FIFOBandwidthLimiter (Javadocs [I2P+ 2.13.0+]

java.lang.Object
- net.i2p.router.transport.FIFOBandwidthLimiter

```
public class FIFOBandwidthLimiter
extends Object
```
FIFO-based bandwidth limiter for managing inbound and outbound traffic. This class provides bandwidth management using First-In-First-Out queues for both inbound and outbound traffic. It implements token bucket algorithm to control data rates and prevent burst traffic patterns. Core Features:
- FIFO request queuing for fair bandwidth allocation
- Token bucket rate limiting
- Separate inbound and outbound management
- Configurable bandwidth limits and refill rates
- Thread-safe operations with atomic counters
- Request satisfaction and partial fulfillment handling
Concurrency Strategy:
- Java 5: Used synchronized ArrayList with head/tail access
- Java 6+: Uses LinkedBlockingDeque for lock-free operations
- Request polling from queue head for efficiency
- Partial request satisfaction with push-back mechanism
Algorithm:
- Token refill at fixed intervals
- Request processing when tokens available
- Burst prevention through token depletion
- Priority-based request handling

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`static interface`	`FIFOBandwidthLimiter.CompleteListener` Listener for bandwidth request completion events.
`static interface`	`FIFOBandwidthLimiter.Request` A bandwidth request, either inbound or outbound.

Constructor Summary
Constructors
Constructor and Description
FIFOBandwidthLimiter(RouterContext context)
FIFOBandwidthLimiter.

Constructors
Constructor and Description
`FIFOBandwidthLimiter(RouterContext context)` FIFOBandwidthLimiter.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`int`	`getCurrentParticipatingBandwidth()` Out bandwidth.
`int`	`getCurrentParticipatingBandwidthIn()` In bandwidth.
`int`	`getInboundBurstBytes()` The max inbound burst, in bytes.
`int`	`getInboundBurstKBytesPerSecond()` The configured maximum, not the current rate.
`int`	`getInboundKBytesPerSecond()` The configured maximum, not the current rate.
`int`	`getMaxShareBandwidth()` In Bytes per second
`int`	`getOutboundBurstBytes()` The max outbound burst, in bytes.
`int`	`getOutboundBurstKBytesPerSecond()` The configured maximum, not the current rate.
`int`	`getOutboundKBytesPerSecond()` The configured maximum, not the current rate.
`float`	`getReceiveBps()` Smoothed one-second receive rate.
`float`	`getReceiveBps15s()` Smoothed 15-second receive rate.
`float`	`getSendBps()` Smoothed one-second send rate.
`float`	`getSendBps15s()` Smoothed 15-second send rate.
`(package private) StringBuilder`	`getStatus()` The current status string.
`long`	`getTotalAllocatedInboundBytes()` Total bytes allocated for inbound messages since start.
`long`	`getTotalAllocatedOutboundBytes()` Total bytes allocated for outbound messages since start.
`long`	`now()` Current time in milliseconds from the System clock.
`boolean`	`receivedParticipatingMessage(int size, float factor)` Check if we should accept an inbound participating message.
`(package private) void`	`refillBandwidthQueues(List<FIFOBandwidthLimiter.Request> buf, long bytesInbound, long bytesOutbound, long maxBurstIn, long maxBurstOut)` More bytes are available - add them to the queue and satisfy any requests we can
`void`	`reinitialize()` Clear and reinitialize the refiller and queues.
`FIFOBandwidthLimiter.Request`	`requestInbound(FIFOBandwidthLimiter.Request candidate, int bytesIn, String purpose)` Request some bytes, reusing the given request if possible.
`FIFOBandwidthLimiter.Request`	`requestInbound(int bytesIn, String purpose)` Request some bytes.
`FIFOBandwidthLimiter.Request`	`requestOutbound(FIFOBandwidthLimiter.Request candidate, int bytesOut, int priority, String purpose)` Request some bytes, reusing the given request if possible.
`FIFOBandwidthLimiter.Request`	`requestOutbound(int bytesOut, int priority, String purpose)` Request some bytes.
`boolean`	`sentParticipatingMessage(int size, float factor)` We intend to send traffic for a participating tunnel with the given size and adjustment factor.
`(package private) void`	`setInboundBurstBytes(int bytes)` Inbound burst maximum, in bytes.
`(package private) void`	`setInboundBurstKBps(int kbytesPerSecond)` Inbound burst rate in KBps.
`(package private) void`	`setOutboundBurstBytes(int bytes)` Outbound burst maximum, in bytes.
`(package private) void`	`setOutboundBurstKBps(int kbytesPerSecond)` Outbound burst rate in KBps.
`void`	`shutdown()` Shut down the bandwidth limiter

