Code:
/ DotNET / DotNET / 8.0 / untmp / whidbey / REDBITS / ndp / fx / src / Data / System / Data / Common / ByteStorage.cs / 1 / ByteStorage.cs
//------------------------------------------------------------------------------ //// Copyright (c) Microsoft Corporation. All rights reserved. // //[....] //[....] //[....] //----------------------------------------------------------------------------- namespace System.Data.Common { using System; using System.Xml; using System.Data.SqlTypes; using System.Collections; internal sealed class ByteStorage : DataStorage { private const Byte defaultValue = 0; private Byte[] values; internal ByteStorage(DataColumn column) : base(column, typeof(Byte), defaultValue) { } override public Object Aggregate(int[] records, AggregateType kind) { bool hasData = false; try { switch (kind) { case AggregateType.Sum: UInt64 sum = defaultValue; foreach (int record in records) { if (IsNull(record)) continue; checked { sum += values[record];} hasData = true; } if (hasData) { return sum; } return NullValue; case AggregateType.Mean: Int64 meanSum = (Int64)defaultValue; int meanCount = 0; foreach (int record in records) { if (IsNull(record)) continue; checked { meanSum += (Int64)values[record];} meanCount++; hasData = true; } if (hasData) { Byte mean; checked {mean = (Byte)(meanSum / meanCount);} return mean; } return NullValue; case AggregateType.Var: case AggregateType.StDev: int count = 0; double var = (double)defaultValue; double prec = (double)defaultValue; double dsum = (double)defaultValue; double sqrsum = (double)defaultValue; foreach (int record in records) { if (IsNull(record)) continue; dsum += (double)values[record]; sqrsum += (double)values[record]*(double)values[record]; count++; } if (count > 1) { var = ((double)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 = var / (count * (count -1)); if (kind == AggregateType.StDev) { return Math.Sqrt(var); } return var; } return NullValue; case AggregateType.Min: Byte min = Byte.MaxValue; for (int i = 0; i < records.Length; i++) { int record = records[i]; if (IsNull(record)) continue; min=Math.Min(values[record], min); hasData = true; } if (hasData) { return min; } return NullValue; case AggregateType.Max: Byte max = Byte.MinValue; for (int i = 0; i < records.Length; i++) { int record = records[i]; if (IsNull(record)) continue; max=Math.Max(values[record], max); hasData = true; } if (hasData) { return max; } return NullValue; case AggregateType.First: if (records.Length > 0) { return values[records[0]]; } return null; case AggregateType.Count: return base.Aggregate(records, kind); } } catch (OverflowException) { throw ExprException.Overflow(typeof(Byte)); } throw ExceptionBuilder.AggregateException(kind, DataType); } override public int Compare(int recordNo1, int recordNo2) { Byte valueNo1 = values[recordNo1]; Byte valueNo2 = values[recordNo2]; if (valueNo1 == defaultValue || valueNo2 == defaultValue) { int bitCheck = CompareBits(recordNo1, recordNo2); if (0 != bitCheck) return bitCheck; } return valueNo1.CompareTo(valueNo2); //return(valueNo1 - valueNo2); // copied from Byte.CompareTo(Byte) } public override int CompareValueTo(int recordNo, object value) { System.Diagnostics.Debug.Assert(0 <= recordNo, "Invalid record"); System.Diagnostics.Debug.Assert(null != value, "null value"); if (NullValue == value) { if (IsNull(recordNo)) { return 0; } return 1; } Byte valueNo1 = values[recordNo]; if ((defaultValue == valueNo1) && IsNull(recordNo)) { return -1; } return valueNo1.CompareTo((Byte)value); //return(valueNo1 - valueNo2); // copied from Byte.CompareTo(Byte) } public override object ConvertValue(object value) { if (NullValue != value) { if (null != value) { value = ((IConvertible)value).ToByte(FormatProvider); } else { value = NullValue; } } return value; } override public void Copy(int recordNo1, int recordNo2) { CopyBits(recordNo1, recordNo2); values[recordNo2] = values[recordNo1]; } override public Object Get(int record) { Byte value = values[record]; if (value != defaultValue) { return value; } return GetBits(record); } override public void Set(int record, Object value) { System.Diagnostics.Debug.Assert(null != value, "null value"); if (NullValue == value) { values[record] = defaultValue; SetNullBit(record, true); } else { values[record] = ((IConvertible)value).ToByte(FormatProvider); SetNullBit(record, false); } } override public void SetCapacity(int capacity) { Byte[] newValues = new Byte[capacity]; if (null != values) { Array.Copy(values, 0, newValues, 0, Math.Min(capacity, values.Length)); } values = newValues; base.SetCapacity(capacity); } override public object ConvertXmlToObject(string s) { return XmlConvert.ToByte(s); } override public string ConvertObjectToXml(object value) { return XmlConvert.ToString((Byte) value); } override protected object GetEmptyStorage(int recordCount) { return new Byte[recordCount]; } override protected void CopyValue(int record, object store, BitArray nullbits, int storeIndex) { Byte[] typedStore = (Byte[]) store; typedStore[storeIndex] = values[record]; nullbits.Set(storeIndex, IsNull(record)); } override protected void SetStorage(object store, BitArray nullbits) { values = (Byte[]) store; SetNullStorage(nullbits); } } } // File provided for Reference Use Only by Microsoft Corporation (c) 2007. // Copyright (c) Microsoft Corporation. All rights reserved.
