VariantStreamSubscription

VariantStreamSubscription

Inherited by StreamSubscription< To >, StreamSubscription< From >, StreamSubscription< T >

Public Functions

Public Functions Documentation

function ~VariantStreamSubscription

virtual ~VariantStreamSubscription()

function dataTypeId

virtual int dataTypeId() const =0

Reimplemented by: StreamSubscription::dataTypeId, StreamSubscription::dataTypeId, StreamSubscription::dataTypeId

function dataTypeName

virtual QString dataTypeName() const =0

Reimplemented by: StreamSubscription::dataTypeName, StreamSubscription::dataTypeName, StreamSubscription::dataTypeName

function callIfNextVar

virtual bool callIfNextVar(
    const ProcessVarFn & fn
) =0

Reimplemented by: StreamSubscription::callIfNextVar, StreamSubscription::callIfNextVar, StreamSubscription::callIfNextVar, StreamSubscriptionAdapter::callIfNextVar

function unsubscribe

virtual bool unsubscribe() =0

Reimplemented by: StreamSubscription::unsubscribe, StreamSubscription::unsubscribe, StreamSubscription::unsubscribe, StreamSubscriptionAdapter::unsubscribe

function isActive

virtual bool isActive() const =0

Reimplemented by: StreamSubscription::isActive, StreamSubscription::isActive, StreamSubscription::isActive, StreamSubscriptionAdapter::isActive

function hasPending

virtual bool hasPending() const =0

Reimplemented by: StreamSubscription::hasPending, StreamSubscription::hasPending, StreamSubscription::hasPending, StreamSubscriptionAdapter::hasPending

function approxPendingCount

virtual size_t approxPendingCount() const =0

Reimplemented by: StreamSubscription::approxPendingCount, StreamSubscription::approxPendingCount, StreamSubscription::approxPendingCount, StreamSubscriptionAdapter::approxPendingCount

function approxItemMemSize

virtual ssize_t approxItemMemSize() const =0

Approximate in-memory size of a single queued item, in bytes.

Reimplemented by: StreamSubscription::approxItemMemSize, StreamSubscription::approxItemMemSize, StreamSubscription::approxItemMemSize, StreamSubscriptionAdapter::approxItemMemSize

Sampled once from a real item as it passes through the stream, so the overload monitor can weight the pending count by actual memory pressure. Returns < 0 if no real size is known yet or the data type does not report one (see BaseDataType::memorySize()).

function enableNotify

virtual int enableNotify() =0

Reimplemented by: StreamSubscription::enableNotify, StreamSubscription::enableNotify, StreamSubscription::enableNotify, StreamSubscriptionAdapter::enableNotify

function disableNotify

virtual void disableNotify() =0

Reimplemented by: StreamSubscription::disableNotify, StreamSubscription::disableNotify, StreamSubscription::disableNotify, StreamSubscriptionAdapter::disableNotify

function acknowledgeNotify

virtual void acknowledgeNotify() =0

Acknowledge an eventfd notification after the fd became readable.

Reimplemented by: StreamSubscription::acknowledgeNotify, StreamSubscription::acknowledgeNotify, StreamSubscription::acknowledgeNotify, StreamSubscriptionAdapter::acknowledgeNotify

Consumers must call this when their watched eventfd wakes them. It drains the fd and clears the coalesced-wakeup flag, so the next push will write the eventfd again.

function rearmNotifyIfPending

virtual void rearmNotifyIfPending() =0

Re-arm the eventfd if there is still undrained data.

Reimplemented by: StreamSubscription::rearmNotifyIfPending, StreamSubscription::rearmNotifyIfPending, StreamSubscription::rearmNotifyIfPending, StreamSubscriptionAdapter::rearmNotifyIfPending

Consumers that process only a bounded batch of items per wakeup must call this after the batch, so the coalesced eventfd wakes them again until the queue is fully drained. A no-op if nothing is pending.

function setThrottleItemsPerSec

virtual void setThrottleItemsPerSec(
    uint itemsPerSec,
    bool allowMore =true
) =0

Reimplemented by: StreamSubscription::setThrottleItemsPerSec, StreamSubscription::setThrottleItemsPerSec, StreamSubscription::setThrottleItemsPerSec, StreamSubscriptionAdapter::setThrottleItemsPerSec

function suspend

virtual void suspend() =0

Reimplemented by: StreamSubscription::suspend, StreamSubscription::suspend, StreamSubscription::suspend, StreamSubscriptionAdapter::suspend

function resume

virtual void resume() =0

Reimplemented by: StreamSubscription::resume, StreamSubscription::resume, StreamSubscription::resume, StreamSubscriptionAdapter::resume

function clearPending

virtual void clearPending() =0

Reimplemented by: StreamSubscription::clearPending, StreamSubscription::clearPending, StreamSubscription::clearPending, StreamSubscriptionAdapter::clearPending

function metadata

virtual MetaStringMap metadata() const =0

Reimplemented by: StreamSubscription::metadata, StreamSubscription::metadata, StreamSubscription::metadata, StreamSubscriptionAdapter::metadata

function metadataValue

virtual MetaValue metadataValue(
    const QString & key,
    const MetaValue & defaultValue =nullptr
) const =0

Reimplemented by: StreamSubscription::metadataValue, StreamSubscriptionAdapter::metadataValue

function metadataValue

virtual MetaValue metadataValue(
    CommonMetadataKey key,
    const MetaValue & defaultValue =nullptr
) const =0

Reimplemented by: StreamSubscription::metadataValue, StreamSubscriptionAdapter::metadataValue

function forcePushNullopt

virtual void forcePushNullopt() =0

Reimplemented by: StreamSubscription::forcePushNullopt, StreamSubscription::forcePushNullopt, StreamSubscription::forcePushNullopt, StreamSubscriptionAdapter::forcePushNullopt

function sourceSubscriptionVar

inline virtual std::shared_ptr< VariantStreamSubscription > sourceSubscriptionVar()

If this subscription is a type-conversion view, return the underlying source-typed subscription it adapts; otherwise return nullptr.

Reimplemented by: StreamSubscriptionAdapter::sourceSubscriptionVar

Used by the IPC stream exporter to serialize the source’s native type onto the wire (so cross-process consumers with different but compatible declared input types each get correctly-decoded samples).

Updated on 2026-06-08 at 21:50:10 +0000