[core] Add unit tests for ambient cache size

test/storage/offline_database.test.cpp

@@ -994,7 +994,8 @@ TEST(OfflineDatabase, PutEvictsLeastRecentlyUsedResources) {
     Response response;
     response.data = randomString(1024);
 
-    for (uint32_t i = 1; i <= 100; i++) {
+    // Add 101 resource to ambient cache, 1 over defined limit.
+    for (uint32_t i = 1; i <= 101; ++i) {
         Resource resource = Resource::style("http://example.com/"s + util::toString(i));
         db.put(resource, response);
         EXPECT_TRUE(bool(db.get(resource))) << i;
@@ -1005,6 +1006,39 @@ TEST(OfflineDatabase, PutEvictsLeastRecentlyUsedResources) {
     EXPECT_EQ(0u, log.uncheckedCount());
 }
 
+TEST(OfflineDatabase, OfflineRegionDoesNotAffectAmbientCacheSize) {
+    FixtureLog log;
+    OfflineDatabase db(":memory:");
+    // 200KB ambient cache limit.
+    db.setMaximumAmbientCacheSize(1024 * 100 * 2);
+
+    Response response;
+    response.data = randomString(1024 * 100);
+
+    // First 100KB ambient cache resource.
+    db.put(Resource::style("http://example.com/ambient1.json"s), response);
+
+    OfflineTilePyramidRegionDefinition definition("http://example.com/style.json", LatLngBounds::world(), 0.0, 0.0, 1.0, false);
+    auto region = db.createRegion(definition, OfflineRegionMetadata());
+
+    // 1MB of offline region data.
+    for (std::size_t i = 0; i < 5; ++i) {
+        const Resource tile = Resource::tile("mapbox://tile_" + std::to_string(i), 1, 0, 0, 0, Tileset::Scheme::XYZ);
+        db.putRegionResource(region->getID(), tile, response);
+
+        const Resource style = Resource::style("mapbox://style_" + std::to_string(i));
+        db.putRegionResource(region->getID(), style, response);
+    }
+
+    // Second 100KB ambient cache resource.
+    db.put(Resource::style("http://example.com/ambient2.json"s), response);
+
+    // Offline region resources should not affect ambient cache size.
+    EXPECT_TRUE(bool(db.get(Resource::style("http://example.com/ambient1.json"s))));
+    EXPECT_TRUE(bool(db.get(Resource::style("http://example.com/ambient2.json"s))));
+    EXPECT_EQ(0u, log.uncheckedCount());
+}
+
 TEST(OfflineDatabase, PutRegionResourceDoesNotEvict) {
     FixtureLog log;
     OfflineDatabase db(":memory:");
@@ -1033,7 +1067,8 @@ TEST(OfflineDatabase, PutFailsWhenEvictionInsuffices) {
     db.setMaximumAmbientCacheSize(1024 * 100);
 
     Response big;
-    big.data = randomString(1024 * 100);
+    // One byte over the cache size.
+    big.data = randomString(1024 * 100 + 1);
 
     EXPECT_FALSE(db.put(Resource::style("http://example.com/big"), big).first);