Class Directory

A Directory is a flat list of files. Files may be written once, when they are created. Once a file is created it may only be opened for read, or deleted. Random access is permitted both when reading and writing.

.NET's i/o APIs not used directly, but rather all i/o is through this API. This permits things such as:

  • implementation of RAM-based indices;
  • implementation indices stored in a database;
  • implementation of an index as a single file;

Directory locking is implemented by an instance of LockFactory, and can be changed for each Directory instance using SetLockFactory(LockFactory).

Inheritance
System.Object
Directory
BaseDirectory
FilterDirectory
NRTCachingDirectory
Assembly: DistributedLucene.Net.dll
Syntax
public abstract class Directory : IDisposable

Properties

Name Description
LockFactory

Get the LockFactory that this Directory instance is using for its locking implementation. Note that this may be null for Directory implementations that provide their own locking implementation.
StatusLatch

Methods

Name Description
AllowOpenInput()
AllowOpenOutput()
ClearLock(String)

Attempt to clear (forcefully unlock and remove) the specified lock. Only call this at a time when you are certain this lock is no longer in use.

Copy(Directory, String, String, IOContext)

Copies the file src to Directory to under the new file name dest.

If you want to copy the entire source directory to the destination one, you can do so like this:

Directory to; // the directory to copy to
foreach (string file in dir.ListAll()) {
    dir.Copy(to, file, newFile, IOContext.DEFAULT); // newFile can be either file, or a new name
}

NOTE: this method does not check whether dest exist and will overwrite it if it does.
CreateOutput(String, IOContext)

Creates a new, empty file in the directory with the given name. Returns a stream writing this file.
CreateSlicer(String, IOContext)

Creates an Directory.IndexInputSlicer for the given file name. Directory.IndexInputSlicer allows other Directory implementations to efficiently open one or more sliced IndexInput instances from a single file handle. The underlying file handle is kept open until the Directory.IndexInputSlicer is closed.

Throws if the file does not exist.

@lucene.internal @lucene.experimental
DeleteFile(String)

Removes an existing file in the directory.

DirectoryExist()
Dispose()

Disposes the store.

Dispose(Boolean)

Disposes the store.

DisposeOnRemoval()
EnsureOpen()
FileExists(String)

Returns true iff a file with the given name exists.
FileLength(String)

Returns the length of a file in the directory. this method follows the following contract:
GetBucketId()
GetLockID()

Return a string identifier that uniquely differentiates this Directory instance from other Directory instances. This ID should be the same if two Directory instances (even in different AppDomains and/or on different machines) are considered "the same index". This is how locking "scopes" to the right index.
ListAll()

Returns an array of strings, one for each file in the directory.
MakeLock(String)

Construct a Lock.

OpenChecksumInput(String, IOContext)

Returns a stream reading an existing file, computing checksum as it reads

OpenInput(String, IOContext)

Returns a stream reading an existing file, with the specified read buffer size. The particular Directory implementation may ignore the buffer size. Currently the only Directory implementations that respect this parameter are FSDirectory and CompoundFileDirectory.

Throws if the file does not exist.
SetBucketId(Int32)
SetLockFactory(LockFactory)

Set the LockFactory that this Directory instance should use for its locking implementation. Each * instance of LockFactory should only be used for one directory (ie, do not share a single instance across multiple Directories).
Sync(ICollection<String>)

Ensure that any writes to these files are moved to stable storage. Lucene uses this to properly commit changes to the index, to prevent a machine/OS crash from corrupting the index.

NOTE: Clients may call this method for same files over and over again, so some impls might optimize for that. For other impls the operation can be a noop, for various reasons.
ToString()
UnregisterInput(IndexInput)

Extension Methods