T
- The type of element in the list.@Internal public final class ListSerializer<T> extends TypeSerializer<List<T>>
Lists
. The serializer relies on an element serializer for the
serialization of the list's elements.
The serialization format for the list is as follows: four bytes for the length of the lost, followed by the serialized representation of each element.
Constructor and Description |
---|
ListSerializer(TypeSerializer<T> elementSerializer)
Creates a list serializer that uses the given serializer to serialize the list's elements.
|
Modifier and Type | Method and Description |
---|---|
void |
copy(DataInputView source,
DataOutputView target)
Copies exactly one record from the source input view to the target output view.
|
List<T> |
copy(List<T> from)
Creates a deep copy of the given element in a new element.
|
List<T> |
copy(List<T> from,
List<T> reuse)
Creates a copy from the given element.
|
List<T> |
createInstance()
Creates a new instance of the data type.
|
List<T> |
deserialize(DataInputView source)
De-serializes a record from the given source input view.
|
List<T> |
deserialize(List<T> reuse,
DataInputView source)
De-serializes a record from the given source input view into the given reuse record instance
if mutable.
|
TypeSerializer<List<T>> |
duplicate()
Creates a deep copy of this serializer if it is necessary, i.e. if it is stateful.
|
boolean |
equals(Object obj) |
TypeSerializer<T> |
getElementSerializer()
Gets the serializer for the elements of the list.
|
int |
getLength()
Gets the length of the data type, if it is a fix length data type.
|
int |
hashCode() |
boolean |
isImmutableType()
Gets whether the type is an immutable type.
|
void |
serialize(List<T> list,
DataOutputView target)
Serializes the given record to the given target output view.
|
TypeSerializerSnapshot<List<T>> |
snapshotConfiguration()
Snapshots the configuration of this TypeSerializer.
|
public ListSerializer(TypeSerializer<T> elementSerializer)
elementSerializer
- The serializer for the elements of the listpublic TypeSerializer<T> getElementSerializer()
public boolean isImmutableType()
TypeSerializer
isImmutableType
in class TypeSerializer<List<T>>
public TypeSerializer<List<T>> duplicate()
TypeSerializer
We need this because Serializers might be used in several threads. Stateless serializers are inherently thread-safe while stateful serializers might not be thread-safe.
duplicate
in class TypeSerializer<List<T>>
public List<T> createInstance()
TypeSerializer
createInstance
in class TypeSerializer<List<T>>
public List<T> copy(List<T> from)
TypeSerializer
copy
in class TypeSerializer<List<T>>
from
- The element reuse be copied.public List<T> copy(List<T> from, List<T> reuse)
TypeSerializer
copy
in class TypeSerializer<List<T>>
from
- The element to be copied.reuse
- The element to be reused. May or may not be used.public int getLength()
TypeSerializer
getLength
in class TypeSerializer<List<T>>
-1
for variable length data types.public void serialize(List<T> list, DataOutputView target) throws IOException
TypeSerializer
serialize
in class TypeSerializer<List<T>>
list
- The record to serialize.target
- The output view to write the serialized data to.IOException
- Thrown, if the serialization encountered an I/O related error. Typically
raised by the output view, which may have an underlying I/O channel to which it
delegates.public List<T> deserialize(DataInputView source) throws IOException
TypeSerializer
deserialize
in class TypeSerializer<List<T>>
source
- The input view from which to read the data.IOException
- Thrown, if the de-serialization encountered an I/O related error.
Typically raised by the input view, which may have an underlying I/O channel from which
it reads.public List<T> deserialize(List<T> reuse, DataInputView source) throws IOException
TypeSerializer
deserialize
in class TypeSerializer<List<T>>
reuse
- The record instance into which to de-serialize the data.source
- The input view from which to read the data.IOException
- Thrown, if the de-serialization encountered an I/O related error.
Typically raised by the input view, which may have an underlying I/O channel from which
it reads.public void copy(DataInputView source, DataOutputView target) throws IOException
TypeSerializer
target.write(source, 8);
.copy
in class TypeSerializer<List<T>>
source
- The input view from which to read the record.target
- The target output view to which to write the record.IOException
- Thrown if any of the two views raises an exception.public boolean equals(Object obj)
equals
in class TypeSerializer<List<T>>
public int hashCode()
hashCode
in class TypeSerializer<List<T>>
public TypeSerializerSnapshot<List<T>> snapshotConfiguration()
TypeSerializer
The snapshot of the TypeSerializer is supposed to contain all information that affects the serialization format of the serializer. The snapshot serves two purposes: First, to reproduce the serializer when the checkpoint/savepoint is restored, and second, to check whether the serialization format is compatible with the serializer used in the restored program.
IMPORTANT: TypeSerializerSnapshots changed after Flink 1.6. Serializers implemented against Flink versions up to 1.6 should still work, but adjust to new model to enable state evolution and be future-proof. See the class-level comments, section "Upgrading TypeSerializers to the new TypeSerializerSnapshot model" for details.
snapshotConfiguration
in class TypeSerializer<List<T>>
null
).TypeSerializerSnapshot.resolveSchemaCompatibility(TypeSerializerSnapshot)
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