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

Class Pack

java.lang.Object

org.eclipse.jgit.internal.storage.file.Pack

All Implemented Interfaces:

java.lang.Iterable<PackIndex.MutableEntry>

public class Pack
extends java.lang.Object
implements java.lang.Iterable<PackIndex.MutableEntry>

A Git version 2 pack file representation. A pack file contains Git objects in delta packed format yielding high compression of lots of object where some objects are similar.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private static class	Pack.Delta

Field Summary

Fields

Modifier and Type	Field	Description
private int	activeCopyRawData
private int	activeWindows
private PackBitmapIndex	bitmapIdx
private PackFile	bitmapIdxFile
private LongList	corruptObjects	Objects we have tried to read, and discovered to be corrupt.
private java.io.RandomAccessFile	fd
private PackFileSnapshot	fileSnapshot
(package private) int	hash
private boolean	invalid
private java.lang.Exception	invalidatingCause
private PackFile	keepFile
(package private) long	length
private PackIndex	loadedIdx
private static org.slf4j.Logger	LOG
private byte[]	packChecksum
private PackFile	packFile
(package private) java.time.Instant	packLastModified
private java.lang.Object	readLock	Serializes reads performed against fd.
private PackReverseIndex	reverseIdx
static java.util.Comparator<Pack>	SORT	Sorts PackFiles to be most recently created to least recently created.
private java.util.concurrent.atomic.AtomicInteger	transientErrorCount

Constructor Summary

Constructors

Constructor	Description
Pack(java.io.File packFile, PackFile bitmapIdxFile)	Construct a reader for an existing, pre-indexed packfile.

Method Summary

Modifier and Type	Method	Description
private void	beginCopyAsIs(ObjectToPack otp)
(package private) boolean	beginWindowCache()
void	close()	Close the resources utilized by this repository
(package private) void	copyAsIs(PackOutputStream out, LocalObjectToPack src, boolean validate, WindowCursor curs)
private void	copyAsIs2(PackOutputStream out, LocalObjectToPack src, boolean validate, WindowCursor curs)
(package private) void	copyPackAsIs(PackOutputStream out, WindowCursor curs)
private byte[]	decompress(long position, int sz, WindowCursor curs)
private void	doClose()
private void	doOpen()
private void	endCopyAsIs()
(package private) boolean	endWindowCache()
private long	findDeltaBase(ObjectId baseId)
private long	findEndOffset(long startOffset)
(package private) ObjectId	findObjectForOffset(long offset)	Search for object id with the specified start offset in associated pack (reverse) index.
(package private) ObjectLoader	get(WindowCursor curs, AnyObjectId id)	Get an object from this pack.
(package private) PackBitmapIndex	getBitmapIndex()
(package private) byte[]	getDeltaHeader(WindowCursor wc, long pos)
(package private) PackFileSnapshot	getFileSnapshot()	Return the @FileSnapshot associated to the underlying packfile that has been used when the object was created.
PackIndex	getIndex()	Get the index for this pack file.
(package private) long	getObjectCount()	Obtain the total number of objects available in this pack.
(package private) long	getObjectSize(WindowCursor curs, long pos)
(package private) long	getObjectSize(WindowCursor curs, AnyObjectId id)
(package private) int	getObjectType(WindowCursor curs, long pos)
(package private) AnyObjectId	getPackChecksum()
PackFile	getPackFile()	Get the File object which locates this pack on disk.
java.lang.String	getPackName()	Get name extracted from pack-*.pack pattern.
private PackReverseIndex	getReverseIdx()
boolean	hasObject(AnyObjectId id)	Determine if an object is contained within the pack file.
private PackIndex	idx()
(package private) int	incrementTransientErrorCount()
(package private) boolean	invalid()
private boolean	isCorrupt(long offset)
java.util.Iterator<PackIndex.MutableEntry>	iterator()
(package private) ObjectLoader	load(WindowCursor curs, long pos)
(package private) ByteWindow	mmap(long pos, int size)
private void	onOpenPack()
private void	openFail(boolean invalidate, java.lang.Exception cause)
(package private) ByteArrayWindow	read(long pos, int size)
private void	readFully(long position, byte[] dstbuf, int dstoff, int cnt, WindowCursor curs)
(package private) LocalObjectRepresentation	representation(WindowCursor curs, AnyObjectId objectId)
(package private) void	resetTransientErrorCount()
(package private) void	resolve(java.util.Set<ObjectId> matches, AbbreviatedObjectId id, int matchLimit)
private void	setCorrupt(long offset)
(package private) void	setInvalid()
boolean	shouldBeKept()	Determines whether a .keep file exists for this pack file.
java.lang.String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Field Detail

