diff options
Diffstat (limited to 'isam/_statrec.c')
-rw-r--r-- | isam/_statrec.c | 265 |
1 files changed, 265 insertions, 0 deletions
diff --git a/isam/_statrec.c b/isam/_statrec.c new file mode 100644 index 00000000000..d93f4fe27f5 --- /dev/null +++ b/isam/_statrec.c @@ -0,0 +1,265 @@ +/* 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 fixed-length-records */ + +#include "isamdef.h" + + +int _nisam_write_static_record(N_INFO *info, const byte *record) +{ + uchar temp[4]; /* Not sizeof(long) */ + + if (info->s->state.dellink != NI_POS_ERROR) + { + ulong filepos=info->s->state.dellink; + info->rec_cache.seek_not_done=1; /* We have done a seek */ + VOID(my_seek(info->dfile,info->s->state.dellink+1,MY_SEEK_SET,MYF(0))); + + if (my_read(info->dfile,(char*) &temp[0],sizeof(temp), MYF(MY_NABP))) + goto err; + info->s->state.dellink=uint4korr(temp); + if (info->s->state.dellink == (uint32) ~0) /* Fix for 64 bit long */ + info->s->state.dellink=NI_POS_ERROR; + info->s->state.del--; + info->s->state.empty-=info->s->base.reclength; + VOID(my_seek(info->dfile,filepos,MY_SEEK_SET,MYF(0))); + if (my_write(info->dfile, (char*) record, info->s->base.reclength, + MYF(MY_NABP))) + goto err; + } + else + { + if (info->s->state.data_file_length > info->s->base.max_data_file_length) + { + my_errno=HA_ERR_RECORD_FILE_FULL; + return(2); + } + if (info->opt_flag & WRITE_CACHE_USED) + { /* Cash in use */ + if (my_b_write(&info->rec_cache, (byte*) record, info->s->base.reclength)) + goto err; + } + else + { + info->rec_cache.seek_not_done=1; /* We have done a seek */ + VOID(my_seek(info->dfile,info->s->state.data_file_length, + MY_SEEK_SET,MYF(0))); + if (my_write(info->dfile,(char*) record,info->s->base.reclength, + MYF(MY_NABP | MY_WAIT_IF_FULL))) + goto err; + } + info->s->state.data_file_length+=info->s->base.reclength; + info->s->state.splitt++; + } + return 0; + err: + return 1; +} + +int _nisam_update_static_record(N_INFO *info, ulong pos, const byte *record) +{ + info->rec_cache.seek_not_done=1; /* We have done a seek */ + VOID(my_seek(info->dfile,pos,MY_SEEK_SET,MYF(0))); + return (my_write(info->dfile,(char*) record,info->s->base.reclength, + MYF(MY_NABP)) != 0); +} + + +int _nisam_delete_static_record(N_INFO *info) +{ + uchar temp[5]; /* 1+sizeof(uint32) */ + + info->s->state.del++; + info->s->state.empty+=info->s->base.reclength; + temp[0]= '\0'; /* Mark that record is deleted */ + int4store(temp+1,info->s->state.dellink); + info->s->state.dellink = info->lastpos; + info->rec_cache.seek_not_done=1; + VOID(my_seek(info->dfile,info->lastpos,MY_SEEK_SET,MYF(0))); + return (my_write(info->dfile,(byte*) temp,(uint) sizeof(temp), + MYF(MY_NABP)) != 0); +} + + +int _nisam_cmp_static_record(register N_INFO *info, register const byte *old) +{ + DBUG_ENTER("_nisam_rectest"); + + /* We are going to do changes; dont let anybody disturb */ + dont_break(); /* Dont allow SIGHUP or SIGINT */ + + if (info->opt_flag & WRITE_CACHE_USED) + { + if (flush_io_cache(&info->rec_cache)) + { + DBUG_RETURN(-1); + } + info->rec_cache.seek_not_done=1; /* We have done a seek */ + } + + if ((info->opt_flag & READ_CHECK_USED)) + { /* If check isn't disabled */ + info->rec_cache.seek_not_done=1; /* We have done a seek */ + VOID(my_seek(info->dfile,info->lastpos,MY_SEEK_SET,MYF(0))); + if (my_read(info->dfile, (char*) info->rec_buff, info->s->base.reclength, + MYF(MY_NABP))) + DBUG_RETURN(-1); + if (memcmp((byte*) info->rec_buff, (byte*) old, + (uint) info->s->base.reclength)) + { + DBUG_DUMP("read",old,info->s->base.reclength); + DBUG_DUMP("disk",info->rec_buff,info->s->base.reclength); + my_errno=HA_ERR_RECORD_CHANGED; /* Record