; /* Write only what is needed */
- }
- temp[0]+=(uchar) (long_block*4);
- DBUG_DUMP("header",(byte*) temp,head_length);
- /* Make a long block for one write */
- record_end= *record+length-head_length;
- del_length=(res_length ? 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)
- {
- pos=record_end+extra_length;
- pos[0]= ' ';
- int3store(pos+1,res_length);
- int4store(pos+4,info->s->state.dellink);
- info->s->state.dellink= filepos+length+extra_length;
- info->s->state.del++;
- info->s->state.empty+=res_length;
- info->s->state.splitt++;
- }
- if (info->opt_flag & WRITE_CACHE_USED && info->update & HA_STATE_WRITE_AT_END)
- {
- 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,MYF(MY_NABP | MY_WAIT_IF_FULL)))
- goto err;
- }
- memcpy(record_end,temp,(size_t) (extra_length+del_length));
- *record=record_end;
- *reclength-=(length-head_length);
- *flag=8;
- DBUG_RETURN(0);
- err:
- DBUG_PRINT("exit",("errno: %d",my_errno));
- DBUG_RETURN(1);
- } /*_nisam_write_part_record */
- /* update record from datafile */
- static int update_dynamic_record(N_INFO *info, ulong filepos, byte *record, uint reclength)
- {
- int flag;
- uint error,length;
- 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= NI_POS_ERROR;
- if ((error=_nisam_get_block_info(&block_info,info->dfile,filepos))
- & (BLOCK_DELETED | BLOCK_ERROR | BLOCK_SYNC_ERROR |
- BLOCK_FATAL_ERROR))
- {
- if (!(error & BLOCK_FATAL_ERROR))
- my_errno=HA_ERR_WRONG_IN_RECORD;
- goto err;
- }
- length=(uint) (block_info.filepos-filepos) + block_info.block_len;
- }
- else
- {
- if (_nisam_find_writepos(info,reclength,&filepos,&length))
- goto err;
- }
- if (_nisam_write_part_record(info,filepos,length,block_info.next_filepos,
- &record,&reclength,&flag))
- goto err;
- if ((filepos=block_info.next_filepos) == NI_POS_ERROR)
- filepos=info->s->state.dellink;
- }
- if (block_info.next_filepos != NI_POS_ERROR)
- if (delete_dynamic_record(info,block_info.next_filepos,1))
- goto err;
- DBUG_RETURN(0);
- err:
- DBUG_RETURN(1);
- }
- /* Delete datarecord from database */
- /* info->rec_cache.seek_not_done is updated in cmp_record */
- static int delete_dynamic_record(N_INFO *info, ulong filepos, uint second_read)
- {
- uint length,b_type;
- BLOCK_INFO block_info;
- DBUG_ENTER("delete_dynamic_record");
- block_info.second_read=second_read;
- do
- {
- if ((b_type=_nisam_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) <
- N_MIN_BLOCK_LENGTH)
- {
- my_errno=HA_ERR_WRONG_IN_RECORD;
- DBUG_RETURN(1);
- }
- block_info.header[0]=0;
- length=(uint) (block_info.filepos-filepos) +block_info.block_len;
- int3store(block_info.header+1,length);
- int4store(block_info.header+4,info->s->state.dellink);
- if (my_pwrite(info->dfile,(byte*) block_info.header,8,filepos,
- MYF(MY_NABP)))
- DBUG_RETURN(1);
- info->s->state.dellink = filepos;
- info->s->state.del++;
- info->s->state.empty+=length;
- filepos=block_info.next_filepos;
- } while (!(b_type & BLOCK_LAST));
- DBUG_RETURN(0);
- }
- /* Pack a record. Return new reclength */
- uint _nisam_rec_pack(N_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 N_RECINFO *rec;
- N_BLOB *blob;
- DBUG_ENTER("_nisam_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+= (rec++)->base.length)
- {
- length=(uint) rec->base.length;
- if ((type = (enum en_fieldtype) rec->base.type) != FIELD_NORMAL)
- {
- if (type == FIELD_BLOB)
- {
- if (!blob->length)
- flag|=bit;
- else
- {
- char *temp_pos;
- memcpy((byte*) to,from,(size_t) length);
- memcpy_fixed(&temp_pos,from+length,sizeof(char*));
- memcpy(to+length,temp_pos,(size_t) blob->length);
- to+=length+blob->length;
- }
- blob++;
- from+=sizeof(char*); /* Skip blob-pointer */
- }
- 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->base.length > 255 && new_length > 127)
- < length)
- {
- if (rec->base.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_ZERO)
- continue; /* Don't store this */
- 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;
- DBUG_PRINT("exit",("packed length: %d",(int) (to-startpos)));
- DBUG_RETURN((uint) (to-startpos));
- } /* _nisam_rec_pack */
- /*
- ** Check if a record was correctly packed. Used only by isamchk
- ** Returns 0 if record is ok.
