Modifier and Type	Class and Description
public static class	SimilarityIndex.TableFullException Thrown by `create()` when file is too large.

Field Summary

Modifier and Type	Field and Description
private long	hashedCnt Total amount of bytes hashed into the structure, including \n.
private int	idGrowAt `idSize` that triggers `idHash` to double in size.
private long[]	idHash Pairings of content keys and counters.
private int	idHashBits `idHash.length == 1 << idHashBits`.
private int	idSize Number of non-zero entries in `idHash`.
private static final int	KEY_SHIFT Shift to apply before storing a key.
private static final long	MAX_COUNT Maximum value of the count field, also mask to extract the count.
public static final SimilarityIndex.TableFullException	TABLE_FULL_OUT_OF_MEMORY A special `TableFullException` used in place of OutOfMemoryError.

Constructor Summary

Access	Constructor and Description
pack-priv	SimilarityIndex()

Method Summary

Modifier and Type	Method and Description
pack-priv void	add(int key, int cnt)
pack-priv long	common(SimilarityIndex dst)
private static long	common(SimilarityIndex src, SimilarityIndex dst)
private static long	common(long[] srcHash, int srcIdx, long[] dstHash, int dstIdx)
pack-priv long	count(int idx)
private static long	countOf(long v)
public static SimilarityIndex	Returns: similarity index for this object create(ObjectLoader the object to hash obj) Create a new similarity index for the given object
pack-priv int	findIndex(int key)
private void	grow()
private static int	growAt(int idHashBits)
pack-priv void	hash(ObjectLoader obj)
pack-priv void	hash(byte[] raw, int ptr, int end)
pack-priv void	hash(InputStream in, long remaining, boolean text)
private void	hashLargeObject(ObjectLoader obj)
pack-priv static boolean	isBinary(ObjectLoader obj)
pack-priv int	key(int idx)
private static int	keyOf(long v)
private int	packedIndex(int idx)
private static long	pair(int key, long cnt)
public int	Returns: the similarity score score(SimilarityIndex the other index dst, int the score representing a 100% match maxScore) Compute the similarity score between this index and another.
pack-priv int	size()
private int	slot(int key)
pack-priv void	sort() Sort the internal table so it can be used for efficient scoring.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

hashedCnt	back to summary
private long hashedCnt Total amount of bytes hashed into the structure, including \n. This is usually the size of the file minus number of CRLF encounters.

idGrowAt	back to summary
private int idGrowAt `idSize` that triggers `idHash` to double in size.

idHash	back to summary
private long[] idHash Pairings of content keys and counters. Slots in the table are actually two ints wedged into a single long. The upper 32 bits stores the content key, and the remaining lower bits stores the number of bytes associated with that key. Empty slots are denoted by 0, which cannot occur because the count cannot be 0. Values can only be positive, which we enforce during key addition.

idHash

back to summary

private long[] idHash

Pairings of content keys and counters.

Slots in the table are actually two ints wedged into a single long. The upper 32 bits stores the content key, and the remaining lower bits stores the number of bytes associated with that key. Empty slots are denoted by 0, which cannot occur because the count cannot be 0. Values can only be positive, which we enforce during key addition.

idHashBits	back to summary
private int idHashBits `idHash.length == 1 << idHashBits`.

idSize	back to summary
private int idSize Number of non-zero entries in `idHash`.

KEY_SHIFT	back to summary
private static final int KEY_SHIFT Shift to apply before storing a key. Within the 64 bit table record space, we leave the highest bit unset so all values are positive. The lower 32 bits to count bytes.

KEY_SHIFT

back to summary

private static final int KEY_SHIFT

Shift to apply before storing a key.

Within the 64 bit table record space, we leave the highest bit unset so all values are positive. The lower 32 bits to count bytes.

MAX_COUNT	back to summary
private static final long MAX_COUNT Maximum value of the count field, also mask to extract the count.

TABLE_FULL_OUT_OF_MEMORY	back to summary
public static final SimilarityIndex.TableFullException TABLE_FULL_OUT_OF_MEMORY A special `TableFullException` used in place of OutOfMemoryError.

