jetbrains.exodus.vfs

Class VirtualFileSystem

java.lang.Object

jetbrains.exodus.vfs.VirtualFileSystem

public class VirtualFileSystem
extends java.lang.Object

VirtualFileSystem allows to deal with data in terms of files, input and output streams. VirtualFileSystem works over an Environment instance, so VirtualFileSystem is a transactional file system with strong isolation guarantees. Any VirtualFileSystem operation requires a Transaction instance. Even creation of VirtualFileSystem can be transactional (using constructors VirtualFileSystem(Environment, VfsConfig, Transaction) and VirtualFileSystem(Environment, VfsConfig, StoreConfig, Transaction)). An application working with VirtualFileSystem should shutdown() file system before stopping itself.

To create a file, use createFile(Transaction, long, String) and createFile(Transaction, long, String) methods. To create file with unique pathname and specified path prefix, use createUniqueFile(Transaction, String). To open existing file or to create the new file, use openFile(Transaction, String, boolean).

To read File contents, open InputStream using readFile(Transaction, File), readFile(Transaction, File, long) and readFile(Transaction, long) methods. To write File contents, open OutputStream using appendFile(Transaction, File), writeFile(Transaction, File), writeFile(Transaction, File, long), writeFile(Transaction, long) and writeFile(Transaction, long, long) methods.

See Also:

File, VfsConfig, Environment, Transaction

Constructor Summary

Constructors

Constructor and Description
VirtualFileSystem(@NotNull jetbrains.exodus.env.Environment env) Creates VirtualFileSystem over specified Environment with default settings VfsConfig.DEFAULT.
VirtualFileSystem(@NotNull jetbrains.exodus.env.Environment env, @NotNull VfsConfig config) Creates VirtualFileSystem over specified Environment with specified VfsConfig.
VirtualFileSystem(@NotNull jetbrains.exodus.env.Environment env, @NotNull VfsConfig config, @NotNull jetbrains.exodus.env.StoreConfig contentsStoreConfig) Creates VirtualFileSystem over specified Environment with specified VfsConfig and StoreConfig.
VirtualFileSystem(@NotNull jetbrains.exodus.env.Environment env, @NotNull VfsConfig config, @NotNull jetbrains.exodus.env.StoreConfig contentsStoreConfig, @Nullable jetbrains.exodus.env.Transaction txn) Creates VirtualFileSystem over specified Environment with specified VfsConfig and StoreConfig inside specified Transaction.
VirtualFileSystem(@NotNull jetbrains.exodus.env.Environment env, @NotNull VfsConfig config, @Nullable jetbrains.exodus.env.Transaction txn) Creates VirtualFileSystem over specified Environment with specified VfsConfig inside specified Transaction.

