org.eclipse.jgit.storage.file
Class ObjectDirectoryPackParser

java.lang.Object
  extended by org.eclipse.jgit.transport.PackParser
      extended by org.eclipse.jgit.storage.file.ObjectDirectoryPackParser

public class ObjectDirectoryPackParser
extends PackParser

Consumes a pack stream and stores as a pack file in ObjectDirectory.

To obtain an instance of a parser, applications should use ObjectInserter.newPackParser(InputStream).


Nested Class Summary
 
Nested classes/interfaces inherited from class org.eclipse.jgit.transport.PackParser
PackParser.ObjectTypeAndSize, PackParser.Source, PackParser.UnresolvedDelta
 
Method Summary
protected  boolean checkCRC(int oldCRC)
          Check the current CRC matches the expected value.
 PackFile getPackFile()
          Get the imported PackFile.
protected  boolean onAppendBase(int typeCode, byte[] data, PackedObjectInfo info)
          Provide the implementation with a base that was outside of the pack.
protected  void onBeginOfsDelta(long streamPosition, long baseStreamPosition, long inflatedSize)
          Event notifying start of a delta referencing its base by offset.
protected  void onBeginRefDelta(long streamPosition, AnyObjectId baseId, long inflatedSize)
          Event notifying start of a delta referencing its base by ObjectId.
protected  void onBeginWholeObject(long streamPosition, int type, long inflatedSize)
          Event notifying the start of an object stored whole (not as a delta).
protected  PackParser.UnresolvedDelta onEndDelta()
          Event notifying the the current object.
protected  void onEndThinPack()
          Event indicating a thin pack has been completely processed.
protected  void onEndWholeObject(PackedObjectInfo info)
          Event notifying the the current object.
protected  void onInflatedObjectData(PackedObjectInfo obj, int typeCode, byte[] data)
          Invoked for commits, trees, tags, and small blobs.
protected  void onObjectData(PackParser.Source src, byte[] raw, int pos, int len)
          Store (and/or checksum) a portion of an object's data.
protected  void onObjectHeader(PackParser.Source src, byte[] raw, int pos, int len)
          Store (and/or checksum) an object header.
protected  void onPackFooter(byte[] hash)
          Provide the implementation with the original stream's pack footer.
protected  void onPackHeader(long objectCount)
          Provide the implementation with the original stream's pack header.
protected  void onStoreStream(byte[] raw, int pos, int len)
          Store bytes received from the raw stream.
 PackLock parse(ProgressMonitor receiving, ProgressMonitor resolving)
          Parse the pack stream.
protected  int readDatabase(byte[] dst, int pos, int cnt)
          Read from the database's current position into the buffer.
protected  PackParser.ObjectTypeAndSize seekDatabase(PackedObjectInfo obj, PackParser.ObjectTypeAndSize info)
          Reposition the database to re-read a previously stored object.
protected  PackParser.ObjectTypeAndSize seekDatabase(PackParser.UnresolvedDelta delta, PackParser.ObjectTypeAndSize info)
          Reposition the database to re-read a previously stored object.
 void setIndexVersion(int version)
          Set the pack index file format version this instance will create.
 void setKeepEmpty(boolean empty)
          Configure this index pack instance to keep an empty pack.
 
Methods inherited from class org.eclipse.jgit.transport.PackParser
buffer, getBaseObjectIds, getLockMessage, getNewObjectIds, getObject, getObjectCount, getSortedObjectList, isAllowThin, isCheckEofAfterPackFooter, isCheckObjectCollisions, newInfo, parse, readObjectHeader, setAllowThin, setCheckEofAfterPackFooter, setCheckObjectCollisions, setLockMessage, setMaxObjectSizeLimit, setNeedBaseObjectIds, setNeedNewObjectIds, setObjectChecker, setObjectChecking
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Method Detail

setIndexVersion

public void setIndexVersion(int version)
Set the pack index file format version this instance will create.

Parameters:
version - the version to write. The special version 0 designates the oldest (most compatible) format available for the objects.
See Also:
PackIndexWriter

setKeepEmpty

public void setKeepEmpty(boolean empty)
Configure this index pack instance to keep an empty pack.

By default an empty pack (a pack with no objects) is not kept, as doi so is completely pointless. With no objects in the pack there is no d stored by it, so the pack is unnecessary.

Parameters:
empty - true to enable keeping an empty pack.

getPackFile

public PackFile getPackFile()
Get the imported PackFile.

This method is supplied only to support testing; applications shouldn't be using it directly to access the imported data.

Returns:
the imported PackFile, if parsing was successful.

parse

public PackLock parse(ProgressMonitor receiving,
                      ProgressMonitor resolving)
               throws IOException
Description copied from class: PackParser
Parse the pack stream.

