com.devexperts.qd

Interface QDAgent

All Superinterfaces:

DataProvider, QDStatsContainer, RecordProvider, SubscriptionContainer, SubscriptionProvider

public interface QDAgent
extends RecordProvider, SubscriptionContainer, QDStatsContainer

The QDAgent represents an individual data consumer in the QDCollector. It is responsible for tracking state of the consumer in the collector, including its total subscription and accumulated data, and to provide access point for that consumer.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	QDAgent.AttachmentStrategy<T>
static class	QDAgent.BufferOverflowStrategy Strategy for handling of stream and history buffer overflow events.
static interface	QDAgent.Builder Builder for collector agents.

Field Summary

Fields inherited from interface com.devexperts.qd.ng.RecordProvider

VOID

Method Summary

Modifier and Type	Method and Description
void	addSubscription(RecordSource source) Adds specified subscription to this agent's data interest.
void	addSubscription(SubscriptionIterator iterator) Deprecated. Use addSubscription(RecordSource)
int	addSubscriptionPart(RecordSource source, int notify) Adds part of a specified subscription to this agent's data interest.
void	close() Closes this agent and releases allocated resources in its QDCollector.
void	closeAndExamineDataBySubscription(RecordSink sink) Closes this agent and with close() and atomically examines all data that is available for this agent in the collector storage.
int	closePart(int notify) Closes part of this agent and releases allocated resources in its QDCollector.
SubscriptionConsumer	getAddingSubscriptionConsumer() Deprecated. Use addSubscription(com.devexperts.qd.SubscriptionIterator) method.
SubscriptionConsumer	getRemovingSubscriptionConsumer() Deprecated. Use removeSubscription(com.devexperts.qd.SubscriptionIterator) method.
RecordProvider	getSnapshotProvider() Returns record provider that is used to retrieve only snapshot from Ticker and History.
void	removeSubscription(RecordSource source) Removes specified subscription from this agent's data interest.
void	removeSubscription(SubscriptionIterator iterator) Deprecated. Use removeSubscription(RecordSource)
int	removeSubscriptionPart(RecordSource source, int notify) Removes part of specified subscription from this agent's data interest.
void	setBufferOverflowStrategy(int max_buffer_size, boolean drop_oldest, boolean log_overflow) Deprecated. Use setMaxBufferSize(int) and setBufferOverflowStrategy(BufferOverflowStrategy)
void	setBufferOverflowStrategy(QDAgent.BufferOverflowStrategy bufferOverflowStrategy) Sets new strategy for handling of stream and history buffer overflow events.
void	setMaxBufferSize(int maxBufferSize) Sets max buffers size for stream and history agents.
void	setStreamOverflowStrategy(int max_buffer_size, boolean drop_oldest, boolean log_overflow) Deprecated. Use setMaxBufferSize(int) and setBufferOverflowStrategy(BufferOverflowStrategy)
void	setSubscription(RecordSource source) Sets specified subscription to be this agent's data interest.
void	setSubscription(SubscriptionIterator iterator) Deprecated. Use setSubscription(RecordSource)
int	setSubscriptionPart(RecordSource source, int notify) Sets part of specified subscription to be this agent's data interest.

Methods inherited from interface com.devexperts.qd.ng.RecordProvider

getMode, retrieve, retrieveData, retrieveSubscription, setDataListener, setRecordListener, setSubscriptionListener

Methods inherited from interface com.devexperts.qd.SubscriptionContainer

examineSubscription, examineSubscription, getSubscriptionSize, isSubscribed

Methods inherited from interface com.devexperts.qd.stats.QDStatsContainer

getStats

Method Detail

getSnapshotProvider

RecordProvider getSnapshotProvider()

Returns record provider that is used to retrieve only snapshot from Ticker and History. This provider does not provide anything for Stream. Subsequent calls to this method on the same agent return the same instance.

getAddingSubscriptionConsumer

SubscriptionConsumer getAddingSubscriptionConsumer()

Deprecated. Use addSubscription(com.devexperts.qd.SubscriptionIterator) method.

Returns subscription consumer that can be used to add subscription. Adding subscription via returned consumer has the same effect as adding it directly via addSubscription(com.devexperts.qd.SubscriptionIterator) method.

getRemovingSubscriptionConsumer

SubscriptionConsumer getRemovingSubscriptionConsumer()

Deprecated. Use removeSubscription(com.devexperts.qd.SubscriptionIterator) method.

Returns subscription consumer that can be used to remove subscription. Removing subscription via returned consumer has the same effect as removing it directly via removeSubscription(com.devexperts.qd.SubscriptionIterator) method.

addSubscription

void addSubscription(SubscriptionIterator iterator)

Deprecated. Use addSubscription(RecordSource)

Adds specified subscription to this agent's data interest. This is a shortcut to adding subscription via corresponding subscription consumer.

addSubscription

void addSubscription(RecordSource source)

Adds specified subscription to this agent's data interest. This is a shortcut for a loop of

     int res = 0;
     do {
         res = addSubscriptionPart(source, res);
     } while (res != 0);
 

All agents support mixed subscription. Subscription can be removed with this method when marked with REMOVE_SYMBOL flag.

addSubscriptionPart

int addSubscriptionPart(RecordSource source,
                        int notify)

Adds part of a specified subscription to this agent's data interest. This method facilitates a cooperative mechanism to execute tasks that spends most of their time under the global lock of the collector.

All agents support mixed subscription. Subscription can be removed with this method when marked with REMOVE_SYMBOL flag.

Parameters:

source - the subscription.

notify - result of previous method invocation or 0 on the first invocation.

Returns:

0 when there is no more work to be done.

