public final class DfsReader extends ObjectReader implements ObjectReuseAsIs
See the base ObjectReader documentation for details. Notably, a
reader is not thread safe.
OBJ_ANY| Modifier and Type | Method and Description |
|---|---|
void |
copyObjectAsIs(PackOutputStream out,
ObjectToPack otp,
boolean validate)
Output a previously selected representation.
|
void |
copyPackAsIs(PackOutputStream out,
CachedPack pack,
boolean validate)
Append an entire pack's contents onto the output stream.
|
BitmapIndex |
getBitmapIndex()
An index that can be used to speed up ObjectWalks.
|
Collection<CachedPack> |
getCachedPacksAndUpdate(BitmapIndex.BitmapBuilder needBitmap)
Obtain the available cached packs that match the bitmap and update
the bitmap by removing the items that are in the CachedPack.
|
long |
getObjectSize(AnyObjectId objectId,
int typeHint)
Get only the size of an object.
|
<T extends ObjectId> |
getObjectSize(Iterable<T> objectIds,
boolean reportMissing)
Asynchronous object size lookup.
|
Set<ObjectId> |
getShallowCommits()
Returns IDs for those commits which should be considered as shallow.
|
boolean |
has(AnyObjectId objectId)
Does the requested object exist in this database?
|
org.eclipse.jgit.internal.storage.dfs.DfsObjectToPack |
newObjectToPack(AnyObjectId objectId,
int type)
Allocate a new
PackWriter state structure for an object. |
ObjectReader |
newReader()
Construct a new reader from the same data.
|
ObjectLoader |
open(AnyObjectId objectId,
int typeHint)
Open an object from this database.
|
<T extends ObjectId> |
open(Iterable<T> objectIds,
boolean reportMissing)
Asynchronous object opening.
|
void |
release()
Release the current window cursor.
|
Collection<ObjectId> |
resolve(AbbreviatedObjectId id)
Resolve an abbreviated ObjectId to its full form.
|
void |
selectObjectRepresentation(PackWriter packer,
ProgressMonitor monitor,
Iterable<ObjectToPack> objects)
Select the best object representation for a packer.
|
void |
setAvoidUnreachableObjects(boolean avoid)
Advise the reader to avoid unreachable objects.
|
void |
writeObjects(PackOutputStream out,
List<ObjectToPack> list)
Write objects to the pack stream in roughly the order given.
|
abbreviate, abbreviate, has, open, walkAdviceBeginCommits, walkAdviceBeginTrees, walkAdviceEndpublic ObjectReader newReader()
ObjectReaderApplications can use this method to build a new reader from the same data source, but for an different thread.
newReader in class ObjectReaderpublic void setAvoidUnreachableObjects(boolean avoid)
ObjectReaderWhile enabled the reader will skip over anything previously proven to be unreachable. This may be dangerous in the face of concurrent writes.
setAvoidUnreachableObjects in class ObjectReaderavoid - true to avoid unreachable objects.public BitmapIndex getBitmapIndex() throws IOException
ObjectReadergetBitmapIndex in class ObjectReaderIOException - when the index fails to loadpublic Collection<CachedPack> getCachedPacksAndUpdate(BitmapIndex.BitmapBuilder needBitmap) throws IOException
ObjectReuseAsIsA cached pack has known starting points and may be sent entirely as-is, with almost no effort on the sender's part.
getCachedPacksAndUpdate in interface ObjectReuseAsIsneedBitmap - the bitmap that contains all of the objects the client wants.IOException - the cached packs cannot be listed from the repository.
Callers may choose to ignore this and continue as-if there
were no cached packs.public Collection<ObjectId> resolve(AbbreviatedObjectId id) throws IOException
ObjectReaderresolve in class ObjectReaderid - abbreviated id to resolve to a complete identity. The
abbreviation must have a length of at least 2.IOException - the object store cannot be read.public boolean has(AnyObjectId objectId) throws IOException
ObjectReaderhas in class ObjectReaderobjectId - identity of the object to test for existence of.IOException - the object store cannot be accessed.public ObjectLoader open(AnyObjectId objectId, int typeHint) throws MissingObjectException, IncorrectObjectTypeException, IOException
ObjectReaderopen in class ObjectReaderobjectId - identity of the object to open.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.ObjectLoader for accessing the object.MissingObjectException - the object does not exist.IncorrectObjectTypeException - typeHint was not OBJ_ANY, and the object's actual type does
not match typeHint.IOException - the object store cannot be accessed.public Set<ObjectId> getShallowCommits()
ObjectReadergetShallowCommits in class ObjectReaderpublic <T extends ObjectId> AsyncObjectLoaderQueue<T> open(Iterable<T> objectIds, boolean reportMissing)
ObjectReaderopen in class ObjectReaderT - type of identifier being supplied.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.public <T extends ObjectId> AsyncObjectSizeQueue<T> getObjectSize(Iterable<T> objectIds, boolean reportMissing)
ObjectReadergetObjectSize in class ObjectReaderT - type of identifier being supplied.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.public long getObjectSize(AnyObjectId objectId, int typeHint) throws MissingObjectException, IncorrectObjectTypeException, IOException
ObjectReaderThe default implementation of this method opens an ObjectLoader. Databases are encouraged to override this if a faster access method is available to them.
getObjectSize in class ObjectReaderobjectId - identity of the object to open.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.MissingObjectException - the object does not exist.IncorrectObjectTypeException - typeHint was not OBJ_ANY, and the object's actual type does
not match typeHint.IOException - the object store cannot be accessed.public org.eclipse.jgit.internal.storage.dfs.DfsObjectToPack newObjectToPack(AnyObjectId objectId, int type)
ObjectReuseAsIsPackWriter state structure for an object.
