move node-mbgl to platform/node/ directory

platform/node/src/util/async_queue.hpp

@@ -0,0 +1,90 @@
+#pragma once
+
+#include <uv.h>
+
+#include <thread>
+#include <mutex>
+#include <functional>
+#include <queue>
+#include <string>
+
+
+#if UV_VERSION_MAJOR == 0 && UV_VERSION_MINOR <= 10
+#define UV_ASYNC_PARAMS(handle) uv_async_t *handle, int
+#else
+#define UV_ASYNC_PARAMS(handle) uv_async_t *handle
+#endif
+
+namespace node_mbgl {
+namespace util {
+
+template <typename T>
+class AsyncQueue {
+public:
+    AsyncQueue(uv_loop_t *loop, std::function<void(T &)> fn) :
+          callback(fn) {
+        async.data = this;
+        uv_async_init(loop, &async, [](UV_ASYNC_PARAMS(handle)) {
+            auto q = reinterpret_cast<AsyncQueue *>(handle->data);
+            q->process();
+        });
+    }
+
+    void send(T &&data) {
+        {
+            std::lock_guard<std::mutex> lock(mutex);
+            queue.push(std::make_unique<T>(std::move(data)));
+        }
+        uv_async_send(&async);
+    }
+
+    void send(std::unique_ptr<T> data) {
+        {
+            std::lock_guard<std::mutex> lock(mutex);
+            queue.push(std::move(data));
+        }
+        uv_async_send(&async);
+    }
+
+    void stop() {
+        uv_close((uv_handle_t *)&async, [](uv_handle_t *handle) {
+            delete reinterpret_cast<AsyncQueue *>(handle->data);
+        });
+    }
+
+    void ref() {
+        uv_ref((uv_handle_t *)&async);
+    }
+
+    void unref() {
+        uv_unref((uv_handle_t *)&async);
+    }
+
+private:
+    ~AsyncQueue() {
+    }
+
+    void process() {
+        std::unique_ptr<T> item;
+        while (true) {
+            mutex.lock();
+            if (queue.empty()) {
+                mutex.unlock();
+                break;
+            }
+            item = std::move(queue.front());
+            queue.pop();
+            mutex.unlock();
+            callback(*item);
+        }
+    }
+
+private:
+    std::mutex mutex;
+    uv_async_t async;
+    std::queue<std::unique_ptr<T>> queue;
+    std::function<void(T &)> callback;
+};
+
+}
+}