Module org.cryptomator.cryptofs

Package org.cryptomator.cryptofs.common

Class BackupHelper

java.lang.Object

org.cryptomator.cryptofs.common.BackupHelper

public final class BackupHelper
extends Object

Utility class for generating a suffix for the backup file to make it unique to its original file.

Method Summary

Modifier and Type	Method	Description
static Path	attemptBackup(Path path)	Do a best-effort attempt to back up the file at the given path.
static String	generateFileIdSuffix(byte[] fileBytes)	Computes the SHA-256 digest of the given byte array and returns a file suffix containing the first 4 bytes in hex string format.

Methods inherited from class java.lang.Object

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

Method Details

generateFileIdSuffix

public static String generateFileIdSuffix(byte[] fileBytes)

Computes the SHA-256 digest of the given byte array and returns a file suffix containing the first 4 bytes in hex string format.

Parameters:

fileBytes - the input byte for which the digest is computed

Returns:

"." + first 4 bytes of SHA-256 digest in hex string format

attemptBackup

public static Path attemptBackup(Path path)
                          throws IOException

Do a best-effort attempt to back up the file at the given path. Fails silently if a _valid_ backup already exists and fails with a log entry, if any IO error occurs while creating or reading the backup file.

Parameters:

path - The file to back up

Throws:

IOException - If the path cannot be read.