org.eclipse.jgit.internal.storage.dfs

Class DfsPackParser

java.lang.Object

org.eclipse.jgit.transport.PackParser

org.eclipse.jgit.internal.storage.dfs.DfsPackParser

public class DfsPackParser
extends PackParser

Parses a pack stream into the DFS, by creating a new pack and index.

Nested Class Summary

Nested classes/interfaces inherited from class org.eclipse.jgit.transport.PackParser

PackParser.ObjectTypeAndSize, PackParser.Source, PackParser.UnresolvedDelta

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	DfsPackParser(DfsObjDatabase db, DfsInserter ins, InputStream in) Initialize a new pack parser.

Method Summary

Modifier and Type	Method and Description
protected boolean	checkCRC(int oldCRC) Check the current CRC matches the expected value.
DfsPackDescription	getPackDescription() Get description of the imported pack, if one was made.
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.

Methods inherited from class org.eclipse.jgit.transport.PackParser

buffer, getBaseObjectIds, getLockMessage, getNewObjectIds, getObject, getObjectCount, getPackSize, getReceivedPackStatistics, getSortedObjectList, isAllowThin, isCheckEofAfterPackFooter, isCheckObjectCollisions, isExpectDataAfterPackFooter, newInfo, parse, readObjectHeader, setAllowThin, setCheckEofAfterPackFooter, setCheckObjectCollisions, setExpectDataAfterPackFooter, setExpectedObjectCount, setLockMessage, setMaxObjectSizeLimit, setNeedBaseObjectIds, setNeedNewObjectIds, setObjectChecker, setObjectChecking, verifySafeObject

Methods inherited from class java.lang.Object

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

Constructor Detail

DfsPackParser

protected DfsPackParser(DfsObjDatabase db,
                        DfsInserter ins,
                        InputStream in)

Initialize a new pack parser.

Parameters:

db - database the objects will be imported into.

ins - inserter the parser will use to help it inject the objects.

in - the stream to parse.

Method Detail

parse

public PackLock parse(ProgressMonitor receiving,
                      ProgressMonitor resolving)
               throws IOException

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.

getPackDescription

public DfsPackDescription getPackDescription()

Get description of the imported pack, if one was made.

Returns:

description of the imported pack, if one was made.

onPackHeader

protected void onPackHeader(long objectCount)
                     throws IOException

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

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

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

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

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

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

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

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

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

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

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(PackedObjectInfo obj,
                                                    PackParser.ObjectTypeAndSize info)
                                             throws IOException

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.

seekDatabase

protected PackParser.ObjectTypeAndSize seekDatabase(PackParser.UnresolvedDelta delta,
                                                    PackParser.ObjectTypeAndSize info)
                                             throws IOException

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.

readDatabase

protected int readDatabase(byte[] dst,
                           int pos,
                           int cnt)
                    throws IOException

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)

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

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

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.