org.eclipse.jgit.util

Class FS_POSIX

java.lang.Object

org.eclipse.jgit.util.FS

org.eclipse.jgit.util.FS_POSIX

public class FS_POSIX
extends FS

Base FS for POSIX based systems

Since:

3.0

Nested Class Summary

Nested classes/interfaces inherited from class org.eclipse.jgit.util.FS

FS.Attributes, FS.ExecutionResult, FS.FileStoreAttributes, FS.FSFactory, FS.LockToken

Field Summary

Fields inherited from class org.eclipse.jgit.util.FS

DETECTED, NO_ENTRIES

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	FS_POSIX() Default constructor.
protected	FS_POSIX(FS src) Constructor

Method Summary

Modifier and Type	Method and Description
boolean	canExecute(File f) Determine if the file is executable (or not).
boolean	createNewFile(File lock) Deprecated.
FS.LockToken	createNewFileAtomic(File file) Create a new file.
protected File	discoverGitExe() Discover the path to the Git executable.
File	findHook(Repository repository, String hookName) Tries to find a hook matching the given one in the given repository.
FS.Attributes	getAttributes(File path) Get the file attributes we care for.
boolean	isCaseSensitive() Is this file system case sensitive
FS	newInstance() Create a new instance of the same type of FS.
File	normalize(File file) Normalize the unicode path to composed form.
String	normalize(String name) Normalize the unicode path to composed form.
boolean	retryFailedLockFileCommit() Does this file system have problems with atomic renames?
ProcessResult	runHookIfPresent(Repository repository, String hookName, String[] args, PrintStream outRedirect, PrintStream errRedirect, String stdinArgs) Checks whether the given hook is defined for the given repository, then runs it with the given arguments.
ProcessBuilder	runInShell(String cmd, String[] args) Initialize a ProcessBuilder to run a command using the system shell.
boolean	setExecute(File f, boolean canExecute) Set a file to be executable by the user.
void	setHidden(File path, boolean hidden) Set the hidden attribute for file whose name starts with a period.
void	setUmask(int umask) Set the umask, overriding any value observed from the shell.
boolean	supportsAtomicCreateNewFile() Does this file system support atomic file creation via java.io.File#createNewFile()? In certain environments (e.g.
boolean	supportsExecute() Does this operating system and JRE support the execute flag on files?
boolean	supportsSymlinks() Does this operating system and JRE supports symbolic links.

Methods inherited from class org.eclipse.jgit.util.FS

createSymLink, delete, detect, detect, discoverGitSystemConfig, execute, exists, fileAttributes, getFileStoreAttributes, getGitSystemConfig, internalRunHookIfPresent, isDirectory, isFile, isHidden, isSymLink, lastModified, lastModifiedInstant, lastModifiedInstant, length, list, readPipe, readPipe, readSymLink, relativize, resolve, resolveGrandparentFile, runHookIfPresent, runProcess, runProcess, searchPath, setAsyncFileStoreAttributes, setGitSystemConfig, setLastModified, setLastModified, setUserHome, userHome, userHomeImpl

Methods inherited from class java.lang.Object

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

Constructor Detail

FS_POSIX

protected FS_POSIX()

Default constructor.

FS_POSIX

protected FS_POSIX(FS src)

Constructor

Parameters:

src - FS to copy some settings from

Method Detail

newInstance

public FS newInstance()

Create a new instance of the same type of FS.

Specified by:

newInstance in class FS

Returns:

a new instance of the same type of FS.

setUmask

public void setUmask(int umask)

Set the umask, overriding any value observed from the shell.

Parameters:

umask - mask to apply when creating files.

Since:

4.0

discoverGitExe

protected File discoverGitExe()

Discover the path to the Git executable.

Specified by:

discoverGitExe in class FS

Returns:

the path to the Git executable or null if it cannot be determined.

isCaseSensitive

public boolean isCaseSensitive()

Is this file system case sensitive

Specified by:

isCaseSensitive in class FS

Returns:

true if this implementation is case sensitive

supportsExecute

public boolean supportsExecute()

Does this operating system and JRE support the execute flag on files?

Specified by:

supportsExecute in class FS

Returns:

true if this implementation can provide reasonably accurate executable bit information; false otherwise.

canExecute

public boolean canExecute(File f)

Determine if the file is executable (or not).

Not all platforms and JREs support executable flags on files. If the feature is unsupported this method will always return false.

If the platform supports symbolic links and f is a symbolic link this method returns false, rather than the state of the executable flags on the target file.

Specified by:

canExecute in class FS

Parameters:

f - abstract path to test.

Returns:

true if the file is believed to be executable by the user.

setExecute

public boolean setExecute(File f,
                          boolean canExecute)

Set a file to be executable by the user.

Not all platforms and JREs support executable flags on files. If the feature is unsupported this method will always return false and no changes will be made to the file specified.

Specified by:

setExecute in class FS

Parameters:

f - path to modify the executable status of.

canExecute - true to enable execution; false to disable it.

