Package org.apache.cassandra.db.marshal

Class UUIDType

java.lang.Object

org.apache.cassandra.db.marshal.AbstractType<UUID>

org.apache.cassandra.db.marshal.UUIDType

All Implemented Interfaces:

Comparator<ByteBuffer>, AssignmentTestable

public class UUIDType
extends AbstractType<UUID>

Compares UUIDs using the following criteria:
- if count of supplied bytes is less than 16, compare counts
- compare UUID version fields
- nil UUID is always lesser
- compare timestamps if both are time-based
- compare lexically, unsigned msb-to-lsb comparison

See Also:

• "com.fasterxml.uuid.UUIDComparator"

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.cassandra.db.marshal.AbstractType

AbstractType.ComparisonType, AbstractType.DefaultArgumentDeserializer

Nested classes/interfaces inherited from interface org.apache.cassandra.cql3.AssignmentTestable

AssignmentTestable.TestResult

Field Summary

Fields

Modifier and Type	Field	Description
static final UUIDType	instance

Fields inherited from class org.apache.cassandra.db.marshal.AbstractType

comparatorSet, comparisonType, isByteOrderComparable, reverseComparator

Method Summary

Modifier and Type	Method	Description
boolean	allowsEmpty()	Defines if the type allows an empty set of bytes (new byte[0]) as valid input.
<V> ByteSource	asComparableBytes(ValueAccessor<V> accessor, V data, ByteComparable.Version v)	Produce a byte-comparable representation of the given value, i.e.
CQL3Type	asCQL3Type()
<VL, VR> int	compareCustom(VL left, ValueAccessor<VL> accessorL, VR right, ValueAccessor<VR> accessorR)	Implement IFF ComparisonType is CUSTOM Compares the byte representation of two instances of this class, for types where this cannot be done by simple in-order comparison of the unsigned bytes Standard Java compare semantics
<V> V	fromComparableBytes(ValueAccessor<V> accessor, ByteSource.Peekable comparableBytes, ByteComparable.Version version)	Translates the given byte-ordered representation to the common, non-byte-ordered binary representation of a payload for this abstract type (the latter, common binary representation is what we mostly work with in the storage engine internals).
Term	fromJSONObject(Object parsed)	Given a parsed JSON string, return a byte representation of the object.
ByteBuffer	fromString(String source)	get a byte representation of the given string.
ArgumentDeserializer	getArgumentDeserializer()
ByteBuffer	getMaskedValue()
TypeSerializer<UUID>	getSerializer()
boolean	isEmptyValueMeaningless()	Returns true for types where empty should be handled like null like Int32Type.
boolean	isValueCompatibleWithInternal(AbstractType<?> otherType)	Needed to handle ReversedType in value-compatibility checks.
int	valueLengthIfFixed()	The length of values for this type if all values are of fixed length, -1 otherwise.

Methods inherited from class org.apache.cassandra.db.marshal.AbstractType

asComparableBytes, asCQLTypeStringList, checkComparable, compare, compare, compareCollectionMembers, compareForCQL, compose, compose, decompose, decomposeUntyped, expandUserTypes, freeze, freezeNestedMulticellTypes, fromComparableBytes, getCompatibleTypeIfKnown, getComponents, getString, getString, getString, isCollection, isCompatibleWith, isCounter, isFreezable, isFrozenCollection, isMultiCell, isNull, isNull, isReversed, isSerializationCompatibleWith, isTuple, isUDT, isValueCompatibleWith, isValueLengthFixed, isVector, parseDefaultParameters, read, readArray, readBuffer, readBuffer, referencesDuration, referencesUserType, referencesUserType, skipValue, subTypes, testAssignment, testAssignment, toCQLString, toJSONString, toJSONString, toString, toString, udfType, unfreeze, unwrap, validate, validate, validateCellValue, validateCollectionMember, withUpdatedUserType, writeValue, writeValue, writtenLength, writtenLength

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Comparator

equals, reversed, thenComparing, thenComparing, thenComparing, thenComparingDouble, thenComparingInt, thenComparingLong

Field Details

instance

public static final UUIDType instance

Method Details

allowsEmpty

public boolean allowsEmpty()

Description copied from class: AbstractType

Defines if the type allows an empty set of bytes (new byte[0]) as valid input. The AbstractType.validate(Object, ValueAccessor) and AbstractType.compose(Object, ValueAccessor) methods must allow empty bytes when this returns true, and must reject empty bytes when this is false.

As of this writing, the main user of this API is for testing to know what types allow empty values and what types don't, so that the data that gets generated understands when ByteBufferUtil.EMPTY_BYTE_BUFFER is allowed as valid data.

Overrides:

allowsEmpty in class AbstractType<UUID>

isEmptyValueMeaningless

public boolean isEmptyValueMeaningless()

Description copied from class: AbstractType

Returns true for types where empty should be handled like null like Int32Type.

