org.eclipse.jgit.lib
Class AnyObjectId

java.lang.Object
  org.eclipse.jgit.lib.AnyObjectId

All Implemented Interfaces:

Comparable<Object>

Direct Known Subclasses:

MutableObjectId, ObjectId

public abstract class AnyObjectId
extends Object
implements Comparable<Object>

A (possibly mutable) SHA-1 abstraction.

If this is an instance of MutableObjectId the concept of equality with this instance can alter at any time, if this instance is modified to represent a different object name.

Constructor Summary

AnyObjectId()

Method Summary

AbbreviatedObjectId	abbreviate(int len) Return an abbreviation (prefix) of this object SHA-1.
int	compareTo(AnyObjectId other) Compare this ObjectId to another and obtain a sort ordering.
int	compareTo(byte[] bs, int p) Compare this ObjectId to a network-byte-order ObjectId.
int	compareTo(int[] bs, int p) Compare this ObjectId to a network-byte-order ObjectId.
int	compareTo(Object other)
ObjectId	copy() Obtain an immutable copy of this current object name value.
void	copyRawTo(byte[] b, int o) Copy this ObjectId to a byte array.
void	copyRawTo(ByteBuffer w) Copy this ObjectId to an output writer in raw binary.
void	copyRawTo(int[] b, int o) Copy this ObjectId to an int array.
void	copyRawTo(OutputStream w) Copy this ObjectId to an output writer in raw binary.
void	copyTo(byte[] b, int o) Copy this ObjectId to a byte array in hex format.
void	copyTo(ByteBuffer b) Copy this ObjectId to a ByteBuffer in hex format.
void	copyTo(char[] tmp, StringBuilder w) Copy this ObjectId to a StringBuilder in hex format.
void	copyTo(char[] tmp, Writer w) Copy this ObjectId to an output writer in hex format.
void	copyTo(OutputStream w) Copy this ObjectId to an output writer in hex format.
void	copyTo(Writer w) Copy this ObjectId to an output writer in hex format.
boolean	equals(AnyObjectId other) Determine if this ObjectId has exactly the same value as another.
static boolean	equals(AnyObjectId firstObjectId, AnyObjectId secondObjectId) Compare to object identifier byte sequences for equality.
boolean	equals(Object o)
int	getByte(int index) Get any byte from the ObjectId.
int	getFirstByte() Get the first 8 bits of the ObjectId.
String	getName()
int	hashCode()
String	name()
boolean	startsWith(AbbreviatedObjectId abbr) Tests if this ObjectId starts with the given abbreviation.
abstract ObjectId	toObjectId() Obtain an immutable copy of this current object name value.
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

AnyObjectId

public AnyObjectId()

Method Detail

equals

public static boolean equals(AnyObjectId firstObjectId,
                             AnyObjectId secondObjectId)

Compare to object identifier byte sequences for equality.

Parameters:

firstObjectId - the first identifier to compare. Must not be null.

secondObjectId - the second identifier to compare. Must not be null.

Returns:

true if the two identifiers are the same.

getFirstByte

public final int getFirstByte()

Get the first 8 bits of the ObjectId. This is a faster version of getByte(0).

Returns:

a discriminator usable for a fan-out style map. Returned values are unsigned and thus are in the range [0,255] rather than the signed byte range of [-128, 127].

getByte

public final int getByte(int index)

Get any byte from the ObjectId. Callers hard-coding getByte(0) should instead use the much faster special case variant getFirstByte().

Parameters:

index - index of the byte to obtain from the raw form of the ObjectId. Must be in range [0, Constants.OBJECT_ID_LENGTH).

Returns:

the value of the requested byte at index. Returned values are unsigned and thus are in the range [0,255] rather than the signed byte range of [-128, 127].

Throws:

ArrayIndexOutOfBoundsException - index is less than 0, equal to Constants.OBJECT_ID_LENGTH, or greater than Constants.OBJECT_ID_LENGTH.

compareTo

public final int compareTo(AnyObjectId other)

Compare this ObjectId to another and obtain a sort ordering.

Parameters:

other - the other id to compare to. Must not be null.

Returns:

< 0 if this id comes before other; 0 if this id is equal to other; > 0 if this id comes after other.

compareTo

public final int compareTo(Object other)

Specified by:

compareTo in interface Comparable<Object>

compareTo

public final int compareTo(byte[] bs,
                           int p)

Compare this ObjectId to a network-byte-order ObjectId.

Parameters:

bs - array containing the other ObjectId in network byte order.

p - position within bs to start the compare at. At least 20 bytes, starting at this position are required.

