Package org.eclipse.jgit.internal.storage.reftree

Class RefTree

java.lang.Object

org.eclipse.jgit.internal.storage.reftree.RefTree

public class RefTree
extends java.lang.Object

Tree of references in the reference graph.

The root corresponds to the "refs/" subdirectory, for example the default reference "refs/heads/master" is stored at path "heads/master" in a RefTree.

Normal references are stored as FileMode.GITLINK tree entries. The ObjectId in the tree entry is the ObjectId the reference refers to.

Symbolic references are stored as FileMode.SYMLINK entries, with the blob storing the name of the target reference.

Annotated tags also store the peeled object using a GITLINK entry with the suffix " ^" (space carrot), for example "tags/v1.0" stores the annotated tag object, while "tags/v1.0 ^" stores the commit the tag annotates.

HEAD is a special case and stored as "..HEAD".

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private static class	RefTree.LockFailureException

Field Summary

Fields

Modifier and Type	Field	Description
private DirCache	contents
static java.lang.String	PEELED_SUFFIX	Suffix applied to GITLINK to indicate its the peeled value of a tag.
private java.util.Map<ObjectId,java.lang.String>	pendingBlobs
(package private) static java.lang.String	ROOT_DOTDOT

Constructor Summary

Constructors

Modifier	Constructor	Description
private	RefTree(DirCache dc)

Method Summary

Modifier and Type	Method	Description
boolean	apply(java.util.Collection<Command> cmdList)	Attempt a batch of commands against this RefTree.
private void	apply(DirCacheEditor ed, Command cmd)
private static void	checkRef(DirCacheEntry ent, Command cmd)
private static void	cleanupPeeledRef(DirCacheEditor ed, Ref ref)
RefTree	copy()	Create a deep copy of this RefTree.
Ref	exactRef(ObjectReader reader, java.lang.String name)	Read one reference.
private static boolean	isValidRef(Command cmd)
static RefTree	newEmptyTree()	Create an empty reference tree.
private static java.lang.String	peeledPath(java.lang.String name)
static RefTree	read(ObjectReader reader, RevTree tree)	Load a reference tree.
private Ref	readRef(ObjectReader reader, java.lang.String name)
static java.lang.String	refName(java.lang.String path)	Convert a path name in a RefTree to the reference name known by Git.
(package private) static java.lang.String	refPath(java.lang.String name)
private Ref	resolve(ObjectReader reader, Ref ref, int depth)
private Ref	toRef(ObjectReader reader, DirCacheEntry e, java.lang.String name)
ObjectId	writeTree(ObjectInserter inserter)	Write this reference tree.

Methods inherited from class java.lang.Object

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

Field Detail

PEELED_SUFFIX

public static final java.lang.String PEELED_SUFFIX

Suffix applied to GITLINK to indicate its the peeled value of a tag.

See Also:

Constant Field Values

ROOT_DOTDOT

static final java.lang.String ROOT_DOTDOT

See Also:

Constant Field Values

contents

private DirCache contents

pendingBlobs

private java.util.Map<ObjectId,java.lang.String> pendingBlobs

Constructor Detail

RefTree

private RefTree(DirCache dc)

Method Detail

newEmptyTree

public static RefTree newEmptyTree()

Create an empty reference tree.

Returns:

a new empty reference tree.

read

public static RefTree read(ObjectReader reader,
                           RevTree tree)
                    throws MissingObjectException,
                           IncorrectObjectTypeException,
                           CorruptObjectException,
                           java.io.IOException

Load a reference tree.

Parameters:

reader - reader to scan the reference tree with.

tree - the tree to read.

Returns:

the ref tree read from the commit.

Throws:

java.io.IOException - the repository cannot be accessed through the reader.

CorruptObjectException - a tree object is corrupt and cannot be read.

IncorrectObjectTypeException - a tree object wasn't actually a tree.

MissingObjectException - a reference tree object doesn't exist.

exactRef

@Nullable
public Ref exactRef(ObjectReader reader,
                    java.lang.String name)
             throws java.io.IOException

Read one reference.

References are always returned peeled (Ref.isPeeled() is true). If the reference points to an annotated tag, the returned reference will be peeled and contain Ref.getPeeledObjectId().

If the reference is a symbolic reference and the chain depth is less than RefDatabase.MAX_SYMBOLIC_REF_DEPTH the returned reference is resolved. If the chain depth is longer, the symbolic reference is returned without resolving.

Parameters:

reader - to access objects necessary to read the requested reference.

name - name of the reference to read.

Returns:

the reference; null if it does not exist.

Throws:

java.io.IOException - cannot read a symbolic reference target.

readRef

private Ref readRef(ObjectReader reader,
                    java.lang.String name)
             throws java.io.IOException

Throws:

java.io.IOException

toRef

private Ref toRef(ObjectReader reader,
                  DirCacheEntry e,
                  java.lang.String name)
           throws java.io.IOException

Throws:

java.io.IOException

resolve

private Ref resolve(ObjectReader reader,
                    Ref ref,
                    int depth)
             throws java.io.IOException

Throws:

java.io.IOException

apply

public boolean apply(java.util.Collection<Command> cmdList)

Attempt a batch of commands against this RefTree.

The batch is applied atomically, either all commands apply at once, or they all reject and the RefTree is left unmodified.

On success (when this method returns true) the command results are left as-is (probably NOT_ATTEMPTED). Result fields are set only when this method returns false to indicate failure.

Parameters:

cmdList - to apply. All commands should still have result NOT_ATTEMPTED.

Returns:

true if the commands applied; false if they were rejected.

isValidRef

private static boolean isValidRef(Command cmd)

apply

private void apply(DirCacheEditor ed,
                   Command cmd)

checkRef

private static void checkRef(@Nullable
                             DirCacheEntry ent,
                             Command cmd)

cleanupPeeledRef

private static void cleanupPeeledRef(DirCacheEditor ed,
                                     Ref ref)

refName

public static java.lang.String refName(java.lang.String path)

Convert a path name in a RefTree to the reference name known by Git.

Parameters:

path - name read from the RefTree structure, for example "heads/master".

Returns:

reference name for the path, "refs/heads/master".

refPath

static java.lang.String refPath(java.lang.String name)

peeledPath

private static java.lang.String peeledPath(java.lang.String name)

writeTree

public ObjectId writeTree(ObjectInserter inserter)
                   throws java.io.IOException

Write this reference tree.

Parameters:

inserter - inserter to use when writing trees to the object database. Caller is responsible for flushing the inserter before trying to read the objects, or exposing them through a reference.

Returns:

the top level tree.

Throws:

java.io.IOException - a tree could not be written.

copy

public RefTree copy()

Create a deep copy of this RefTree.

Returns:

a deep copy of this RefTree.