Package org.eclipse.jgit.lib

Class ObjectReader.Filter

  • All Implemented Interfaces:
    AutoCloseable
    Enclosing class:
    ObjectReader
    public abstract static class ObjectReader.Filter
extends ObjectReader
    Wraps a delegate ObjectReader.
    Since:
    4.4

    • Constructor Detail

      • Filter

        public Filter()

    • Method Detail

      • delegate

        protected abstract ObjectReader delegate()
        Returns:
        delegate ObjectReader to handle all processing.
        Since:
        4.4

      • newReader

        public ObjectReader newReader()
        Description copied from class: ObjectReader
        Construct a new reader from the same data.

        Applications can use this method to build a new reader from the same data source, but for an different thread.

        Specified by:
        newReader in class ObjectReader
        Returns:
        a brand new reader, using the same data source.

      • abbreviate

        public AbbreviatedObjectId abbreviate​(AnyObjectId objectId)
                               throws IOException
        Description copied from class: ObjectReader
        Obtain a unique abbreviation (prefix) of an object SHA-1. This method uses a reasonable default for the minimum length. Callers who don't care about the minimum length should prefer this method. The returned abbreviation would expand back to the argument ObjectId when passed to ObjectReader.resolve(AbbreviatedObjectId), assuming no new objects are added to this repository between calls.
        Overrides:
        abbreviate in class ObjectReader
        Parameters:
        objectId - object identity that needs to be abbreviated.
        Returns:
        SHA-1 abbreviation.
        Throws:
        IOException - the object store cannot be read.

      • abbreviate

        public AbbreviatedObjectId abbreviate​(AnyObjectId objectId,
                                      int len)
                               throws IOException
        Description copied from class: ObjectReader
        Obtain a unique abbreviation (prefix) of an object SHA-1. The returned abbreviation would expand back to the argument ObjectId when passed to ObjectReader.resolve(AbbreviatedObjectId), assuming no new objects are added to this repository between calls. The default implementation of this method abbreviates the id to the minimum length, then resolves it to see if there are multiple results. When multiple results are found, the length is extended by 1 and resolve is tried again.
        Overrides:
        abbreviate in class ObjectReader
        Parameters:
        objectId - object identity that needs to be abbreviated.
        len - minimum length of the abbreviated string. Must be in the range [2, 40].
        Returns:
        SHA-1 abbreviation. If no matching objects exist in the repository, the abbreviation will match the minimum length.
        Throws:
        IOException - the object store cannot be read.

      • resolve

        public Collection<ObjectId> resolve​(AbbreviatedObjectId id)
                             throws IOException
        Description copied from class: ObjectReader
        Resolve an abbreviated ObjectId to its full form. This method searches for an ObjectId that begins with the abbreviation, and returns at least some matching candidates. If the returned collection is empty, no objects start with this abbreviation. The abbreviation doesn't belong to this repository, or the repository lacks the necessary objects to complete it. If the collection contains exactly one member, the abbreviation is (currently) unique within this database. There is a reasonably high probability that the returned id is what was previously abbreviated. If the collection contains 2 or more members, the abbreviation is not unique. In this case the implementation is only required to return at least 2 candidates to signal the abbreviation has conflicts. User friendly implementations should return as many candidates as reasonably possible, as the caller may be able to disambiguate further based on context. However since databases can be very large (e.g. 10 million objects) returning 625,000 candidates for the abbreviation "0" is simply unreasonable, so implementors should draw the line at around 256 matches.
        Specified by:
        resolve in class ObjectReader
        Parameters:
        id - abbreviated id to resolve to a complete identity. The abbreviation must have a length of at least 2.
        Returns:
        candidates that begin with the abbreviated identity.
        Throws:
        IOException - the object store cannot be read.

      • has

        public boolean has​(AnyObjectId objectId)
            throws IOException
        Description copied from class: ObjectReader
        Does the requested object exist in this database?
        Overrides:
        has in class ObjectReader
        Parameters:
        objectId - identity of the object to test for existence of.
        Returns:
        true if the specified object is stored in this database.
        Throws:
        IOException - the object store cannot be accessed.

      • has

        public boolean has​(AnyObjectId objectId,
                   int typeHint)
            throws IOException
        Description copied from class: ObjectReader
        Does the requested object exist in this database?
        Overrides:
        has in class ObjectReader
        Parameters:
        objectId - identity of the object to test for existence of.
        typeHint - hint about the type of object being requested, e.g. Constants.OBJ_BLOB; ObjectReader.OBJ_ANY if the object type is not known, or does not matter to the caller.
        Returns:
        true if the specified object is stored in this database.
        Throws:
        IncorrectObjectTypeException - typeHint was not OBJ_ANY, and the object's actual type does not match typeHint.
        IOException - the object store cannot be accessed.

      • open

        public <T extends ObjectId> AsyncObjectLoaderQueue<T> open​(Iterable<T> objectIds,
                                                           boolean reportMissing)
        Description copied from class: ObjectReader
        Asynchronous object opening.
        Overrides:
        open in class ObjectReader
        Parameters:
        objectIds - objects to open from the object store. The supplied collection must not be modified until the queue has finished.
        reportMissing - if true missing objects are reported by calling failure with a MissingObjectException. This may be more expensive for the implementation to guarantee. If false the implementation may choose to report MissingObjectException, or silently skip over the object with no warning.
        Returns:
        queue to read the objects from.

      • getObjectSize

        public <T extends ObjectId> AsyncObjectSizeQueue<T> getObjectSize​(Iterable<T> objectIds,
                                                                  boolean reportMissing)
        Description copied from class: ObjectReader
        Asynchronous object size lookup.
        Overrides:
        getObjectSize in class ObjectReader
        Parameters:
        objectIds - objects to get the size of from the object store. The supplied collection must not be modified until the queue has finished.
        reportMissing - if true missing objects are reported by calling failure with a MissingObjectException. This may be more expensive for the implementation to guarantee. If false the implementation may choose to report MissingObjectException, or silently skip over the object with no warning.
        Returns:
        queue to read object sizes from.

      • setAvoidUnreachableObjects

        public void setAvoidUnreachableObjects​(boolean avoid)
        Description copied from class: ObjectReader
        Advise the reader to avoid unreachable objects.

        While enabled the reader will skip over anything previously proven to be unreachable. This may be dangerous in the face of concurrent writes.

        Overrides:
        setAvoidUnreachableObjects in class ObjectReader
        Parameters:
        avoid - true to avoid unreachable objects.

      • close

        public void close()
        Description copied from class: ObjectReader

        Release any resources used by this reader.

        A reader that has been released can be used again, but may need to be released after the subsequent usage.

        Specified by:
        close in interface AutoCloseable
        Specified by:
        close in class ObjectReader