Package ghidra.formats.gfilesystem

Class FileCache

java.lang.Object

ghidra.formats.gfilesystem.FileCache

public class FileCache
extends java.lang.Object

File caching implementation.

Caches files based on a hash of the contents of the file.
Files are retrieved using the hash string.
Cached files are stored in a file with a name that is the hex encoded value of the hash.
Cached files are obfuscated/de-obfuscated when written/read to/from disk. See ObfuscatedFileByteProvider, ObfuscatedInputStream, ObfuscatedOutputStream.
Cached files are organized into a nested directory structure to prevent overwhelming a single directory with thousands of files.

Nested directory structure is based on the file's name:

   File: AABBCCDDEEFF... → AA/AABBCCDDEEFF...

Cache size is not bounded.

Cache maintenance is done during startup if interval since last maintenance has been exceeded.

Files are not removed from the cache after being added, except during startup maintenance.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	FileCache.FileCacheEntry	Represents a cached file.
class	FileCache.FileCacheEntryBuilder	Allows creating file cache entries at the caller's convenience.

Field Summary

Fields

Modifier and Type	Field	Description
static int	MAX_INMEM_FILESIZE	Max size of a file that will be kept in memCache (2Mb)
static int	MD5_HEXSTR_LEN

Constructor Summary

Constructors

Constructor	Description
FileCache(java.io.File cacheDir)	Creates a new FileCache instance where files are stored under the specified cacheDir

Method Summary

Modifier and Type	Method	Description
static void	performCacheMaintOnOldDirIfNeeded(java.io.File oldCacheDir)	Deprecated, for removal: This API element is subject to removal in a future version. Marked as deprecated to ensure this is removed in a few versions after most user's old-style cache dirs have been cleaned up.
void	purge()	Deletes all stored files from this file cache that are under a "NN" two hex digit nesting dir.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

MAX_INMEM_FILESIZE

public static final int MAX_INMEM_FILESIZE

Max size of a file that will be kept in memCache (2Mb)

See Also:

Constant Field Values

MD5_HEXSTR_LEN

public static final int MD5_HEXSTR_LEN

See Also:

Constant Field Values

Constructor Detail

FileCache

public FileCache(java.io.File cacheDir)
          throws java.io.IOException

Creates a new FileCache instance where files are stored under the specified cacheDir

Parameters:

cacheDir - where to store the files

Throws:

java.io.IOException - if there was a problem creating subdirectories under cacheDir or when pruning expired files.

Method Detail

performCacheMaintOnOldDirIfNeeded

@Deprecated(forRemoval=true,
            since="10.1")
public static void performCacheMaintOnOldDirIfNeeded(java.io.File oldCacheDir)

Deprecated, for removal: This API element is subject to removal in a future version.

Marked as deprecated to ensure this is removed in a few versions after most user's old-style cache dirs have been cleaned up.

Backwards compatible with previous cache directories to age off the files located therein.

Parameters:

oldCacheDir - the old 2-level cache directory

purge

public void purge()

Deletes all stored files from this file cache that are under a "NN" two hex digit nesting dir.

Will cause other processes which are accessing or updating the cache to error.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object