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Diffstat (limited to 'sql/discover.cc')
| -rw-r--r-- | sql/discover.cc | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/sql/discover.cc b/sql/discover.cc new file mode 100644 index 00000000000..e260f44a8db --- /dev/null +++ b/sql/discover.cc @@ -0,0 +1,172 @@ +/* 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 for discover of frm file from handler */ + +#include "mysql_priv.h" +#include <my_dir.h> + +/* + Read the contents of a .frm file + + SYNOPSIS + readfrm() + + name path to table-file "db/name" + frmdata frm data + len length of the read frmdata + + RETURN VALUES + 0 ok + 1 Could not open file + 2 Could not stat file + 3 Could not allocate data for read + Could not read file + + frmdata and len are set to 0 on error +*/ + +int readfrm(const char *name, + const void **frmdata, uint *len) +{ + int error; + char index_file[FN_REFLEN]; + File file; + ulong read_len; + char *read_data; + MY_STAT state; + DBUG_ENTER("readfrm"); + DBUG_PRINT("enter",("name: '%s'",name)); + + *frmdata= NULL; // In case of errors + *len= 0; + error= 1; + if ((file=my_open(fn_format(index_file,name,"",reg_ext,4), + O_RDONLY | O_SHARE, + MYF(0))) < 0) + goto err_end; + + // Get length of file + error= 2; + if (my_fstat(file, &state, MYF(0))) + goto err; + read_len= state.st_size; + + // Read whole frm file + error= 3; + read_data= 0; + if (read_string(file, &read_data, read_len)) + goto err; + + // Setup return data + *frmdata= (void*) read_data; + *len= read_len; + error= 0; + + err: + if (file > 0) + VOID(my_close(file,MYF(MY_WME))); + + err_end: /* Here when no file */ + DBUG_RETURN (error); +} /* readfrm */ + + +/* + Write the content of a frm data pointer + to a frm file + + SYNOPSIS + writefrm() + + name path to table-file "db/name" + frmdata frm data + len length of the frmdata + + RETURN VALUES + 0 ok + 2 Could not write file +*/ + +int writefrm(const char *name, const void *frmdata, uint len) +{ + File file; + char index_file[FN_REFLEN]; + int error; + DBUG_ENTER("writefrm"); + DBUG_PRINT("enter",("name: '%s' len: %d ",name,len)); + //DBUG_DUMP("frmdata", (char*)frmdata, len); + + error= 0; + if ((file=my_create(fn_format(index_file,name,"",reg_ext,4), + CREATE_MODE,O_RDWR | O_TRUNC,MYF(MY_WME))) >= 0) + { + if (my_write(file,(byte*)frmdata,len,MYF(MY_WME | MY_NABP))) + error= 2; + } + VOID(my_close(file,MYF(0))); + DBUG_RETURN(error); +} /* writefrm */ + + + + +/* + Try to discover table from handler and + if found, write the frm file to disk. + + RETURN VALUES: + 0 : Table existed in handler and created + on disk if so requested + 1 : Table does not exist + >1 : error + +*/ + +int create_table_from_handler(const char *db, + const char *name, + bool create_if_found) +{ + int error= 0; + const void* frmblob = NULL; + char path[FN_REFLEN]; + uint frmlen = 0; + DBUG_ENTER("create_table_from_handler"); + DBUG_PRINT("enter", ("create_if_found: %d", create_if_found)); + + if (ha_discover(db, name, &frmblob, &frmlen)) + DBUG_RETURN(1); // Table does not exist + + // Table exists in handler + if (create_if_found) + { + (void)strxnmov(path,FN_REFLEN,mysql_data_home,"/",db,"/",name,NullS); + // Save the frm file + error = writefrm(path, frmblob, frmlen); + } + + err: + if (frmblob) + my_free((char*) frmblob,MYF(0)); + DBUG_RETURN(error); +} + +int table_exists_in_handler(const char *db, + const char *name) +{ + return (create_table_from_handler(db, name, false) == 0); +} |