mysql5/mysql-5.7.27/sql/ndb_repl_tab.h

255 lines
6.5 KiB
C++

/*
Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved.
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; version 2 of the License.
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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef NDB_REPL_TAB_H
#define NDB_REPL_TAB_H
#include <my_global.h>
#ifdef HAVE_NDB_BINLOG
#include <mysql_com.h> /* NAME_CHAR_LEN */
#include <ndbapi/NdbApi.hpp>
/*
Ndb_rep_tab_key
This class represents the key columns of the
mysql.ndb_replication system table
It is used when reading values from that table
*/
class Ndb_rep_tab_key
{
public:
static const uint DB_MAXLEN= NAME_CHAR_LEN - 1;
static const uint TABNAME_MAXLEN= NAME_CHAR_LEN - 1;
/* Char arrays in varchar format with 1 length byte and
* trailing 0
*/
char db[ DB_MAXLEN + 2 ];
char table_name[ TABNAME_MAXLEN + 2 ];
uint server_id;
Ndb_rep_tab_key()
{
db[0] = 0;
table_name[0] = 0;
server_id = 0;
}
/* Constructor from normal null terminated strings */
Ndb_rep_tab_key(const char* _db,
const char* _table_name,
uint _server_id);
/* Add null terminators to VARCHAR format string values */
void null_terminate_strings();
const char* get_db() const
{
return &db[1];
};
const char* get_table_name() const
{
return &table_name[1];
};
static const int MIN_MATCH_VAL = 1;
static const int EXACT_MATCH_DB = 4;
static const int EXACT_MATCH_TABLE_NAME = 2;
static const int EXACT_MATCH_SERVER_ID = 1;
static const int EXACT_MATCH_QUALITY =
MIN_MATCH_VAL +
EXACT_MATCH_DB +
EXACT_MATCH_TABLE_NAME +
EXACT_MATCH_SERVER_ID;
/*
This static method attempts an exact, then a wild
match between the passed key (with optional wild
characters), and the passed candidate row
returns :
1 : Exact match
0 : Wild match
-1 : No match
*/
static int attempt_match(const char* keyptr,
const uint keylen,
const char* candidateptr,
const uint candidatelen,
const int exactmatchvalue);
/* This static method compares a fixed key value with
* a possibly wildcard containing candidate_row.
* If there is no match, 0 is returned.
* >0 means there is a match, with larger numbers
* indicating a better match quality.
* An exact match returns EXACT_MATCH_QUALITY
*/
static int get_match_quality(const Ndb_rep_tab_key* key,
const Ndb_rep_tab_key* candidate_row);
};
/*
Ndb_rep_tab_row
This class represents a row in the mysql.ndb_replication table
*/
class Ndb_rep_tab_row
{
public:
static const uint MAX_CONFLICT_FN_SPEC_LEN = 255;
static const uint CONFLICT_FN_SPEC_BUF_LEN =
MAX_CONFLICT_FN_SPEC_LEN + 1; /* Trailing '\0' */
Ndb_rep_tab_key key;
uint binlog_type;
bool cfs_is_null;
/* Buffer has space for leading length byte */
char conflict_fn_spec[ CONFLICT_FN_SPEC_BUF_LEN + 1 ];
Ndb_rep_tab_row();
void null_terminate_strings()
{
key.null_terminate_strings();
uint speclen= 0;
speclen = conflict_fn_spec[0];
assert(speclen <= MAX_CONFLICT_FN_SPEC_LEN);
conflict_fn_spec[1 + speclen] = '\0';
}
const char* get_conflict_fn_spec()
{
return &conflict_fn_spec[1];
}
void set_conflict_fn_spec_null(bool null)
{
if (null)
{
cfs_is_null = true;
conflict_fn_spec[0] = 0;
conflict_fn_spec[1] = 0;
}
else
{
cfs_is_null = false;
}
}
};
/**
Ndb_rep_tab_reader
A helper class for accessing the mysql.ndb_replication
table
*/
class Ndb_rep_tab_reader
{
private:
static const char *ndb_rep_db;
static const char *ndb_replication_table;
static const char *nrt_db;
static const char *nrt_table_name;
static const char *nrt_server_id;
static const char *nrt_binlog_type;
static const char *nrt_conflict_fn;
Uint32 binlog_flags;
char conflict_fn_buffer[ Ndb_rep_tab_row::CONFLICT_FN_SPEC_BUF_LEN ];
char warning_msg_buffer[ FN_REFLEN ];
const char* conflict_fn_spec;
const char* warning_msg;
/**
check_schema
Checks that the schema of the mysql.ndb_replication table
is acceptable.
Returns
0 if ok
-1 if a column has an error. Col name in error_str
-2 if there's a more general error. Error description in
error_str
*/
static
int check_schema(const NdbDictionary::Table* reptab,
NdbDictionary::Dictionary* dict,
const char** error_str);
/**
scan_candidates
Scans the ndb_replication table for rows matching the
passed db, table_name, server_id triple.
Returns the quality of the match made.
-1 = Error in processing, see msg
0 = No match, use defaults.
>0 = Use data in best_match
if msg is set on return it contains a warning.
Warnings may be produces in non error scenarios
*/
int scan_candidates(Ndb* ndb,
const NdbDictionary::Table* reptab,
const char* db,
const char* table_name,
uint server_id,
Ndb_rep_tab_row& best_match);
public:
Ndb_rep_tab_reader();
~Ndb_rep_tab_reader() {};
/**
lookup
lookup scans the mysql.ndb_replication table for
the best matching entry for the supplied db,
table_name, server_id triple.
A buffer for the conflict_fn spec, and for any
error or warning messages must be supplied.
The passed binlog_flags, conflict_fn_spec and
message may be updated as a result
Returns :
0 : Success.
<0 : Error.
*/
int lookup(Ndb* ndb,
/* Keys */
const char* db,
const char* table_name,
uint server_id);
/* Following only valid after a call to lookup() */
Uint32 get_binlog_flags() const;
const char* get_conflict_fn_spec() const;
const char* get_warning_message() const;
};
/* #ifdef HAVE_NDB_BINLOG */
#endif
/* #ifdef NDB_REPL_TAB_H */
#endif