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Client subscription add batch pop() and stats()

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This commit is contained in:
Michael Davidsaver
2022-11-27 08:20:13 -08:00
parent a4c6540c97
commit febc823301
3 changed files with 126 additions and 24 deletions
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src/clientmon.cpp
+72 -9
View File
@@ -66,6 +66,9 @@ struct SubscriptionImpl : public OperationBase, public Subscription
std::deque<Entry> queue;
uint32_t window =0u; // flow control window. number of updates server may send to us
uint32_t unack =0u; // updates pop()'d, but not ack'd
size_t nSrvSquash =0u;
size_t nCliSquash =0u;
size_t queueMax =0u;
// user code has seen pop()==nullptr
bool needNotify = true;
bool ackPending = false; // ackTick scheduled
@@ -140,14 +143,27 @@ struct SubscriptionImpl : public OperationBase, public Subscription
});
}
virtual Value pop() override final
{
Value ret;
{
Guard G(lock);
virtual void stats(SubscriptionStat& ret, bool reset) override final {
Guard G(lock);
ret.limitQueue = queueSize;
ret.maxQueue = queueMax;
ret.nSrvSquash = nSrvSquash;
ret.nCliSquash = nCliSquash;
ret.nQueue = queue.size();
if(reset) {
nSrvSquash = nCliSquash = queueMax = 0u;
}
}
void _pop(Value& ret, bool canthrow)
{
{
if(!queue.empty()) {
auto ent(queue.front());
auto ent(std::move(queue.front()));
if(!canthrow && ent.exc)
return;
queue.pop_front();
if(pipeline) {
@@ -170,7 +186,6 @@ struct SubscriptionImpl : public OperationBase, public Subscription
unack++;
}
log_info_printf(monevt, "channel '%s' monitor pop() %s %u,%u\n",
channelName.c_str(),
ent.exc ? "exception" : ent.val ? "data" : "null!",
@@ -188,9 +203,42 @@ struct SubscriptionImpl : public OperationBase, public Subscription
channelName.c_str());
}
}
}
virtual Value pop() override final
{
Value ret;
{
Guard G(lock);
_pop(ret, true);
}
return ret;
}
virtual bool doPop(std::vector<Value>& out, size_t limit) override final
{
out.clear();
if(!limit) {
limit = queueSize; // alloc for worst case
}
out.reserve(limit);
Guard G(lock);
while(out.size() < limit) {
Value temp;
_pop(temp, out.empty()); // only throw if out is empty
if(!temp)
break;
out.emplace_back(std::move(temp));
}
return !needNotify;
}
virtual std::shared_ptr<Subscription> shared_from_this() const override final {
// on worker?
std::shared_ptr<Subscription> ret;
@@ -436,6 +484,7 @@ void Connection::handle_MONITOR()
from_wire_type(M, rxRegistry, data);
RequestInfo* info=nullptr;
bool servSquash = false;
if(M.good()) {
auto it = opByIOID.find(ioid);
if(it!=opByIOID.end()) {
@@ -463,7 +512,15 @@ void Connection::handle_MONITOR()
BitMask overrun;
from_wire(M, overrun);
(void)overrun; // ignoring
for(auto i : range(overrun.wsize())) {
(void)i;
if(overrun.word(i)) {
// this update Value is the result of combining
// two or more Values on the server side.
servSquash = true;
break;
}
}
}
}
@@ -589,6 +646,7 @@ void Connection::handle_MONITOR()
mon->chan->name.c_str());
mon->queue.back().val.assign(update.val);
mon->nCliSquash++;
}
if(final && !update.exc) {
@@ -604,11 +662,16 @@ void Connection::handle_MONITOR()
peerName.c_str(), mon->chan->name.c_str());
notify = false;
}
if(mon->queueMax < mon->queue.size())
mon->queueMax = mon->queue.size();
}
if(notify)
notify = mon->wantToNotify();
}
if(servSquash)
mon->nSrvSquash++;
} // release mon->lock
if(mon->state==SubscriptionImpl::Done || final) {
mon->state=SubscriptionImpl::Done;
src/pvxs/client.h
+49 -10
View File
@@ -157,9 +157,23 @@ public:
#endif
};
//! Information about the state of a Subscription
struct SubscriptionStat {
//! Number of events in the queue
size_t nQueue=0;
//! Number of Value updates where the server reported at least
//! one update dropped/squashed.
