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// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
using System.Collections;
using System.Data.SqlTypes;
using System.Diagnostics;
using System.Diagnostics.CodeAnalysis;
using System.IO;
using System.Xml;
using System.Xml.Serialization;
namespace System.Data.Common
{
internal sealed class SqlSingleStorage : DataStorage
{
private SqlSingle[] _values = default!; // Late-initialized
public SqlSingleStorage(DataColumn column)
: base(column, typeof(SqlSingle), SqlSingle.Null, SqlSingle.Null, StorageType.SqlSingle)
{
}
public override object Aggregate(int[] records, AggregateType kind)
{
bool hasData = false;
try
{
switch (kind)
{
case AggregateType.Sum:
SqlSingle sum = 0.0f;
foreach (int record in records)
{
if (IsNull(record))
continue;
checked { sum += _values[record]; }
hasData = true;
}
if (hasData)
return sum;
return _nullValue;
case AggregateType.Mean:
SqlDouble meanSum = 0.0f;
int meanCount = 0;
foreach (int record in records)
{
if (IsNull(record))
continue;
checked { meanSum += _values[record].ToSqlDouble(); }
meanCount++;
hasData = true;
}
if (hasData)
{
SqlSingle mean = 0;
checked { mean = (meanSum / meanCount).ToSqlSingle(); }
return mean;
}
return _nullValue;
case AggregateType.Var:
case AggregateType.StDev:
int count = 0;
SqlDouble var = 0;
SqlDouble prec = 0;
SqlDouble dsum = 0;
SqlDouble sqrsum = 0;
foreach (int record in records)
{
if (IsNull(record))
continue;
dsum += _values[record].ToSqlDouble();
sqrsum += (_values[record]).ToSqlDouble() * (_values[record]).ToSqlDouble();
count++;
}
if (count > 1)
{
var = count * sqrsum - (dsum * dsum);
prec = var / (dsum * dsum);
// we are dealing with the risk of a cancellation error
// double is guaranteed only for 15 digits so a difference
// with a result less than 1e-15 should be considered as zero
if ((prec < 1e-15) || (var < 0))
var = 0;
else
var /= (count * (count - 1));
if (kind == AggregateType.StDev)
{
return Math.Sqrt(var.Value);
}
return var;
}
return _nullValue;
case AggregateType.Min:
SqlSingle min = SqlSingle.MaxValue;
for (int i = 0; i < records.Length; i++)
{
int record = records[i];
if (IsNull(record))
continue;
if ((SqlSingle.LessThan(_values[record], min)).IsTrue)
min = _values[record];
hasData = true;
}
if (hasData)
return min;
return _nullValue;
case AggregateType.Max:
SqlSingle max = SqlSingle.MinValue;
for (int i = 0; i < records.Length; i++)
{
int record = records[i];
if (IsNull(record))
continue;
if ((SqlSingle.GreaterThan(_values[record], max)).IsTrue)
max = _values[record];
hasData = true;
}
if (hasData)
return max;
return _nullValue;
case AggregateType.First: // Does not seem to be implemented
if (records.Length > 0)
{
return _values[records[0]];
}
return null!;
case AggregateType.Count:
count = 0;
for (int i = 0; i < records.Length; i++)
{
if (!IsNull(records[i]))
count++;
}
return count;
}
}
catch (OverflowException)
{
throw ExprException.Overflow(typeof(SqlSingle));
}
throw ExceptionBuilder.AggregateException(kind, _dataType);
}
public override int Compare(int recordNo1, int recordNo2)
{
return _values[recordNo1].CompareTo(_values[recordNo2]);
}
public override int CompareValueTo(int recordNo, object? value)
{
Debug.Assert(null != value, "null value");
return _values[recordNo].CompareTo((SqlSingle)value);
}
public override object ConvertValue(object? value)
{
if (null != value)
{
return SqlConvert.ConvertToSqlSingle(value);
}
return _nullValue;
}
public override void Copy(int recordNo1, int recordNo2)
{
_values[recordNo2] = _values[recordNo1];
}
public override object Get(int record)
{
return _values[record];
}
public override bool IsNull(int record)
{
return (_values[record].IsNull);
}
public override void Set(int record, object value)
{
_values[record] = SqlConvert.ConvertToSqlSingle(value);
}
public override void SetCapacity(int capacity)
{
Array.Resize(ref _values, capacity);
}
[RequiresUnreferencedCode(DataSet.RequiresUnreferencedCodeMessage)]
[RequiresDynamicCode(DataSet.RequiresDynamicCodeMessage)]
public override object ConvertXmlToObject(string s)
{
SqlSingle newValue = default;
string tempStr = string.Concat("<col>", s, "</col>"); // this is done since you can give fragment to reader
StringReader strReader = new StringReader(tempStr);
IXmlSerializable tmp = newValue;
using (XmlTextReader xmlTextReader = new XmlTextReader(strReader))
{
tmp.ReadXml(xmlTextReader);
}
return ((SqlSingle)tmp);
}
[RequiresUnreferencedCode(DataSet.RequiresUnreferencedCodeMessage)]
[RequiresDynamicCode(DataSet.RequiresDynamicCodeMessage)]
public override string ConvertObjectToXml(object value)
{
Debug.Assert(!DataStorage.IsObjectNull(value), "we should have null here");
Debug.Assert((value.GetType() == typeof(SqlSingle)), "wrong input type");
StringWriter strwriter = new StringWriter(FormatProvider);
using (XmlTextWriter xmlTextWriter = new XmlTextWriter(strwriter))
{
((IXmlSerializable)value).WriteXml(xmlTextWriter);
}
return (strwriter.ToString());
}
protected override object GetEmptyStorage(int recordCount)
{
return new SqlSingle[recordCount];
}
protected override void CopyValue(int record, object store, BitArray nullbits, int storeIndex)
{
SqlSingle[] typedStore = (SqlSingle[])store;
typedStore[storeIndex] = _values[record];
nullbits.Set(storeIndex, IsNull(record));
}
protected override void SetStorage(object store, BitArray nullbits)
{
_values = (SqlSingle[])store;
//SetNullStorage(nullbits);
}
}
}
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