Class AnyObjectId

  • All Implemented Interfaces:
    java.lang.Comparable<AnyObjectId>
    Direct Known Subclasses:
    MutableObjectId, ObjectId

    public abstract class AnyObjectId
    extends java.lang.Object
    implements java.lang.Comparable<AnyObjectId>
    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

      Constructors 
      Constructor Description
      AnyObjectId()  
    • Method Summary

      All Methods Static Methods Instance Methods Abstract Methods Concrete Methods 
      Modifier and Type Method Description
      AbbreviatedObjectId abbreviate​(int len)
      Return an abbreviation (prefix) of this object SHA-1.
      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​(AnyObjectId other)
      Compare this ObjectId to another and obtain a sort ordering.
      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​(int[] b, int o)
      Copy this ObjectId to an int array.
      void copyRawTo​(java.io.OutputStream w)
      Copy this ObjectId to an output writer in raw binary.
      void copyRawTo​(java.nio.ByteBuffer 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​(char[] tmp, java.io.Writer w)
      Copy this ObjectId to an output writer in hex format.
      void copyTo​(char[] tmp, java.lang.StringBuilder w)
      Copy this ObjectId to a StringBuilder in hex format.
      void copyTo​(java.io.OutputStream w)
      Copy this ObjectId to an output writer in hex format.
      void copyTo​(java.io.Writer w)
      Copy this ObjectId to an output writer in hex format.
      void copyTo​(java.nio.ByteBuffer b)
      Copy this ObjectId to a ByteBuffer in hex format.
      boolean equals​(java.lang.Object o)  
      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.
      int getByte​(int index)
      Get any byte from the ObjectId.
      int getFirstByte()
      Get the first 8 bits of the ObjectId.
      java.lang.String getName()  
      int hashCode()  
      java.lang.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.
      java.lang.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:
        java.lang.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.
        Specified by:
        compareTo in interface java.lang.Comparable<AnyObjectId>
        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​(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 java.lang.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​(java.lang.Object o)
        Overrides:
        equals in class java.lang.Object
      • copyRawTo

        public void copyRawTo​(java.nio.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​(java.io.OutputStream w)
                       throws java.io.IOException
        Copy this ObjectId to an output writer in raw binary.
        Parameters:
        w - the stream to write to.
        Throws:
        java.io.IOException - the stream writing failed.
      • copyTo

        public void copyTo​(java.io.OutputStream w)
                    throws java.io.IOException
        Copy this ObjectId to an output writer in hex format.
        Parameters:
        w - the stream to copy to.
        Throws:
        java.io.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​(java.nio.ByteBuffer b)
        Copy this ObjectId to a ByteBuffer in hex format.
        Parameters:
        b - the buffer to copy to.
      • copyTo

        public void copyTo​(java.io.Writer w)
                    throws java.io.IOException
        Copy this ObjectId to an output writer in hex format.
        Parameters:
        w - the stream to copy to.
        Throws:
        java.io.IOException - the stream writing failed.
      • copyTo

        public void copyTo​(char[] tmp,
                           java.io.Writer w)
                    throws java.io.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:
        java.io.IOException - the stream writing failed.
      • copyTo

        public void copyTo​(char[] tmp,
                           java.lang.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 java.lang.String toString()
        Overrides:
        toString in class java.lang.Object
      • name

        public final java.lang.String name()
        Returns:
        string form of the SHA-1, in lower case hexadecimal.
      • getName

        public final java.lang.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.