Port location queries to use the new coverage data for selecting backends

We now no longer query backends that cover the area of interest if we have
already found another one that claims to provide high quality data.

src/lib/manager.cpp

@@ -647,33 +647,43 @@ LocationReply* Manager::queryLocation(const LocationRequest &req) const
         return reply;
     }
 
-    for (const auto &b : d->m_backends) {
-        const auto backend = BackendPrivate::impl(b);
-        if (d->shouldSkipBackend(backend, req)) {
-            continue;
-        }
-        if (req.hasCoordinate() && backend->isLocationExcluded(req.location())) {
-            qCDebug(Log) << "Skipping backend based on location filter:" << backend->backendId();
-            continue;
-        }
-        reply->addAttribution(backend->attribution());
+    QSet<QString> triedBackends;
+    bool foundNonGlobalCoverage = false;
+    for (const auto coverageType : { CoverageArea::Realtime, CoverageArea::Regular, CoverageArea::Any }) {
+        for (const auto &b : d->m_backends) {
+            const auto backend = BackendPrivate::impl(b);
+            if (triedBackends.contains(backend->backendId()) || d->shouldSkipBackend(backend, req)) {
+                continue;
+            }
+            const auto coverage = b.coverageArea(coverageType);
+            if (coverage.isEmpty() || !coverage.coversLocation(req.location())) {
+                continue;
+            }
+            triedBackends.insert(backend->backendId());
+            foundNonGlobalCoverage |= !coverage.isGlobal();
 
-        auto cache = Cache::lookupLocation(backend->backendId(), req.cacheKey());
-        switch (cache.type) {
-            case CacheHitType::Negative:
-                qCDebug(Log) << "Negative cache hit for backend" << backend->backendId();
-                break;
-            case CacheHitType::Positive:
-                qCDebug(Log) << "Positive cache hit for backend" << backend->backendId();
-                reply->addAttributions(std::move(cache.attributions));
-                reply->addResult(std::move(cache.data));
-                break;
-            case CacheHitType::Miss:
-                qCDebug(Log) << "Cache miss for backend" << backend->backendId();
-                if (backend->queryLocation(req, reply, d->nam())) {
-                    ++pendingOps;
-                }
-                break;
+            reply->addAttribution(backend->attribution());
+
+            auto cache = Cache::lookupLocation(backend->backendId(), req.cacheKey());
+            switch (cache.type) {
+                case CacheHitType::Negative:
+                    qCDebug(Log) << "Negative cache hit for backend" << backend->backendId();
+                    break;
+                case CacheHitType::Positive:
+                    qCDebug(Log) << "Positive cache hit for backend" << backend->backendId();
+                    reply->addAttributions(std::move(cache.attributions));
+                    reply->addResult(std::move(cache.data));
+                    break;
+                case CacheHitType::Miss:
+                    qCDebug(Log) << "Cache miss for backend" << backend->backendId();
+                    if (backend->queryLocation(req, reply, d->nam())) {
+                        ++pendingOps;
+                    }
+                    break;
+            }
+        }
+        if (pendingOps && foundNonGlobalCoverage) {
+            break;
         }
     }
     reply->setPendingOps(pendingOps);