Module kala.compress.compressors.gzip

Package kala.compress.compressors.gzip

Class ExtraField

java.lang.Object

kala.compress.compressors.gzip.ExtraField

All Implemented Interfaces:

java.lang.Iterable<ExtraField.SubField>

public class ExtraField
extends java.lang.Object
implements java.lang.Iterable<ExtraField.SubField>

If the FLG.FEXTRA bit is set, an "extra field" is present in the header, with total length XLEN bytes. It consists of a series of subfields, each of the form:

 +---+---+---+---+==================================+
 |SI1|SI2|  LEN  |... LEN bytes of subfield data ...|
 +---+---+---+---+==================================+
 

This class does not expose the internal subfields list to prevent adding subfields without total extra length validation. However a copy of the list is available.

Since:

1.28.0

See Also:

RFC 1952 GZIP File Format Specification

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	ExtraField.SubField	If the FLG.FEXTRA bit is set, an "extra field" is present in the header, with total length XLEN bytes.

Field Summary

Fields

Modifier and Type	Field	Description
private static int	MAX_SIZE
private java.util.List<ExtraField.SubField>	subFields
private int	totalSize
private static byte[]	ZERO_BYTES

Constructor Summary

Constructors

Constructor	Description
ExtraField()	Constructs a new instance.

Method Summary

Modifier and Type	Method	Description
ExtraField	addSubField(java.lang.String id, byte[] payload)	Append a subfield by a 2-chars ISO-8859-1 string.
(package private) static ExtraField	fromBytes(byte[] bytes)
ExtraField.SubField	getSubFieldAt(int index)	Gets the subfield at the given index.
java.util.Iterator<ExtraField.SubField>	iterator()	Returns an iterator over the SubField elements in this extra field in proper sequence.
(package private) byte[]	toByteArray()

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Field Detail

MAX_SIZE

private static final int MAX_SIZE

See Also:

Constant Field Values

ZERO_BYTES

private static final byte[] ZERO_BYTES

subFields

private final java.util.List<ExtraField.SubField> subFields

totalSize

private int totalSize

Constructor Detail

ExtraField

public ExtraField()

Constructs a new instance.

Method Detail

fromBytes

static ExtraField fromBytes(byte[] bytes)
                     throws java.io.IOException

Throws:

java.io.IOException

addSubField

public ExtraField addSubField(java.lang.String id,
                              byte[] payload)
                       throws java.io.IOException

Append a subfield by a 2-chars ISO-8859-1 string. The char at index 0 and 1 are respectiovely si1 and si2 (subfield id 1 and 2).

Parameters:

id - The subfield ID.

payload - The subfield payload.

Returns:

this instance.

Throws:

java.lang.NullPointerException - if id is null.

java.lang.NullPointerException - if payload is null.

java.lang.IllegalArgumentException - if the subfield is not 2 characters or the payload is null

java.io.IOException - if appending this subfield would exceed the max size 65535 of the extra header.

getSubFieldAt

public ExtraField.SubField getSubFieldAt(int index)

Gets the subfield at the given index.

Parameters:

index - index of the element to return

Returns:

the subfield at the specified position in this list

Throws:

java.lang.IndexOutOfBoundsException - if the index is out of range (index < 0 || index >= size())

iterator

public java.util.Iterator<ExtraField.SubField> iterator()

Returns an iterator over the SubField elements in this extra field in proper sequence.

Specified by:

iterator in interface java.lang.Iterable<ExtraField.SubField>

Returns:

an iterator over the SubField elements in this extra field in proper sequence.

toByteArray

byte[] toByteArray()