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

- Constructor Detail
  - FIFOBandwidthLimiter
```
public FIFOBandwidthLimiter(RouterContext context)
```
    FIFOBandwidthLimiter.
- Method Detail
  - getCurrentParticipatingBandwidth
```
public int getCurrentParticipatingBandwidth()
```
    Out bandwidth. Actual bandwidth, not smoothed, not bucketed.
    Returns:
    Bps in recent period (a few seconds)
  - getCurrentParticipatingBandwidthIn
```
public int getCurrentParticipatingBandwidthIn()
```
    In bandwidth. Actual bandwidth, not smoothed, not bucketed.
    Returns:
    Bps in recent period (a few seconds)
  - getInboundBurstBytes
```
public int getInboundBurstBytes()
```
    The max inbound burst, in bytes.
    Returns:
    the inbound burst bytes
  - getInboundBurstKBytesPerSecond
```
public int getInboundBurstKBytesPerSecond()
```
    The configured maximum, not the current rate. In binary K, i.e. rate / 1024.
    Returns:
    the inbound burst k bytes per second
  - getInboundKBytesPerSecond
```
public int getInboundKBytesPerSecond()
```
    The configured maximum, not the current rate. In binary K, i.e. rate / 1024.
    Returns:
    the inbound k bytes per second
  - getMaxShareBandwidth
```
public int getMaxShareBandwidth()
```
    In Bytes per second
    Returns:
    the max share bandwidth
  - getOutboundBurstBytes
```
public int getOutboundBurstBytes()
```
    The max outbound burst, in bytes.
    Returns:
    the outbound burst bytes
  - getOutboundBurstKBytesPerSecond
```
public int getOutboundBurstKBytesPerSecond()
```
    The configured maximum, not the current rate. In binary K, i.e. rate / 1024.
    Returns:
    the outbound burst k bytes per second
  - getOutboundKBytesPerSecond
```
public int getOutboundKBytesPerSecond()
```
    The configured maximum, not the current rate. In binary K, i.e. rate / 1024.
    Returns:
    the outbound k bytes per second
  - getReceiveBps
```
public float getReceiveBps()
```
    Smoothed one-second receive rate.
    Returns:
    smoothed one second rate
  - getReceiveBps15s
```
public float getReceiveBps15s()
```
    Smoothed 15-second receive rate.
    Returns:
    smoothed 15 second rate
  - getSendBps
```
public float getSendBps()
```
    Smoothed one-second send rate.
    Returns:
    smoothed one second rate
  - getSendBps15s
```
public float getSendBps15s()
```
    Smoothed 15-second send rate.
    Returns:
    smoothed 15 second rate
  - getStatus
```
StringBuilder getStatus()
```
    The current status string.
  - getTotalAllocatedInboundBytes
```
public long getTotalAllocatedInboundBytes()
```
    Total bytes allocated for inbound messages since start.
    Returns:
    the total allocated inbound bytes
  - getTotalAllocatedOutboundBytes
```
public long getTotalAllocatedOutboundBytes()
```
    Total bytes allocated for outbound messages since start.
    Returns:
    the total allocated outbound bytes
  - now
```
public long now()
```
    Current time in milliseconds from the System clock.
  - receivedParticipatingMessage
```
public boolean receivedParticipatingMessage(int size,
                                            float factor)
```
    Check if we should accept an inbound participating message.
    Parameters:
    size - bytes
    factor - multiplier of size for the drop calculation, 1 for no adjustment
    Returns:
    true for accepted, false for drop
  - refillBandwidthQueues
```
final void refillBandwidthQueues(List<FIFOBandwidthLimiter.Request> buf,
                                 long bytesInbound,
                                 long bytesOutbound,
                                 long maxBurstIn,
                                 long maxBurstOut)
```
    More bytes are available - add them to the queue and satisfy any requests we can
    Parameters:
    buf - contains satisfied outbound requests, really just to avoid object thrash, not really used
    maxBurstIn - allow up to this many bytes in from the burst section for this time period (may be negative)
    maxBurstOut - allow up to this many bytes in from the burst section for this time period (may be negative)
  - reinitialize