have changed */ + DBUG_RETURN(1); + } + } + DBUG_RETURN(0); +} + + /* Read a fixed-length-record */ + /* Returns 0 if Ok. */ + /* 1 if record is deleted */ + /* MY_FILE_ERROR on read-error or locking-error */ + +int _nisam_read_static_record(register N_INFO *info, register ulong pos, + register byte *record) +{ + int error; + + if (pos != NI_POS_ERROR) + { + if (info->opt_flag & WRITE_CACHE_USED && + info->rec_cache.pos_in_file <= pos && + flush_io_cache(&info->rec_cache)) + return(-1); + info->rec_cache.seek_not_done=1; /* We have done a seek */ + + error=my_pread(info->dfile,(char*) record,info->s->base.reclength, + pos,MYF(MY_NABP)) != 0; + if (info->s->r_locks == 0 && info->s->w_locks == 0) + VOID(_nisam_writeinfo(info,0)); + if (! error) + { + if (!*record) return(1); /* Record is deleted */ + info->update|= HA_STATE_AKTIV; /* Record is read */ + my_errno=HA_ERR_RECORD_DELETED; + return(0); + } + return(-1); /* Error on read */ + } + VOID(_nisam_writeinfo(info,0)); /* No such record */ + return(-1); +} /* _nisam_read_record */ + + +int _nisam_read_rnd_static_record(N_INFO *info, byte *buf, + register ulong filepos, + int skipp_deleted_blocks) +{ + int locked,error,cache_read; + uint cache_length; + ISAM_SHARE *share=info->s; + DBUG_ENTER("_nisam_read_rnd_static_record"); + + cache_read=0; + LINT_INIT(cache_length); + if (info->opt_flag & WRITE_CACHE_USED && + (info->rec_cache.pos_in_file <= filepos || skipp_deleted_blocks) && + flush_io_cache(&info->rec_cache)) + DBUG_RETURN(-1); + if (info->opt_flag & READ_CACHE_USED) + { /* Cash in use */ + if (filepos == my_b_tell(&info->rec_cache) && + (skipp_deleted_blocks || !filepos)) + { + cache_read=1; /* Read record using cache */ + cache_length=(uint) (info->rec_cache.rc_end - info->rec_cache.rc_pos); + } + else + info->rec_cache.seek_not_done=1; /* Filepos is changed */ + } +#ifndef NO_LOCKING + locked=0; + if (info->lock_type == F_UNLCK) + { + if (filepos >= share->state.data_file_length) + { /* Test if new records */ + if (_nisam_readinfo(info,F_RDLCK,0)) + DBUG_RETURN(-1); + locked=1; + } + else + { /* We don't nead new info */ +#ifndef UNSAFE_LOCKING + if ((! cache_read || share->base.reclength > cache_length) && + share->r_locks == 0 && share->w_locks == 0) + { /* record not in cache */ + if (my_lock(share->kfile,F_RDLCK,0L,F_TO_EOF, + MYF(MY_SEEK_NOT_DONE) | info->lock_wait)) + DBUG_RETURN(-1); + locked=1; + } +#else + info->tmp_lock_type=F_RDLCK; +#endif + } + } +#endif + if (filepos >= share->state.data_file_length) + { +#ifndef NO_LOCKING + DBUG_PRINT("test",("filepos: %ld (%ld) records: %ld del: %ld", + filepos/share->base.reclength,filepos, + share->state.records, share->state.del)); + VOID(_nisam_writeinfo(info,0)); +#endif + my_errno=HA_ERR_END_OF_FILE; + DBUG_RETURN(-1); + } + info->lastpos= filepos; + info->nextpos= filepos+share->base.reclength; + + if (! cache_read) /* No cacheing */ + { + error=_nisam_read_static_record(info,filepos,buf); + if (error > 0) + my_errno=HA_ERR_RECORD_DELETED; + DBUG_RETURN(error); + } + + /* Read record with cacheing */ + error=my_b_read(&info->rec_cache,(byte*) buf,share->base.reclength); + +#ifndef NO_LOCKING + if (locked) + VOID(_nisam_writeinfo(info,0)); /* Unlock keyfile */ +#endif + if (!error) + { + if (!buf[0]) + { /* Record is removed */ + my_errno=HA_ERR_RECORD_DELETED; + DBUG_RETURN(1); + } + /* Found and may be updated */ + info->update|= HA_STATE_AKTIV | HA_STATE_KEY_CHANGED; + DBUG_RETURN(0); + } + if (info->rec_cache.error != -1 || my_errno == 0) + my_errno=HA_ERR_WRONG_IN_RECORD; + DBUG_RETURN(-1); /* Something wrong (EOF?) */ +} |