- */
- my_bool _nisam_rec_check(N_INFO *info,const char *from)
- {
- uint length,new_length,flag,bit,i;
- char *pos,*end,*packpos,*to;
- enum en_fieldtype type;
- reg3 N_RECINFO *rec;
- DBUG_ENTER("_nisam_rec_check");
- packpos=info->rec_buff; to= info->rec_buff+info->s->base.pack_bits;
- rec=info->s->rec;
- flag= *packpos; bit=1;
- for (i=info->s->base.fields ; i-- > 0; from+= (rec++)->base.length)
- {
- length=(uint) rec->base.length;
- if ((type = (enum en_fieldtype) rec->base.type) != FIELD_NORMAL)
- {
- if (type == FIELD_BLOB)
- {
- uint blob_length= _calc_blob_length(length,from);
- if (!blob_length && !(flag & bit))
- goto err;
- if (blob_length)
- to+=length+ blob_length;
- from+=sizeof(char*);
- }
- else if (type == FIELD_SKIP_ZERO)
- {
- if (memcmp((byte*) from,zero_string,length) == 0)
- {
- if (!(flag & bit))
- goto err;
- }
- else
- 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 pre-spaces */
- while (pos < end && *pos == ' ')
- pos++;
- }
- new_length=(uint) (end-pos);
- if (new_length +1 + test(rec->base.length > 255 && new_length > 127)
- < length)
- {
- if (!(flag & bit))
- goto err;
- if (rec->base.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_ZERO)
- to+=length; /* Not packed field */
- continue;
- }
- if ((bit= bit << 1) >= 256)
- {
- flag= *++packpos;
- bit=1;
- }
- }
- else
- {
- to+=length;
- }
- }
- if (bit != 1)
- *packpos= (char) (uchar) flag;
- if (info->packed_length == (uint) (to - info->rec_buff) &&
- (bit == 1 || !(flag & ~(bit - 1))))
- 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 */
- uint _nisam_rec_unpack(register N_INFO *info, register byte *to, byte *from,
- uint found_length)
- {
- uint flag,bit,length,rec_length,min_pack_length;
- enum en_fieldtype type;
- byte *from_end,*to_end,*packpos;
- reg3 N_RECINFO *rec,*end_field;
- DBUG_ENTER("_nisam_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->base.length;
- if ((type = (enum en_fieldtype) rec->base.type) != FIELD_NORMAL)
- {
- if (type == FIELD_ZERO)
- continue; /* Skip this */
- if (flag & bit)
- {
- if (type == FIELD_BLOB)
- {
- bzero((byte*) to,rec_length+sizeof(char*));
- to+=sizeof(char*);
- }
- else if (type == FIELD_SKIP_ZERO)
- bzero((byte*) to,rec_length);
- else if (type == FIELD_SKIP_ENDSPACE ||
- type == FIELD_SKIP_PRESPACE)
- {
- if (rec->base.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)
- {
- ulong blob_length=_calc_blob_length(rec_length,from);
- if ((ulong) (from_end-from) - rec_length < blob_length ||
- min_pack_length > (uint) (from_end -(from+rec_length+blob_length)))
- goto err;
- memcpy((byte*) to,(byte*) from,(size_t) rec_length);
- from+=rec_length;
- /* memcpy crasches alpha egcs 1.1.2 */
- bmove((byte*) to+rec_length,(byte*) &from,sizeof(char*));
- from+=blob_length;
- to+=sizeof(char*);
- }
- 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 (to == to_end && from == from_end && (bit == 1 || !(flag & ~(bit-1))))
- DBUG_RETURN((info->packed_length=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);
- } /* _nisam_rec_unpack */
- /* Calc length of blob. Update info in blobs->length */
- uint _calc_total_blob_length(N_INFO *info, const byte *record)
- {
- uint i,length;
- N_BLOB *blob;
- for (i=length=0, blob= info->blobs; i++ < info->s->base.blobs ; blob++)
- {
- blob->length=_calc_blob_length(blob->pack_length,record + blob->offset);
