C# Directory.FileExists方法代码示例

        private static void UnidirectionalSync(AzureDirectory sourceDirectory, Directory destinationDirectory)
        {
            var sourceFiles = sourceDirectory.ListAll();

            var fileNameFilter = IndexFileNameFilter.Filter;
            byte[] buffer = new byte[16384];

            foreach (string sourceFile in sourceFiles)
            {
                // only copy file if it is accepted by Lucene's default filter
                // and it does not already exist (except for segment map files, we always want those)
                if (fileNameFilter.Accept(null, sourceFile) && (!destinationDirectory.FileExists(sourceFile) || sourceFile.StartsWith("segment")))
                {
                    IndexOutput indexOutput = null;
                    IndexInput indexInput = null;
                    try
                    {
                        indexOutput = destinationDirectory.CreateOutput(sourceFile);
                        indexInput = sourceDirectory.OpenInput(sourceFile);

                        long length = indexInput.Length();
                        long position = 0;
                        while (position < length)
                        {
                            int bytesToRead = position + 16384L > length ? (int)(length - position) : 16384;
                            indexInput.ReadBytes(buffer, 0, bytesToRead);
                            indexOutput.WriteBytes(buffer, bytesToRead);

                            position += bytesToRead;
                        }
                    }
                    finally
                    {
                        try
                        {
                            indexOutput?.Close();
                        }
                        finally
                        {
                            indexInput?.Close();
                        }
                    }
                }
            }

            // we'll remove old files from both AzureDirectory's cache directory, as well as our destination directory
            // (only when older than 45 minutes - old files may still have active searches on them so we need a margin)
            var referenceTimestamp = LuceneTimestampFromDateTime(DateTime.UtcNow.AddMinutes(-45));

            // remove old files from AzureDirectory cache directory
            RemoveOldFiles(sourceDirectory.CacheDirectory, sourceFiles, referenceTimestamp);

            // remove old files from destination directory
            RemoveOldFiles(destinationDirectory, sourceFiles, referenceTimestamp);
        }

 private void EnsureIndexVersionMatches(LuceneDirectory directory)
 {
     if (directory.FileExists(IndexVersionFilename) == false)
         throw new InvalidOperationException("Could not find " + IndexVersionFilename + " for '" + name + "', resetting index");
     
     using (var indexInput = directory.OpenInput(IndexVersionFilename))
     {
         var versionToCheck = IndexVersion;
         var versionFromDisk = indexInput.ReadString();
         if (versionFromDisk != versionToCheck)
             throw new InvalidOperationException("Index for " + name + " is of version " + versionFromDisk +
                                                 " which is not compatible with " + versionToCheck + ", resetting index");
     }
 }

		// LUCENE-1468
		private void  CheckDirectoryFilter(Directory dir)
		{
			System.String name = "file";
			try
			{
				dir.CreateOutput(name).Close();
				Assert.IsTrue(dir.FileExists(name));
				Assert.IsTrue(new System.Collections.ArrayList(dir.ListAll()).Contains(name));
			}
			finally
			{
				dir.Close();
			}
		}

 private static void EnsureIndexVersionMatches(Directory directory, IndexDefinition indexDefinition)
 {
     var versionToCheck = IndexVersion;
     if (indexDefinition.IsMapReduce)
     {
         versionToCheck = MapReduceIndexVersion;
     }
     var indexVersion = IndexVersionFileName(indexDefinition);
     if (directory.FileExists(indexVersion) == false)
     {
         throw new InvalidOperationException("Could not find " + indexVersion + " " + indexDefinition.IndexId + ", resetting index");
     }
     using (var indexInput = directory.OpenInput(indexVersion))
     {
         var versionFromDisk = indexInput.ReadString();
         if (versionFromDisk != versionToCheck)
             throw new InvalidOperationException("Index " + indexDefinition.IndexId + " is of version " + versionFromDisk +
                                                 " which is not compatible with " + versionToCheck + ", resetting index");
     }
 }

		protected virtual IndexSearcher CreateSearcher(Directory dir)
		{
			if (!dir.FileExists("segments.gen"))
				GetWriter().Commit();
			var s = new IndexSearcher(dir, readOnly: true);
			return s;
		}

        protected virtual IndexSearcher CreateSearcher(Directory dir)
        {
			if (!dir.FileExists("segments.gen"))
			{
				logger.Info("No segments.gen (whatever that means)");
				GetWriter().Commit();
			}
            var s = new IndexSearcher(dir, readOnly: true);
            return s;
        }