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
- CollectionDataContract.cs
- ControlBuilderAttribute.cs
- StylusTip.cs
- EntityKey.cs
- SrgsOneOf.cs
- AdapterDictionary.cs
- ValidatingReaderNodeData.cs
- WebPartTracker.cs
- MetabaseServerConfig.cs
- CollectionType.cs
- ProgramNode.cs
- SapiGrammar.cs
- ComplexBindingPropertiesAttribute.cs
- Properties.cs
- CheckBoxStandardAdapter.cs
- BoolExpressionVisitors.cs
- SQLBytes.cs
- Int32CollectionConverter.cs
- CopyNamespacesAction.cs
- CancellationHandler.cs
- ContainerFilterService.cs
- X509Certificate.cs
- X509WindowsSecurityToken.cs
- PingOptions.cs
- Exceptions.cs
- ListBase.cs
- DbException.cs
- MarkerProperties.cs
- securitycriticaldata.cs
- TabItemAutomationPeer.cs
- GenerateScriptTypeAttribute.cs
- ToolStripLabel.cs
- PagerSettings.cs
- AccessDataSourceWizardForm.cs
- SoapEnumAttribute.cs
- ToolStripRenderEventArgs.cs
- TypefaceMetricsCache.cs
- CustomValidator.cs
- UserControlCodeDomTreeGenerator.cs
- RoleManagerModule.cs
- Currency.cs
- MsmqIntegrationBindingElement.cs
- CodeStatementCollection.cs
- BasicHttpBindingCollectionElement.cs
- ValueTable.cs
- HttpCapabilitiesEvaluator.cs
- TaskFormBase.cs
- StyleHelper.cs
- EndpointAddressProcessor.cs
- TypefaceCollection.cs
- SignedXml.cs
- TextEditorContextMenu.cs
- diagnosticsswitches.cs
- embossbitmapeffect.cs
- GenericEnumConverter.cs
- PassportAuthentication.cs
- ZipIOLocalFileDataDescriptor.cs
- Int16.cs
- GradientSpreadMethodValidation.cs
- XmlWriterTraceListener.cs
- BamlBinaryReader.cs
- BufferModesCollection.cs
- AppLevelCompilationSectionCache.cs
- CodeTypeReference.cs
- Metadata.cs
- Run.cs
- SignatureGenerator.cs
- DrawingContextDrawingContextWalker.cs
- WmlFormAdapter.cs
- UIElementParaClient.cs
- GACIdentityPermission.cs
- Environment.cs
- HttpHeaderCollection.cs
- EtwTrace.cs
- ClosableStream.cs
- RoleService.cs
- DataGridItemCollection.cs
- ReceiveActivityDesignerTheme.cs
- ProcessHostMapPath.cs
- CompleteWizardStep.cs
- SerializationSectionGroup.cs
- SqlFunctions.cs
- FormatVersion.cs
- Normalization.cs
- FrameworkObject.cs
- PieceNameHelper.cs
- OpCellTreeNode.cs
- CodeComment.cs
- DataControlFieldCollection.cs
- ClockGroup.cs
- ExpandSegmentCollection.cs
- MobileTextWriter.cs
- DataViewSetting.cs
- XamlGridLengthSerializer.cs
- XmlDocument.cs
- EncryptedKey.cs
- EntitySqlException.cs
- MapPathBasedVirtualPathProvider.cs
- UserPreferenceChangedEventArgs.cs
- IndexedString.cs