Constructor Detail

SimilarityIndex	back to summary
pack-priv SimilarityIndex()

Method Detail

add	back to summary
pack-priv void add(int key, int cnt) throws TableFullException

common	back to summary
pack-priv long common(SimilarityIndex dst)

common	back to summary
private static long common(SimilarityIndex src, SimilarityIndex dst)

common	back to summary
private static long common(long[] srcHash, int srcIdx, long[] dstHash, int dstIdx)

count	back to summary
pack-priv long count(int idx)

countOf	back to summary
private static long countOf(long v)

create	back to summary
public static SimilarityIndex create(ObjectLoader obj) throws IOException, TableFullException Create a new similarity index for the given object Parameters obj:ObjectLoader the object to hash Returns:SimilarityIndex similarity index for this object Exceptions IOException: file contents cannot be read from the repository. TableFullException: object hashing overflowed the storage capacity of the SimilarityIndex.

create

back to summary

public static SimilarityIndex create(ObjectLoader obj) throws IOException, TableFullException

Create a new similarity index for the given object

Parameters

obj:ObjectLoader: the object to hash

Returns:SimilarityIndex

similarity index for this object

Exceptions

IOException:: file contents cannot be read from the repository.
TableFullException:: object hashing overflowed the storage capacity of the SimilarityIndex.

findIndex	back to summary
pack-priv int findIndex(int key)

grow	back to summary
private void grow() throws TableFullException Annotations @SuppressWarnings:UnusedException

growAt	back to summary
private static int growAt(int idHashBits)

hash	back to summary
pack-priv void hash(ObjectLoader obj) throws MissingObjectException, IOException, TableFullException

hash	back to summary
pack-priv void hash(byte[] raw, int ptr, int end) throws TableFullException

hash	back to summary
pack-priv void hash(InputStream in, long remaining, boolean text) throws IOException, TableFullException

hashLargeObject	back to summary
private void hashLargeObject(ObjectLoader obj) throws IOException, TableFullException

isBinary	back to summary
pack-priv static boolean isBinary(ObjectLoader obj) throws IOException

key	back to summary
pack-priv int key(int idx)

keyOf	back to summary
private static int keyOf(long v)

packedIndex	back to summary
private int packedIndex(int idx)

pair	back to summary
private static long pair(int key, long cnt) throws TableFullException

score	back to summary
public int score(SimilarityIndex dst, int maxScore) Compute the similarity score between this index and another. A region of a file is defined as a line in a text file or a fixed-size block in a binary file. To prepare an index, each region in the file is hashed; the values and counts of hashes are retained in a sorted table. Define the similarity fraction F as the count of matching regions between the two files divided between the maximum count of regions in either file. The similarity score is F multiplied by the maxScore constant, yielding a range [0, maxScore]. It is defined as maxScore for the degenerate case of two empty files. The similarity score is symmetrical; i.e. a.score(b) == b.score(a). Parameters dst:SimilarityIndex the other index maxScore:int the score representing a 100% match Returns:int the similarity score

score

back to summary

public int score(SimilarityIndex dst, int maxScore)

Compute the similarity score between this index and another.

A region of a file is defined as a line in a text file or a fixed-size block in a binary file. To prepare an index, each region in the file is hashed; the values and counts of hashes are retained in a sorted table. Define the similarity fraction F as the count of matching regions between the two files divided between the maximum count of regions in either file. The similarity score is F multiplied by the maxScore constant, yielding a range [0, maxScore]. It is defined as maxScore for the degenerate case of two empty files.

The similarity score is symmetrical; i.e. a.score(b) == b.score(a).

Parameters

dst:SimilarityIndex: the other index
maxScore:int: the score representing a 100% match

Returns:int

the similarity score

size	back to summary
pack-priv int size()

slot	back to summary
private int slot(int key)

sort	back to summary
pack-priv void sort() Sort the internal table so it can be used for efficient scoring. Once sorted, additional lines/blocks cannot be added to the index.

sort

back to summary

pack-priv void sort()

Sort the internal table so it can be used for efficient scoring.

Once sorted, additional lines/blocks cannot be added to the index.

org.eclipse.jgit.diff back to summary

public Class SimilarityIndex.TableFullException

Class Inheritance

extends Exception

java.lang.Object
java.lang.Throwable
java.lang.Exception
org.eclipse.jgit.diff.SimilarityIndex.TableFullException

Thrown by create() when file is too large.

Field Summary

Modifier and Type	Field and Description
private static final long	serialVersionUID Hides java.lang.Exception.serialVersionUID.

Constructor Summary

Access	Constructor and Description
public	TableFullException()

Field Detail

serialVersionUID	back to summary
private static final long serialVersionUID Hides java.lang.Exception.serialVersionUID.

Constructor Detail

TableFullException	back to summary
public TableFullException()

public Class SimilarityIndex

Nested and Inner Type Summary

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail

public Class SimilarityIndex.TableFullException

Field Summary

Constructor Summary

Field Detail

Constructor Detail