org.eclipse.jgit.treewalk

Class CanonicalTreeParser

java.lang.Object

org.eclipse.jgit.treewalk.AbstractTreeIterator

org.eclipse.jgit.treewalk.CanonicalTreeParser

public class CanonicalTreeParser
extends AbstractTreeIterator

Parses raw Git trees from the canonical semi-text/semi-binary format.

Field Summary

Fields inherited from class org.eclipse.jgit.treewalk.AbstractTreeIterator

attributesNode, DEFAULT_PATH_SIZE, mode, parent, path, pathLen, pathOffset, zeroid

Constructor Summary

Constructors

Constructor and Description
CanonicalTreeParser() Create a new parser.
CanonicalTreeParser(byte[] prefix, ObjectReader reader, AnyObjectId treeId) Create a new parser for a tree appearing in a subset of a repository.

Method Summary

Modifier and Type	Method and Description
void	back(int delta) Move to prior entry, populating this iterator with the entry data.
CanonicalTreeParser	createSubtreeIterator(ObjectReader reader) Create a new iterator for the current entry's subtree.
CanonicalTreeParser	createSubtreeIterator(ObjectReader reader, MutableObjectId idBuffer) Create a new iterator for the current entry's subtree.
CanonicalTreeParser	createSubtreeIterator0(ObjectReader reader, AnyObjectId id) Back door to quickly create a subtree iterator for any subtree.
boolean	eof() Is this tree iterator at its EOF point (no more entries)?
boolean	first() Is this tree iterator positioned on its first entry?
AttributesNode	getEntryAttributesNode(ObjectReader reader) Retrieve the AttributesNode for the current entry.
CanonicalTreeParser	getParent() Deprecated. internal use only
boolean	hasId() Whether the entry has a valid ObjectId.
byte[]	idBuffer() Get the byte array buffer object IDs must be copied out of.
int	idOffset() Get the position within AbstractTreeIterator.idBuffer() of this entry's ObjectId.
CanonicalTreeParser	next() Get this iterator, or its parent, if the tree is at eof.
void	next(int delta) Move to next entry, populating this iterator with the entry data.
void	reset() Position this iterator on the first entry.
void	reset(byte[] treeData) Reset this parser to walk through the given tree data.
void	reset(ObjectReader reader, AnyObjectId id) Reset this parser to walk through the given tree.
CanonicalTreeParser	resetRoot(ObjectReader reader, AnyObjectId id) Reset this parser to walk through the given tree.

Methods inherited from class org.eclipse.jgit.treewalk.AbstractTreeIterator

createEmptyTreeIterator, ensurePathCapacity, findFile, findFile, getEntryFileMode, getEntryObjectId, getEntryObjectId, getEntryPathBuffer, getEntryPathHashCode, getEntryPathLength, getEntryPathString, getEntryRawMode, getName, getNameLength, getNameOffset, growPath, idEqual, isWorkTree, needsStopWalk, pathCompare, pathCompare, skip, stopWalk, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

CanonicalTreeParser

public CanonicalTreeParser()

Create a new parser.

CanonicalTreeParser

public CanonicalTreeParser(byte[] prefix,
                           ObjectReader reader,
                           AnyObjectId treeId)
                    throws IncorrectObjectTypeException,
                           IOException

Create a new parser for a tree appearing in a subset of a repository.

Parameters:

prefix - position of this iterator in the repository tree. The value may be null or the empty array to indicate the prefix is the root of the repository. A trailing slash ('/') is automatically appended if the prefix does not end in '/'.

reader - reader to load the tree data from.

treeId - identity of the tree being parsed; used only in exception messages if data corruption is found.

Throws:

MissingObjectException - the object supplied is not available from the repository.

IncorrectObjectTypeException - the object supplied as an argument is not actually a tree and cannot be parsed as though it were a tree.

IOException - a loose object or pack file could not be read.

Method Detail

getParent

@Deprecated
public CanonicalTreeParser getParent()

Deprecated. internal use only

Get the parent of this tree parser.

Returns:

the parent of this tree parser.

reset

public void reset(byte[] treeData)

Reset this parser to walk through the given tree data.

Parameters:

treeData - the raw tree content.

resetRoot

public CanonicalTreeParser resetRoot(ObjectReader reader,
                                     AnyObjectId id)
                              throws IncorrectObjectTypeException,
                                     IOException

Reset this parser to walk through the given tree.

Parameters:

reader - reader to use during repository access.

id - identity of the tree being parsed; used only in exception messages if data corruption is found.

Returns:

the root level parser.

Throws:

MissingObjectException - the object supplied is not available from the repository.

IncorrectObjectTypeException - the object supplied as an argument is not actually a tree and cannot be parsed as though it were a tree.

IOException - a loose object or pack file could not be read.

next

public CanonicalTreeParser next()

Get this iterator, or its parent, if the tree is at eof.

Returns:

this iterator, or its parent, if the tree is at eof.

reset

public void reset(ObjectReader reader,
                  AnyObjectId id)
           throws IncorrectObjectTypeException,
                  IOException

Reset this parser to walk through the given tree.

Parameters:

reader - reader to use during repository access.

id - identity of the tree being parsed; used only in exception messages if data corruption is found.

Throws:

MissingObjectException - the object supplied is not available from the repository.

IncorrectObjectTypeException - the object supplied as an argument is not actually a tree and cannot be parsed as though it were a tree.