- length+=blob->length;
- }
- return length;
- }
- uint _calc_blob_length(uint length, const byte *pos)
- {
- switch (length) {
- case 1:
- return (uint) (uchar) *pos;
- case 2:
- {
- short j; shortget(j,pos);
- return (uint) (unsigned short) j;
- }
- #ifdef MSDOS
- break; /* skip microsoft warning */
- #endif
- case 3:
- return uint3korr(pos);
- case 4:
- {
- long j; longget(j,pos);
- return (uint) j;
- }
- #ifdef MSDOS
- break;
- #endif
- default:
- break;
- }
- return 0; /* Impossible */
- }
- /* Read record from datafile */
- /* Returns 0 if ok, -1 if error */
- int _nisam_read_dynamic_record(N_INFO *info, ulong filepos, byte *buf)
- {
- int flag;
- uint b_type,left_length;
- byte *to;
- BLOCK_INFO block_info;
- File file;
- DBUG_ENTER("ni_read_dynamic_record");
- if (filepos != NI_POS_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=_nisam_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=fix_rec_buff_for_blob(info,block_info.rec_len)))
- 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 */
- VOID(_nisam_writeinfo(info,0));
- DBUG_RETURN(_nisam_rec_unpack(info,buf,info->rec_buff,block_info.rec_len) !=
- MY_FILE_ERROR ? 0 : -1);
- }
- VOID(_nisam_writeinfo(info,0));
- DBUG_RETURN(-1); /* Wrong data to read */
- panic:
- my_errno=HA_ERR_WRONG_IN_RECORD;
- err:
- VOID(_nisam_writeinfo(info,0));
- DBUG_RETURN(-1);
- }
- byte *fix_rec_buff_for_blob(N_INFO *info, uint length)
- {
- uint extra;
- if (! info->rec_buff || length > info->alloced_rec_buff_length)
- {
- byte *newptr;
- extra=ALIGN_SIZE(MAX_DYN_BLOCK_HEADER)+N_SPLITT_LENGTH+
- DYN_DELETE_BLOCK_HEADER;
- if (!(newptr=(byte*) my_realloc((gptr) info->rec_alloc,length+extra,
- MYF(MY_ALLOW_ZERO_PTR))))
- return newptr;
- info->rec_alloc=newptr;
- info->rec_buff=newptr+ALIGN_SIZE(DYN_DELETE_BLOCK_HEADER);
- info->alloced_rec_buff_length=length;
- }
- return info->rec_buff;
- }
- /* Compare of record one disk with packed record in memory */
- int _nisam_cmp_dynamic_record(register N_INFO *info, register const byte *record)
- {
- uint flag,reclength,b_type;
- ulong filepos;
- byte *buffer;
- BLOCK_INFO block_info;
- DBUG_ENTER("_nisam_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;
- 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+
- _calc_total_blob_length(info,record))))
- DBUG_RETURN(-1);
- }
- reclength=_nisam_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=_nisam_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 (_nisam_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 _nisam_cmp_buffer(File file, const byte *buff, ulong filepos, uint length)
- {
- uint next_length;
- char temp_buff[IO_SIZE*2];
- DBUG_ENTER("_nisam_cmp_buffer");
- VOID(my_seek(file,filepos,MY_SEEK_SET,MYF(0)));
- next_length= IO_SIZE*2 - (uint) (filepos & (IO_SIZE-1));
- while (length > IO_SIZE*2)
- {
- if (my_read(file,temp_buff,next_length,MYF(MY_NABP)))
- goto err;
- if (memcmp((byte*) buff,temp_buff,next_length))
- DBUG_RETURN(1);
- buff+=next_length;
- length-= next_length;
- next_length=IO_SIZE*2;
- }
- if (my_read(file,temp_buff,length,MYF(MY_NABP)))
- goto err;
- DBUG_RETURN(memcmp((byte*) buff,temp_buff,length));
- err:
- DBUG_RETURN(1);
- }
- int _nisam_read_rnd_dynamic_record(N_INFO *info, byte *buf, register ulong filepos, int skipp_deleted_blocks)
- {
