net.named_data.jndn.encoding.tlv

Class TlvEncoder

java.lang.Object

net.named_data.jndn.encoding.tlv.TlvEncoder

public class TlvEncoder
extends Object

A TlvEncoder holds an output buffer and has methods to output NDN-TLV.

Constructor Summary

Constructors

Constructor and Description
TlvEncoder() Create a new TlvEncoder with a default DynamicByteBuffer.
TlvEncoder(int initialCapacity) Create a new TlvEncoder to use a DynamicByteBuffer with the initialCapacity.

Method Summary

Modifier and Type	Method and Description
int	getLength() Get the number of bytes that have been written to the output.
ByteBuffer	getOutput() Return a slice of the output buffer up to the current length of the output encoding.
void	writeBlobTlv(int type, ByteBuffer value) Write the type, then the length of the buffer then the buffer value from its position() to limit() to the output just before getLength() from the back.
void	writeBuffer(ByteBuffer buffer) Write the buffer from its position() to limit() to the output just before getLength() from the back.
void	writeNonNegativeInteger(long value) Encode value as a non-negative integer and write it to the output just before getLength() from the back.
void	writeNonNegativeIntegerTlv(int type, long value) Write the type, then the length of the encoded value then encode value as a non-negative integer and write it to the output just before getLength() from the back.
void	writeOptionalBlobTlv(int type, ByteBuffer value) If the byte buffer value is null or value.remaining() is zero then do nothing, otherwise call writeBlobTlv.
void	writeOptionalNonNegativeIntegerTlv(int type, long value) If value is negative or null then do nothing, otherwise call writeNonNegativeIntegerTlv.
void	writeOptionalNonNegativeIntegerTlvFromDouble(int type, double value) If value is negative or null then do nothing, otherwise call writeNonNegativeIntegerTlv.
void	writeTypeAndLength(int type, int length) Encode the type and length as VAR-NUMBER and write to the output just before getLength() from the back.
void	writeVarNumber(int varNumber) Encode varNumber as a VAR-NUMBER in NDN-TLV and write it to the output just before getLength() from the back.

Methods inherited from class java.lang.Object

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

Constructor Detail

TlvEncoder

public TlvEncoder(int initialCapacity)

Create a new TlvEncoder to use a DynamicByteBuffer with the initialCapacity. When done, you should call getOutput().

Parameters:

initialCapacity - The initial capacity of buffer().

TlvEncoder

public TlvEncoder()

Create a new TlvEncoder with a default DynamicByteBuffer. When done, you should call getOutput().

Method Detail

getLength

public final int getLength()

Get the number of bytes that have been written to the output. You can save this number, write sub TLVs, then subtract the new length from this to get the total length of the sub TLVs.

Returns:

The number of bytes that have been written to the output.

writeVarNumber

public final void writeVarNumber(int varNumber)

Encode varNumber as a VAR-NUMBER in NDN-TLV and write it to the output just before getLength() from the back. Advance getLength().

Parameters:

varNumber - The non-negative number to encode. This is a Java 32-bit int, so this does not support encoding a 64-bit VAR-NUMBER.

writeTypeAndLength

public final void writeTypeAndLength(int type,
                                     int length)

Encode the type and length as VAR-NUMBER and write to the output just before getLength() from the back. Advance getLength().

Parameters:

type - The type of the TLV. This is a Java 32-bit int, so this does not support encoding a 64-bit type code.

length - The non-negative length of the TLV. This is a Java 32-bit int, so this does not support encoding a 64-bit length.

writeNonNegativeInteger

public final void writeNonNegativeInteger(long value)

Encode value as a non-negative integer and write it to the output just before getLength() from the back. Advance getLength(). This does not write a type or length for the value.

Parameters:

value - The non-negative integer to encode. This is a Java 64-bit long, so encoding of 64-bit values is supported (actually 63-bit because a Java long is signed).

Throws:

Error - if the value is negative.

writeNonNegativeIntegerTlv

public final void writeNonNegativeIntegerTlv(int type,
                                             long value)

Write the type, then the length of the encoded value then encode value as a non-negative integer and write it to the output just before getLength() from the back. Advance getLength().

Parameters:

type - The type of the TLV. This is a Java 32-bit int, so this does not support encoding a 64-bit type code.

value - The non-negative integer to encode. This is a Java 64-bit long, so encoding of 64-bit values is supported (actually 63-bit because a Java long is signed).

Throws:

Error - if the value is negative.

writeOptionalNonNegativeIntegerTlv

public final void writeOptionalNonNegativeIntegerTlv(int type,
                                                     long value)

If value is negative or null then do nothing, otherwise call writeNonNegativeIntegerTlv.

Parameters:

type - The type of the TLV. This is a Java 32-bit int, so this does not support encoding a 64-bit type code.

value - If negative do nothing, otherwise the integer to encode. This is a Java 64-bit long, so encoding of 64-bit values is supported (actually 63-bit because a Java long is signed).

writeOptionalNonNegativeIntegerTlvFromDouble

public final void writeOptionalNonNegativeIntegerTlvFromDouble(int type,
                                                               double value)

If value is negative or null then do nothing, otherwise call writeNonNegativeIntegerTlv.

Parameters:

type - The type of the TLV. This is a Java 32-bit int, so this does not support encoding a 64-bit type code.

value - If negative do nothing, otherwise use (long)Math.round(value).

writeBuffer

public final void writeBuffer(ByteBuffer buffer)

Write the buffer from its position() to limit() to the output just before getLength() from the back. Advance getLength() of the output. This does NOT change buffer.position(). Note that this does not encode a type and length; for that see writeBlobTlv.

Parameters:

buffer - The byte buffer with the bytes to write. If buffer is null, then do nothing.

writeBlobTlv

public final void writeBlobTlv(int type,
                               ByteBuffer value)

Write the type, then the length of the buffer then the buffer value from its position() to limit() to the output just before getLength() from the back. Advance getLength() of the output. This does NOT change value.position().

Parameters:

type - The type of the TLV. This is a Java 32-bit int, so this does not support encoding a 64-bit type code.

value - The byte buffer with the bytes of the blob. If value is null, then just write the type and length 0.

writeOptionalBlobTlv

public final void writeOptionalBlobTlv(int type,
                                       ByteBuffer value)

If the byte buffer value is null or value.remaining() is zero then do nothing, otherwise call writeBlobTlv.

Parameters:

type - The type of the TLV. This is a Java 32-bit int, so this does not support encoding a 64-bit type code.

value - If null or value.remaining() is zero do nothing, otherwise the buffer with the bytes of the blob.

getOutput

public final ByteBuffer getOutput()

Return a slice of the output buffer up to the current length of the output encoding.

Returns:

A ByteBuffer which shares the same underlying buffer with the output buffer.