ants.core
Class DLResponseCapsule

java.lang.Object
  |
  +--ants.core.Capsule
        |
        +--ants.core.DLResponseCapsule

public class DLResponseCapsule

extends Capsule

Demand Load Response capsule. DLResponseCapsules are only created by a DLRequestCapsule that has been delivered to a node that can satisfy the request. DLResponseCapsules contain a single "chunk" of a CodeGroup.

A DLResponseCapsule packet contains the following fields (on top of the base Capsule fields):

• payloadID: the TypeID of the CapsuleClass for which this DLResponseCapsule holds code.
• groupID: the TypeID of the CodeGroup to which this DLResponseCapsule's CapsuleClass should be added.
• array len: the length of the array (next entry) (short).
• Array of groupIDs: the TypeIDs of the other CodeGroup's in the Protocol to which this DLResponseCapsule will be added.
• chunkMask: the chunk in the CodeGroup's chunk list which this DLResponseCapsule provides.
• clen: the length of this chunk (int, could be short) (could be nuked, implicit in packet length)
• coff: the offset of this chunk in the CapsuleClass's code array. (int, could be short).
• name: A string name of the CapsuleClass this DLResponseCapsule represents.
• code: the chunk itself.

Author:

David Wetherall

See Also:

DLProtocol, DLRequestCapsule, CodeGroup

Field Summary

static java.lang.String

VERSION

Fields inherited from class ants.core.Capsule

MAX_TTL

Method Summary

Xdr	decode() Decode a capsule header from this Capsule's xdr field.
Xdr	encode() Encode this capsule's header into a new Xdr.
boolean	evaluate(Node node) Evalute a DLResponseCapsule at this node.
int	length() Return the length of the capsule header that all capsule encodings will include.
java.lang.String	toString() String representation of a Capsule.

Methods inherited from class ants.core.Capsule

create, encodeCapsuleForSend, findExtension, findMID, findPID, getDst, getPrevious, getSrc, getTTL, prime, setDst

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

VERSION

public static final java.lang.String VERSION

Method Detail

length

public int length()

Description copied from class: Capsule

Return the length of the capsule header that all capsule encodings will include.

Overrides:

length in class Capsule

Tags copied from class: Capsule

Returns:

the length of the capsule header

encode

public Xdr encode()

Description copied from class: Capsule

Encode this capsule's header into a new Xdr. Return the new Xdr.

Because this header must go first in the Xdr, this encoder unilaterally sets the xdr buffer pointer to the beginning of the buffer and writes its data there.

The format of the Xdr is:

 MethodID         (16 bytes)
 src address      ( 4 bytes)
 dst address      ( 4 bytes)
 previous address ( 4 bytes)
 TTL              ( 4 bytes)
 

Overrides:
encode in class Capsule

Tags copied from class: Capsule

Returns:
the new Xdr representing this capsule.
See Also: 
#xdr

decode

public Xdr decode()

Description copied from class: Capsule

Decode a capsule header from this Capsule's xdr field.

Overrides:

decode in class Capsule

Tags copied from class: Capsule

Returns:

the new Xdr based on the current xdr.

evaluate

public boolean evaluate(Node node)

Evalute a DLResponseCapsule at this node. Looks up the appropriate CapsuleClass and CodeGroup info, creating new ones if necessary.

XXX should deal with unanticipated DLResponseCapsules better.

Overrides:

evaluate in class Capsule

Tags copied from class: Capsule

Parameters:

node - the local node interface

Returns:

an indicationof whether the forwarding was successful.

toString

public java.lang.String toString()

Description copied from class: Capsule

String representation of a Capsule. Includes the class name, source and destination.

Overrides:

toString in class Capsule