org.eclipse.jgit.lib

Interface Ref

All Known Implementing Classes:

ObjectIdRef, ObjectIdRef.PeeledNonTag, ObjectIdRef.PeeledTag, ObjectIdRef.Unpeeled, SymbolicRef

public interface Ref

Pairing of a name and the ObjectId it currently has.

A ref in Git is (more or less) a variable that holds a single object identifier. The object identifier can be any valid Git object (blob, tree, commit, annotated tag, ...).

The ref name has the attributes of the ref that was asked for as well as the ref it was resolved to for symbolic refs plus the object id it points to and (for tags) the peeled target object id, i.e. the tag resolved recursively until a non-tag object is referenced.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	Ref.Storage Location where a Ref is stored.

Method Summary

Modifier and Type	Method and Description
Ref	getLeaf() Traverse target references until isSymbolic() is false.
String	getName() What this ref is called within the repository.
ObjectId	getObjectId() Cached value of this ref.
ObjectId	getPeeledObjectId() Cached value of ref^{} (the ref peeled to commit).
Ref.Storage	getStorage() How was this ref obtained?
Ref	getTarget() Get the reference this reference points to, or this.
boolean	isPeeled() Whether the Ref represents a peeled tag.
boolean	isSymbolic() Test if this reference is a symbolic reference.

Method Detail

getName

@NonNull
String getName()

What this ref is called within the repository.

Returns:

name of this ref.

isSymbolic

boolean isSymbolic()

Test if this reference is a symbolic reference.

A symbolic reference does not have its own ObjectId value, but instead points to another Ref in the same database and always uses that other reference's value as its own.

Returns:

true if this is a symbolic reference; false if this reference contains its own ObjectId.

getLeaf

@NonNull
Ref getLeaf()

Traverse target references until isSymbolic() is false.

If isSymbolic() is false, returns this.

If isSymbolic() is true, this method recursively traverses getTarget() until isSymbolic() returns false.

This method is effectively

 return isSymbolic() ? getTarget().getLeaf() : this;
 

Returns:

the reference that actually stores the ObjectId value.

getTarget

@NonNull
Ref getTarget()

Get the reference this reference points to, or this.

If isSymbolic() is true this method returns the reference it directly names, which might not be the leaf reference, but could be another symbolic reference.

If this is a leaf level reference that contains its own ObjectId,this method returns this.

Returns:

the target reference, or this.

getObjectId

@Nullable
ObjectId getObjectId()

Cached value of this ref.

Returns:

the value of this ref at the last time we read it. May be null to indicate a ref that does not exist yet or a symbolic ref pointing to an unborn branch.

getPeeledObjectId

@Nullable
ObjectId getPeeledObjectId()

Cached value of ref^{} (the ref peeled to commit).

Returns:

if this ref is an annotated tag the id of the commit (or tree or blob) that the annotated tag refers to; null if this ref does not refer to an annotated tag.

isPeeled

boolean isPeeled()

Whether the Ref represents a peeled tag.

Returns:

whether the Ref represents a peeled tag.

getStorage

@NonNull
Ref.Storage getStorage()

How was this ref obtained?

The current storage model of a Ref may influence how the ref must be updated or deleted from the repository.

Returns:

type of ref.