Package org.apache.cassandra.db.marshal

Class EmptyType

java.lang.Object

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

org.apache.cassandra.db.marshal.EmptyType

All Implemented Interfaces:

Comparator<ByteBuffer>, AssignmentTestable

public class EmptyType
extends AbstractType<Void>

A type that only accept empty data. It is only useful as a value validation type, not as a comparator since column names can't be empty.

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 EmptyType	instance

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

comparatorSet, comparisonType, isByteOrderComparable, reverseComparator

Method Summary

Modifier and Type	Method	Description
<V> ByteSource	asComparableBytes(ValueAccessor<V> accessor, V data, ByteComparable.Version version)	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<Void>	getSerializer()
<V> String	getString(V value, ValueAccessor<V> accessor)	get a string representation of the bytes used for various identifier (NOT just for log messages)
ByteBuffer	readBuffer(DataInputPlus in)
ByteBuffer	readBuffer(DataInputPlus in, int maxValueSize)
String	toJSONString(ByteBuffer buffer, ProtocolVersion protocolVersion)	Converts the specified value into its JSON representation.
int	valueLengthIfFixed()	The length of values for this type if all values are of fixed length, -1 otherwise.
void	writeValue(ByteBuffer value, DataOutputPlus out)
<V> long	writtenLength(V value, ValueAccessor<V> accessor)

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

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

Method Details

asComparableBytes

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

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<Void>

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<Void>

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)

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<Void>

getString

public <V> String getString(V value,
 ValueAccessor<V> accessor)

Description copied from class: AbstractType

get a string representation of the bytes used for various identifier (NOT just for log messages)

Overrides:

getString in class AbstractType<Void>

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<Void>

Throws:

MarshalException

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<Void>

Parameters:

parsed - the result of parsing a json string

Throws:

MarshalException

asCQL3Type

public CQL3Type asCQL3Type()

Overrides:

asCQL3Type in class AbstractType<Void>

toJSONString

public String toJSONString(ByteBuffer buffer,
 ProtocolVersion protocolVersion)

Description copied from class: AbstractType

Converts the specified value into its JSON representation.

The buffer position will stay the same.

Overrides:

toJSONString in class AbstractType<Void>

Parameters:

buffer - the value to convert

protocolVersion - the protocol version to use for the conversion

Returns:

a JSON string representing the specified value

getSerializer

public TypeSerializer<Void> getSerializer()

Specified by:

getSerializer in class AbstractType<Void>

getArgumentDeserializer

public ArgumentDeserializer getArgumentDeserializer()

Overrides:

getArgumentDeserializer in class AbstractType<Void>

Returns:

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

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<Void>

writtenLength

public <V> long writtenLength(V value,
 ValueAccessor<V> accessor)

Overrides:

writtenLength in class AbstractType<Void>

readBuffer

public ByteBuffer readBuffer(DataInputPlus in)

Overrides:

readBuffer in class AbstractType<Void>

readBuffer

public ByteBuffer readBuffer(DataInputPlus in,
 int maxValueSize)

Overrides:

readBuffer in class AbstractType<Void>

writeValue

public void writeValue(ByteBuffer value,
 DataOutputPlus out)

Overrides:

writeValue in class AbstractType<Void>

getMaskedValue

public ByteBuffer getMaskedValue()

Overrides:

getMaskedValue in class AbstractType<Void>

Returns:

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