Class 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 Description
      ObjectDirectory​(Config cfg, java.io.File dir, java.io.File[] alternatePaths, FS fs, java.io.File shallowFile)
      Initialize a reference to an on-disk object directory.
    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method 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?
      java.io.File fileFor​(AnyObjectId objectId)
      Compute the location of a loose object file.
      java.io.File getDirectory()  
      java.util.Collection<PackFile> getPacks()  
      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.
      ObjectReader newReader()
      Create a new ObjectReader to read existing objects.
      PackFile openPack​(java.io.File pack)
      Add a single existing pack to the list of available pack files.
      java.lang.String toString()  
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
    • Constructor Detail

      • ObjectDirectory

        public ObjectDirectory​(Config cfg,
                               java.io.File dir,
                               java.io.File[] alternatePaths,
                               FS fs,
                               java.io.File shallowFile)
                        throws java.io.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:
        java.io.IOException - an alternate object cannot be opened.
    • Method Detail

      • getDirectory

        public final java.io.File getDirectory()
        Returns:
        the location of the objects directory.
      • exists

        public boolean exists()
        Description copied from class: ObjectDatabase
        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 java.io.IOException
        Description copied from class: ObjectDatabase
        Initialize a new object database at this location.
        Overrides:
        create in class ObjectDatabase
        Throws:
        java.io.IOException - the database could not be created.
      • newInserter

        public org.eclipse.jgit.internal.storage.file.ObjectDirectoryInserter newInserter()
        Description copied from class: ObjectDatabase
        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.
      • close

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

        public java.util.Collection<PackFile> getPacks()
        Returns:
        unmodifiable collection of all known pack files local to this directory. Most recent packs are presented first. Packs most likely to contain more recent objects appear before packs containing objects referenced by commits further back in the history of the repository.
      • openPack

        public PackFile openPack​(java.io.File pack)
                          throws java.io.IOException
        Add a single existing pack to the list of available pack files.
        Parameters:
        pack - path of the pack file to open.
        Returns:
        the pack that was opened and added to the database.
        Throws:
        java.io.IOException - index file could not be opened, read, or is not recognized as a Git pack file index.
      • toString

        public java.lang.String toString()
        Overrides:
        toString in class java.lang.Object
      • has

        public boolean has​(AnyObjectId objectId)
        Description copied from class: ObjectDatabase
        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 java.io.File fileFor​(AnyObjectId objectId)
        Compute the location of a loose object file.
        Parameters:
        objectId - identity of the loose object to map to the directory.
        Returns:
        location of the object, if it were to exist as a loose object.
      • newCachedDatabase

        public ObjectDatabase newCachedDatabase()
        Description copied from class: ObjectDatabase
        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()
        Description copied from class: ObjectDatabase
        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.