org.apache.beam.runners.spark.coders

Class CoderHelpers

java.lang.Object

org.apache.beam.runners.spark.coders.CoderHelpers

public final class CoderHelpers
extends java.lang.Object

Serialization utility class.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	CoderHelpers.FromByteFunction<K,V> A function for converting a byte array pair to a key-value pair.

Method Summary

Modifier and Type	Method and Description
static <T> T	fromByteArray(byte[] serialized, Coder<T> coder) Utility method for deserializing a byte array using the specified coder.
static <T> java.lang.Iterable<T>	fromByteArrays(java.util.Collection<byte[]> serialized, Coder<T> coder) Utility method for deserializing a Iterable of byte arrays using the specified coder.
static <T> org.apache.spark.api.java.function.Function<byte[],T>	fromByteFunction(Coder<T> coder) A function wrapper for converting a byte array to an object.
static <K,V> org.apache.spark.api.java.function.PairFunction<scala.Tuple2<ByteArray,java.lang.Iterable<byte[]>>,K,java.lang.Iterable<V>>	fromByteFunctionIterable(Coder<K> keyCoder, Coder<V> valueCoder) A function wrapper for converting a byte array pair to a key-value pair, where values are Iterable.
static <T> byte[]	toByteArray(T value, Coder<T> coder) Utility method for serializing an object using the specified coder.
static <T> java.util.List<byte[]>	toByteArrays(java.lang.Iterable<T> values, Coder<T> coder) Utility method for serializing a Iterable of values using the specified coder.
static <T> byte[]	toByteArrayWithTs(T value, Coder<T> coder, Instant timestamp) Utility method for serializing an object using the specified coder, appending timestamp representation.
static <K,V> org.apache.spark.api.java.function.PairFunction<scala.Tuple2<K,V>,ByteArray,byte[]>	toByteFunction(Coder<K> keyCoder, Coder<V> valueCoder) A function wrapper for converting a key-value pair to a byte array pair.
static <T> org.apache.spark.api.java.function.Function<T,byte[]>	toByteFunction(Coder<T> coder) A function wrapper for converting an object to a bytearray.
static <K,V> org.apache.spark.api.java.function.PairFunction<scala.Tuple2<K,V>,ByteArray,byte[]>	toByteFunctionWithTs(Coder<K> keyCoder, Coder<V> valueCoder, org.apache.spark.api.java.function.Function<scala.Tuple2<K,V>,Instant> timestamp) A function wrapper for converting a key-value pair to a byte array pair, where the key in resulting ByteArray contains (key, timestamp).

Methods inherited from class java.lang.Object

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

Method Detail

toByteArray

public static <T> byte[] toByteArray(T value,
                                     Coder<T> coder)

Utility method for serializing an object using the specified coder.

Type Parameters:

T - type of value that is serialized

Parameters:

value - Value to serialize.

coder - Coder to serialize with.

Returns:

Byte array representing serialized object.

toByteArrayWithTs

public static <T> byte[] toByteArrayWithTs(T value,
                                           Coder<T> coder,
                                           Instant timestamp)

Utility method for serializing an object using the specified coder, appending timestamp representation. This is useful when sorting by timestamp

Type Parameters:

T - type of value that is serialized

Parameters:

value - Value to serialize.

coder - Coder to serialize with.

timestamp - timestamp to be bundled into key's ByteArray representation

Returns:

Byte array representing serialized object.

toByteArrays

public static <T> java.util.List<byte[]> toByteArrays(java.lang.Iterable<T> values,
                                                      Coder<T> coder)

Utility method for serializing a Iterable of values using the specified coder.

Type Parameters:

T - type of value that is serialized

Parameters:

values - Values to serialize.

coder - Coder to serialize with.

Returns:

List of bytes representing serialized objects.

fromByteArray

public static <T> T fromByteArray(byte[] serialized,
                                  Coder<T> coder)

Utility method for deserializing a byte array using the specified coder.

Type Parameters:

T - Type of object to be returned.

Parameters:

serialized - bytearray to be deserialized.

coder - Coder to deserialize with.

Returns:

Deserialized object.

fromByteArrays

public static <T> java.lang.Iterable<T> fromByteArrays(java.util.Collection<byte[]> serialized,
                                                       Coder<T> coder)

Utility method for deserializing a Iterable of byte arrays using the specified coder.

Type Parameters:

T - Type of object to be returned.

Parameters:

serialized - bytearrays to be deserialized.

coder - Coder to deserialize with.

Returns:

Iterable of deserialized objects.

toByteFunction

public static <T> org.apache.spark.api.java.function.Function<T,byte[]> toByteFunction(Coder<T> coder)

A function wrapper for converting an object to a bytearray.

Type Parameters:

T - The type of the object being serialized.

Parameters:

coder - Coder to serialize with.

Returns:

A function that accepts an object and returns its coder-serialized form.

fromByteFunction

public static <T> org.apache.spark.api.java.function.Function<byte[],T> fromByteFunction(Coder<T> coder)

A function wrapper for converting a byte array to an object.

Type Parameters:

T - The type of the object being deserialized.

Parameters:

coder - Coder to deserialize with.

Returns:

A function that accepts a byte array and returns its corresponding object.

toByteFunction

public static <K,V> org.apache.spark.api.java.function.PairFunction<scala.Tuple2<K,V>,ByteArray,byte[]> toByteFunction(Coder<K> keyCoder,
                                                                                                                       Coder<V> valueCoder)

A function wrapper for converting a key-value pair to a byte array pair.

Type Parameters:

K - The type of the key being serialized.

V - The type of the value being serialized.

Parameters:

keyCoder - Coder to serialize keys.

valueCoder - Coder to serialize values.

Returns:

A function that accepts a key-value pair and returns a pair of byte arrays.

toByteFunctionWithTs

public static <K,V> org.apache.spark.api.java.function.PairFunction<scala.Tuple2<K,V>,ByteArray,byte[]> toByteFunctionWithTs(Coder<K> keyCoder,
                                                                                                                             Coder<V> valueCoder,
                                                                                                                             org.apache.spark.api.java.function.Function<scala.Tuple2<K,V>,Instant> timestamp)

A function wrapper for converting a key-value pair to a byte array pair, where the key in resulting ByteArray contains (key, timestamp).

Type Parameters:

K - The type of the key being serialized.

V - The type of the value being serialized.

Parameters:

keyCoder - Coder to serialize keys.

valueCoder - Coder to serialize values.

timestamp - timestamp of the input Tuple2

Returns:

A function that accepts a key-value pair and returns a pair of byte arrays.

fromByteFunctionIterable

public static <K,V> org.apache.spark.api.java.function.PairFunction<scala.Tuple2<ByteArray,java.lang.Iterable<byte[]>>,K,java.lang.Iterable<V>> fromByteFunctionIterable(Coder<K> keyCoder,
                                                                                                                                                                         Coder<V> valueCoder)

A function wrapper for converting a byte array pair to a key-value pair, where values are Iterable.

Type Parameters:

K - The type of the key being deserialized.

V - The type of the value being deserialized.

Parameters:

keyCoder - Coder to deserialize keys.

valueCoder - Coder to deserialize values.

Returns:

A function that accepts a pair of byte arrays and returns a key-value pair.