Overrides:

isEmptyValueMeaningless in class AbstractType<UUID>

compareCustom

public <VL,
VR> int compareCustom(VL left,
 ValueAccessor<VL> accessorL,
 VR right,
 ValueAccessor<VR> accessorR)

Description copied from class: AbstractType

Implement IFF ComparisonType is CUSTOM Compares the byte representation of two instances of this class, for types where this cannot be done by simple in-order comparison of the unsigned bytes Standard Java compare semantics

Overrides:

compareCustom in class AbstractType<UUID>

asComparableBytes

public <V> ByteSource asComparableBytes(ValueAccessor<V> accessor,
 V data,
 ByteComparable.Version v)

Description copied from class: AbstractType

Produce a byte-comparable representation of the given value, i.e. a sequence of bytes that compares the same way using lexicographical unsigned byte comparison as the original value using the type's comparator. We use a slightly stronger requirement to be able to use the types in tuples. Precisely, for any pair x, y of non-equal valid values of this type and any bytes b1, b2 between 0x10 and 0xEF, (+ stands for concatenation) compare(x, y) == compareLexicographicallyUnsigned(asByteComparable(x)+b1, asByteComparable(y)+b2) (i.e. the values compare like the original type, and an added 0x10-0xEF byte at the end does not change that) and: asByteComparable(x)+b1 is not a prefix of asByteComparable(y) (weakly prefix free) (i.e. a valid representation of a value may be a prefix of another valid representation of a value only if the following byte in the latter is smaller than 0x10 or larger than 0xEF). These properties are trivially true if the encoding compares correctly and is prefix free, but also permits a little more freedom that enables somewhat more efficient encoding of arbitrary-length byte-comparable blobs. Depending on the type, this method can be called for null or empty input, in which case the output is allowed to be null (the clustering/tuple encoding will accept and handle it).

Overrides:

asComparableBytes in class AbstractType<UUID>

fromComparableBytes

public <V> V fromComparableBytes(ValueAccessor<V> accessor,
 ByteSource.Peekable comparableBytes,
 ByteComparable.Version version)

Description copied from class: AbstractType

Translates the given byte-ordered representation to the common, non-byte-ordered binary representation of a payload for this abstract type (the latter, common binary representation is what we mostly work with in the storage engine internals). If the given bytes don't correspond to the encoding of some payload value for this abstract type, an IllegalArgumentException may be thrown.

Overrides:

fromComparableBytes in class AbstractType<UUID>

Parameters:

accessor - value accessor used to construct the value.

comparableBytes - A byte-ordered representation (presumably of a payload for this abstract type).

version - The byte-comparable version used to construct the representation.

Returns:

A of a payload for this abstract type, corresponding to the given byte-ordered representation, constructed using the supplied value accessor.

See Also:

• AbstractType.asComparableBytes(org.apache.cassandra.db.marshal.ValueAccessor<V>, V, org.apache.cassandra.utils.bytecomparable.ByteComparable.Version)

isValueCompatibleWithInternal

public boolean isValueCompatibleWithInternal(AbstractType<?> otherType)

Description copied from class: AbstractType

Needed to handle ReversedType in value-compatibility checks. Subclasses should implement this instead of isValueCompatibleWith().

Overrides:

isValueCompatibleWithInternal in class AbstractType<UUID>

fromString

public ByteBuffer fromString(String source)
                      throws MarshalException

Description copied from class: AbstractType

get a byte representation of the given string.

Specified by:

fromString in class AbstractType<UUID>

Throws:

MarshalException

asCQL3Type

public CQL3Type asCQL3Type()

Overrides:

asCQL3Type in class AbstractType<UUID>

getSerializer

public TypeSerializer<UUID> getSerializer()

Specified by:

getSerializer in class AbstractType<UUID>

getArgumentDeserializer

public ArgumentDeserializer getArgumentDeserializer()

Overrides:

getArgumentDeserializer in class AbstractType<UUID>

Returns:

the deserializer used to deserialize the function arguments of this type.

fromJSONObject

public Term fromJSONObject(Object parsed)
                    throws MarshalException

Description copied from class: AbstractType

Given a parsed JSON string, return a byte representation of the object.

Specified by:

fromJSONObject in class AbstractType<UUID>

Parameters:

parsed - the result of parsing a json string

Throws:

MarshalException

valueLengthIfFixed

public int valueLengthIfFixed()

Description copied from class: AbstractType

The length of values for this type if all values are of fixed length, -1 otherwise. This has an impact on serialization.

see AbstractType.writeValue(java.nio.ByteBuffer, org.apache.cassandra.io.util.DataOutputPlus)

see AbstractType.read(org.apache.cassandra.db.marshal.ValueAccessor<V>, org.apache.cassandra.io.util.DataInputPlus, int)

see AbstractType.writtenLength(java.nio.ByteBuffer)

see AbstractType.skipValue(org.apache.cassandra.io.util.DataInputPlus)

Overrides:

valueLengthIfFixed in class AbstractType<UUID>

getMaskedValue

public ByteBuffer getMaskedValue()

Overrides:

getMaskedValue in class AbstractType<UUID>

Returns:

A fixed, serialized value to be used when the column is masked, to be returned instead of the real value.