Overrides:
parse in class PackParser
Parameters:
receiving - receives progress feedback during the initial receiving objects phase. If null, NullProgressMonitor will be used.
resolving - receives progress feedback during the resolving objects phase.
Returns:
the pack lock, if one was requested by setting PackParser.setLockMessage(String).
Throws:
IOException - the stream is malformed, or contains corrupt objects.

onPackHeader

protected void onPackHeader(long objectCount)
                     throws IOException
Description copied from class: PackParser
Provide the implementation with the original stream's pack header.

Specified by:
onPackHeader in class PackParser
Parameters:
objectCount - number of objects expected in the stream.
Throws:
IOException - the implementation refuses to work with this many objects.

onBeginWholeObject

protected void onBeginWholeObject(long streamPosition,
                                  int type,
                                  long inflatedSize)
                           throws IOException
Description copied from class: PackParser
Event notifying the start of an object stored whole (not as a delta).

Specified by:
onBeginWholeObject in class PackParser
Parameters:
streamPosition - position of this object in the incoming stream.
type - type of the object; one of Constants.OBJ_COMMIT, Constants.OBJ_TREE, Constants.OBJ_BLOB, or Constants.OBJ_TAG.
inflatedSize - size of the object when fully inflated. The size stored within the pack may be larger or smaller, and is not yet known.
Throws:
IOException - the object cannot be recorded.

onEndWholeObject

protected void onEndWholeObject(PackedObjectInfo info)
                         throws IOException
Description copied from class: PackParser
Event notifying the the current object.

Specified by:
onEndWholeObject in class PackParser
Parameters:
info - object information.
Throws:
IOException - the object cannot be recorded.

onBeginOfsDelta

protected void onBeginOfsDelta(long streamPosition,
                               long baseStreamPosition,
                               long inflatedSize)
                        throws IOException
Description copied from class: PackParser
Event notifying start of a delta referencing its base by offset.

Specified by:
onBeginOfsDelta in class PackParser
Parameters:
streamPosition - position of this object in the incoming stream.
baseStreamPosition - position of the base object in the incoming stream. The base must be before the delta, therefore baseStreamPosition < deltaStreamPosition. This is not the position returned by a prior end object event.
inflatedSize - size of the delta when fully inflated. The size stored within the pack may be larger or smaller, and is not yet known.
Throws:
IOException - the object cannot be recorded.

onBeginRefDelta

protected void onBeginRefDelta(long streamPosition,
                               AnyObjectId baseId,
                               long inflatedSize)
                        throws IOException
Description copied from class: PackParser
Event notifying start of a delta referencing its base by ObjectId.

Specified by:
onBeginRefDelta in class PackParser
Parameters:
streamPosition - position of this object in the incoming stream.
baseId - name of the base object. This object may be later in the stream, or might not appear at all in the stream (in the case of a thin-pack).
inflatedSize - size of the delta when fully inflated. The size stored within the pack may be larger or smaller, and is not yet known.
Throws:
IOException - the object cannot be recorded.

onEndDelta

protected PackParser.UnresolvedDelta onEndDelta()
                                         throws IOException
Description copied from class: PackParser
Event notifying the the current object.

Overrides:
onEndDelta in class PackParser
Returns:
object information that must be populated with at least the offset.
Throws:
IOException - the object cannot be recorded.

onInflatedObjectData

protected void onInflatedObjectData(PackedObjectInfo obj,
                                    int typeCode,
                                    byte[] data)
                             throws IOException
Description copied from class: PackParser
Invoked for commits, trees, tags, and small blobs.

Specified by:
onInflatedObjectData in class PackParser
Parameters:
obj - the object info, populated.
typeCode - the type of the object.
data - inflated data for the object.
Throws:
IOException - the object cannot be archived.

onObjectHeader

protected void onObjectHeader(PackParser.Source src,
                              byte[] raw,
                              int pos,
                              int len)
                       throws IOException
Description copied from class: PackParser
Store (and/or checksum) an object header.

Invoked after any of the onBegin() events. The entire header is supplied in a single invocation, before any object data is supplied.

Specified by:
onObjectHeader in class PackParser
Parameters:
src - where the data came from
raw - buffer to read data from.
pos - first offset within buffer that is valid.
len - number of bytes in buffer that are valid.
Throws:
IOException - the stream cannot be archived.

onObjectData

protected void onObjectData(PackParser.Source src,
                            byte[] raw,
                            int pos,
                            int len)
                     throws IOException
Description copied from class: PackParser
Store (and/or checksum) a portion of an object's data.

This method may be invoked multiple times per object, depending on the size of the object, the size of the parser's internal read buffer, and the alignment of the object relative to the read buffer.

Invoked after PackParser.onObjectHeader(Source, byte[], int, int).

