mcs/class/referencesource/System.Web/Util/HashCodeCombiner.cs

   1 //------------------------------------------------------------------------------
   2 // <copyright file="HashCodeCombiner.cs" company="Microsoft">
   3 //     Copyright (c) Microsoft Corporation.  All rights reserved.
   4 // </copyright>
   5 //------------------------------------------------------------------------------
   6
   7 /*
   8  * HashCodeCombiner class
   9  *
  10  * Copyright (c) 1999 Microsoft Corporation
  11  */
  12
  13 namespace System.Web.Util {
  14 using System.Text;
  15 using System.IO;
  16 using System.Globalization;
  17 using System.Diagnostics;
  18 using System.Diagnostics.CodeAnalysis;
  19 using System.Web.Security.Cryptography;
  20
  21 /*
  22  * Class used to combine several hashcodes into a single hashcode
  23  */
  24 internal class HashCodeCombiner {
  25
  26     private long _combinedHash;
  27
  28     internal HashCodeCombiner() {
  29        // Start with a seed (obtained from String.GetHashCode implementation)
  30        _combinedHash = 5381;
  31     }
  32
  33     internal HashCodeCombiner(long initialCombinedHash)   {
  34         _combinedHash = initialCombinedHash;
  35     }
  36
  37     internal static int CombineHashCodes(int h1, int h2) {
  38         return ((h1 << 5) + h1) ^ h2;
  39     }
  40
  41     internal static int CombineHashCodes(int h1, int h2, int h3) {
  42         return CombineHashCodes(CombineHashCodes(h1, h2), h3);
  43     }
  44
  45     internal static int CombineHashCodes(int h1, int h2, int h3, int h4) {
  46         return CombineHashCodes(CombineHashCodes(h1, h2), CombineHashCodes(h3, h4));
  47     }
  48
  49     internal static int CombineHashCodes(int h1, int h2, int h3, int h4, int h5) {
  50         return CombineHashCodes(CombineHashCodes(h1, h2, h3, h4), h5);
  51     }
  52
  53     internal static string GetDirectoryHash(VirtualPath virtualDir) {
  54         HashCodeCombiner hashCodeCombiner = new HashCodeCombiner();
  55         hashCodeCombiner.AddDirectory(virtualDir.MapPathInternal());
  56         return hashCodeCombiner.CombinedHashString;
  57     }
  58
  59     internal void AddArray(string[] a) {
  60         if (a != null) {
  61             int n = a.Length;
  62             for (int i = 0; i < n; i++) {
  63                 AddObject(a[i]);
  64             }
  65         }
  66     }
  67
  68     internal void AddInt(int n) {
  69         _combinedHash = ((_combinedHash << 5) + _combinedHash) ^ n;
  70         Debug.Trace("HashCodeCombiner", "Adding " + n.ToString("x") + " --> " + _combinedHash.ToString("x"));
  71     }
  72
  73     internal void AddObject(int n) {
  74         AddInt(n);
  75     }
  76
  77     internal void AddObject(byte b) {
  78         AddInt(b.GetHashCode());
  79     }
  80
  81     internal void AddObject(long l) {
  82         AddInt(l.GetHashCode());
  83     }
  84
  85     internal void AddObject(bool b) {
  86         AddInt(b.GetHashCode());
  87     }
  88
  89     internal void AddObject(string s) {
  90         if (s != null)
  91             AddInt(StringUtil.GetStringHashCode(s));
  92     }
  93
  94     internal void AddObject(Type t) {
  95         if (t != null)
  96             AddObject(System.Web.UI.Util.GetAssemblyQualifiedTypeName(t));
  97     }
  98
  99     internal void AddObject(object o) {
 100         if (o != null)
 101             AddInt(o.GetHashCode());
 102     }
 103
 104     internal void AddCaseInsensitiveString(string s) {
 105         if (s != null)
 106             AddInt(StringUtil.GetNonRandomizedHashCode(s, ignoreCase:true));
 107     }
 108
 109     internal void AddDateTime(DateTime dt) {
 110         Debug.Trace("HashCodeCombiner", "Ticks: " + dt.Ticks.ToString("x", CultureInfo.InvariantCulture));
 111         Debug.Trace("HashCodeCombiner", "Hashcode: " + dt.GetHashCode().ToString("x", CultureInfo.InvariantCulture));
 112         AddInt(dt.GetHashCode());
 113     }
 114
 115     private void AddFileSize(long fileSize) {
 116         Debug.Trace("HashCodeCombiner", "file size: " + fileSize.ToString("x", CultureInfo.InvariantCulture));
 117         Debug.Trace("HashCodeCombiner", "Hashcode: " + fileSize.GetHashCode().ToString("x", CultureInfo.InvariantCulture));
 118         AddInt(fileSize.GetHashCode());
 119     }
 120
 121     [SuppressMessage("Microsoft.Security", "CA2122:DoNotIndirectlyExposeMethodsWithLinkDemands", Justification = "This call site is trusted.")]