- int flag,info_read,fatal_errcode;
- uint left_len,b_type;
- byte *to;
- BLOCK_INFO block_info;
- ISAM_SHARE *share=info->s;
- DBUG_ENTER("_nisam_read_rnd_dynamic_record");
- info_read=0;
- fatal_errcode= -1;
- LINT_INIT(to);
- #ifndef NO_LOCKING
- if (info->lock_type == F_UNLCK)
- {
- #ifndef UNSAFE_LOCKING
- if (share->r_locks == 0 && share->w_locks == 0)
- {
- if (my_lock(share->kfile,F_RDLCK,0L,F_TO_EOF,
- MYF(MY_SEEK_NOT_DONE) | info->lock_wait))
- DBUG_RETURN(fatal_errcode);
- }
- #else
- info->tmp_lock_type=F_RDLCK;
- #endif
- }
- else
- info_read=1; /* memory-keyinfoblock is ok */
- #endif /* !NO_LOCKING */
- flag=block_info.second_read=0;
- left_len=1;
- do
- {
- if (filepos >= share->state.data_file_length)
- {
- #ifndef NO_LOCKING
- if (!info_read)
- { /* Check if changed */
- info_read=1;
- info->rec_cache.seek_not_done=1;
- if (my_pread(share->kfile,(char*) &share->state.header,
- share->state_length, 0L,MYF(MY_NABP)))
- goto err;
- }
- if (filepos >= share->state.data_file_length)
- #endif
- {
- my_errno= HA_ERR_END_OF_FILE;
- goto err;
- }
- }
- if (info->opt_flag & READ_CACHE_USED)
- {
- if (_nisam_read_cache(&info->rec_cache,(byte*) block_info.header,filepos,
- sizeof(block_info.header),
- test(!flag && skipp_deleted_blocks) | 2))
- goto err;
- b_type=_nisam_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(-1);
- info->rec_cache.seek_not_done=1;
- b_type=_nisam_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))
- && skipp_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;
- fatal_errcode=1;
- }
- 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=fix_rec_buff_for_blob(info,block_info.rec_len)))
- 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 */
- if (info->opt_flag & READ_CACHE_USED)
- {
- if (_nisam_read_cache(&info->rec_cache,(byte*) to,block_info.filepos,
- block_info.data_len,
- test(!flag && skipp_deleted_blocks)))
- goto err;
- }
- else
- {
- VOID(my_seek(info->dfile,block_info.filepos,MY_SEEK_SET,MYF(0)));
- if (my_read(info->dfile,(byte*) to,block_info.data_len,MYF(MY_NABP)))
- goto err;
- }
- if (flag++ == 0)
- {
- info->nextpos=block_info.filepos+block_info.block_len;
- skipp_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;
- VOID(_nisam_writeinfo(info,0));
- if (_nisam_rec_unpack(info,buf,info->rec_buff,block_info.rec_len) !=
- MY_FILE_ERROR)
- DBUG_RETURN(0);
- DBUG_RETURN(fatal_errcode); /* Wrong record */
- panic:
- my_errno=HA_ERR_WRONG_IN_RECORD; /* Something is fatal wrong */
- err:
- VOID(_nisam_writeinfo(info,0));
- DBUG_RETURN(fatal_errcode);
- }
- /* Read and process header from a dynamic-record-file */
- uint _nisam_get_block_info(BLOCK_INFO *info, File file, ulong filepos)
- {
- uint return_val=0,length;
- uchar *header=info->header;
- if (file >= 0)
- {
- VOID(my_seek(file,filepos,MY_SEEK_SET,MYF(0)));
- if ((length=my_read(file,(char*) header,BLOCK_INFO_HEADER_LENGTH,MYF(0)))
- == MY_FILE_ERROR)
- return BLOCK_FATAL_ERROR;
- if (length != BLOCK_INFO_HEADER_LENGTH)
- { /* Test if short block */
- if (length < 3)
- {
- my_errno=HA_ERR_WRONG_IN_RECORD; /* Garbage */
- return BLOCK_FATAL_ERROR;
- }
- bzero((byte*) header+length,BLOCK_INFO_HEADER_LENGTH-length);
- }
- }
- DBUG_DUMP("header",(byte*) header,BLOCK_INFO_HEADER_LENGTH);
- if (info->second_read)
- {
- if (info->header[0] <= 8)
- return_val=BLOCK_SYNC_ERROR;
