[core] add test about number of maximum concurrent requests

test/src/mbgl/test/fake_file_source.hpp

@@ -1,6 +1,7 @@
 #pragma once
 
 #include <mbgl/storage/file_source.hpp>
+#include <mbgl/storage/online_file_source.hpp>
 
 #include <algorithm>
 #include <list>
@@ -56,6 +57,19 @@ public:
     }
 
     std::list<FakeFileRequest*> requests;
+
 };
 
+class FakeOnlineFileSource : public OnlineFileSource, public FakeFileSource {
+public:
+    std::unique_ptr<AsyncRequest> request(const Resource& resource, Callback callback) override {
+        return FakeFileSource::request(resource, callback);
+    }
+
+    bool respond(Resource::Kind kind, const Response& response) {
+        return FakeFileSource::respond(kind, response);
+    }
+};
+
+
 } // namespace mbgl

test/src/mbgl/test/stub_file_source.hpp

@@ -1,6 +1,7 @@
 #pragma once
 
 #include <mbgl/storage/file_source.hpp>
+#include <mbgl/storage/online_file_source.hpp>
 #include <mbgl/util/timer.hpp>
 
 #include <unordered_map>
@@ -37,6 +38,8 @@ public:
     ResponseFunction imageResponse;
 
 private:
+    friend class StubOnlineFileSource;
+
     // The default behavior is to throw if no per-kind callback has been set.
     optional<Response> defaultResponse(const Resource&);
 
@@ -45,4 +48,15 @@ private:
     util::Timer timer;
 };
 
+class StubOnlineFileSource : public StubFileSource, public OnlineFileSource {
+public:
+
+    StubOnlineFileSource(ResponseType t = ResponseType::Asynchronous) : StubFileSource(t) {};
+    ~StubOnlineFileSource() override = default;
+
+    std::unique_ptr<AsyncRequest> request(const Resource& r, Callback c) override { return StubFileSource::request(r, c); };
+    void remove(AsyncRequest* r) { StubFileSource::remove(r); };
+};
+
+
 } // namespace mbgl

test/storage/offline_download.test.cpp

@@ -61,7 +61,7 @@ public:
     }
 
     util::RunLoop loop;
-    StubFileSource fileSource;
+    StubOnlineFileSource fileSource;
     OfflineDatabase db;
     std::size_t size = 0;
 
@@ -277,8 +277,8 @@ TEST(OfflineDownload, Activate) {
 }
 
 TEST(OfflineDownload, DoesNotFloodTheFileSourceWithRequests) {
-    FakeFileSource fileSource;
     OfflineTest test;
+    FakeOnlineFileSource fileSource;
     auto region = test.createRegion();
     ASSERT_TRUE(region);
     OfflineDownload download(
@@ -297,7 +297,7 @@ TEST(OfflineDownload, DoesNotFloodTheFileSourceWithRequests) {
     fileSource.respond(Resource::Kind::Style, test.response("style.json"));
     test.loop.runOnce();
 
-    EXPECT_EQ(HTTPFileSource::maximumConcurrentRequests(), fileSource.requests.size());
+    EXPECT_EQ(fileSource.getMaximumConcurrentRequests(), fileSource.requests.size());
 }
 
 TEST(OfflineDownload, GetStatusNoResources) {

test/storage/online_file_source.test.cpp

@@ -517,6 +517,15 @@ TEST(OnlineFileSource, TEST_REQUIRES_SERVER(LowHighPriorityRequestsMany)) {
     loop.run();
 }
 
+TEST(OnlineFileSource, TEST_REQUIRES_SERVER(MaximumConcurrentRequests)) {
+    util::RunLoop loop;
+    OnlineFileSource fs;
+
+    ASSERT_EQ(fs.getMaximumConcurrentRequests(), 20u);
+
+    fs.setMaximumConcurrentRequests(10);
+    ASSERT_EQ(fs.getMaximumConcurrentRequests(), 10u);
+}
 TEST(OnlineFileSource, TEST_REQUIRES_SERVER(RequestSameUrlMultipleTimes)) {
     util::RunLoop loop;
     OnlineFileSource fs;