Method Summary

Modifier and Type	Method and Description
java.io.OutputStream	appendFile(@NotNull jetbrains.exodus.env.Transaction txn, @NotNull File file) Returns OutputStream to write the contents of the specified file from the end of the file.
@NotNull File	createFile(@NotNull jetbrains.exodus.env.Transaction txn, long fileDescriptor, @NotNull java.lang.String path) Creates new file inside specified Transaction with specified file descriptor and path and returns the File instance.
@NotNull File	createFile(@NotNull jetbrains.exodus.env.Transaction txn, @NotNull java.lang.String path) Creates new file inside specified Transaction with specified path and returns the File instance.
File	createUniqueFile(@NotNull jetbrains.exodus.env.Transaction txn, @NotNull java.lang.String pathPrefix) Creates new File with unique auto-generated path starting with specified pathPrefix.
@Nullable File	deleteFile(@NotNull jetbrains.exodus.env.Transaction txn, @NotNull java.lang.String path) Deletes existing file with the specified path.
long	diskUsage(@NotNull jetbrains.exodus.env.Transaction txn) Returns total size of all the files in the filesystem.
void	dump(@NotNull jetbrains.exodus.env.Transaction txn, @NotNull java.nio.file.Path directory)
@Nullable IOCancellingPolicyProvider	getCancellingPolicyProvider()
@Nullable ClusterConverter	getClusterConverter()
VfsConfig	getConfig()
jetbrains.exodus.env.Environment	getEnvironment()
long	getFileLength(@NotNull jetbrains.exodus.env.Transaction txn, @NotNull File file)
long	getFileLength(@NotNull jetbrains.exodus.env.Transaction txn, long fileDescriptor)
@NotNull java.lang.Iterable<File>	getFiles(@NotNull jetbrains.exodus.env.Transaction txn)
long	getNumberOfFiles(@NotNull jetbrains.exodus.env.Transaction txn)
@Nullable File	openFile(@NotNull jetbrains.exodus.env.Transaction txn, @NotNull java.lang.String path, boolean create) Returns existing File with specified path or creates the new one if create is true, otherwise returns null.
VfsInputStream	readFile(@NotNull jetbrains.exodus.env.Transaction txn, @NotNull File file) Returns InputStream to read contents of the specified file from the beginning.
@NotNull VfsInputStream	readFile(@NotNull jetbrains.exodus.env.Transaction txn, @NotNull File file, long fromPosition) Returns InputStream to read contents of the specified file from the specified position.
VfsInputStream	readFile(@NotNull jetbrains.exodus.env.Transaction txn, long fileDescriptor) Returns InputStream to read contents of the specified file from the beginning.
boolean	renameFile(@NotNull jetbrains.exodus.env.Transaction txn, @NotNull File origin, @NotNull java.lang.String newPath) Renames origin file to the specified newPath and returns true if the file was actually renamed.
void	setCancellingPolicyProvider(@NotNull IOCancellingPolicyProvider cancellingPolicyProvider)
void	setClusterConverter(@Nullable ClusterConverter clusterConverter)
void	shutdown() Shuts down the VirtualFileSystem.
void	touchFile(@NotNull jetbrains.exodus.env.Transaction txn, @NotNull File file) Touches the specified File, i.e.
java.io.OutputStream	writeFile(@NotNull jetbrains.exodus.env.Transaction txn, @NotNull File file) Returns OutputStream to write the contents of the specified file from the beginning.
java.io.OutputStream	writeFile(@NotNull jetbrains.exodus.env.Transaction txn, @NotNull File file, long fromPosition) Returns OutputStream to write the contents of the specified file from the specified position.
java.io.OutputStream	writeFile(@NotNull jetbrains.exodus.env.Transaction txn, long fileDescriptor) Returns OutputStream to write the contents of the specified file from the beginning.
java.io.OutputStream	writeFile(@NotNull jetbrains.exodus.env.Transaction txn, long fileDescriptor, long fromPosition) Returns OutputStream to write the contents of the specified file from the specified position.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

VirtualFileSystem

public VirtualFileSystem(@NotNull
                         @NotNull jetbrains.exodus.env.Environment env)

Creates VirtualFileSystem over specified Environment with default settings VfsConfig.DEFAULT.

Parameters:

env - Environment instance

See Also:

Environment

VirtualFileSystem

public VirtualFileSystem(@NotNull
                         @NotNull jetbrains.exodus.env.Environment env,
                         @NotNull
                         @NotNull VfsConfig config)

Creates VirtualFileSystem over specified Environment with specified VfsConfig.

Parameters:

env - Environment instance

config - VfsConfig instance

See Also:

Environment, VfsConfig

VirtualFileSystem

public VirtualFileSystem(@NotNull
                         @NotNull jetbrains.exodus.env.Environment env,
                         @NotNull
                         @NotNull VfsConfig config,
                         @Nullable
                         @Nullable jetbrains.exodus.env.Transaction txn)

Creates VirtualFileSystem over specified Environment with specified VfsConfig inside specified Transaction.

Parameters:

env - Environment instance

config - VfsConfig instance

txn - Transaction instance

See Also:

Environment, VfsConfig, Transaction

VirtualFileSystem

public VirtualFileSystem(@NotNull
                         @NotNull jetbrains.exodus.env.Environment env,
                         @NotNull
                         @NotNull VfsConfig config,
                         @NotNull
                         @NotNull jetbrains.exodus.env.StoreConfig contentsStoreConfig)

Creates VirtualFileSystem over specified Environment with specified VfsConfig and StoreConfig. StoreConfig is used to open the Store for contents of VirtualFileSystem's files.