Returns:

a negative integer, zero, or a positive integer as this object is less than, equal to, or greater than the specified object.

compareTo

public final int compareTo(int[] bs,
                           int p)

Compare this ObjectId to a network-byte-order ObjectId.

Parameters:

bs - array containing the other ObjectId in network byte order.

p - position within bs to start the compare at. At least 5 integers, starting at this position are required.

Returns:

a negative integer, zero, or a positive integer as this object is less than, equal to, or greater than the specified object.

startsWith

public boolean startsWith(AbbreviatedObjectId abbr)

Tests if this ObjectId starts with the given abbreviation.

Parameters:

abbr - the abbreviation.

Returns:

true if this ObjectId begins with the abbreviation; else false.

hashCode

public final int hashCode()

Overrides:

hashCode in class Object

equals

public final boolean equals(AnyObjectId other)

Determine if this ObjectId has exactly the same value as another.

Parameters:

other - the other id to compare to. May be null.

Returns:

true only if both ObjectIds have identical bits.

equals

public final boolean equals(Object o)

Overrides:

equals in class Object

copyRawTo

public void copyRawTo(ByteBuffer w)

Copy this ObjectId to an output writer in raw binary.

Parameters:

w - the buffer to copy to. Must be in big endian order.

copyRawTo

public void copyRawTo(byte[] b,
                      int o)

Copy this ObjectId to a byte array.

Parameters:

b - the buffer to copy to.

o - the offset within b to write at.

copyRawTo

public void copyRawTo(int[] b,
                      int o)

Copy this ObjectId to an int array.

Parameters:

b - the buffer to copy to.

o - the offset within b to write at.

copyRawTo

public void copyRawTo(OutputStream w)
               throws IOException

Copy this ObjectId to an output writer in raw binary.

Parameters:

w - the stream to write to.

Throws:

IOException - the stream writing failed.

copyTo

public void copyTo(OutputStream w)
            throws IOException

Copy this ObjectId to an output writer in hex format.

Parameters:

w - the stream to copy to.

Throws:

IOException - the stream writing failed.

copyTo

public void copyTo(byte[] b,
                   int o)

Copy this ObjectId to a byte array in hex format.

Parameters:

b - the buffer to copy to.

o - the offset within b to write at.

copyTo

public void copyTo(ByteBuffer b)

Copy this ObjectId to a ByteBuffer in hex format.

Parameters:

b - the buffer to copy to.

copyTo

public void copyTo(Writer w)
            throws IOException

Copy this ObjectId to an output writer in hex format.

Parameters:

w - the stream to copy to.

Throws:

IOException - the stream writing failed.

copyTo

public void copyTo(char[] tmp,
                   Writer w)
            throws IOException

Copy this ObjectId to an output writer in hex format.

Parameters:

tmp - temporary char array to buffer construct into before writing. Must be at least large enough to hold 2 digits for each byte of object id (40 characters or larger).

w - the stream to copy to.

Throws:

IOException - the stream writing failed.

copyTo

public void copyTo(char[] tmp,
                   StringBuilder w)

Copy this ObjectId to a StringBuilder in hex format.

Parameters:

tmp - temporary char array to buffer construct into before writing. Must be at least large enough to hold 2 digits for each byte of object id (40 characters or larger).

w - the string to append onto.

toString

public String toString()

Overrides:

toString in class Object

name

public final String name()

Returns:

string form of the SHA-1, in lower case hexadecimal.

getName

public final String getName()

Returns:

string form of the SHA-1, in lower case hexadecimal.

abbreviate

public AbbreviatedObjectId abbreviate(int len)

Return an abbreviation (prefix) of this object SHA-1.

This implementation does not guarantee uniqueness. Callers should instead use ObjectReader.abbreviate(AnyObjectId, int) to obtain a unique abbreviation within the scope of a particular object database.

Parameters:

len - length of the abbreviated string.

Returns:

SHA-1 abbreviation.

copy

public final ObjectId copy()

Obtain an immutable copy of this current object name value.

Only returns this if this instance is an unsubclassed instance of ObjectId; otherwise a new instance is returned holding the same value.

This method is useful to shed any additional memory that may be tied to the subclass, yet retain the unique identity of the object id for future lookups within maps and repositories.

Returns:

an immutable copy, using the smallest memory footprint possible.

toObjectId

public abstract ObjectId toObjectId()

Obtain an immutable copy of this current object name value.

See copy() if this is a possibly subclassed (but immutable) identity and the application needs a lightweight identity only reference.

Returns:

an immutable copy. May be this if this is already an immutable instance.