See Also:

QDCollector.executeLockBoundTask(Executor, Runnable)

removeSubscription

void removeSubscription(SubscriptionIterator iterator)

Deprecated. Use removeSubscription(RecordSource)

Removes specified subscription from this agent's data interest. This is a shortcut to removing subscription via corresponding subscription consumer.

removeSubscription

void removeSubscription(RecordSource source)

Removes specified subscription from this agent's data interest. This is a shortcut for a loop of

     int res = 0;
     do {
         res = removeSubscriptionPart(source, res);
     } while (res != 0);
 

removeSubscriptionPart

int removeSubscriptionPart(RecordSource source,
                           int notify)

Removes part of specified subscription from this agent's data interest. This method facilitates a cooperative mechanism to execute tasks that spends most of their time under the global lock of the collector.

Parameters:

source - the subscription.

notify - result of previous method invocation or 0 on the first invocation.

Returns:

0 when there is no more work to be done.

See Also:

QDCollector.executeLockBoundTask(Executor, Runnable)

setSubscription

void setSubscription(SubscriptionIterator iterator)

Deprecated. Use setSubscription(RecordSource)

Sets specified subscription to be this agent's data interest. This method keeps state of survived subscription; in other words, it uses addAll+retainAll operations in contrast to removeAll+addAll operations.

setSubscription

void setSubscription(RecordSource source)

Sets specified subscription to be this agent's data interest. This is a shortcut for a loop of

     int res = 0;
     do {
         res = setSubscriptionPart(source, res);
     } while (res != 0);
 

setSubscriptionPart

int setSubscriptionPart(RecordSource source,
                        int notify)

Sets part of specified subscription to be this agent's data interest. This method facilitates a cooperative mechanism to execute tasks that spends most of their time under the global lock of the collector.

Parameters:

source - the subscription.

notify - result of previous method invocation or 0 on the first invocation.

Returns:

0 when there is no more work to be done.

See Also:

QDCollector.executeLockBoundTask(Executor, Runnable)

close

void close()

Closes this agent and releases allocated resources in its QDCollector. Closed agent can not be activated again and shall not be used anymore. Attempt to use closed agent will result in no action - subscription will be ignored and data retrieval will retrieve no data.

This is a shortcut for a loop of

     int res = 0;
     do {
         res = closePart(res);
     } while (res != 0);
 

closePart

int closePart(int notify)

Closes part of this agent and releases allocated resources in its QDCollector. This method facilitates a cooperative mechanism to execute tasks that spends most of their time under the global lock of the collector.

Agents that started closing can not be activated again and shall not be used anymore. Attempt to use agent that had started closing result in no action - subscription will be ignored and data retrieval will retrieve no data.

Parameters:

notify - result of previous method invocation or 0 on the first invocation.

Returns:

0 when there is no more work to be done.

See Also:

QDCollector.executeLockBoundTask(Executor, Runnable)

closeAndExamineDataBySubscription

void closeAndExamineDataBySubscription(RecordSink sink)

Closes this agent and with close() and atomically examines all data that is available for this agent in the collector storage.

See Also:

close()

setStreamOverflowStrategy

void setStreamOverflowStrategy(int max_buffer_size,
                               boolean drop_oldest,
                               boolean log_overflow)

Deprecated. Use setMaxBufferSize(int) and setBufferOverflowStrategy(BufferOverflowStrategy)

Sets new strategy for handling of stream and history buffer overflow events. New strategy settings apply only for newly distributed data. Their effect on already accumulated data is not defined. Has no effect on ticker agents.

Parameters:

max_buffer_size - how many records to keep in buffer, default is 1000000

drop_oldest - which record shall be dropped - oldest (true) or newest (false), default is true

log_overflow - whether overflow event shall be logged or not, default is true. This value is ignored. Dropped events on overflow are always logged.

Throws:

IllegalArgumentException - if max_buffer_size is not a positive integer

setBufferOverflowStrategy

void setBufferOverflowStrategy(int max_buffer_size,
                               boolean drop_oldest,
                               boolean log_overflow)

Deprecated. Use setMaxBufferSize(int) and setBufferOverflowStrategy(BufferOverflowStrategy)

Sets new strategy for handling of stream and history buffer overflow events. New strategy settings apply only for newly distributed data. Their effect on already accumulated data is not defined. Has no effect on ticker agents.

Parameters:

max_buffer_size - how many records to keep in buffer, default is 1000000

drop_oldest - which record shall be dropped - oldest (true) or newest (false), default is true

log_overflow - whether overflow event shall be logged or not, default is true. This value is ignored. Dropped events on overflow are always logged.

Throws:

IllegalArgumentException - if max_buffer_size is not a positive integer

setMaxBufferSize

void setMaxBufferSize(int maxBufferSize)

Sets max buffers size for stream and history agents. The effect on already accumulated data is not defined. It has no effect on ticker agents.

Parameters:

maxBufferSize - how many records to keep in buffer, default is 1000000

Throws:

IllegalArgumentException - if maxBufferSize is not a positive integer

See Also:

setBufferOverflowStrategy(BufferOverflowStrategy)

setBufferOverflowStrategy

void setBufferOverflowStrategy(QDAgent.BufferOverflowStrategy bufferOverflowStrategy)

Sets new strategy for handling of stream and history buffer overflow events. New strategy settings apply only for newly distributed data. The effect on already accumulated data is not defined. It has no effect on ticker agents.

Parameters:

bufferOverflowStrategy - the strategy, default is QDAgent.BufferOverflowStrategy.DROP_OLDEST.

Throws:

NullPointerException - if bufferOverflowStrategy is null.

See Also:

setMaxBufferSize(int)