Parameters:

env - Environment instance

config - VfsConfig instance

contentsStoreConfig - StoreConfig instance

See Also:

Environment, VfsConfig, StoreConfig

VirtualFileSystem

public VirtualFileSystem(@NotNull
                         @NotNull jetbrains.exodus.env.Environment env,
                         @NotNull
                         @NotNull VfsConfig config,
                         @NotNull
                         @NotNull jetbrains.exodus.env.StoreConfig contentsStoreConfig,
                         @Nullable
                         @Nullable jetbrains.exodus.env.Transaction txn)

Creates VirtualFileSystem over specified Environment with specified VfsConfig and StoreConfig inside specified Transaction. StoreConfig is used to open the Store for contents of VirtualFileSystem's files.

Parameters:

env - Environment instance

config - VfsConfig instance

contentsStoreConfig - StoreConfig instance

txn - Transaction instance

See Also:

Environment, VfsConfig, StoreConfig, Transaction

Method Detail

getEnvironment

public jetbrains.exodus.env.Environment getEnvironment()

Returns:

Environment instance which the VirtualFileSystem works over.

createFile

@NotNull
public @NotNull File createFile(@NotNull
                                          @NotNull jetbrains.exodus.env.Transaction txn,
                                          @NotNull
                                          @NotNull java.lang.String path)

Creates new file inside specified Transaction with specified path and returns the File instance.

Parameters:

txn - Transaction instance

path - file path

Returns:

new File

Throws:

FileExistsException - if a File with specified path already exists

See Also:

createFile(Transaction, long, String), File

createFile

@NotNull
public @NotNull File createFile(@NotNull
                                          @NotNull jetbrains.exodus.env.Transaction txn,
                                          long fileDescriptor,
                                          @NotNull
                                          @NotNull java.lang.String path)

Creates new file inside specified Transaction with specified file descriptor and path and returns the File instance.

Parameters:

txn - Transaction instance

fileDescriptor - file descriptor

path - file path

Returns:

new File

Throws:

FileExistsException - if a File with specified path already exists

See Also:

createFile(Transaction, String), File, File.getDescriptor()

createUniqueFile

public File createUniqueFile(@NotNull
                             @NotNull jetbrains.exodus.env.Transaction txn,
                             @NotNull
                             @NotNull java.lang.String pathPrefix)

Creates new File with unique auto-generated path starting with specified pathPrefix.

Parameters:

txn - Transaction instance

pathPrefix - prefix which the path of the result will start from

Returns:

new File

See Also:

File, File.getPath()

openFile

@Nullable
public @Nullable File openFile(@NotNull
                                          @NotNull jetbrains.exodus.env.Transaction txn,
                                          @NotNull
                                          @NotNull java.lang.String path,
                                          boolean create)

Returns existing File with specified path or creates the new one if create is true, otherwise returns null. If create is true it never returns null.

Parameters:

txn - Transaction instance

path - file path

create - true if new file creation is allowed

Returns:

existing or newly created File if if create is true, or null

See Also:

File

renameFile

public boolean renameFile(@NotNull
                          @NotNull jetbrains.exodus.env.Transaction txn,
                          @NotNull
                          @NotNull File origin,
                          @NotNull
                          @NotNull java.lang.String newPath)

Renames origin file to the specified newPath and returns true if the file was actually renamed. Otherwise another file with the path newPath exists. File contents and file descriptor are not affected.

Parameters:

txn - Transaction instance

origin - origin File

newPath - new name of the file

Returns:

true if the file was actually renamed, otherwise another file with the path newPath exists

See Also:

File, File.getDescriptor()

deleteFile

@Nullable
public @Nullable File deleteFile(@NotNull
                                            @NotNull jetbrains.exodus.env.Transaction txn,
                                            @NotNull
                                            @NotNull java.lang.String path)

Deletes existing file with the specified path.

Parameters:

txn - Transaction instance

path - file path

Returns:

deleted File or null if no file with specified pathexists.

