Package org.apache.cassandra.utils.bytecomparable

Class ByteSource.AbstractEscaper

java.lang.Object

org.apache.cassandra.utils.bytecomparable.ByteSource.AbstractEscaper

All Implemented Interfaces:

ByteSource

Direct Known Subclasses:

ByteSource.AccessorEscaper, ByteSource.ArrayEscaper, ByteSource.BufferEscaper, ByteSource.MemoryEscaper

Enclosing interface:

ByteSource

public abstract static class ByteSource.AbstractEscaper
extends java.lang.Object
implements ByteSource

Variable-length encoding. Escapes 0s as ESCAPE + zero or more ESCAPED_0_CONT + ESCAPED_0_DONE. If the source ends in 0, we use ESCAPED_0_CONT to make sure that the encoding remains smaller than that source with a further 0 at the end. Finishes in an escaped state (either with ESCAPE or ESCAPED_0_CONT), which in ByteSource.Multi is followed by a component separator between 0x10 and 0xFE. E.g. "A\0\0B" translates to 4100FEFF4200 "A\0B\0" 4100FF4200FE (+00 for ByteComparable.Version.LEGACY) "A\0" 4100FE (+00 for ByteComparable.Version.LEGACY) "AB" 414200 If in a single byte source, the bytes could be simply passed unchanged, but this would not allow us to combine components. This translation preserves order, and since the encoding for 0 is higher than the separator also makes sure shorter components are treated as smaller. The encoding is not prefix-free, since e.g. the encoding of "A" (4100) is a prefix of the encoding of "A\0" (4100FE), but the byte following the prefix is guaranteed to be FE or FF, which makes the encoding weakly prefix-free. Additionally, any such prefix sequence will compare smaller than the value to which it is a prefix, because any permitted separator byte will be smaller than the byte following the prefix.

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.cassandra.utils.bytecomparable.ByteSource

ByteSource.AbstractEscaper, ByteSource.AccessorEscaper<V>, ByteSource.ArrayEscaper, ByteSource.BufferEscaper, ByteSource.MemoryEscaper, ByteSource.Multi, ByteSource.Number, ByteSource.Peekable, ByteSource.Separator, ByteSource.SignedFixedLengthFloat<V>, ByteSource.SignedFixedLengthNumber<V>, ByteSource.VariableLengthInteger, ByteSource.VariableLengthUnsignedInteger

Field Summary

Fields inherited from interface org.apache.cassandra.utils.bytecomparable.ByteSource

EMPTY, END_OF_STREAM, ESCAPE, ESCAPED_0_CONT, ESCAPED_0_DONE, EXCLUDED, GT_NEXT_COMPONENT, GTGT_NEXT_COMPONENT, LT_NEXT_COMPONENT, LTLT_NEXT_COMPONENT, MAX_NEXT_COMPONENT, MAX_SEPARATOR, MIN_NEXT_COMPONENT, MIN_SEPARATOR, NEXT_COMPONENT, NEXT_COMPONENT_EMPTY, NEXT_COMPONENT_EMPTY_REVERSED, NEXT_COMPONENT_NULL, TERMINATOR

Method Summary

Modifier and Type	Method	Description
protected abstract byte	get(int index)
protected abstract int	limit()
int	next()	Consume the next byte, unsigned.

Methods inherited from class java.lang.Object

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

Method Detail

next

public final int next()

Description copied from interface: ByteSource

Consume the next byte, unsigned. Must be between 0 and 255, or END_OF_STREAM if there are no more bytes.

Specified by:

next in interface ByteSource

get

protected abstract byte get(int index)

limit

protected abstract int limit()