Specified by:
onObjectData in class PackParser
Parameters:
src - where the data came from
raw - buffer to read data from.
pos - first offset within buffer that is valid.
len - number of bytes in buffer that are valid.
Throws:
IOException - the stream cannot be archived.

onStoreStream

protected void onStoreStream(byte[] raw,
                             int pos,
                             int len)
                      throws IOException
Description copied from class: PackParser
Store bytes received from the raw stream.

This method is invoked during PackParser.parse(ProgressMonitor) as data is consumed from the incoming stream. Implementors may use this event to archive the raw incoming stream to the destination repository in large chunks, without paying attention to object boundaries.

The only component of the pack not supplied to this method is the last 20 bytes of the pack that comprise the trailing SHA-1 checksum. Those are passed to PackParser.onPackFooter(byte[]).

Specified by:
onStoreStream in class PackParser
Parameters:
raw - buffer to copy data out of.
pos - first offset within the buffer that is valid.
len - number of bytes in the buffer that are valid.
Throws:
IOException - the stream cannot be archived.

onPackFooter

protected void onPackFooter(byte[] hash)
                     throws IOException
Description copied from class: PackParser
Provide the implementation with the original stream's pack footer.

Specified by:
onPackFooter in class PackParser
Parameters:
hash - the trailing 20 bytes of the pack, this is a SHA-1 checksum of all of the pack data.
Throws:
IOException - the stream cannot be archived.

seekDatabase

protected PackParser.ObjectTypeAndSize seekDatabase(PackParser.UnresolvedDelta delta,
                                                    PackParser.ObjectTypeAndSize info)
                                             throws IOException
Description copied from class: PackParser
Reposition the database to re-read a previously stored object.

If the database is computing CRC-32 checksums for object data, it should reset its internal CRC instance during this method call.

Specified by:
seekDatabase in class PackParser
Parameters:
delta - the object position to begin reading from. This is an instance previously returned by PackParser.onEndDelta().
info - object to populate with type and size.
Returns:
the info object.
Throws:
IOException - the database cannot reposition to this location.

seekDatabase

protected PackParser.ObjectTypeAndSize seekDatabase(PackedObjectInfo obj,
                                                    PackParser.ObjectTypeAndSize info)
                                             throws IOException
Description copied from class: PackParser
Reposition the database to re-read a previously stored object.

If the database is computing CRC-32 checksums for object data, it should reset its internal CRC instance during this method call.

Specified by:
seekDatabase in class PackParser
Parameters:
obj - the object position to begin reading from. This is from PackParser.newInfo(AnyObjectId, UnresolvedDelta, ObjectId).
info - object to populate with type and size.
Returns:
the info object.
Throws:
IOException - the database cannot reposition to this location.

readDatabase

protected int readDatabase(byte[] dst,
                           int pos,
                           int cnt)
                    throws IOException
Description copied from class: PackParser
Read from the database's current position into the buffer.

Specified by:
readDatabase in class PackParser
Parameters:
dst - the buffer to copy read data into.
pos - position within dst to start copying data into.
cnt - ideal target number of bytes to read. Actual read length may be shorter.
Returns:
number of bytes stored.
Throws:
IOException - the database cannot be accessed.

checkCRC

protected boolean checkCRC(int oldCRC)
Description copied from class: PackParser
Check the current CRC matches the expected value.

This method is invoked when an object is read back in from the database and its data is used during delta resolution. The CRC is validated after the object has been fully read, allowing the parser to verify there was no silent data corruption.

Implementations are free to ignore this check by always returning true if they are performing other data integrity validations at a lower level.

Specified by:
checkCRC in class PackParser
Parameters:
oldCRC - the prior CRC that was recorded during the first scan of the object from the pack stream.
Returns:
true if the CRC matches; false if it does not.

onAppendBase

protected boolean onAppendBase(int typeCode,
                               byte[] data,
                               PackedObjectInfo info)
                        throws IOException
Description copied from class: PackParser
Provide the implementation with a base that was outside of the pack.

This event only occurs on a thin pack for base objects that were outside of the pack and came from the local repository. Usually an implementation uses this event to compress the base and append it onto the end of the pack, so the pack stays self-contained.

Specified by:
onAppendBase in class PackParser
Parameters:
typeCode - type of the base object.
data - complete content of the base object.
info - packed object information for this base. Implementors must populate the CRC and offset members if returning true.
Returns:
true if the info should be included in the object list returned by PackParser.getSortedObjectList(Comparator), false if it should not be included.
Throws:
IOException - the base could not be included into the pack.

onEndThinPack

protected void onEndThinPack()
                      throws IOException
Description copied from class: PackParser
Event indicating a thin pack has been completely processed.

This event is invoked only if a thin pack has delta references to objects external from the pack. The event is called after all of those deltas have been resolved.

Specified by:
onEndThinPack in class PackParser
Throws:
IOException - the pack cannot be archived.


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