PackWriter allocates these objects to keep track of the
per-object state, and how to load the objects efficiently into the
generated stream. Implementers may subclass this type with additional
object state, such as to remember what file and offset contains the
object's pack encoded data.
newObjectToPack in interface ObjectReuseAsIsobjectId - the id of the object that will be packed.type - the Git type of the object that will be packed.public void selectObjectRepresentation(PackWriter packer, ProgressMonitor monitor, Iterable<ObjectToPack> objects) throws IOException, MissingObjectException
ObjectReuseAsIs
Implementations should iterate through all available representations of
an object, and pass them in turn to the PackWriter though
PackWriter.select(ObjectToPack, StoredObjectRepresentation) so
the writer can select the most suitable representation to reuse into the
output stream.
If the implementation returns CachedPack from #getCachedPacksAndUpdate(BitmapBuilder)
it must consider the representation of any object that is stored in any
of the offered CachedPacks. PackWriter relies on this behavior to prune
duplicate objects out of the pack stream when it selects a CachedPack and
the object was also reached through the thin-pack enumeration.
The implementation may choose to consider multiple objects at once on concurrent threads, but must evaluate all representations of an object within the same thread.
selectObjectRepresentation in interface ObjectReuseAsIspacker - the packer that will write the object in the near future.monitor - progress monitor, implementation should update the monitor
once for each item in the iteration when selection is done.objects - the objects that are being packed.MissingObjectException - there is no representation available for the object, as it is
no longer in the repository. Packing will abort.IOException - the repository cannot be accessed. Packing will abort.public void copyObjectAsIs(PackOutputStream out, ObjectToPack otp, boolean validate) throws IOException, StoredObjectRepresentationNotAvailableException
ObjectReuseAsIs
PackWriter invokes this method only if a representation
previously given to it by selectObjectRepresentation was chosen
for reuse into the output stream. The otp argument is an instance
created by this reader's own newObjectToPack, and the
representation data saved within it also originated from this reader.
Implementors must write the object header before copying the raw data to the output stream. The typical implementation is like:
MyToPack mtp = (MyToPack) otp;
byte[] raw;
if (validate)
raw = validate(mtp); // throw SORNAE here, if at all
else
raw = readFast(mtp);
out.writeHeader(mtp, mtp.inflatedSize);
out.write(raw);
copyObjectAsIs in interface ObjectReuseAsIsout - stream the object should be written to.otp - the object's saved representation information.validate - if true the representation must be validated and not be
corrupt before being reused. If false, validation may be
skipped as it will be performed elsewhere in the processing
pipeline.IOException - the stream's write method threw an exception. Packing will
abort.StoredObjectRepresentationNotAvailableException - the previously selected representation is no longer
available. If thrown before out.writeHeader the pack
writer will try to find another representation, and write
that one instead. If throw after out.writeHeader,
packing will abort.public void writeObjects(PackOutputStream out, List<ObjectToPack> list) throws IOException
ObjectReuseAsIsPackWriter invokes this method to write out one or more objects,
in approximately the order specified by the iteration over the list. A
simple implementation of this method would just iterate the list and
output each object:
for (ObjectToPack obj : list) out.writeObject(obj)However more sophisticated implementors may try to perform some (small) reordering to access objects that are stored close to each other at roughly the same time. Implementations may choose to write objects out of order, but this may increase pack file size due to using a larger header format to reach a delta base that is later in the stream. It may also reduce data locality for the reader, slowing down data access. Invoking
PackOutputStream.writeObject(ObjectToPack) will cause
ObjectReuseAsIs.copyObjectAsIs(PackOutputStream, ObjectToPack, boolean) to be
invoked recursively on this if the current object is scheduled
for reuse.writeObjects in interface ObjectReuseAsIsout - the stream to write each object to.list - the list of objects to write. Objects should be written in
approximately this order. Implementors may resort the list
elements in-place during writing if desired.IOException - the stream cannot be written to, or one or more required
objects cannot be accessed from the object database.public void copyPackAsIs(PackOutputStream out, CachedPack pack, boolean validate) throws IOException
ObjectReuseAsIsThe entire pack, excluding its header and trailing footer is sent.
copyPackAsIs in interface ObjectReuseAsIsout - stream to append the pack onto.pack - the cached pack to send.validate - if true the representation must be validated and not be
corrupt before being reused. If false, validation may be
skipped as it will be performed elsewhere in the processing
pipeline.IOException - the pack cannot be read, or stream did not accept a write.public void release()
release in class ObjectReaderCopyright © 2013. All rights reserved.