Class FileSwitchDirectory
- java.lang.Object
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- org.apache.lucene.store.Directory
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- org.apache.lucene.store.FileSwitchDirectory
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- All Implemented Interfaces:
Closeable,AutoCloseable
public class FileSwitchDirectory extends Directory
Expert: A Directory instance that switches files between two other Directory instances.Files with the specified extensions are placed in the primary directory; others are placed in the secondary directory. The provided Set must not change once passed to this class, and must allow multiple threads to call contains at once.
Locks with a name having the specified extensions are delegated to the primary directory; others are delegated to the secondary directory. Ideally, both Directory instances should use the same lock factory.
- WARNING: This API is experimental and might change in incompatible ways in the next release.
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Constructor Summary
Constructors Constructor Description FileSwitchDirectory(Set<String> primaryExtensions, Directory primaryDir, Directory secondaryDir, boolean doClose)
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description voidclose()Closes the directory.IndexOutputcreateOutput(String name, IOContext context)Creates a new, empty file in the directory and returns anIndexOutputinstance for appending data to this file.IndexOutputcreateTempOutput(String prefix, String suffix, IOContext context)Creates a new, empty, temporary file in the directory and returns anIndexOutputinstance for appending data to this file.voiddeleteFile(String name)Removes an existing file in the directory.longfileLength(String name)Returns the byte length of a file in the directory.static StringgetExtension(String name)Utility method to return a file's extension.Set<String>getPendingDeletions()Returns a set of files currently pending deletion in this directory.DirectorygetPrimaryDir()Return the primary directoryDirectorygetSecondaryDir()Return the secondary directoryString[]listAll()Returns names of all files stored in this directory.LockobtainLock(String name)Acquires and returns aLockfor a file with the given name.IndexInputopenInput(String name, IOContext context)Opens a stream for reading an existing file.voidrename(String source, String dest)Renamessourcefile todestfile wheredestmust not already exist in the directory.voidsync(Collection<String> names)Ensures that any writes to these files are moved to stable storage (made durable).voidsyncMetaData()Ensures that directory metadata, such as recent file renames, are moved to stable storage.-
Methods inherited from class org.apache.lucene.store.Directory
copyFrom, ensureOpen, getTempFileName, openChecksumInput, toString
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Method Detail
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getPrimaryDir
public Directory getPrimaryDir()
Return the primary directory
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getSecondaryDir
public Directory getSecondaryDir()
Return the secondary directory
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obtainLock
public Lock obtainLock(String name) throws IOException
Description copied from class:DirectoryAcquires and returns aLockfor a file with the given name.- Specified by:
obtainLockin classDirectory- Parameters:
name- the name of the lock file- Throws:
LockObtainFailedException- (optional specific exception) if the lock could not be obtained because it is currently held elsewhere.IOException- if any i/o error occurs attempting to gain the lock
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close
public void close() throws IOExceptionDescription copied from class:DirectoryCloses the directory.- Specified by:
closein interfaceAutoCloseable- Specified by:
closein interfaceCloseable- Specified by:
closein classDirectory- Throws:
IOException
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listAll
public String[] listAll() throws IOException
Description copied from class:DirectoryReturns names of all files stored in this directory. The output must be in sorted (UTF-16, java'sString.compareTo(java.lang.String)) order.- Specified by:
listAllin classDirectory- Throws:
IOException- in case of I/O error
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getExtension
public static String getExtension(String name)
Utility method to return a file's extension.
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deleteFile
public void deleteFile(String name) throws IOException
Description copied from class:DirectoryRemoves an existing file in the directory.This method must throw either
NoSuchFileExceptionorFileNotFoundExceptionifnamepoints to a non-existing file.- Specified by:
deleteFilein classDirectory- Parameters:
name- the name of an existing file.- Throws:
IOException- in case of I/O error
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fileLength
public long fileLength(String name) throws IOException
Description copied from class:DirectoryReturns the byte length of a file in the directory.This method must throw either
NoSuchFileExceptionorFileNotFoundExceptionifnamepoints to a non-existing file.- Specified by:
fileLengthin classDirectory- Parameters:
name- the name of an existing file.- Throws:
IOException- in case of I/O error
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createOutput
public IndexOutput createOutput(String name, IOContext context) throws IOException
Description copied from class:DirectoryCreates a new, empty file in the directory and returns anIndexOutputinstance for appending data to this file.This method must throw
FileAlreadyExistsExceptionif the file already exists.- Specified by:
createOutputin classDirectory- Parameters:
name- the name of the file to create.- Throws:
IOException- in case of I/O error
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createTempOutput
public IndexOutput createTempOutput(String prefix, String suffix, IOContext context) throws IOException
Description copied from class:DirectoryCreates a new, empty, temporary file in the directory and returns anIndexOutputinstance for appending data to this file.The temporary file name (accessible via
IndexOutput.getName()) will start withprefix, end withsuffixand have a reserved file extension.tmp.- Specified by:
createTempOutputin classDirectory- Throws:
IOException
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sync
public void sync(Collection<String> names) throws IOException
Description copied from class:DirectoryEnsures that any writes to these files are moved to stable storage (made durable).Lucene uses this to properly commit changes to the index, to prevent a machine/OS crash from corrupting the index.
- Specified by:
syncin classDirectory- Throws:
IOException- See Also:
Directory.syncMetaData()
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rename
public void rename(String source, String dest) throws IOException
Description copied from class:DirectoryRenamessourcefile todestfile wheredestmust not already exist in the directory.It is permitted for this operation to not be truly atomic, for example both
sourceanddestcan be visible temporarily inDirectory.listAll(). However, the implementation of this method must ensure the content ofdestappears as the entiresourceatomically. So oncedestis visible for readers, the entire content of previoussourceis visible.This method is used by IndexWriter to publish commits.
- Specified by:
renamein classDirectory- Throws:
IOException
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syncMetaData
public void syncMetaData() throws IOExceptionDescription copied from class:DirectoryEnsures that directory metadata, such as recent file renames, are moved to stable storage.- Specified by:
syncMetaDatain classDirectory- Throws:
IOException- See Also:
Directory.sync(Collection)
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openInput
public IndexInput openInput(String name, IOContext context) throws IOException
Description copied from class:DirectoryOpens a stream for reading an existing file.This method must throw either
NoSuchFileExceptionorFileNotFoundExceptionifnamepoints to a non-existing file.- Specified by:
openInputin classDirectory- Parameters:
name- the name of an existing file.- Throws:
IOException- in case of I/O error
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getPendingDeletions
public Set<String> getPendingDeletions() throws IOException
Description copied from class:DirectoryReturns a set of files currently pending deletion in this directory.- Specified by:
getPendingDeletionsin classDirectory- Throws:
IOException
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