Package org.eclipse.jgit.internal.storage.file

Class RefDirectory

  • public class RefDirectory
extends RefDatabase
    Traditional file system based RefDatabase.

    This is the classical reference database representation for a Git repository. References are stored in two formats: loose, and packed.

    Loose references are stored as individual files within the refs/ directory. The file name matches the reference name and the file contents is the current ObjectId in string form.

    Packed references are stored in a single text file named packed-refs. In the packed format, each reference is stored on its own line. This file reduces the number of files needed for large reference spaces, reducing the overall size of a Git repository on disk.

    • Field Detail

      • SYMREF

        public static final String SYMREF
        Magic string denoting the start of a symbolic reference file.
        See Also:
        Constant Field Values

      • PACKED_REFS_HEADER

        public static final String PACKED_REFS_HEADER
        Magic string denoting the header of a packed-refs file.
        See Also:
        Constant Field Values

      • PACKED_REFS_PEELED

        public static final String PACKED_REFS_PEELED
        If in the header, denotes the file has peeled data.
        See Also:
        Constant Field Values

    • Method Detail

      • close

        public void close()
        Description copied from class: RefDatabase
        Close any resources held by this database.
        Specified by:
        close in class RefDatabase

      • refresh

        public void refresh()
        Description copied from class: RefDatabase
        Triggers a refresh of all internal data structures.

        In case the RefDatabase implementation has internal caches this method will trigger that all these caches are cleared.

        Implementors should overwrite this method if they use any kind of caches.

        Overrides:
        refresh in class RefDatabase

      • isNameConflicting

        public boolean isNameConflicting​(String name)
                          throws IOException
        Description copied from class: RefDatabase
        Determine if a proposed reference name overlaps with an existing one.

        Reference names use '/' as a component separator, and may be stored in a hierarchical storage such as a directory on the local filesystem.

        If the reference "refs/heads/foo" exists then "refs/heads/foo/bar" must not exist, as a reference cannot have a value and also be a container for other references at the same time.

        If the reference "refs/heads/foo/bar" exists than the reference "refs/heads/foo" cannot exist, for the same reason.

        Specified by:
        isNameConflicting in class RefDatabase
        Parameters:
        name - proposed name.
        Returns:
        true if the name overlaps with an existing reference; false if using this name right now would be safe.
        Throws:
        IOException - the database could not be read to check for conflicts.
        See Also:
        RefDatabase.getConflictingNames(String)

      • getRef

        public Ref getRef​(String needle)
           throws IOException
        Description copied from class: RefDatabase
        Read a single reference.

        Aside from taking advantage of RefDatabase.SEARCH_PATH, this method may be able to more quickly resolve a single reference name than obtaining the complete namespace by getRefs(ALL).get(name).

        Specified by:
        getRef in class RefDatabase
        Parameters:
        needle - the name of the reference. May be a short name which must be searched for using the standard RefDatabase.SEARCH_PATH.
        Returns:
        the reference (if it exists); else null.
        Throws:
        IOException - the reference space cannot be accessed.

      • getRefs

        public Map<String,​Ref> getRefs​(String prefix)
                              throws IOException
        Description copied from class: RefDatabase
        Get a section of the reference namespace.
        Specified by:
        getRefs in class RefDatabase
        Parameters:
        prefix - prefix to search the namespace with; must end with /. If the empty string (RefDatabase.ALL), obtain a complete snapshot of all references.
        Returns:
        modifiable map that is a complete snapshot of the current reference namespace, with prefix removed from the start of each key. The map can be an unsorted map.
        Throws:
        IOException - the reference space cannot be accessed.

      • getAdditionalRefs

        public List<Ref> getAdditionalRefs()
                            throws IOException
        Description copied from class: RefDatabase
        Get the additional reference-like entities from the repository.

        The result list includes non-ref items such as MERGE_HEAD and FETCH_RESULT cast to be refs. The names of these refs are not returned by getRefs(ALL) but are accepted by RefDatabase.getRef(String)

        Specified by:
        getAdditionalRefs in class RefDatabase
        Returns:
        a list of additional refs
        Throws:
        IOException - the reference space cannot be accessed.

      • peel

        public Ref peel​(Ref ref)
         throws IOException
        Description copied from class: RefDatabase
        Peel a possibly unpeeled reference by traversing the annotated tags.

        If the reference cannot be peeled (as it does not refer to an annotated tag) the peeled id stays null, but Ref.isPeeled() will be true.

        Implementors should check Ref.isPeeled() before performing any additional work effort.

        Specified by:
        peel in class RefDatabase
        Parameters:
        ref - The reference to peel
        Returns:
        ref if ref.isPeeled() is true; otherwise a new Ref object representing the same data as Ref, but isPeeled() will be true and getPeeledObjectId() will contain the peeled object (or null).
        Throws:
        IOException - the reference space or object space cannot be accessed.

      • newUpdate

        public org.eclipse.jgit.internal.storage.file.RefDirectoryUpdate newUpdate​(String name,
                                                                           boolean detach)
                                                                    throws IOException
        Description copied from class: RefDatabase
        Create a new update command to create, modify or delete a reference.
        Specified by:
        newUpdate in class RefDatabase
        Parameters:
        name - the name of the reference.
        detach - if true and name is currently a SymbolicRef, the update will replace it with an ObjectIdRef. Otherwise, the update will recursively traverse SymbolicRefs and operate on the leaf ObjectIdRef.
        Returns:
        a new update for the requested name; never null.
        Throws:
        IOException - the reference space cannot be accessed.

      • newRename

        public org.eclipse.jgit.internal.storage.file.RefDirectoryRename newRename​(String fromName,
                                                                           String toName)
                                                                    throws IOException
        Description copied from class: RefDatabase
        Create a new update command to rename a reference.
        Specified by:
        newRename in class RefDatabase
        Parameters:
        fromName - name of reference to rename from
        toName - name of reference to rename to
        Returns:
        an update command that knows how to rename a branch to another.
        Throws:
        IOException - the reference space cannot be accessed.

      • pack

        public void pack​(List<String> refs)
          throws IOException
        Adds a set of refs to the set of packed-refs. Only non-symbolic refs are added. If a ref with the given name already existed in packed-refs it is updated with the new value. Each loose ref which was added to the packed-ref file is deleted. If a given ref can't be locked it will not be added to the pack file.
        Parameters:
        refs - the refs to be added. Must be fully qualified.
        Throws:
        IOException