LOG

private static final org.slf4j.Logger LOG

SORT

public static final java.util.Comparator<Pack> SORT

Sorts PackFiles to be most recently created to least recently created.

packFile

private final PackFile packFile

keepFile

private PackFile keepFile

hash

final int hash

fd

private java.io.RandomAccessFile fd

readLock

private final java.lang.Object readLock

Serializes reads performed against fd.

length

long length

activeWindows

private int activeWindows

activeCopyRawData

private int activeCopyRawData

packLastModified

java.time.Instant packLastModified

fileSnapshot

private PackFileSnapshot fileSnapshot

invalid

private volatile boolean invalid

invalidatingCause

private volatile java.lang.Exception invalidatingCause

bitmapIdxFile

@Nullable
private PackFile bitmapIdxFile

transientErrorCount

private java.util.concurrent.atomic.AtomicInteger transientErrorCount

packChecksum

private byte[] packChecksum

loadedIdx

private volatile PackIndex loadedIdx

reverseIdx

private PackReverseIndex reverseIdx

bitmapIdx

private PackBitmapIndex bitmapIdx

corruptObjects

private volatile LongList corruptObjects

Objects we have tried to read, and discovered to be corrupt.

The list is allocated after the first corruption is found, and filled in as more entries are discovered. Typically this list is never used, as pack files do not usually contain corrupt objects.

Constructor Detail

Pack

public Pack(java.io.File packFile,
            @Nullable
            PackFile bitmapIdxFile)

Construct a reader for an existing, pre-indexed packfile.

Parameters:

packFile - path of the .pack file holding the data.

bitmapIdxFile - existing bitmap index file with the same base as the pack

Method Detail

idx

private PackIndex idx()
               throws java.io.IOException

Throws:

java.io.IOException

getPackFile

public PackFile getPackFile()

Get the File object which locates this pack on disk.

Returns:

the File object which locates this pack on disk.

getIndex

public PackIndex getIndex()
                   throws java.io.IOException

Get the index for this pack file.

Returns:

the index for this pack file.

Throws:

java.io.IOException

getPackName

public java.lang.String getPackName()

Get name extracted from pack-*.pack pattern.

Returns:

name extracted from pack-*.pack pattern.

hasObject

public boolean hasObject(AnyObjectId id)
                  throws java.io.IOException

Determine if an object is contained within the pack file.

For performance reasons only the index file is searched; the main pack content is ignored entirely.

Parameters:

id - the object to look for. Must not be null.

Returns:

true if the object is in this pack; false otherwise.

Throws:

java.io.IOException - the index file cannot be loaded into memory.

shouldBeKept

public boolean shouldBeKept()

Determines whether a .keep file exists for this pack file.

Returns:

true if a .keep file exist.

get

ObjectLoader get(WindowCursor curs,
                 AnyObjectId id)
          throws java.io.IOException

Get an object from this pack.

Parameters:

curs - temporary working space associated with the calling thread.

id - the object to obtain from the pack. Must not be null.

Returns:

the object loader for the requested object if it is contained in this pack; null if the object was not found.

Throws:

java.io.IOException - the pack file or the index could not be read.

resolve

void resolve(java.util.Set<ObjectId> matches,
             AbbreviatedObjectId id,
             int matchLimit)
      throws java.io.IOException

Throws:

java.io.IOException

close

public void close()

Close the resources utilized by this repository

iterator

public java.util.Iterator<PackIndex.MutableEntry> iterator()

Provide iterator over entries in associated pack index, that should also exist in this pack file. Objects returned by such iterator are mutable during iteration.

Iterator returns objects in SHA-1 lexicographical order.

Specified by:

iterator in interface java.lang.Iterable<PackIndex.MutableEntry>

See Also:

PackIndex.iterator()

getObjectCount

long getObjectCount()
             throws java.io.IOException

Obtain the total number of objects available in this pack. This method relies on pack index, giving number of effectively available objects.

Returns:

number of objects in index of this pack, likewise in this pack

Throws:

java.io.IOException - the index file cannot be loaded into memory.

findObjectForOffset

ObjectId findObjectForOffset(long offset)
                      throws java.io.IOException

Search for object id with the specified start offset in associated pack (reverse) index.

