/// <summary>
/// Creates a new connection and initializes it with random connection string generated from the factory's source
/// Note: if rnd is null, create a connection with minimal string required to connect to the target database
/// </summary>
/// <param name="rnd">Randomizes Connection Pool enablement, the application Name to randomize connection pool</param>
/// <param name="options"></param>
/// <returns></returns>
public DataStressConnection CreateConnection(Random rnd = null, ConnectionStringOptions options = ConnectionStringOptions.Default)
{
// Determine connection options (connection string, identity, etc)
string connectionString = CreateBaseConnectionString(rnd, options);
bool clearPoolBeforeClose = false;
if (rnd != null)
{
// Connection string and/or identity are randomized
// We implement this using the Application Name field in the connection string since this field
// should not affect behaviour other than connection pooling, since all connections in a pool
// must have the exact same connection string (including Application Name)
if (rnd.NextBool(.1))
{
// Disable pooling
connectionString = connectionString + ";Pooling=false;";
}
else if (rnd.NextBool(0.001))
{
// Use a unique Application Name to get a new connection from a new pool. We do this in order to
// stress the code that creates/deletes pools.
connectionString = string.Format("{0}; Pooling=true; Application Name=\"{1}\";", connectionString, GetRandomApplicationName());
// Tell DataStressConnection to call SqlConnection.ClearPool when closing the connection. This ensures
// we do not keep a large number of connections in the pool that we will never use again.
clearPoolBeforeClose = true;
}
else
{
switch (CurrentPoolingStressMode)
{
case PoolingStressMode.RandomizeConnectionStrings:
// Use one of the pre-generated Application Names in order to get a pooled connection with a randomized connection string
connectionString = string.Format("{0}; Pooling=true; Application Name=\"{1}\";", connectionString, _applicationNames[rnd.Next(_applicationNames.Count)]);
break;
default:
throw DataStressErrors.UnhandledCaseError(CurrentPoolingStressMode);
}
}
}
// All options have been determined, now create
DbConnection con = DbFactory.CreateConnection();
con.ConnectionString = connectionString;
return(new DataStressConnection(con, clearPoolBeforeClose));
}
protected virtual object GetRandomData(Random rnd, DbType dbType, int maxLength)
{
byte[] buffer;
switch (dbType)
{
case DbType.Boolean:
return(rnd.Next(2) == 0 ? false : true);
case DbType.Byte:
return(rnd.Next(byte.MinValue, byte.MaxValue + 1));
case DbType.Int16:
return(rnd.Next(short.MinValue, short.MaxValue + 1));
case DbType.Int32:
return(rnd.Next(2) == 0 ? int.MaxValue / rnd.Next(1, 3) : int.MinValue / rnd.Next(1, 3));
case DbType.Int64:
return(rnd.Next(2) == 0 ? long.MaxValue / rnd.Next(1, 3) : long.MinValue / rnd.Next(1, 3));
case DbType.Single:
return(rnd.NextDouble() * (rnd.Next(2) == 0 ? float.MaxValue : float.MinValue));
case DbType.Double:
return(rnd.NextDouble() * (rnd.Next(2) == 0 ? double.MaxValue : double.MinValue));
case DbType.Decimal:
return(rnd.Next(short.MinValue, short.MaxValue + 1));
case DbType.DateTime:
case DbType.DateTime2:
return(DateTime.Now);
case DbType.Date:
return(DateTime.Now.Date);
case DbType.Time:
return(DateTime.Now.TimeOfDay.ToString("c"));
case DbType.DateTimeOffset:
return(DateTimeOffset.Now);
case DbType.Guid:
buffer = new byte[16];
rnd.NextBytes(buffer);
return(new Guid(buffer));
case DbType.Object:
case DbType.Binary:
rnd.NextBytes(buffer = new byte[rnd.Next(1, maxLength)]);
return(buffer);
case DbType.String:
case DbType.Xml:
string openTag = "<Data>";
string closeTag = "</Data>";
int tagLength = openTag.Length + closeTag.Length;
if (tagLength > maxLength)
{
// Case (1): tagLength > maxTargetLength
return("");
}
else
{
StringBuilder builder = new StringBuilder(maxLength);
builder.Append(openTag);
// The data is just a repeat of one character because to the managed provider
// it is only really the length that matters, not the content of the data
char characterToUse = (char)rnd.Next((int)'@', (int)'~'); // Choosing random characters in this range to avoid special
// xml chars like '<' or '&'
int numRepeats = rnd.Next(0, maxLength - tagLength); // Case (2): tagLength == maxTargetLength
// Case (3): tagLength < maxTargetLength <-- most common
builder.Append(characterToUse, numRepeats);
builder.Append(closeTag);
DataStressErrors.Assert(builder.Length <= maxLength, "Incorrect length of randomly generated string");
return(builder.ToString());
}
default:
throw DataStressErrors.UnhandledCaseError(dbType);
}
}
private DbType GetDbType(TableColumn column)
{
switch (column.ColumnName)
{
case "bit_FLD": return(DbType.Boolean);
case "tinyint_FLD": return(DbType.Byte);
case "smallint_FLD": return(DbType.Int16);
case "int_FLD": return(DbType.Int32);
case "PrimaryKey": return(DbType.Int32);
case "bigint_FLD": return(DbType.Int64);
case "real_FLD": return(DbType.Single);
case "float_FLD": return(DbType.Double);
case "smallmoney_FLD": return(DbType.Decimal);
case "money_FLD": return(DbType.Decimal);
case "decimal_FLD": return(DbType.Decimal);
case "numeric_FLD": return(DbType.Decimal);
case "datetime_FLD": return(DbType.DateTime);
case "smalldatetime_FLD": return(DbType.DateTime);
case "datetime2_FLD": return(DbType.DateTime2);
case "timestamp_FLD": return(DbType.Binary);
case "date_FLD": return(DbType.Date);
case "time_FLD": return(DbType.Time);
case "datetimeoffset_FLD": return(DbType.DateTimeOffset);
case "uniqueidentifier_FLD": return(DbType.Guid);
case "sql_variant_FLD": return(DbType.Object);
case "image_FLD": return(DbType.Binary);
case "varbinary_FLD": return(DbType.Binary);
case "binary_FLD": return(DbType.Binary);
case "char_FLD": return(DbType.String);
case "varchar_FLD": return(DbType.String);
case "text_FLD": return(DbType.String);
case "ntext_FLD": return(DbType.String);
case "nvarchar_FLD": return(DbType.String);
case "nchar_FLD": return(DbType.String);
case "nvarcharmax_FLD": return(DbType.String);
case "varbinarymax_FLD": return(DbType.Binary);
case "varcharmax_FLD": return(DbType.String);
case "xml_FLD": return(DbType.Xml);
default: throw DataStressErrors.UnhandledCaseError(column.ColumnName);
}
}
