Fix rpc file getting deleted when launching gsr-ui twice. Use unix domain socket instead

include/Rpc.hpp

@@ -4,31 +4,47 @@
 #include <functional>
 #include <unordered_map>
 #include <string>
+#include <poll.h>
 
-typedef struct _IO_FILE FILE;
+#define GSR_RPC_MAX_CONNECTIONS 8
+#define GSR_RPC_MAX_POLLS (1 + GSR_RPC_MAX_CONNECTIONS) /* +1 to include the socket_fd itself for accept */
+#define GSR_RPC_MAX_MESSAGE_SIZE 128
 
 namespace gsr {
     using RpcCallback = std::function<void(const std::string &name)>;
 
+    enum class RpcOpenResult {
+        OK,
+        CONNECTION_REFUSED,
+        ERROR
+    };
+
     class Rpc {
     public:
-        Rpc() = default;
+        struct PollData {
+            char buffer[GSR_RPC_MAX_MESSAGE_SIZE];
+            int buffer_size = 0;
+        };
+
+        Rpc();
         Rpc(const Rpc&) = delete;
         Rpc& operator=(const Rpc&) = delete;
         ~Rpc();
 
         bool create(const char *name);
-        bool open(const char *name);
+        RpcOpenResult open(const char *name);
         bool write(const char *str, size_t size);
         void poll();
 
         bool add_handler(const std::string &name, RpcCallback callback);
     private:
-        bool open_filepath(const char *filepath);
+        void handle_client_data(int client_fd, PollData &poll_data);
     private:
-        int fd = 0;
-        FILE *file = nullptr;
-        std::string fifo_filepath;
+        int socket_fd = 0;
+        std::string socket_filepath;
+        struct pollfd polls[GSR_RPC_MAX_POLLS];
+        PollData polls_data[GSR_RPC_MAX_POLLS];
+        int num_polls = 0;
         std::unordered_map<std::string, RpcCallback> handlers_by_name;
     };
 }