Package ghidra.formats.gfilesystem

Class FileSystemCache

java.lang.Object

ghidra.formats.gfilesystem.FileSystemCache

All Implemented Interfaces:

FileSystemEventListener

public class FileSystemCache
extends java.lang.Object
implements FileSystemEventListener

A threadsafe cache of GFileSystem instances (organized by their FSRLRoot)

Any filesystems that are not referenced by outside users (via a FileSystemRef) will be closed and removed from the cache when the next cacheMaint() is performed.

Constructor Summary

Constructors

Constructor	Description
FileSystemCache(GFileSystem rootFS)	Creates a new FileSystemCache object.

Method Summary

Modifier and Type	Method	Description
void	add(GFileSystem fs)	Adds a new GFileSystem to the cache.
void	cacheMaint()	Performs maintainence on the filesystem cache, closing() any filesystems that are not used anymore.
void	clear()	Forcefully closes any filesystems in the cache, then clears the list of cached filesystems.
void	closeAllUnused()	Removes any unused filesystems in the cache.
FileSystemRef	getFilesystemRefMountedAt(FSRL containerFSRL)	Returns a new FileSystemRef to a already mounted filesystem (keeping the filesystem pinned in memory without the risk of it being closed during a race condition).
java.util.List<FSRLRoot>	getMountedFilesystems()	Returns a list of mounted file systems.
FileSystemRef	getRef(FSRLRoot fsrl)	Returns a new FileSystemRef to an existing, already open filesystem.
boolean	isFilesystemMountedAt(FSRL containerFSRL)	Returns true if there is a filesystem in the cache that has a containerFSRL that is equiv to the specified FSRL.
void	onFilesystemClose(GFileSystem fs)	Called by GFilesystem's Closeable.close(), before any destructive changes are made to the filesystem instance.
void	onFilesystemRefChange(GFileSystem fs, FileSystemRefManager refManager)	Called by FileSystemRefManager when a new FileSystemRef is created or released.

Methods inherited from class java.lang.Object

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

Constructor Detail

FileSystemCache

public FileSystemCache(GFileSystem rootFS)

Creates a new FileSystemCache object.

Parameters:

rootFS - reference to the global root file system, which is a special case file system that is not subject to eviction.

Method Detail

clear

public void clear()

Forcefully closes any filesystems in the cache, then clears the list of cached filesystems.

closeAllUnused

public void closeAllUnused()

Removes any unused filesystems in the cache.

getMountedFilesystems

public java.util.List<FSRLRoot> getMountedFilesystems()

Returns a list of mounted file systems.

Returns:

List of FSRLRoot of filesystems that are currently mounted.

add

public void add(GFileSystem fs)

Adds a new GFileSystem to the cache.

Parameters:

fs - GFileSystem to add to this cache.

getRef

public FileSystemRef getRef(FSRLRoot fsrl)

Returns a new FileSystemRef to an existing, already open filesystem. Caller is responsible for closing it.

Returns NULL if the requested filesystem isn't already open and mounted in the cache.

Parameters:

fsrl - FSRLRoot of the desired filesystem.

Returns:

a new FileSystemRef or null if the filesystem is not currently mounted.

isFilesystemMountedAt

public boolean isFilesystemMountedAt(FSRL containerFSRL)

Returns true if there is a filesystem in the cache that has a containerFSRL that is equiv to the specified FSRL.

Parameters:

containerFSRL - FSRL location to query for currently mounted filesystem.

Returns:

true if there is a filesystem mounted using that containerFSRL.

getFilesystemRefMountedAt

public FileSystemRef getFilesystemRefMountedAt(FSRL containerFSRL)

Returns a new FileSystemRef to a already mounted filesystem (keeping the filesystem pinned in memory without the risk of it being closed during a race condition).

The caller is responsible for closing it when done.

Returns null if there is no filesystem mounted at the requested container fsrl.

Parameters:

containerFSRL - FSRL location where a filesystem is already mounted

Returns:

new FileSystemRef to the already mounted filesystem, or null

onFilesystemClose

public void onFilesystemClose(GFileSystem fs)

Description copied from interface: FileSystemEventListener

Called by GFilesystem's Closeable.close(), before any destructive changes are made to the filesystem instance.

Specified by:

onFilesystemClose in interface FileSystemEventListener

Parameters:

fs - GFileSystem that is about to be closed.

onFilesystemRefChange

public void onFilesystemRefChange(GFileSystem fs,
                                  FileSystemRefManager refManager)

Description copied from interface: FileSystemEventListener

Called by FileSystemRefManager when a new FileSystemRef is created or released.

Specified by:

onFilesystemRefChange in interface FileSystemEventListener

Parameters:

fs - GFileSystem that is being updated.

refManager - FileSystemRefManager that is tracking the modified GFileSystem.

cacheMaint

public void cacheMaint()

Performs maintainence on the filesystem cache, closing() any filesystems that are not used anymore.