public UngroupedAverageProvider(string field, IRecordProvider provider) : base(provider)
{
this.field = field;
if (!provider.MetaData.ColumnDescriptors.ContainsKey(field))
{
throw new MalformedQueryException($"Could not find field named {field}");
}
MetaData = new RecordMetaData();
MetaData.AddField($"avg_of_{field}", ColumnType.Float);
}
public ComputedFieldProvider(string fieldName, ColumnType type,
Func<RecordMetaData, byte[], dynamic> computation, IRecordProvider provider) : base(provider)
{
this.fieldName = fieldName;
this.type = type;
this.computation = computation;
MetaData = new RecordMetaData();
foreach (var columnDescriptor in provider.MetaData.ColumnDescriptors)
{
MetaData.ColumnDescriptors.Add(columnDescriptor.Key, columnDescriptor.Value);
}
MetaData.AddField(fieldName, type);
}
public bool IsValid(byte[] record, RecordMetaData metaData)
{
if (!metaData.ColumnDescriptors.ContainsKey(Property))
{
throw new MalformedQueryException($"No field named {Property} found.");
}
var offset = metaData.ColumnDescriptors[Property].Offset;
var width = metaData.ColumnDescriptors[Property].Width;
for (int i = 0; i < width; i++)
{
if (i == Value.Length) return record[offset + i] == 0;
if (record[offset + i] != Value[i]) return false;
}
return true;
}
public bool IsValid(byte[] record, RecordMetaData metaData)
{
return !constraint.IsValid(record, metaData);
}