Returns:

true if the change succeeded; false otherwise.

runInShell

public ProcessBuilder runInShell(String cmd,
                                 String[] args)

Initialize a ProcessBuilder to run a command using the system shell.

Specified by:

runInShell in class FS

Parameters:

cmd - command to execute. This string should originate from the end-user, and thus is platform specific.

args - arguments to pass to command. These should be protected from shell evaluation.

Returns:

a partially completed process builder. Caller should finish populating directory, environment, and then start the process.

runHookIfPresent

public ProcessResult runHookIfPresent(Repository repository,
                                      String hookName,
                                      String[] args,
                                      PrintStream outRedirect,
                                      PrintStream errRedirect,
                                      String stdinArgs)
                               throws JGitInternalException

Checks whether the given hook is defined for the given repository, then runs it with the given arguments.

Overrides:

runHookIfPresent in class FS

Parameters:

repository - The repository for which a hook should be run.

hookName - The name of the hook to be executed.

args - Arguments to pass to this hook. Cannot be null, but can be an empty array.

outRedirect - A print stream on which to redirect the hook's stdout. Can be null, in which case the hook's standard output will be lost.

errRedirect - A print stream on which to redirect the hook's stderr. Can be null, in which case the hook's standard error will be lost.

stdinArgs - A string to pass on to the standard input of the hook. May be null.

Returns:

The ProcessResult describing this hook's execution.

Throws:

JGitInternalException - if we fail to run the hook somehow. Causes may include an interrupted process or I/O errors.

retryFailedLockFileCommit

public boolean retryFailedLockFileCommit()

Does this file system have problems with atomic renames?

Specified by:

retryFailedLockFileCommit in class FS

Returns:

true if the caller should retry a failed rename of a lock file.

supportsSymlinks

public boolean supportsSymlinks()

Does this operating system and JRE supports symbolic links. The capability to handle symbolic links is detected at runtime.

Overrides:

supportsSymlinks in class FS

Returns:

true if symbolic links may be used

setHidden

public void setHidden(File path,
                      boolean hidden)
               throws IOException

Set the hidden attribute for file whose name starts with a period.

Overrides:

setHidden in class FS

Parameters:

path - a File object.

hidden - whether to set the file hidden

Throws:

IOException

getAttributes

public FS.Attributes getAttributes(File path)

Get the file attributes we care for.

Overrides:

getAttributes in class FS

Parameters:

path - a File object.

Returns:

the file attributes we care for.

normalize

public File normalize(File file)

Normalize the unicode path to composed form.

Overrides:

normalize in class FS

Parameters:

file - a File object.

Returns:

NFC-format File

normalize

public String normalize(String name)

Normalize the unicode path to composed form.

Overrides:

normalize in class FS

Parameters:

name - path name

Returns:

NFC-format string

findHook

public File findHook(Repository repository,
                     String hookName)

Tries to find a hook matching the given one in the given repository.

Overrides:

findHook in class FS

Parameters:

repository - The repository within which to find a hook.

hookName - The name of the hook we're trying to find.

Returns:

The File containing this particular hook if it exists in the given repository, null otherwise.

supportsAtomicCreateNewFile

public boolean supportsAtomicCreateNewFile()

Does this file system support atomic file creation via java.io.File#createNewFile()? In certain environments (e.g. on NFS) it is not guaranteed that when two file system clients run createNewFile() in parallel only one will succeed. In such cases both clients may think they created a new file.

Overrides:

supportsAtomicCreateNewFile in class FS

Returns:

true if this implementation support atomic creation of new Files by File.createNewFile()

createNewFile

@Deprecated
public boolean createNewFile(File lock)
                                  throws IOException

Deprecated.

Description copied from class: FS

Create a new file. See File.createNewFile(). Subclasses of this class may take care to provide a safe implementation for this even if FS.supportsAtomicCreateNewFile() is false

Overrides:

createNewFile in class FS

Parameters:

lock - the file to be created

Returns:

true if the file was created, false if the file already existed

Throws:

IOException

createNewFileAtomic

public FS.LockToken createNewFileAtomic(File file)
                                 throws IOException

Create a new file. See File.createNewFile(). Subclasses of this class may take care to provide a safe implementation for this even if FS.supportsAtomicCreateNewFile() is false

An implementation of the File#createNewFile() semantics which can create a unique file atomically also on NFS. If the config option core.supportsAtomicCreateNewFile = true (which is the default) then simply Files#createFile() is called. But if core.supportsAtomicCreateNewFile = false then after successful creation of the lock file a hard link to that lock file is created and the attribute nlink of the lock file is checked to be 2. If multiple clients manage to create the same lock file nlink would be greater than 2 showing the error. The hard link needs to be retained until the corresponding file is no longer needed in order to prevent that another process can create the same file concurrently using another NFS client which might not yet see the file due to caching.

Overrides:

createNewFileAtomic in class FS

Parameters:

file - the unique file to be created atomically

Returns:

LockToken this lock token must be held until the file is no longer needed

Throws:

IOException

Since:

5.0

See Also:

"https://www.time-travellers.org/shane/papers/NFS_considered_harmful.html"