Parameters:

offset - start offset of object to find

Returns:

object id for this offset, or null if no object was found

Throws:

java.io.IOException - the index file cannot be loaded into memory.

getFileSnapshot

PackFileSnapshot getFileSnapshot()

Return the @FileSnapshot associated to the underlying packfile that has been used when the object was created.

Returns:

the packfile @FileSnapshot that the object is loaded from.

getPackChecksum

AnyObjectId getPackChecksum()

decompress

private final byte[] decompress(long position,
                                int sz,
                                WindowCursor curs)
                         throws java.io.IOException,
                                java.util.zip.DataFormatException

Throws:

java.io.IOException

java.util.zip.DataFormatException

copyPackAsIs

void copyPackAsIs(PackOutputStream out,
                  WindowCursor curs)
           throws java.io.IOException

Throws:

java.io.IOException

copyAsIs

final void copyAsIs(PackOutputStream out,
                    LocalObjectToPack src,
                    boolean validate,
                    WindowCursor curs)
             throws java.io.IOException,
                    StoredObjectRepresentationNotAvailableException

Throws:

java.io.IOException

StoredObjectRepresentationNotAvailableException

copyAsIs2

private void copyAsIs2(PackOutputStream out,
                       LocalObjectToPack src,
                       boolean validate,
                       WindowCursor curs)
                throws java.io.IOException,
                       StoredObjectRepresentationNotAvailableException

Throws:

java.io.IOException

StoredObjectRepresentationNotAvailableException

invalid

boolean invalid()

setInvalid

void setInvalid()

incrementTransientErrorCount

int incrementTransientErrorCount()

resetTransientErrorCount

void resetTransientErrorCount()

readFully

private void readFully(long position,
                       byte[] dstbuf,
                       int dstoff,
                       int cnt,
                       WindowCursor curs)
                throws java.io.IOException

Throws:

java.io.IOException

beginCopyAsIs

private void beginCopyAsIs(ObjectToPack otp)
                    throws StoredObjectRepresentationNotAvailableException

Throws:

StoredObjectRepresentationNotAvailableException

endCopyAsIs

private void endCopyAsIs()

beginWindowCache

boolean beginWindowCache()
                  throws java.io.IOException

Throws:

java.io.IOException

endWindowCache

boolean endWindowCache()

doOpen

private void doOpen()
             throws java.io.IOException

Throws:

java.io.IOException

openFail

private void openFail(boolean invalidate,
                      java.lang.Exception cause)

doClose

private void doClose()

read

ByteArrayWindow read(long pos,
                     int size)
              throws java.io.IOException

Throws:

java.io.IOException

mmap

ByteWindow mmap(long pos,
                int size)
         throws java.io.IOException

Throws:

java.io.IOException

onOpenPack

private void onOpenPack()
                 throws java.io.IOException

Throws:

java.io.IOException

load

ObjectLoader load(WindowCursor curs,
                  long pos)
           throws java.io.IOException,
                  LargeObjectException

Throws:

java.io.IOException

LargeObjectException

findDeltaBase

private long findDeltaBase(ObjectId baseId)
                    throws java.io.IOException,
                           MissingObjectException

Throws:

java.io.IOException

MissingObjectException

getDeltaHeader

byte[] getDeltaHeader(WindowCursor wc,
                      long pos)
               throws java.io.IOException,
                      java.util.zip.DataFormatException

Throws:

java.io.IOException

java.util.zip.DataFormatException

getObjectType

int getObjectType(WindowCursor curs,
                  long pos)
           throws java.io.IOException

Throws:

java.io.IOException

getObjectSize

long getObjectSize(WindowCursor curs,
                   AnyObjectId id)
            throws java.io.IOException

Throws:

java.io.IOException

getObjectSize

long getObjectSize(WindowCursor curs,
                   long pos)
            throws java.io.IOException

Throws:

java.io.IOException

representation

LocalObjectRepresentation representation(WindowCursor curs,
                                         AnyObjectId objectId)
                                  throws java.io.IOException

Throws:

java.io.IOException

findEndOffset

private long findEndOffset(long startOffset)
                    throws java.io.IOException,
                           CorruptObjectException

Throws:

java.io.IOException

CorruptObjectException

getBitmapIndex

PackBitmapIndex getBitmapIndex()
                        throws java.io.IOException

Throws:

java.io.IOException

getReverseIdx

private PackReverseIndex getReverseIdx()
                                throws java.io.IOException

Throws:

java.io.IOException

isCorrupt

private boolean isCorrupt(long offset)

setCorrupt

private void setCorrupt(long offset)

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object