input handling using SCSP ring buffer

1 files changed, 60 insertions, 0 deletions

diff --git a/include/reader.h b/include/reader.h
index cad8bf3..8ff6d72 100644
--- a/include/reader.h
+++ b/include/reader.h
@@ -11,6 +11,7 @@
 #include <termios.h>
 #include <unistd.h>
 
+#include <atomic>
 #include <string>
 #include <vector>
 
@@ -19,6 +20,7 @@
 typedef struct EditorCfg {
 	int screenrows;
 	int screencols;
+    int speed;
 	struct termios termios_inst;
 } EditorCfg;
 
@@ -47,3 +49,61 @@ int is_number(char *strnum);
 size_t split(const std::string &txt,
              std::vector<std::string> &strings,
              const std::string &delims);
+
+
+
+template <typename T>
+class
+SCPCQueue
+{
+private:
+    std::vector<T> buff;
+    const size_t capacity;
+
+    alignas(64) std::atomic<size_t> head;
+    alignas(64) std::atomic<size_t> tail;
+
+public:
+    SCPCQueue(size_t size)
+        : buff(size + 1), capacity(size + 1), head(0), tail(0) {}
+
+    SCPCQueue(const SCPCQueue&) = delete;
+    SCPCQueue& operator=(const SCPCQueue&) = delete;
+
+    bool
+    push(const T& data)
+    {
+        const size_t cur_tail = tail.load(std::memory_order_relaxed);
+        const size_t next_tail = (cur_tail + 1) % capacity;
+
+        if (next_tail == head.load(std::memory_order_acquire)) {
+            /* Queue is full */
+            return false;
+        }
+
+        buff[cur_tail] = data;
+
+        tail.store(next_tail, std::memory_order_release);
+
+        return true;
+    }
+    bool pop(T &result)
+    {
+	    const size_t cur_head = head.load(std::memory_order_relaxed);
+
+	    if (cur_head == tail.load(std::memory_order_acquire)) {
+            return false;
+	    }
+	    result = buff[cur_head];
+
+	    const size_t next_head = (cur_head + 1) % capacity;
+
+	    head.store(next_head, std::memory_order_release);
+
+        return true;
+    }
+};
+
+void producer(SCPCQueue<char> &queue);
+
+void consumer(SCPCQueue<char> &queue, EditorCfg *cfg);