Code:
/ Dotnetfx_Win7_3.5.1 / Dotnetfx_Win7_3.5.1 / 3.5.1 / DEVDIV / depot / DevDiv / releases / whidbey / NetFXspW7 / ndp / fx / src / CompMod / System / Collections / Specialized / FixedStringLookup.cs / 1 / FixedStringLookup.cs
//------------------------------------------------------------------------------ //// Copyright (c) Microsoft Corporation. All rights reserved. // //----------------------------------------------------------------------------- namespace System.Collections.Specialized { using System; using System.Collections; using System.Diagnostics; using System.Globalization; // This class provides a very efficient way to lookup an entry in a list of strings, // providing that they are declared in a particular way. // It requires the set of strings to be orderded into an array of arrays of strings. // The first indexer must the length of the string, so that each sub-array is of the // same length. The contained array must be in alphabetical order. Furthermore, if the // table is to be searched case-insensitively, the strings must all be lower case. internal static class FixedStringLookup { // Returns whether the match is found in the lookup table internal static bool Contains(string[][] lookupTable, string value, bool ignoreCase) { int length = value.Length; if (length <= 0 || length - 1 >= lookupTable.Length) { return false; } string[] subArray = lookupTable[length - 1]; if (subArray == null) { return false; } return Contains(subArray, value, ignoreCase); } #if DEBUG internal static void VerifyLookupTable(string[][] lookupTable, bool ignoreCase) { for (int i = 0; i < lookupTable.Length; i++) { string[] subArray = lookupTable[i]; if (subArray != null) { string lastValue = null; for (int j = 0; j < subArray.Length; j++) { string value = subArray[j]; // Must all be the length of the hashed position Debug.Assert(value.Length == i + 1, "Lookup table contains an item in the wrong subtable. Item name: " + value); if (lastValue != null) { // Must be sorted within the sub array; Debug.Assert(string.Compare(lastValue, value, ((ignoreCase) ? StringComparison.OrdinalIgnoreCase : StringComparison.Ordinal)) < 0, String.Format(CultureInfo.InvariantCulture, "Lookup table is out of order. Items {0} and {1} are reversed", lastValue, value)); } lastValue = value; } } } } #endif // This routine finds a hit within a single sorted array, with the assumption that the // value and all the strings are of the same length. private static bool Contains(string[] array, string value, bool ignoreCase) { int min = 0; int max = array.Length; int pos = 0; char searchChar; while (pos < value.Length) { if (ignoreCase) { searchChar = char.ToLower(value[pos], CultureInfo.InvariantCulture); } else { searchChar = value[pos]; } if ((max - min) <= 1) { // we are down to a single item, so we can stay on this row until the end. if (searchChar != array[min][pos]) { return false; } pos++; continue; } // There are multiple items to search, use binary search to find one of the hits if (!FindCharacter(array, searchChar, pos, ref min, ref max)) { return false; } // and move to next char pos++; } return true; } // Do a binary search on the character array at the specific position and constrict the ranges appropriately. private static bool FindCharacter(string[] array, char value, int pos, ref int min, ref int max) { int index = min; while (min < max) { index = (min + max) / 2; char comp = array[index][pos]; if (value == comp) { // We have a match. Now adjust to any adjacent matches int newMin = index; while (newMin > min && array[newMin - 1][pos] == value) { newMin--; } min = newMin; int newMax = index + 1; while (newMax < max && array[newMax][pos] == value) { newMax++; } max = newMax; return true; } if (value < comp) { max = index; } else { min = index + 1; } } return false; } } } // File provided for Reference Use Only by Microsoft Corporation (c) 2007. //------------------------------------------------------------------------------ //// Copyright (c) Microsoft Corporation. All rights reserved. // //----------------------------------------------------------------------------- namespace System.Collections.Specialized { using System; using System.Collections; using System.Diagnostics; using System.Globalization; // This class provides a very efficient way to lookup an entry in a list of strings, // providing that they are declared in a particular way. // It requires the set of strings to be orderded into an array of arrays of strings. // The first indexer must the length of the string, so that each sub-array is of the // same length. The contained array must be in alphabetical order. Furthermore, if the // table is to be searched case-insensitively, the strings must all be lower case. internal static class FixedStringLookup { // Returns whether the match is found in the lookup table internal static bool Contains(string[][] lookupTable, string value, bool ignoreCase) { int length = value.Length; if (length <= 0 || length - 1 >= lookupTable.Length) { return