Link Menu
![Network programming in C#, Network Programming in VB.NET, Network Programming in .NET](/images/book.jpg)
This book is available now!
Buy at Amazon US or
Buy at Amazon UK
- ShapingWorkspace.cs
- CmsUtils.cs
- glyphs.cs
- StructureChangedEventArgs.cs
- SimpleLine.cs
- ContextQuery.cs
- DateTimeOffsetStorage.cs
- TableColumn.cs
- Compiler.cs
- KnownBoxes.cs
- SqlBooleanizer.cs
- PermissionListSet.cs
- SequenceDesigner.cs
- FontFamilyValueSerializer.cs
- Page.cs
- ToolBarDesigner.cs
- GeneralTransform3DGroup.cs
- WebExceptionStatus.cs
- SqlCommand.cs
- PublishLicense.cs
- EFColumnProvider.cs
- MetadataStore.cs
- BigInt.cs
- HitTestDrawingContextWalker.cs
- PartDesigner.cs
- CurrentChangingEventManager.cs
- OleDbParameter.cs
- SecurityKeyIdentifierClause.cs
- DiffuseMaterial.cs
- PropertyPanel.cs
- HttpInputStream.cs
- Attributes.cs
- SerializerDescriptor.cs
- ComplexTypeEmitter.cs
- SpecialFolderEnumConverter.cs
- VisualBasicExpressionConverter.cs
- CustomTypeDescriptor.cs
- NativeMethods.cs
- PackWebRequest.cs
- SByteConverter.cs
- ListBoxItemWrapperAutomationPeer.cs
- Parallel.cs
- SafeRightsManagementQueryHandle.cs
- Error.cs
- AccessDataSourceView.cs
- _ConnectionGroup.cs
- DbgUtil.cs
- OdbcCommandBuilder.cs
- QilGeneratorEnv.cs
- SmtpReplyReaderFactory.cs
- SqlTrackingWorkflowInstance.cs
- XmlAutoDetectWriter.cs
- IPCCacheManager.cs
- FigureParagraph.cs
- MediaPlayerState.cs
- SolidBrush.cs
- WindowsListViewItemStartMenu.cs
- _DisconnectOverlappedAsyncResult.cs
- UnsupportedPolicyOptionsException.cs
- Classification.cs
- PixelFormat.cs
- GenericParameterDataContract.cs
- DataServiceConfiguration.cs
- MappingModelBuildProvider.cs
- WebPartConnectionsConnectVerb.cs
- DataFieldConverter.cs
- ClientSection.cs
- BufferedGraphicsManager.cs
- DbInsertCommandTree.cs
- MatrixCamera.cs
- TextRunCacheImp.cs
- MappingMetadataHelper.cs
- SecurityRuntime.cs
- BitVec.cs
- SegmentInfo.cs
- Propagator.ExtentPlaceholderCreator.cs
- URLMembershipCondition.cs
- SplayTreeNode.cs
- Funcletizer.cs
- DataGridTableCollection.cs
- CmsUtils.cs
- ITextView.cs
- SQLStringStorage.cs
- ActiveXHost.cs
- SiblingIterators.cs
- MemberAccessException.cs
- SelectionList.cs
- IpcChannel.cs
- PassportAuthenticationEventArgs.cs
- DataObjectSettingDataEventArgs.cs
- RoleGroupCollection.cs
- TextCharacters.cs
- DBParameter.cs
- Memoizer.cs
- Message.cs
- DialogBaseForm.cs
- SecurityException.cs
- filewebrequest.cs
- ConnectivityStatus.cs
- BooleanToVisibilityConverter.cs