- }
- else
- {
- if (info->header[0] > 8)
- return_val=BLOCK_SYNC_ERROR;
- }
- info->next_filepos= (ulong) NI_POS_ERROR; /* Dummy ifall no next block */
- switch (info->header[0]) {
- case 0:
- if ((info->block_len=(uint) uint3korr(header+1)) < N_MIN_BLOCK_LENGTH)
- return BLOCK_FATAL_ERROR;
- info->filepos=filepos;
- info->next_filepos=uint4korr(header+4);
- if (info->next_filepos == (uint32) ~0) /* Fix for 64 bit long */
- info->next_filepos=NI_POS_ERROR;
- return return_val | BLOCK_DELETED; /* Deleted block */
- case 1:
- info->rec_len=info->data_len=info->block_len=uint2korr(header+1);
- info->filepos=filepos+3;
- return return_val | BLOCK_FIRST | BLOCK_LAST;
- case 2:
- info->block_len=(info->rec_len=info->data_len=uint2korr(header+1))+1;
- info->filepos=filepos+3;
- return return_val | BLOCK_FIRST | BLOCK_LAST;
- case 3:
- info->rec_len=info->data_len=uint2korr(header+1);
- info->block_len=uint2korr(header+3);
- info->filepos=filepos+5;
- return return_val | BLOCK_FIRST | BLOCK_LAST;
- case 4:
- info->rec_len=uint2korr(header+1);
- info->block_len=info->data_len=uint2korr(header+3);
- info->next_filepos=uint4korr(header+5);
- info->second_read=1;
- info->filepos=filepos+9;
- return return_val | BLOCK_FIRST;
- #if defined(_MSC_VER) || !defined(__WIN__)
- case 5:
- info->rec_len=info->data_len=info->block_len=uint3korr(header+1);
- info->filepos=filepos+4;
- return return_val | BLOCK_FIRST | BLOCK_LAST;
- case 6:
- info->block_len=(info->rec_len=info->data_len=uint3korr(header+1))+1;
- info->filepos=filepos+4;
- return return_val | BLOCK_FIRST | BLOCK_LAST;
- case 7:
- info->rec_len=info->data_len=uint3korr(header+1);
- info->block_len=uint3korr(header+4);
- info->filepos=filepos+7;
- return return_val | BLOCK_FIRST | BLOCK_LAST;
- case 8:
- info->rec_len=uint3korr(header+1);
- info->block_len=info->data_len=uint3korr(header+4);
- info->next_filepos=uint4korr(header+7);
- info->second_read=1;
- info->filepos=filepos+11;
- return return_val | BLOCK_FIRST;
- #endif
- case 9:
- info->data_len=info->block_len=uint2korr(header+1);
- info->filepos=filepos+3;
- return return_val | BLOCK_LAST;
- case 10:
- info->block_len=(info->data_len=uint2korr(header+1))+1;
- info->filepos=filepos+3;
- return return_val | BLOCK_LAST;
- case 11:
- info->data_len=uint2korr(header+1);
- info->block_len=uint2korr(header+3);
- info->filepos=filepos+5;
- return return_val | BLOCK_LAST;
- case 12:
- info->data_len=info->block_len=uint2korr(header+1);
- info->next_filepos=uint4korr(header+3);
- info->second_read=1;
- info->filepos=filepos+7;
- return return_val;
- #if defined(_MSC_VER) || !defined(__WIN__)
- case 13:
- info->data_len=info->block_len=uint3korr(header+1);
- info->filepos=filepos+4;
- return return_val | BLOCK_LAST;
- case 14:
- info->block_len=(info->data_len=uint3korr(header+1))+1;
- info->filepos=filepos+4;
- return return_val | BLOCK_LAST;
- case 15:
- info->data_len=uint3korr(header+1);
- info->block_len=uint3korr(header+4);
- info->filepos=filepos+7;
- return return_val | BLOCK_LAST;
- case 16:
- info->data_len=info->block_len=uint3korr(header+1);
- info->next_filepos=uint4korr(header+4);
- info->second_read=1;
- info->filepos=filepos+8;
- return return_val;
- #endif
- default:
- my_errno=HA_ERR_WRONG_IN_RECORD; /* Garbage */
- return BLOCK_ERROR;
- }
- }