size_t nSrvSquash=0;
//! Number of Value updates dropped/squashed due to client queue overflow
size_t nCliSquash=0;
//! Max queue size so far
size_t maxQueue=0;
//! Limit on queue size
size_t limitQueue=0;
};
//! Handle for monitor subscription
struct PVXS_API Subscription {
virtual ~Subscription() =0;
protected:
@@ -172,16 +186,16 @@ public:
//! Blocks until any in-progress callback has completed.
virtual bool cancel() =0;
//! Ask a server to stop sending updates to this Subscription
//! Ask a server to stop (true) or re-start (false), sending updates to this Subscription
virtual void pause(bool p=true) =0;
//! Shorthand for @code pause(false) @endcode
inline void resume() { pause(false); }
/** De-queue update from subscription event queue.
*
* If the queue is empty, return an empty/invalid Value (Value::valid()==false).
* A data update is returned as a Value.
* An error or special event is thrown.
* If the queue is empty, return an empty/invalid Value (Value::valid()==false).
* A data update is returned as a Value.
* An error or special event is thrown.
*
* @returns A valid Value until the queue is empty
* @throws Connected (depending on MonitorBuilder::maskConnected())
@@ -194,18 +208,43 @@ public:
* std::shared_ptr<Subscription> sub(...);
* try {
* while(auto update = sub.pop()) {
* // have data update
* ...
* }
* } catch(Connected& con) {
* } catch(Finished& con) {
* } catch(Disconnect& con) {
* } catch(RemoteError& con) {
* } catch(std::exception& con) {
* // queue empty
* } catch(Connected& con) { // if MonitorBuilder::maskConnected(false)
* } catch(Finished& con) { // if MonitorBuilder::maskDisconnected(false)
* } catch(Disconnect& con) { // if MonitorBuilder::maskDisconnected(false)
* } catch(RemoteError& con) { // error message from server
* } catch(std::exception& con) { // client side error
* }
* @endcode
*/
virtual Value pop() =0;
protected:
virtual bool doPop(std::vector<Value>& out, size_t limit=0u) =0;
public:
#ifdef PVXS_EXPERT_API_ENABLED
/** De-queue a batch of updates from subscription event queue.
*
* @param out Updated with any Values dequeued. Will always be clear()d
* @param limit When non-zero, an upper limit on the number of Values which will be dequeued.
* @return true if the queue was not emptied, and pop() should be called again.
* false if the queue was emptied, and a further onEvent() callback may be awaited.
* @throws the same exceptions as non-batch pop()
*
* @since UNRELEASED Added
*/
inline bool pop(std::vector<Value>& out, size_t limit=0u)
{ return doPop(out, limit); }
#endif
//! Poll statistics
//! @since UNRELEASED
virtual void stats(SubscriptionStat&, bool reset = false) =0;
protected:
virtual void _onEvent(std::function<void(Subscription&)>&&) =0;
public:
src/pvxs/source.h
+5 -5
View File
@@ -45,15 +45,15 @@ public:
//! Information about a running monitor
struct MonitorStat {
//! Number of available elements in the output flow window.
size_t window;
size_t window=0;
//! Number of un-sent updates in the local queue. Doesn't count updates
//! serialized and in the TX buffer.
size_t nQueue, limitQueue;
size_t nQueue=0, limitQueue=0;
bool running;
bool finished;
bool pipeline;
bool running=false;
bool finished=false;
bool pipeline=false;
};
//! Handle for active subscription