freenet.client.async

Class BaseSingleFileFetcher

java.lang.Object

freenet.node.SendableRequest

freenet.node.BaseSendableGet

freenet.node.SendableGet

freenet.client.async.BaseSingleFileFetcher

All Implemented Interfaces:

HasKeyListener, RequestSelectionTreeNode, RandomGrabArrayItem, java.io.Serializable

Direct Known Subclasses:

SimpleSingleFileFetcher

public abstract class BaseSingleFileFetcher
extends SendableGet
implements HasKeyListener

Base class implements most of what is needed for fetching a single block. WARNING: Changing non-transient members on classes that are Serializable can result in restarting downloads or losing uploads.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	cancelled
long	cooldownWakeupTime
protected FetchContext	ctx
protected boolean	deleteFetchContext
protected boolean	finished
protected ClientKey	key

Fields inherited from class freenet.node.SendableGet

parent

Fields inherited from class freenet.node.SendableRequest

parentGrabArray, persistent, realTimeFlag

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	BaseSingleFileFetcher(ClientKey key, int maxRetries, FetchContext ctx, ClientRequester parent, boolean deleteFetchContext, boolean realTimeFlag)

Method Summary

Modifier and Type	Method and Description
void	cancel(ClientContext context)
SendableRequestItem	chooseKey(KeysFetchingLocally fetching, ClientContext context) Choose a key to fetch.
long	countAllKeys(ClientContext context) All key identifiers.
long	countSendableKeys(ClientContext context) All key identifiers currently eligible to be sent.
RequestClient	getClient() Get client context object.
ClientRequester	getClientRequest() Get the ClientRequest.
FetchContext	getContext() Get the fetch context (settings) object.
long	getCooldownWakeup(SendableRequestItem token, ClientContext context) Get the time at which the key specified by the given token will wake up from the cooldown queue.
ClientKey	getKey(SendableRequestItem token) Get a numbered key to fetch.
short	getPriorityClass() Get the priority class of the request.
SendableGet	getRequest(Key key)
long	getWakeupTime(ClientContext context, long now) Unless this is a RandomGrabArrayItem, this will return the wakeup time for the subtree rooted at this node.
boolean	isCancelled() If true, the request has been cancelled, or has completed, either way it need not be registered any more.
boolean	isEmpty()
boolean	isSSK() Is this an SSK? For purposes of determining which scheduler to use.
Key[]	listKeys() What keys are we interested in? For purposes of checking the datastore.
KeyListener	makeKeyListener(ClientContext context, boolean onStartup) Create a KeyListener, a transient object used to determine which keys we want, and to handle any blocks found.
protected abstract void	notFoundInStore(ClientContext context)
protected abstract void	onBlockDecodeError(SendableRequestItem token, ClientContext context)
void	onChangedFetchContext(ClientContext context) Reread the cached cooldown values (and anything else) from the FetchContext after it changes.
protected void	onEnterFiniteCooldown(ClientContext context)
void	onGotKey(Key key, KeyBlock block, ClientContext context)
void	onResume(ClientContext context)
abstract void	onSuccess(ClientKeyBlock block, boolean fromStore, java.lang.Object token, ClientContext context) Called when/if the low-level request succeeds.
void	onSuccess(KeyBlock lowLevelBlock, boolean fromStore, SendableRequestItem token, ClientContext context)
boolean	preRegister(ClientContext context, boolean toNetwork) Called after checking the datastore and before registering the request to be sent.
void	reschedule(ClientContext context)
protected boolean	retry(ClientContext context) Try again - returns true if we can retry
void	schedule(ClientContext context)
void	unregister(ClientContext context, short oldPrio) Unregister the request.
void	unregisterAll(ClientContext context) Remove the pendingKeys item and then remove from the queue as well.

Methods inherited from class freenet.node.SendableGet

clearWakeupTime, getClientGetState, getNodeKey, getScheduler, getSender, internalError, isInsert, onFailure, reduceWakeupTime, translateException

Methods inherited from class freenet.node.SendableRequest

getParentGrabArray, getSchedulerGroup, hashCode, knowsParentGrabArray, objectToString, persistent, realTimeFlag, setParentGrabArray

Methods inherited from class java.lang.Object

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

Field Detail

key

protected final ClientKey key

cancelled

protected boolean cancelled

finished

protected boolean finished

ctx

protected final FetchContext ctx

deleteFetchContext

protected boolean deleteFetchContext

cooldownWakeupTime

public transient long cooldownWakeupTime

Constructor Detail

BaseSingleFileFetcher

protected BaseSingleFileFetcher(ClientKey key,
                                int maxRetries,
                                FetchContext ctx,
                                ClientRequester parent,
                                boolean deleteFetchContext,
                                boolean realTimeFlag)

Method Detail

countAllKeys

public long countAllKeys(ClientContext context)

Description copied from class: SendableRequest

All key identifiers. Including those not currently eligible to be sent because they are on a cooldown queue, requests for them are in progress, etc.

Specified by:

countAllKeys in class SendableRequest

countSendableKeys

public long countSendableKeys(ClientContext context)

Description copied from class: SendableRequest

All key identifiers currently eligible to be sent. Does not include those currently running, on the cooldown queue etc.

Specified by:

countSendableKeys in class SendableRequest

chooseKey

public SendableRequestItem chooseKey(KeysFetchingLocally fetching,
                                     ClientContext context)

Description copied from class: SendableRequest

Choose a key to fetch. Must not modify any persisted structures, but will update cooldowns etc to avoid it being chosen again soon. There is a separate callback for when a fetch fails, succeeds, etc. Hence it is safe to call these outside of the PersistentJobRunner.