```
public void reinitialize()
```
    Clear and reinitialize the refiller and queues.
  - requestInbound
```
public FIFOBandwidthLimiter.Request requestInbound(FIFOBandwidthLimiter.Request candidate,
                                                   int bytesIn,
                                                   String purpose)
```
    Request some bytes, reusing the given request if possible. Does not block. If the candidate is a SimpleRequest that is complete (fully allocated and not aborted), it is reset and re-queued, avoiding a new allocation. If the candidate is the shared no-op request and the shortcut still applies, it is returned as-is.
    Parameters:
    candidate - the request from a previous allocation for this consumer, or null for a new request
    bytesIn - the number of bytes requested
    purpose - the purpose of the request, for logging
    Returns:
    the request to use; never null
  - requestInbound
```
public FIFOBandwidthLimiter.Request requestInbound(int bytesIn,
                                                   String purpose)
```
    Request some bytes. Does not block.
  - requestOutbound
```
public FIFOBandwidthLimiter.Request requestOutbound(FIFOBandwidthLimiter.Request candidate,
                                                    int bytesOut,
                                                    int priority,
                                                    String purpose)
```
    Request some bytes, reusing the given request if possible. Does not block. If the candidate is a SimpleRequest that is complete (fully allocated and not aborted), it is reset and re-queued, avoiding a new allocation. If the candidate is the shared no-op request and the shortcut still applies, it is returned as-is.
    Parameters:
    candidate - the request from a previous allocation for this consumer, or null for a new request
    bytesOut - the number of bytes requested
    priority - 0 for now
    purpose - the purpose of the request, for logging
    Returns:
    the request to use; never null
  - requestOutbound
```
public FIFOBandwidthLimiter.Request requestOutbound(int bytesOut,
                                                    int priority,
                                                    String purpose)
```
    Request some bytes. Does not block.
  - sentParticipatingMessage
```
public boolean sentParticipatingMessage(int size,
                                        float factor)
```
    We intend to send traffic for a participating tunnel with the given size and adjustment factor. Returns true if the message can be sent within the current share bandwidth limits, or false if it should be dropped.
    Parameters:
    size - bytes
    factor - multiplier of size for the drop calculation, 1 for no adjustment
    Returns:
    true for accepted, false for drop
  - setInboundBurstBytes
```
void setInboundBurstBytes(int bytes)
```
    Inbound burst maximum, in bytes.
  - setInboundBurstKBps
```
void setInboundBurstKBps(int kbytesPerSecond)
```
    Inbound burst rate in KBps.
  - setOutboundBurstBytes
```
void setOutboundBurstBytes(int bytes)
```
    Outbound burst maximum, in bytes.
  - setOutboundBurstKBps
```
void setOutboundBurstKBps(int kbytesPerSecond)
```
    Outbound burst rate in KBps.
  - shutdown
```
public void shutdown()
```
    Shut down the bandwidth limiter

Class FIFOBandwidthLimiter

Nested Class Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

FIFOBandwidthLimiter

Method Detail

getCurrentParticipatingBandwidth

getCurrentParticipatingBandwidthIn

getInboundBurstBytes

getInboundBurstKBytesPerSecond

getInboundKBytesPerSecond

getMaxShareBandwidth

getOutboundBurstBytes

getOutboundBurstKBytesPerSecond

getOutboundKBytesPerSecond

getReceiveBps

getReceiveBps15s

getSendBps

getSendBps15s

getStatus

getTotalAllocatedInboundBytes

getTotalAllocatedOutboundBytes

now

receivedParticipatingMessage

refillBandwidthQueues

reinitialize

requestInbound

requestInbound

requestOutbound

requestOutbound

sentParticipatingMessage

setInboundBurstBytes

setInboundBurstKBps

setOutboundBurstBytes

setOutboundBurstKBps

shutdown