 122     private void AddFileVersionInfo(FileVersionInfo fileVersionInfo) {
 123         Debug.Trace("HashCodeCombiner", "FileMajorPart: " + fileVersionInfo.FileMajorPart.GetHashCode().ToString("x", CultureInfo.InvariantCulture));
 124         Debug.Trace("HashCodeCombiner", "FileMinorPart: " + fileVersionInfo.FileMinorPart.GetHashCode().ToString("x", CultureInfo.InvariantCulture));
 125         Debug.Trace("HashCodeCombiner", "FileBuildPart: " + fileVersionInfo.FileBuildPart.GetHashCode().ToString("x", CultureInfo.InvariantCulture));
 126         Debug.Trace("HashCodeCombiner", "FilePrivatePart: " + fileVersionInfo.FilePrivatePart.GetHashCode().ToString("x", CultureInfo.InvariantCulture));
 127         AddInt(fileVersionInfo.FileMajorPart.GetHashCode());
 128         AddInt(fileVersionInfo.FileMinorPart.GetHashCode());
 129         AddInt(fileVersionInfo.FileBuildPart.GetHashCode());
 130         AddInt(fileVersionInfo.FilePrivatePart.GetHashCode());
 131     }
 132
 133     private void AddFileContentHashKey(string fileContentHashKey) {
 134         AddInt(StringUtil.GetNonRandomizedHashCode(fileContentHashKey));
 135     }
 136
 137     internal void AddFileContentHash(string fileName) {
 138         // Convert file content to hash bytes
 139         byte[] fileContentBytes = File.ReadAllBytes(fileName);
 140         byte[] fileContentHashBytes = CryptoUtil.ComputeSHA256Hash(fileContentBytes);
 141
 142         // Convert byte[] to hex string representation
 143         StringBuilder sbFileContentHashBytes = new StringBuilder();
 144         for (int index = 0; index < fileContentHashBytes.Length; index++) {
 145             sbFileContentHashBytes.Append(fileContentHashBytes[index].ToString("X2", CultureInfo.InvariantCulture));
 146         }
 147
 148         AddFileContentHashKey(sbFileContentHashBytes.ToString());
 149     }
 150
 151     internal void AddFile(string fileName) {
 152         Debug.Trace("HashCodeCombiner", "AddFile: " + fileName);
 153         if (!FileUtil.FileExists(fileName)) {
 154
 155             // Review: Should we change the dependency model to take directory into account?
 156             if (FileUtil.DirectoryExists(fileName)) {
 157                 // Add as a directory dependency if it's a directory.
 158                 AddDirectory(fileName);
 159                 return;
 160             }
 161
 162             Debug.Trace("HashCodeCombiner", "Could not find target " + fileName);
 163             return;
 164         }
 165
 166         AddExistingFile(fileName);
 167     }
 168
 169     // Same as AddFile, but only called for a file which is known to exist
 170     private void AddExistingFile(string fileName) {
 171         Debug.Trace("HashCodeCombiner", "AddExistingFile: " + fileName);
 172
 173         AddInt(StringUtil.GetStringHashCode(fileName));
 174         FileInfo file = new FileInfo(fileName);
 175         if (!AppSettings.PortableCompilationOutput) {
 176             AddDateTime(file.CreationTimeUtc);
 177         }
 178         AddDateTime(file.LastWriteTimeUtc);
 179         AddFileSize(file.Length);
 180     }
 181
 182     [SuppressMessage("Microsoft.Security", "CA2122:DoNotIndirectlyExposeMethodsWithLinkDemands", Justification = "This call site is trusted.")]
 183     internal void AddExistingFileVersion(string fileName) {
 184         Debug.Trace("HashCodeCombiner", "AddExistingFileVersion: " + fileName);
 185
 186         AddInt(StringUtil.GetStringHashCode(fileName));
 187         FileVersionInfo fileVersionInfo = FileVersionInfo.GetVersionInfo(fileName);
 188
 189         AddFileVersionInfo(fileVersionInfo);
 190     }
 191
 192     internal void AddDirectory(string directoryName) {
 193
 194         DirectoryInfo directory = new DirectoryInfo(directoryName);
 195         if (!directory.Exists) {
 196             return;
 197         }
 198
 199         AddObject(directoryName);
 200
 201         // Go through all the files in the directory
 202         foreach (FileData fileData in FileEnumerator.Create(directoryName)) {
 203
 204             if (fileData.IsDirectory)
 205                 AddDirectory(fileData.FullName);
 206             else
 207                 AddExistingFile(fileData.FullName);
 208         }
 209
 210         if (!AppSettings.PortableCompilationOutput) {
 211             AddDateTime(directory.CreationTimeUtc);
 212             AddDateTime(directory.LastWriteTimeUtc);
 213         }
 214     }
 215
 216     // Same as AddDirectory, but only look at files that don't have a culture
 217     internal void AddResourcesDirectory(string directoryName) {
 218
 219         DirectoryInfo directory = new DirectoryInfo(directoryName);
 220         if (!directory.Exists) {
 221             return;
 222         }
 223
 224         AddObject(directoryName);
 225
 226         // Go through all the files in the directory
 227         foreach (FileData fileData in FileEnumerator.Create(directoryName)) {
 228
 229             if (fileData.IsDirectory)
 230                 AddResourcesDirectory(fileData.FullName);
 231             else {
 232                 // Ignore the file if it has a culture, since only neutral files
 233                 // need to re-trigger compilation (VSWhidbey 359029)
 234                 string fullPath = fileData.FullName;
 235                 if (System.Web.UI.Util.GetCultureName(fullPath) == null) {
 236                     AddExistingFile(fullPath);
 237                 }
 238             }
 239         }
 240
 241         if (!AppSettings.PortableCompilationOutput) {
 242             AddDateTime(directory.CreationTimeUtc);
 243         }
 244     }
 245
 246     internal long CombinedHash { get { return _combinedHash; } }
 247     internal int CombinedHash32 { get { return _combinedHash.GetHashCode(); } }
 248
 249     internal string CombinedHashString {
 250         get {
 251             return _combinedHash.ToString("x", CultureInfo.InvariantCulture);
 252         }
 253     }
 254 }
 255
 256
 257 }