Specified by:

chooseKey in class SendableRequest

Returns:

An object identifying a specific key. null indicates no keys available.

getKey

public ClientKey getKey(SendableRequestItem token)

Description copied from class: SendableGet

Get a numbered key to fetch.

Specified by:

getKey in class SendableGet

getContext

public FetchContext getContext()

Description copied from class: SendableGet

Get the fetch context (settings) object.

Specified by:

getContext in class SendableGet

isSSK

public boolean isSSK()

Description copied from class: SendableRequest

Is this an SSK? For purposes of determining which scheduler to use.

Specified by:

isSSK in class SendableRequest

retry

protected boolean retry(ClientContext context)

Try again - returns true if we can retry

onEnterFiniteCooldown

protected void onEnterFiniteCooldown(ClientContext context)

getClientRequest

public ClientRequester getClientRequest()

Description copied from class: SendableRequest

Get the ClientRequest. This DOES need to be cached on the request itself.

Specified by:

getClientRequest in class SendableRequest

getPriorityClass

public short getPriorityClass()

Description copied from class: SendableRequest

Get the priority class of the request.

Specified by:

getPriorityClass in class SendableRequest

cancel

public void cancel(ClientContext context)

unregisterAll

public void unregisterAll(ClientContext context)

Remove the pendingKeys item and then remove from the queue as well. Call unregister(container) if you only want to remove from the queue.

unregister

public void unregister(ClientContext context,
                       short oldPrio)

Description copied from class: SendableRequest

Unregister the request.

Overrides:

unregister in class SendableGet

oldPrio - If we are changing priorities it can matter what the old priority is. However the parent method, SendableRequest, ignores this. In any case, (short)-1 means not specified (look it up).

isCancelled

public boolean isCancelled()

Description copied from class: SendableRequest

If true, the request has been cancelled, or has completed, either way it need not be registered any more. isEmpty() on the other hand means there are no queued blocks.

Specified by:

isCancelled in interface HasKeyListener

Specified by:

isCancelled in class SendableRequest

isEmpty

public boolean isEmpty()

getClient

public RequestClient getClient()

Description copied from class: SendableRequest

Get client context object. This isn't called as frequently as you might expect - once on registration, and then when there is an error. So it doesn't need to be stored on the request itself, hence we pass in a container.

Specified by:

getClient in class SendableRequest

onGotKey

public void onGotKey(Key key,
                     KeyBlock block,
                     ClientContext context)

onSuccess

public void onSuccess(KeyBlock lowLevelBlock,
                      boolean fromStore,
                      SendableRequestItem token,
                      ClientContext context)

onBlockDecodeError

protected abstract void onBlockDecodeError(SendableRequestItem token,
                                           ClientContext context)

onSuccess

public abstract void onSuccess(ClientKeyBlock block,
                               boolean fromStore,
                               java.lang.Object token,
                               ClientContext context)

Called when/if the low-level request succeeds.

getCooldownWakeup

public long getCooldownWakeup(SendableRequestItem token,
                              ClientContext context)

Description copied from class: SendableGet

Get the time at which the key specified by the given token will wake up from the cooldown queue.

Specified by:

getCooldownWakeup in class SendableGet

Returns:

schedule

public void schedule(ClientContext context)

reschedule

public void reschedule(ClientContext context)

getRequest

public SendableGet getRequest(Key key)

listKeys

public Key[] listKeys()

Description copied from class: SendableGet

What keys are we interested in? For purposes of checking the datastore. This is in SendableGet, *not* KeyListener, in order to deal with it in smaller chunks.

Specified by:

listKeys in class SendableGet

makeKeyListener

public KeyListener makeKeyListener(ClientContext context,
                                   boolean onStartup)

Description copied from interface: HasKeyListener

Create a KeyListener, a transient object used to determine which keys we want, and to handle any blocks found.

Specified by:

makeKeyListener in interface HasKeyListener

Returns:

Null if the HasKeyListener is finished/cancelled/etc.

notFoundInStore

protected abstract void notFoundInStore(ClientContext context)

preRegister

public boolean preRegister(ClientContext context,
                           boolean toNetwork)

Description copied from class: BaseSendableGet

Called after checking the datastore and before registering the request to be sent. Some gets may want to cancel here, some may want to send an event to FCP.

Specified by:

preRegister in class BaseSendableGet

toNetwork - If true, we are actually going to send requests (unless we cancel in this callback). If false, we completed all the work assigned.

Returns:

True to cancel the request at this stage i.e. not go to network, in which case *the BSG must handle the failure itself*.

getWakeupTime

public long getWakeupTime(ClientContext context,
                          long now)

Description copied from interface: RequestSelectionTreeNode

Unless this is a RandomGrabArrayItem, this will return the wakeup time for the subtree rooted at this node. For a RandomGrabArrayItem it returns the wakeup time for just that single request.

Specified by:

getWakeupTime in interface RequestSelectionTreeNode

Specified by:

getWakeupTime in interface RandomGrabArrayItem

onChangedFetchContext

public void onChangedFetchContext(ClientContext context)

Reread the cached cooldown values (and anything else) from the FetchContext after it changes. FIXME: Ideally this should be a generic mechanism, but that looks too complex without significant changes to data structures. For now it's just a hack to make changing the polling interval in USKs work.

Parameters:

context - The context object.

See Also:

Bug

onResume

public void onResume(ClientContext context)