See Also:

File

getNumberOfFiles

public long getNumberOfFiles(@NotNull
                             @NotNull jetbrains.exodus.env.Transaction txn)

Parameters:

txn - Transaction instance

Returns:

total number of files in the VirtualFileSystem

getFiles

@NotNull
public @NotNull java.lang.Iterable<File> getFiles(@NotNull
                                                            @NotNull jetbrains.exodus.env.Transaction txn)

Parameters:

txn - Transaction instance

Returns:

Iterable to iterate over all the files in the VirtualFileSystem

See Also:

File

getFileLength

public long getFileLength(@NotNull
                          @NotNull jetbrains.exodus.env.Transaction txn,
                          @NotNull
                          @NotNull File file)

Parameters:

txn - Transaction instance

file - File instance

Returns:

length of specified file in bytes

See Also:

File

getFileLength

public long getFileLength(@NotNull
                          @NotNull jetbrains.exodus.env.Transaction txn,
                          long fileDescriptor)

Parameters:

txn - Transaction instance

fileDescriptor - file descriptor

Returns:

length of specified file in bytes

See Also:

File, File.getDescriptor()

diskUsage

public long diskUsage(@NotNull
                      @NotNull jetbrains.exodus.env.Transaction txn)

Returns total size of all the files in the filesystem.

Parameters:

txn - Transaction instance

Returns:

total size of all the files in the filesystem

readFile

public VfsInputStream readFile(@NotNull
                               @NotNull jetbrains.exodus.env.Transaction txn,
                               @NotNull
                               @NotNull File file)

Returns InputStream to read contents of the specified file from the beginning.

Parameters:

txn - Transaction instance

file - File instance

Returns:

InputStream to read contents of the specified file from the beginning

See Also:

readFile(Transaction, long), readFile(Transaction, File, long), writeFile(Transaction, File), writeFile(Transaction, long), writeFile(Transaction, File, long), writeFile(Transaction, long, long), appendFile(Transaction, File), touchFile(Transaction, File)

readFile

public VfsInputStream readFile(@NotNull
                               @NotNull jetbrains.exodus.env.Transaction txn,
                               long fileDescriptor)

Returns InputStream to read contents of the specified file from the beginning.

Parameters:

txn - Transaction instance

fileDescriptor - file descriptor

Returns:

InputStream to read contents of the specified file from the beginning

See Also:

readFile(Transaction, File), readFile(Transaction, File, long), writeFile(Transaction, File), writeFile(Transaction, long), writeFile(Transaction, File, long), writeFile(Transaction, long, long), appendFile(Transaction, File), touchFile(Transaction, File), File.getDescriptor()

readFile

@NotNull
public @NotNull VfsInputStream readFile(@NotNull
                                                  @NotNull jetbrains.exodus.env.Transaction txn,
                                                  @NotNull
                                                  @NotNull File file,
                                                  long fromPosition)

Returns InputStream to read contents of the specified file from the specified position.

Parameters:

txn - Transaction instance

file - File instance

fromPosition - file position to read from

Returns:

InputStream to read contents of the specified file from the specified position

See Also:

readFile(Transaction, File), readFile(Transaction, long), writeFile(Transaction, File), writeFile(Transaction, long), writeFile(Transaction, File, long), writeFile(Transaction, long, long), appendFile(Transaction, File), touchFile(Transaction, File)

touchFile

public void touchFile(@NotNull
                      @NotNull jetbrains.exodus.env.Transaction txn,
                      @NotNull
                      @NotNull File file)

Touches the specified File, i.e. sets its last modified time to current time.

Parameters:

txn - Transaction instance

file - File instance

See Also:

readFile(Transaction, File), readFile(Transaction, long), readFile(Transaction, File, long), writeFile(Transaction, File), writeFile(Transaction, long), writeFile(Transaction, File, long), writeFile(Transaction, long, long), appendFile(Transaction, File), File.getLastModified()

writeFile

public java.io.OutputStream writeFile(@NotNull
                                      @NotNull jetbrains.exodus.env.Transaction txn,
                                      @NotNull
                                      @NotNull File file)

Returns OutputStream to write the contents of the specified file from the beginning.