false; } string[] subArray = lookupTable[length - 1]; if (subArray == null) { return false; } return Contains(subArray, value, ignoreCase); } #if DEBUG internal static void VerifyLookupTable(string[][] lookupTable, bool ignoreCase) { for (int i = 0; i < lookupTable.Length; i++) { string[] subArray = lookupTable[i]; if (subArray != null) { string lastValue = null; for (int j = 0; j < subArray.Length; j++) { string value = subArray[j]; // Must all be the length of the hashed position Debug.Assert(value.Length == i + 1, "Lookup table contains an item in the wrong subtable. Item name: " + value); if (lastValue != null) { // Must be sorted within the sub array; Debug.Assert(string.Compare(lastValue, value, ((ignoreCase) ? StringComparison.OrdinalIgnoreCase : StringComparison.Ordinal)) < 0, String.Format(CultureInfo.InvariantCulture, "Lookup table is out of order. Items {0} and {1} are reversed", lastValue, value)); } lastValue = value; } } } } #endif // This routine finds a hit within a single sorted array, with the assumption that the // value and all the strings are of the same length. private static bool Contains(string[] array, string value, bool ignoreCase) { int min = 0; int max = array.Length; int pos = 0; char searchChar; while (pos < value.Length) { if (ignoreCase) { searchChar = char.ToLower(value[pos], CultureInfo.InvariantCulture); } else { searchChar = value[pos]; } if ((max - min) <= 1) { // we are down to a single item, so we can stay on this row until the end. if (searchChar != array[min][pos]) { return false; } pos++; continue; } // There are multiple items to search, use binary search to find one of the hits if (!FindCharacter(array, searchChar, pos, ref min, ref max)) { return false; } // and move to next char pos++; } return true; } // Do a binary search on the character array at the specific position and constrict the ranges appropriately. private static bool FindCharacter(string[] array, char value, int pos, ref int min, ref int max) { int index = min; while (min < max) { index = (min + max) / 2; char comp = array[index][pos]; if (value == comp) { // We have a match. Now adjust to any adjacent matches int newMin = index; while (newMin > min && array[newMin - 1][pos] == value) { newMin--; } min = newMin; int newMax = index + 1; while (newMax < max && array[newMax][pos] == value) { newMax++; } max = newMax; return true; } if (value < comp) { max = index; } else { min = index + 1; } } return false; } } } // File provided for Reference Use Only by Microsoft Corporation (c) 2007.
Link Menu
This book is available now!
Buy at Amazon US or
Buy at Amazon UK
- TextTreeNode.cs
- VisualSerializer.cs
- NativeCppClassAttribute.cs
- XPathNodeInfoAtom.cs
- CustomBindingElementCollection.cs
- IndentTextWriter.cs
- ScriptServiceAttribute.cs
- XmlCharCheckingReader.cs
- DataGridViewCellLinkedList.cs
- GACMembershipCondition.cs
- HttpDictionary.cs
- LiteralControl.cs
- DocumentPaginator.cs
- HttpSessionStateWrapper.cs
- ListViewItemSelectionChangedEvent.cs
- ListArgumentProvider.cs
- FrameworkElement.cs
- WindowsNonControl.cs
- SolidBrush.cs
- MimeParameter.cs
- XmlEnumAttribute.cs
- Int64Converter.cs
- RegexNode.cs
- ToolboxComponentsCreatedEventArgs.cs
- ColumnWidthChangedEvent.cs
- ResourceExpressionBuilder.cs
- HebrewNumber.cs
- NamespaceMapping.cs
- SyndicationDeserializer.cs
- GZipDecoder.cs
- FixedSOMContainer.cs
- TextBoxLine.cs
- Utilities.cs
- DataPagerFieldItem.cs
- RectangleF.cs
- ContextMenuStrip.cs
- DataGridAddNewRow.cs
- SymLanguageType.cs
- BufferedWebEventProvider.cs
- AspCompat.cs
- RemoteWebConfigurationHostServer.cs
- StyleBamlTreeBuilder.cs
- CodeNamespace.cs
- PTConverter.cs
- FixedHighlight.cs
- RC2CryptoServiceProvider.cs
- ListViewDataItem.cs
- KeyTime.cs
- XmlTextReaderImplHelpers.cs
- PreviewPrintController.cs
- DataGridCellItemAutomationPeer.cs
- AstTree.cs
- MLangCodePageEncoding.cs
- MessageSecurityProtocol.cs
- UnicastIPAddressInformationCollection.cs
- ToolStripPanelSelectionBehavior.cs
- Effect.cs
- TextContainer.cs
- UIAgentCrashedException.cs
- ProxyWebPart.cs
- AvTrace.cs
- FileCodeGroup.cs
- XmlExtensionFunction.cs
- ReceiveActivityDesigner.cs
- MemberListBinding.cs
- XmlNotation.cs
- XmlElementAttribute.cs
- DefaultValueAttribute.cs
- EmptyElement.cs
- ReadOnlyHierarchicalDataSource.cs
- MobileUserControl.cs
- DataBindingCollection.cs
- Separator.cs
- EntryWrittenEventArgs.cs
- UIElementParagraph.cs
- AccessViolationException.cs
- SafeNativeMethodsOther.cs
- NavigationProperty.cs
- CompilerInfo.cs
- EditorBrowsableAttribute.cs
- DashStyles.cs
- PropertyRef.cs
- ChangesetResponse.cs
- SqlDataReader.cs
- OdbcHandle.cs
- UniqueIdentifierService.cs
- TimeSpanFormat.cs
- Root.cs
- XmlILModule.cs
- FormattedTextSymbols.cs
- DynamicMethod.cs
- HttpWrapper.cs
- XamlSerializer.cs
- MergeFailedEvent.cs
- ASCIIEncoding.cs
- WindowsPrincipal.cs
- GeneralTransform3D.cs
- DataGridHeadersVisibilityToVisibilityConverter.cs
- ControlBindingsConverter.cs
- TrackingServices.cs