org.embulk.spi

Class Page

java.lang.Object

org.embulk.spi.Page

public abstract class Page
extends Object

An in-process (in-JVM) container of data records.

It serializes records to byte[] (in Buffer) for the following purposes.

• A) Avoid slowness by handling many Java Objects
• B) Avoid complexity by type-safe primitive arrays
• C) Track memory consumption by records
• D) Use off-heap memory

(C) and (D) may not be so meaningful as of Embulk v0.7+ (or since earlier) as recent Embulk unlikely allocates so many Pages at the same time. Recent Embulk is streaming-driven instead of multithreaded queue-based.

Page is NOT for inter-process communication. For multi-process execution such as the deprecated MapReduce Executor, the executor plugin takes responsibility about interoperable serialization.

Since:

0.4.0

Constructor Summary

Constructors

Constructor and Description
Page()

Method Summary

Modifier and Type	Method and Description
static Page	allocate(int length) Deprecated. It is to be removed, implemented only for compatibility. Plugins should no longer call it directly.
abstract Buffer	buffer()
abstract JsonValue	getJsonValueReference(int index) Returns a JSON value from the JSON value references in this Page at index.
abstract String	getStringReference(int index) Returns a string from the string references in this Page at index.
abstract List<String>	getStringReferences() Deprecated. Do not call this method directly from plugins.
abstract ImmutableValue	getValueReference(int index) Deprecated. Use getJsonValueReference(int) instead.
abstract List<ImmutableValue>	getValueReferences() Deprecated. Do not call this method directly from plugins.
abstract void	release()
abstract Page	setStringReferences(List<String> values) Deprecated. Do not call this method directly from plugins.
abstract Page	setValueReferences(List<ImmutableValue> values) Deprecated. Do not call this method directly from plugins.
static Page	wrap(Buffer buffer) Deprecated. It is to be removed, implemented only for compatibility. Plugins should no longer call it directly.

Methods inherited from class java.lang.Object

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

Constructor Detail

Page

public Page()

Method Detail

setStringReferences

@Deprecated
public abstract Page setStringReferences(List<String> values)

Deprecated. Do not call this method directly from plugins.

Sets the list of string references in this Page.

Parameters:

values - the list of string references to set

Returns:

this Page itself

Since:

0.4.0

setValueReferences

@Deprecated
public abstract Page setValueReferences(List<ImmutableValue> values)

Deprecated. Do not call this method directly from plugins.

Sets the list of JSON value references in this Page in the msgpack-java representation.

The JSON values are converted to JsonValue from the msgpack-java representation.

Parameters:

values - the list of JSON value references to set in the msgpack-java representation

Returns:

this Page itself

Since:

0.8.0

getStringReferences

@Deprecated
public abstract List<String> getStringReferences()

Deprecated. Do not call this method directly from plugins.

Returns the list of string references in this Page.

Returns:

the list of string references in this Page

Since:

0.6.0

getValueReferences

@Deprecated
public abstract List<ImmutableValue> getValueReferences()

Deprecated. Do not call this method directly from plugins.

Returns the list of JSON value references in this Page in the msgpack-java representation.

The JSON values are converted to the msgpack-java representation from JsonValue in this Page.

Returns:

the list of JSON value references in this Page in the msgpack-java representation

Since:

0.8.0

getStringReference

public abstract String getStringReference(int index)

Returns a string from the string references in this Page at index.

Parameters:

index - the index of the string reference to return

Returns:

the string from the string references in this Page at index

Since:

0.4.0

getValueReference

@Deprecated
public abstract ImmutableValue getValueReference(int index)

Deprecated. Use getJsonValueReference(int) instead.

Returns a JSON value from the JSON value references in this Page at index in the msgpack-java representation.

The JSON value is converted to the msgpack-java representatino from JsonValue in this Page.

Parameters:

index - the index of the JSON value reference to return

Returns:

the JSON value from the JSON value references in this Page at index in the msgpack-java representation

Since:

0.8.0

getJsonValueReference

public abstract JsonValue getJsonValueReference(int index)

Returns a JSON value from the JSON value references in this Page at index.

Parameters:

index - the index of the JSON value reference to return

Returns:

the JSON value from the JSON value references in this Page at index

Since:

0.10.42

release

public abstract void release()

Since:

0.4.0

buffer

public abstract Buffer buffer()

Since:

0.4.0

allocate

@Deprecated
public static Page allocate(int length)

Deprecated. It is to be removed, implemented only for compatibility. Plugins should no longer call it directly.

Creates a new Page instance.

Parameters:

length - length of the internal Buffer of the created Page

Returns:

Page created

Since:

0.4.0

wrap

@Deprecated
public static Page wrap(Buffer buffer)

Deprecated. It is to be removed, implemented only for compatibility. Plugins should no longer call it directly.

Creates a new Page instance wrapping an internal Buffer.

Parameters:

buffer - the internal Buffer

Returns:

Page created

Since:

0.4.0