IOException - a loose object or pack file could not be read.

createSubtreeIterator

public CanonicalTreeParser createSubtreeIterator(ObjectReader reader,
                                                 MutableObjectId idBuffer)
                                          throws IncorrectObjectTypeException,
                                                 IOException

Create a new iterator for the current entry's subtree.

The parent reference of the iterator must be this, otherwise the caller would not be able to exit out of the subtree iterator correctly and return to continue walking this.

Overrides:

createSubtreeIterator in class AbstractTreeIterator

Parameters:

reader - reader to load the tree data from.

idBuffer - temporary ObjectId buffer for use by this method.

Returns:

a new parser that walks over the current subtree.

Throws:

IncorrectObjectTypeException - the current entry is not actually a tree and cannot be parsed as though it were a tree.

IOException - a loose object or pack file could not be read.

createSubtreeIterator0

public final CanonicalTreeParser createSubtreeIterator0(ObjectReader reader,
                                                        AnyObjectId id)
                                                 throws IOException

Back door to quickly create a subtree iterator for any subtree.

Don't use this unless you are ObjectWalk. The method is meant to be called only once the current entry has been identified as a tree and its identity has been converted into an ObjectId.

Parameters:

reader - reader to load the tree data from.

id - ObjectId of the tree to open.

Returns:

a new parser that walks over the current subtree.

Throws:

IOException - a loose object or pack file could not be read.

createSubtreeIterator

public CanonicalTreeParser createSubtreeIterator(ObjectReader reader)
                                          throws IncorrectObjectTypeException,
                                                 IOException

Create a new iterator for the current entry's subtree.

The parent reference of the iterator must be this, otherwise the caller would not be able to exit out of the subtree iterator correctly and return to continue walking this.

Specified by:

createSubtreeIterator in class AbstractTreeIterator

Parameters:

reader - reader to load the tree data from.

Returns:

a new parser that walks over the current subtree.

Throws:

IncorrectObjectTypeException - the current entry is not actually a tree and cannot be parsed as though it were a tree.

IOException - a loose object or pack file could not be read.

hasId

public boolean hasId()

Whether the entry has a valid ObjectId.

Specified by:

hasId in class AbstractTreeIterator

Returns:

true if the entry has a valid ObjectId.

idBuffer

public byte[] idBuffer()

Get the byte array buffer object IDs must be copied out of.

The id buffer contains the bytes necessary to construct an ObjectId for the current entry of this iterator. The buffer can be the same buffer for all entries, or it can be a unique buffer per-entry. Implementations are encouraged to expose their private buffer whenever possible to reduce garbage generation and copying costs.

Specified by:

idBuffer in class AbstractTreeIterator

Returns:

byte array the implementation stores object IDs within.

See Also:

AbstractTreeIterator.getEntryObjectId()

idOffset

public int idOffset()

Get the position within AbstractTreeIterator.idBuffer() of this entry's ObjectId.

Specified by:

idOffset in class AbstractTreeIterator

Returns:

offset into the array returned by AbstractTreeIterator.idBuffer() where the ObjectId must be copied out of.

reset

public void reset()

Position this iterator on the first entry. The default implementation of this method uses back(1) until first() is true. This is most likely not the most efficient method of repositioning the iterator to its first entry, so subclasses are strongly encouraged to override the method.

Overrides:

reset in class AbstractTreeIterator

first

public boolean first()

Is this tree iterator positioned on its first entry?

An iterator is positioned on the first entry if back(1) would be an invalid request as there is no entry before the current one.

An empty iterator (one with no entries) will be first() && eof().

Specified by:

first in class AbstractTreeIterator

Returns:

true if the iterator is positioned on the first entry.

eof

public boolean eof()

Is this tree iterator at its EOF point (no more entries)?

An iterator is at EOF if there is no current entry.

Specified by:

eof in class AbstractTreeIterator

Returns:

true if we have walked all entries and have none left.

next

public void next(int delta)

Move to next entry, populating this iterator with the entry data.

The delta indicates how many moves forward should occur. The most common delta is 1 to move to the next entry.

Implementations must populate the following members:

• AbstractTreeIterator.mode
• AbstractTreeIterator.path (from AbstractTreeIterator.pathOffset to AbstractTreeIterator.pathLen)
• AbstractTreeIterator.pathLen

as well as any implementation dependent information necessary to accurately return data from AbstractTreeIterator.idBuffer() and AbstractTreeIterator.idOffset() when demanded.

Specified by:

next in class AbstractTreeIterator

Parameters:

delta - number of entries to move the iterator by. Must be a positive, non-zero integer.

back

public void back(int delta)

Move to prior entry, populating this iterator with the entry data.

The delta indicates how many moves backward should occur.The most common delta is 1 to move to the prior entry.

Implementations must populate the following members:

• AbstractTreeIterator.mode
• AbstractTreeIterator.path (from AbstractTreeIterator.pathOffset to AbstractTreeIterator.pathLen)
• AbstractTreeIterator.pathLen

as well as any implementation dependent information necessary to accurately return data from AbstractTreeIterator.idBuffer() and AbstractTreeIterator.idOffset() when demanded.

Specified by:

back in class AbstractTreeIterator

Parameters:

delta - number of entries to move the iterator by. Must be a positive, non-zero integer.

getEntryAttributesNode

public AttributesNode getEntryAttributesNode(ObjectReader reader)
                                      throws IOException

Retrieve the AttributesNode for the current entry.

Parameters:

reader - ObjectReader used to parse the .gitattributes entry.

Returns:

AttributesNode for the current entry.

Throws:

IOException

Since:

4.2