org.eclipse.jgit.internal.storage.file

Class ObjectDirectory

java.lang.Object

org.eclipse.jgit.lib.ObjectDatabase

org.eclipse.jgit.internal.storage.file.ObjectDirectory

public class ObjectDirectory
extends ObjectDatabase

Traditional file system based ObjectDatabase.

This is the classical object database representation for a Git repository, where objects are stored loose by hashing them into directories by their ObjectId, or are stored in compressed containers known as PackFiles.

Optionally an object database can reference one or more alternates; other ObjectDatabase instances that are searched in addition to the current database.

Databases are divided into two halves: a half that is considered to be fast to search (the PackFiles), and a half that is considered to be slow to search (loose objects). When alternates are present the fast half is fully searched (recursively through all alternates) before the slow half is considered.

Constructor Summary

Constructors

Constructor and Description
ObjectDirectory(Config cfg, File dir, File[] alternatePaths, FS fs, File shallowFile) Initialize a reference to an on-disk object directory.

Method Summary

Modifier and Type	Method and Description
void	close() Close any resources held by this database.
void	create() Initialize a new object database at this location.
boolean	exists() Does this database exist yet?
File	fileFor(AnyObjectId objectId)
File	getDirectory()
File	getPackDirectory() Getter for the field packDirectory.
Collection<PackFile>	getPacks()
File	getPreservedDirectory() Getter for the field preservedDirectory.
boolean	has(AnyObjectId objectId) Does the requested object exist in this database?
ObjectDatabase	newCachedDatabase() Create a new cached database instance over this database.
org.eclipse.jgit.internal.storage.file.ObjectDirectoryInserter	newInserter() Create a new ObjectInserter to insert new objects.
PackInserter	newPackInserter() Create a new inserter that inserts all objects as pack files, not loose objects.
ObjectReader	newReader() Create a new ObjectReader to read existing objects.
PackFile	openPack(File pack)
String	toString()

Methods inherited from class org.eclipse.jgit.lib.ObjectDatabase

open, open

Methods inherited from class java.lang.Object

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

Constructor Detail

ObjectDirectory

public ObjectDirectory(Config cfg,
                       File dir,
                       File[] alternatePaths,
                       FS fs,
                       File shallowFile)
                throws IOException

Initialize a reference to an on-disk object directory.

Parameters:

cfg - configuration this directory consults for write settings.

dir - the location of the objects directory.

alternatePaths - a list of alternate object directories

fs - the file system abstraction which will be necessary to perform certain file system operations.

shallowFile - file which contains IDs of shallow commits, null if shallow commits handling should be turned off

Throws:

IOException - an alternate object cannot be opened.

Method Detail

getDirectory

public final File getDirectory()

getPackDirectory

public final File getPackDirectory()

Getter for the field packDirectory.

Returns:

the location of the pack directory.

Since:

4.10

getPreservedDirectory

public final File getPreservedDirectory()

Getter for the field preservedDirectory.

Returns:

the location of the preserved directory.

exists

public boolean exists()

Does this database exist yet?

Overrides:

exists in class ObjectDatabase

Returns:

true if this database is already created; false if the caller should invoke ObjectDatabase.create() to create this database location.

create

public void create()
            throws IOException

Initialize a new object database at this location.

Overrides:

create in class ObjectDatabase

Throws:

IOException - the database could not be created.

newInserter

public org.eclipse.jgit.internal.storage.file.ObjectDirectoryInserter newInserter()

Create a new ObjectInserter to insert new objects.

The returned inserter is not itself thread-safe, but multiple concurrent inserter instances created from the same ObjectDatabase must be thread-safe.

Returns:

writer the caller can use to create objects in this database.

newPackInserter

public PackInserter newPackInserter()

Create a new inserter that inserts all objects as pack files, not loose objects.

Returns:

new inserter.

close

public void close()

Close any resources held by this database.

Specified by:

close in class ObjectDatabase

getPacks

public Collection<PackFile> getPacks()

openPack

public PackFile openPack(File pack)
                  throws IOException

Add a single existing pack to the list of available pack files.

Throws:

IOException

toString

public String toString()

Overrides:

toString in class Object

has

public boolean has(AnyObjectId objectId)

Does the requested object exist in this database?

This is a one-shot call interface which may be faster than allocating a ObjectDatabase.newReader() to perform the lookup.

Overrides:

has in class ObjectDatabase

Parameters:

objectId - identity of the object to test for existence of.

Returns:

true if the specified object is stored in this database.

fileFor

public File fileFor(AnyObjectId objectId)

Compute the location of a loose object file.

newCachedDatabase

public ObjectDatabase newCachedDatabase()

Create a new cached database instance over this database. This instance might optimize queries by caching some information about database. So some modifications done after instance creation might fail to be noticed.

Overrides:

newCachedDatabase in class ObjectDatabase

Returns:

new cached database instance

newReader

public ObjectReader newReader()

Create a new ObjectReader to read existing objects.

The returned reader is not itself thread-safe, but multiple concurrent reader instances created from the same ObjectDatabase must be thread-safe.

Specified by:

newReader in class ObjectDatabase

Returns:

reader the caller can use to load objects from this database.