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    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
    Implements
    System.IDisposable
    Inherited Members
    System.Object.Equals(System.Object)
    System.Object.Equals(System.Object, System.Object)
    System.Object.GetHashCode()
    System.Object.GetType()
    System.Object.MemberwiseClone()
    System.Object.ReferenceEquals(System.Object, System.Object)
    Namespace: Lucene.Net.Store
    Assembly: Lucene.Net.dll
    Syntax
    public abstract class Directory : IDisposable

    Properties

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    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.

    Declaration
    public abstract LockFactory LockFactory { get; }
    Property Value
    Type Description
    LockFactory

    Methods

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    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.

    Declaration
    public abstract void ClearLock(string name)
    Parameters
    Type Name Description
    System.String name

    name of the lock to be cleared.

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    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.

    Declaration
    public virtual void Copy(Directory to, string src, string dest, IOContext context)
    Parameters
    Type Name Description
    Directory to
    System.String src
    System.String dest
    IOContext context
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    CreateOutput(String, IOContext)

    Creates a new, empty file in the directory with the given name. Returns a stream writing this file.

    Declaration
    public abstract IndexOutput CreateOutput(string name, IOContext context)
    Parameters
    Type Name Description
    System.String name
    IOContext context
    Returns
    Type Description
    IndexOutput
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    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 System.IO.FileNotFoundException if the file does not exist.

    @lucene.internal

    This is a Lucene.NET EXPERIMENTAL API, use at your own risk
    Declaration
    public virtual Directory.IndexInputSlicer CreateSlicer(string name, IOContext context)
    Parameters
    Type Name Description
    System.String name
    IOContext context
    Returns
    Type Description
    Directory.IndexInputSlicer
    Exceptions
    Type Condition
    System.IO.IOException

    if an System.IO.IOException occurs

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    DeleteFile(String)

    Removes an existing file in the directory.

    Declaration
    public abstract void DeleteFile(string name)
    Parameters
    Type Name Description
    System.String name
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    Dispose()

    Disposes the store.

    Declaration
    public void Dispose()
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    Dispose(Boolean)

    Disposes the store.

    Declaration
    protected abstract void Dispose(bool disposing)
    Parameters
    Type Name Description
    System.Boolean disposing
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    EnsureOpen()

    Declaration
    protected virtual void EnsureOpen()
    Exceptions
    Type Condition
    System.ObjectDisposedException

    if this Directory is closed

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    FileExists(String)

    Returns true iff a file with the given name exists.

    Declaration
    [Obsolete("this method will be removed in 5.0")]
    public abstract bool FileExists(string name)
    Parameters
    Type Name Description
    System.String name
    Returns
    Type Description
    System.Boolean
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    FileLength(String)

    Returns the length of a file in the directory. this method follows the following contract:

    Declaration
    public abstract long FileLength(string name)
    Parameters
    Type Name Description
    System.String name

    the name of the file for which to return the length.

    Returns
    Type Description
    System.Int64
    Exceptions
    Type Condition
    System.IO.IOException

    if there was an IO error while retrieving the file's length.

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    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.

    Declaration
    public virtual string GetLockID()
    Returns
    Type Description
    System.String
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    ListAll()

    Returns an array of strings, one for each file in the directory.

    Declaration
    public abstract string[] ListAll()
    Returns
    Type Description
    System.String[]
    Exceptions
    Type Condition
    System.IO.DirectoryNotFoundException

    if the directory is not prepared for any write operations (such as CreateOutput(String, IOContext)).

    System.IO.IOException

    in case of other IO errors

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    MakeLock(String)

    Construct a Lock.

    Declaration
    public abstract Lock MakeLock(string name)
    Parameters
    Type Name Description
    System.String name

    the name of the lock file

    Returns
    Type Description
    Lock
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    OpenChecksumInput(String, IOContext)

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

    Declaration
    public virtual ChecksumIndexInput OpenChecksumInput(string name, IOContext context)
    Parameters
    Type Name Description
    System.String name
    IOContext context
    Returns
    Type Description
    ChecksumIndexInput
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    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 System.IO.FileNotFoundException if the file does not exist.

    Declaration
    public abstract IndexInput OpenInput(string name, IOContext context)
    Parameters
    Type Name Description
    System.String name
    IOContext context
    Returns
    Type Description
    IndexInput
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    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).

    Declaration
    public abstract void SetLockFactory(LockFactory lockFactory)
    Parameters
    Type Name Description
    LockFactory lockFactory

    instance of LockFactory.

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    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.

    Declaration
    public abstract void Sync(ICollection<string> names)
    Parameters
    Type Name Description
    System.Collections.Generic.ICollection<System.String> names
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    ToString()

    Declaration
    public override string ToString()
    Returns
    Type Description
    System.String
    Overrides
    System.Object.ToString()

    Implements

    System.IDisposable

    Extension Methods

    Number.IsNumber(Object)
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