TunnelGateway (Javadocs [I2P+ 2.13.0+]

java.lang.Object
- net.i2p.router.tunnel.TunnelGateway

Direct Known Subclasses:
PumpedTunnelGateway, TunnelGatewayZeroHop
```
abstract class TunnelGateway
extends Object
```
Serve as the gatekeeper for a tunnel, accepting messages, coalescing and/or fragmenting them before wrapping them up for tunnel delivery. The flow here is:
1. add an I2NPMessage (and a target tunnel/router, if necessary)
2. that message is queued up into a TunnelGateway.Pending and offered to the assigned QueuePreprocessor.
3. that QueuePreprocessor may then take off any of the TunnelGateway.Pending messages or instruct the TunnelGateway to offer it the messages again in a short while (in an attempt to coalesce them).
4. when the QueueProcessor accepts a TunnelGateway.Pending, it preprocesses it into fragments, forwarding each preprocessed fragment group through the Sender.
5. the Sender then encrypts the preprocessed data and delivers it to the Receiver.
6. the Receiver now has the encrypted message and may do with it as it pleases (e.g. wrap it as necessary and enqueue it onto the OutNetMessagePool, or if debugging, verify that it can be decrypted properly)
Unused directly - see PumpedTunnelGateway, ThrottledPumpedTunnelGateway, and TunnelGatewayZeroHop overrides.

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`protected class`	`TunnelGateway.DelayedFlush` DelayedFlush.
`static interface`	`TunnelGateway.QueuePreprocessor` Interface for preprocessing queued tunnel messages.
`static interface`	`TunnelGateway.Receiver` Interface for receiving encrypted tunnel data.
`static interface`	`TunnelGateway.Sender` Interface for sending preprocessed tunnel data.

Field Summary

Fields
Modifier and Type	Field and Description
`protected RouterContext`	`_context` router context
`protected TunnelGateway.DelayedFlush`	`_delayedFlush` delayed flush timer
`protected long`	`_lastFlush` last flush time
`protected Log`	`_log` log instance
`protected int`	`_messagesSent` messages sent count
`protected TunnelGateway.QueuePreprocessor`	`_preprocessor` queue preprocessor
`protected List<PendingGatewayMessage>`	`_queue` message queue
`protected TunnelGateway.Receiver`	`_receiver` receiver
`protected TunnelGateway.Sender`	`_sender` sender

Constructor Summary

Constructors
Modifier	Constructor and Description
`protected`	`TunnelGateway(RouterContext context, TunnelGateway.QueuePreprocessor preprocessor, TunnelGateway.Sender sender, TunnelGateway.Receiver receiver)` Creates a new TunnelGateway.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`boolean`	`add(I2NPMessage msg, Hash toRouter, TunnelId toTunnel)` Add a message to be sent down the tunnel, either sending it now (perhaps coalesced with other pending messages) or after a brief pause (_flushFrequency).
`boolean`	`add(TunnelGatewayMessage msg)` Add a message to be sent down the tunnel, where we are the inbound gateway.
`int`	`getMessagesSent()` Get the number of messages sent.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - _context
```
protected final RouterContext _context
```
    router context
  - _delayedFlush
```
protected final TunnelGateway.DelayedFlush _delayedFlush
```
    delayed flush timer
  - _lastFlush
```
protected long _lastFlush
```
    last flush time
  - _log
```
protected final Log _log
```
    log instance
  - _messagesSent
```
protected int _messagesSent
```
    messages sent count
  - _preprocessor
```
protected final TunnelGateway.QueuePreprocessor _preprocessor
```
    queue preprocessor
  - _queue
```
protected final List<PendingGatewayMessage> _queue
```
    message queue
  - _receiver
```
protected final TunnelGateway.Receiver _receiver
```
    receiver
  - _sender
```
protected final TunnelGateway.Sender _sender
```
    sender
- Constructor Detail
  - TunnelGateway
```
protected TunnelGateway(RouterContext context,
                        TunnelGateway.QueuePreprocessor preprocessor,
                        TunnelGateway.Sender sender,
                        TunnelGateway.Receiver receiver)
```
    Creates a new TunnelGateway.
    Parameters:
    context - the router context
    preprocessor - this pulls Pending messages off a list, builds some full preprocessed messages, and pumps those into the sender
    sender - this takes a preprocessed message, encrypts it, and sends it to the receiver
    receiver - this receives the encrypted message and forwards it off to the first hop
- Method Detail
  - add
```
public boolean add(I2NPMessage msg,
                   Hash toRouter,
                   TunnelId toTunnel)
```
    Add a message to be sent down the tunnel, either sending it now (perhaps coalesced with other pending messages) or after a brief pause (_flushFrequency). If it is queued up past its expiration, it is silently dropped. UNUSED - see overrides
    Parameters:
    msg - message to be sent through the tunnel
    toRouter - router to send to after the endpoint (or null for endpoint processing)
    toTunnel - tunnel to send to after the endpoint (or null for endpoint or router processing)
    Returns:
    true if the message was accepted, false if dropped
  - add
```
public boolean add(TunnelGatewayMessage msg)
```
    Add a message to be sent down the tunnel, where we are the inbound gateway.
    Parameters:
    msg - message received to be sent through the tunnel
    Returns:
    true if the message was accepted, false if dropped
  - getMessagesSent
```
public int getMessagesSent()
```
    Get the number of messages sent.
    Returns:
    the number of messages sent

Class TunnelGateway

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

_context

_delayedFlush

_lastFlush

_log

_messagesSent

_preprocessor

_queue

_receiver

_sender

Constructor Detail

TunnelGateway

Method Detail

add

add

getMessagesSent