Parameters:

txn - Transaction instance

file - File instance

Returns:

OutputStream to write the contents of the specified file from the beginning

See Also:

readFile(Transaction, File), readFile(Transaction, long), readFile(Transaction, File, long), writeFile(Transaction, long), writeFile(Transaction, File, long), writeFile(Transaction, long, long), appendFile(Transaction, File), touchFile(Transaction, File)

writeFile

public java.io.OutputStream writeFile(@NotNull
                                      @NotNull jetbrains.exodus.env.Transaction txn,
                                      @NotNull
                                      @NotNull File file,
                                      long fromPosition)

Returns OutputStream to write the contents of the specified file from the specified position. If the position is greater than the file length then the method returns the same stream as appendFile(Transaction, File) does.

Parameters:

txn - Transaction instance

file - File instance

fromPosition - file position to write from

Returns:

OutputStream to write the contents of the specified file from the specified position

See Also:

readFile(Transaction, File), readFile(Transaction, long), readFile(Transaction, File, long), writeFile(Transaction, File), writeFile(Transaction, long), writeFile(Transaction, long, long), appendFile(Transaction, File), touchFile(Transaction, File)

writeFile

public java.io.OutputStream writeFile(@NotNull
                                      @NotNull jetbrains.exodus.env.Transaction txn,
                                      long fileDescriptor)

Returns OutputStream to write the contents of the specified file from the beginning. Writing to the returned stream doesn't change the File's last modified time.

Parameters:

txn - Transaction instance

fileDescriptor - file descriptor

Returns:

OutputStream to write the contents of the specified file from the beginning

See Also:

readFile(Transaction, File), readFile(Transaction, long), readFile(Transaction, File, long), writeFile(Transaction, File), writeFile(Transaction, File, long), writeFile(Transaction, long, long), appendFile(Transaction, File), touchFile(Transaction, File), File.getDescriptor(), File.getLastModified()

writeFile

public java.io.OutputStream writeFile(@NotNull
                                      @NotNull jetbrains.exodus.env.Transaction txn,
                                      long fileDescriptor,
                                      long fromPosition)

Returns OutputStream to write the contents of the specified file from the specified position. If the position is greater than the file length then the method returns the same stream as appendFile(Transaction, File) does. Writing to the returned stream doesn't change the File's last modified time.

Parameters:

txn - Transaction instance

fileDescriptor - file descriptor

fromPosition - file position to write from

Returns:

OutputStream to write the contents of the specified file from the specified position

See Also:

readFile(Transaction, File), readFile(Transaction, long), readFile(Transaction, File, long), writeFile(Transaction, File), writeFile(Transaction, long), writeFile(Transaction, File, long), appendFile(Transaction, File), touchFile(Transaction, File), File.getDescriptor(), File.getLastModified()

appendFile

public java.io.OutputStream appendFile(@NotNull
                                       @NotNull jetbrains.exodus.env.Transaction txn,
                                       @NotNull
                                       @NotNull File file)

Returns OutputStream to write the contents of the specified file from the end of the file. If the file is empty the contents is written from the beginning.

Parameters:

txn - Transaction instance

file - File instance

Returns:

@linkplain OutputStream} to write the contents of the specified file from the end of the file

See Also:

readFile(Transaction, File), readFile(Transaction, long), readFile(Transaction, File, long), writeFile(Transaction, File), writeFile(Transaction, long), writeFile(Transaction, File, long), writeFile(Transaction, long, long), touchFile(Transaction, File)

shutdown

public void shutdown()

Shuts down the VirtualFileSystem.

getConfig

public VfsConfig getConfig()

Returns:

VfsConfig used to create the VirtualFileSystem

getCancellingPolicyProvider

@Nullable
public @Nullable IOCancellingPolicyProvider getCancellingPolicyProvider()

setCancellingPolicyProvider

public void setCancellingPolicyProvider(@NotNull
                                        @NotNull IOCancellingPolicyProvider cancellingPolicyProvider)

getClusterConverter

@Nullable
public @Nullable ClusterConverter getClusterConverter()

setClusterConverter

public void setClusterConverter(@Nullable
                                @Nullable ClusterConverter clusterConverter)

dump

public void dump(@NotNull
                 @NotNull jetbrains.exodus.env.Transaction txn,
                 @NotNull
                 @NotNull java.nio.file.Path directory)
          throws java.io.IOException

Throws:

java.io.IOException