/**
* Load schema meta data.
*
* @param dataSource data source
* @param maxConnectionCount count of max connections permitted to use for this query
* @param databaseType database type
* @return schema meta data
* @throws SQLException SQL exception
*/
public static SchemaMetaData Load(IDataSource dataSource, int maxConnectionCount, string databaseType)
{
List <string> tableNames;
using (var connection = dataSource.CreateConnection())
{
connection.Open();
tableNames = LoadAllTableNames(connection, databaseType);
}
Console.WriteLine($"Loading {tableNames.Count} tables' meta data.");
if (tableNames.Count == 0)
{
return(new SchemaMetaData(new Dictionary <string, TableMetaData>(0)));
}
var groupInt = Math.Max(tableNames.Count / maxConnectionCount, 1);
var tableGroups = tableNames.Select((o, i) => new
{
Index = i % groupInt,
TableName = o
}).GroupBy(o => o.Index).Select(o => o.Select(g => g.TableName).ToList()).ToList();
IDictionary <string, TableMetaData> tableMetaDataMap = 1 == tableGroups.Count
? Load(dataSource.CreateConnection(), tableGroups[0], databaseType) : AsyncLoad(dataSource, maxConnectionCount, tableNames, tableGroups, databaseType);
return(new SchemaMetaData(tableMetaDataMap));
}
public static TableMetaData Load(IDataSource dataSource, string table, string databaseType)
{
using (var connection = dataSource.CreateConnection())
{
connection.Open();
return(new TableMetaData(ColumnMetaDataLoader.Load(connection, table, databaseType), IndexMetaDataLoader.Load(connection, table, databaseType)));
}
}
public IDbConnection GetConnection(IDataSource ds)
{
if(!_isInTransaction) return null;
IDbConnection con = _dbConnectionsByDataSource[ds] as IDbConnection;
if(con == null)
{
con = ds.CreateConnection();
_dbConnectionsByDataSource.Add(ds, con);
con.Open();
}
return con;
}
private static IDictionary <string, TableMetaData> AsyncLoad(IDataSource dataSource, int maxConnectionCount, List <string> tableNames,
List <List <string> > tableGroups, string databaseType)
{
ConcurrentDictionary <string, TableMetaData> result = new ConcurrentDictionary <string, TableMetaData>();
var tasks = tableGroups.Select(o => Task.Run(() =>
{
var tableMetaData = Load(dataSource.CreateConnection(), o, databaseType);
foreach (var entry in tableMetaData)
{
result.TryAdd(entry.Key, entry.Value);
}
})).ToArray();
Task.WaitAll(tasks);
return(result);
}
public DacHelper()
{
_ds = DataSourceFactory.GetDataSource();
connstring = _ds.ConnString;
conn = _ds.CreateConnection();
}
