/// <summary>
/// Utility function to consume a single row of a reader in a random fashion after Read/ReadAsync has been invoked.
/// </summary>
protected virtual async Task ConsumeRowAsync(DataStressReader reader, bool sequentialAccess, CancellationToken token, Random rnd)
{
for (int i = 0; i < reader.FieldCount; i++)
{
if (rnd.Next(10) == 0)
{
break; // stop reading from this row
}
if (rnd.Next(2) == 0)
{
continue; // skip this field
}
bool hasBeenRead = false;
// If the field is not null, we can optionally use streaming API
if ((!await reader.IsDBNullSyncOrAsync(i, token, rnd)) && (rnd.NextBool()))
{
Type t = reader.GetFieldType(i);
if (t == typeof(byte[]))
{
await ConsumeBytesAsync(reader, i, token, rnd);
hasBeenRead = true;
}
else if (t == typeof(string))
{
await ConsumeCharsAsync(reader, i, token, rnd);
hasBeenRead = true;
}
}
// If the field has not yet been read, or if it is non-sequential then we can re-read it
if ((!hasBeenRead) || (!sequentialAccess))
{
if (!await reader.IsDBNullSyncOrAsync(i, token, rnd))
{
// Field value is not null, we can use new GetFieldValue<T> methods
await reader.GetValueSyncOrAsync(i, token, rnd);
}
else
{
// Field value is null, we have to use old GetValue method
reader.GetValue(i);
}
}
// Do IsDBNull check again with 50% probability
if (rnd.NextBool())
{
await reader.IsDBNullSyncOrAsync(i, token, rnd);
}
}
}
protected virtual async Task ConsumeBytesAsync(DataStressReader reader, int i, CancellationToken token, Random rnd)
{
byte[] buffer = new byte[255];
if (rnd.NextBool())
{
// We can optionally use GetBytes
reader.GetBytes(i, rnd.Next(20), buffer, rnd.Next(20), rnd.Next(200));
}
else if (reader.GetName(i) != "timestamp_FLD")
{
// Timestamp appears to be binary, but cannot be read by Stream
DataStressStream stream = reader.GetStream(i);
await stream.ReadSyncOrAsync(buffer, rnd.Next(20), rnd.Next(200), token, rnd);
}
else
{
// It is timestamp column, so read it later with GetValueSyncOrAsync
await reader.GetValueSyncOrAsync(i, token, rnd);
}
}
