[core] Add client defined network status

This API will let the client force a network status. If set
to Offline, we won't make network requests.

When set make to Online, it will trigger the pending requests
and try to fetch tiles from the network.

2 files changed, 32 insertions, 0 deletions

diff --git a/include/mbgl/storage/network_status.hpp b/include/mbgl/storage/network_status.hpp
index 2a0ab78edd..4202793661 100644
--- a/include/mbgl/storage/network_status.hpp
+++ b/include/mbgl/storage/network_status.hpp
@@ -1,6 +1,7 @@
 #ifndef MBGL_STORAGE_NETWORK_STATUS
 #define MBGL_STORAGE_NETWORK_STATUS
 
+#include <atomic>
 #include <mutex>
 #include <set>
 
@@ -12,12 +13,21 @@ class AsyncTask;
 
 class NetworkStatus {
 public:
+    enum class Status : uint8_t {
+        Online,
+        Offline,
+    };
+
+    Status Get();
+    void Set(Status);
+
     static void Reachable();
 
     static void Subscribe(util::AsyncTask* async);
     static void Unsubscribe(util::AsyncTask* async);
 
 private:
+    static std::atomic<bool> online;
     static std::mutex mtx;
     static std::set<util::AsyncTask*> observers;
 };
diff --git a/src/mbgl/storage/network_status.cpp b/src/mbgl/storage/network_status.cpp
index 796cc5d27f..1ef5619bd6 100644
--- a/src/mbgl/storage/network_status.cpp
+++ b/src/mbgl/storage/network_status.cpp
@@ -9,9 +9,27 @@
 
 namespace mbgl {
 
+std::atomic<bool> NetworkStatus::online(true);
 std::mutex NetworkStatus::mtx;
 std::set<util::AsyncTask *> NetworkStatus::observers;
 
+NetworkStatus::Status NetworkStatus::Get() {
+    if (online) {
+        return Status::Online;
+    } else {
+        return Status::Offline;
+    }
+}
+
+void NetworkStatus::Set(Status status) {
+    if (status == Status::Online) {
+        online = true;
+        Reachable();
+    } else {
+        online = false;
+    }
+}
+
 void NetworkStatus::Subscribe(util::AsyncTask *async) {
     std::lock_guard<std::mutex> lock(NetworkStatus::mtx);
     observers.insert(async);
@@ -23,6 +41,10 @@ void NetworkStatus::Unsubscribe(util::AsyncTask *async) {
 }
 
 void NetworkStatus::Reachable() {
+    if (!online) {
+        return;
+    }
+
     std::lock_guard<std::mutex> lock(NetworkStatus::mtx);
     for (auto async : observers) {
         async->send();