00001
00002
00003
00004
00005
00006
00007
00008
00009
00010
00011
00012
00013
00014
00015
00016 #include "myisam_priv.h"
00017
00018
00019
00020
00021
00022
00023
00024
00025 int mi_rprev(MI_INFO *info, unsigned char *buf, int inx)
00026 {
00027 int error,changed;
00028 register uint32_t flag;
00029 MYISAM_SHARE *share=info->s;
00030
00031 if ((inx = _mi_check_index(info,inx)) < 0)
00032 return(errno);
00033 flag=SEARCH_SMALLER;
00034 if (info->lastpos == HA_OFFSET_ERROR && info->update & HA_STATE_NEXT_FOUND)
00035 flag=0;
00036
00037 if (fast_mi_readinfo(info))
00038 return(errno);
00039 changed=_mi_test_if_changed(info);
00040 if (!flag)
00041 error=_mi_search_last(info, share->keyinfo+inx,
00042 share->state.key_root[inx]);
00043 else if (!changed)
00044 error=_mi_search_next(info,share->keyinfo+inx,info->lastkey,
00045 info->lastkey_length,flag,
00046 share->state.key_root[inx]);
00047 else
00048 error=_mi_search(info,share->keyinfo+inx,info->lastkey,
00049 USE_WHOLE_KEY, flag, share->state.key_root[inx]);
00050
00051 if (share->concurrent_insert)
00052 {
00053 if (!error)
00054 {
00055 while (info->lastpos >= info->state->data_file_length)
00056 {
00057
00058 if ((error=_mi_search_next(info,share->keyinfo+inx,info->lastkey,
00059 info->lastkey_length,
00060 SEARCH_SMALLER,
00061 share->state.key_root[inx])))
00062 break;
00063 }
00064 }
00065 }
00066 info->update&= (HA_STATE_CHANGED | HA_STATE_ROW_CHANGED);
00067 info->update|= HA_STATE_PREV_FOUND;
00068 if (error)
00069 {
00070 if (errno == drizzled::HA_ERR_KEY_NOT_FOUND)
00071 errno= drizzled::HA_ERR_END_OF_FILE;
00072 }
00073 else if (!buf)
00074 {
00075 return(info->lastpos==HA_OFFSET_ERROR ? errno : 0);
00076 }
00077 else if (!(*info->read_record)(info,info->lastpos,buf))
00078 {
00079 info->update|= HA_STATE_AKTIV;
00080 return(0);
00081 }
00082 return(errno);
00083 }