Diff: utility/BlynkFifo.h

Revision:

0:58b20b438383

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/utility/BlynkFifo.h	Sat May 07 08:02:50 2016 +0000
@@ -0,0 +1,95 @@
+/**
+ * @file       BlynkFifo.h
+ * @author     Volodymyr Shymanskyy
+ * @license    This project is released under the MIT License (MIT)
+ * @copyright  Copyright (c) 2015 Volodymyr Shymanskyy
+ * @date       Feb 2015
+ * @brief      FIFO implementation
+ *
+ */
+
+#ifndef BlynkFifo_h
+#define BlynkFifo_h
+
+#include <utility/BlynkUtility.h>
+
+template<typename T, unsigned SIZE>
+class BlynkFifo {
+
+    BlynkFifo(const BlynkFifo<T, SIZE> & rb);
+
+public:
+
+    BlynkFifo() : fst(0), lst(0), flag(0) {}
+    ~BlynkFifo() {}
+
+    void clear() {
+        fst = 0;
+        lst = 0;
+        flag = 0;
+    }
+
+    size_t write(const T* data, size_t n)
+    {
+        if ((n = BlynkMin(n, getFree()))) {
+            const size_t ch1 = BlynkMin(n, SIZE - lst);
+            memcpy(buffer + lst, data, ch1 * sizeof(T));
+            lst = (lst + ch1) % SIZE;
+
+            if (ch1 < n) {
+                const size_t ch2 = n - ch1;
+                memcpy(buffer + lst, data + ch1, ch2 * sizeof(T));
+                lst = (lst + ch2) % SIZE;
+            }
+
+            if (fst == lst) {
+                flag = 1;
+            }
+        }
+        return n;
+    }
+
+    size_t read(T* dest, size_t n)
+    {
+        if ((n = BlynkMin(n, getOccupied()))) {
+            flag = 0;
+
+            const size_t ch1 = BlynkMin(n, SIZE - fst);
+            memcpy(dest, buffer + fst, ch1 * sizeof(T));
+            fst = (fst + ch1) % SIZE;
+
+            if (ch1 < n) {
+                const size_t ch2 = n - ch1;
+                memcpy(dest + ch1, buffer + fst, ch2 * sizeof(T));
+                fst = (fst + ch2) % SIZE;
+            }
+        }
+        return n;
+    }
+
+    bool push(const T& data) {
+        return write(&data, 1) == 1;
+    }
+
+    size_t getOccupied() const {
+        if (lst == fst) {
+            return flag ? SIZE : 0;
+        } else if (lst > fst) {
+            return lst - fst;
+        } else {
+            return SIZE + lst - fst;
+        }
+    }
+
+    size_t getFree() const {
+        return SIZE - getOccupied();
+    }
+
+private:
+    T buffer[SIZE];
+    size_t fst;
+    size_t lst;
+    uint8_t flag;
+};
+
+#endif