FrontendCommon: Add HTTPDownloader class

src/frontend-common/http_downloader.h

@@ -0,0 +1,84 @@
+#pragma once
+#include "common/types.h"
+#include <atomic>
+#include <functional>
+#include <mutex>
+#include <string>
+#include <vector>
+
+namespace FrontendCommon {
+
+class HTTPDownloader
+{
+public:
+  enum : s32
+  {
+    HTTP_OK = 200
+  };
+
+  struct Request
+  {
+    using Data = std::vector<u8>;
+    using Callback = std::function<void(s32 status_code, const Data& data)>;
+
+    enum class Type
+    {
+      Get,
+      Post,
+    };
+
+    enum class State
+    {
+      Pending,
+      Cancelled,
+      Started,
+      Receiving,
+      Complete,
+    };
+
+    HTTPDownloader* parent;
+    Callback callback;
+    std::string url;
+    std::string post_data;
+    Data data;
+    u64 start_time;
+    s32 status_code = 0;
+    u32 content_length = 0;
+    Type type = Type::Get;
+    std::atomic<State> state{State::Pending};
+  };
+
+  HTTPDownloader();
+  virtual ~HTTPDownloader();
+
+  static std::unique_ptr<HTTPDownloader> Create();
+
+  void SetUserAgent(std::string name);
+  void SetTimeout(float timeout);
+  void SetMaxActiveRequests(u32 max_active_requests);
+
+  void CreateRequest(std::string url, Request::Callback callback);
+  void CreatePostRequest(std::string url, std::string post_data, Request::Callback callback);
+  void PollRequests();
+  void WaitForAllRequests();
+
+protected:
+  virtual Request* InternalCreateRequest() = 0;
+  virtual void InternalPollRequests() = 0;
+
+  virtual bool StartRequest(Request* request) = 0;
+  virtual void CloseRequest(Request* request) = 0;
+
+  void LockedAddRequest(Request* request);
+  u32 LockedGetActiveRequestCount();
+  void LockedPollRequests(std::unique_lock<std::mutex>& lock);
+
+  std::string m_user_agent;
+  float m_timeout;
+  u32 m_max_active_requests;
+
+  std::mutex m_pending_http_request_lock;
+  std::vector<Request*> m_pending_http_requests;
+};
+
+} // namespace FrontendCommon