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136 lines
2.6 KiB
136 lines
2.6 KiB
#ifndef TinyGsmFifo_h
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#define TinyGsmFifo_h
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template <class T, unsigned N>
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class TinyGsmFifo
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{
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public:
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TinyGsmFifo()
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{
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clear();
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}
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void clear()
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{
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_r = 0;
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_w = 0;
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}
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// writing thread/context API
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//-------------------------------------------------------------
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bool writeable(void)
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{
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return free() > 0;
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}
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int free(void)
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{
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int s = _r - _w;
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if (s <= 0)
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s += N;
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return s - 1;
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}
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bool put(const T& c)
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{
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int i = _w;
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int j = i;
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i = _inc(i);
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if (i == _r) // !writeable()
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return false;
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_b[j] = c;
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_w = i;
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return true;
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}
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int put(const T* p, int n, bool t = false)
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{
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int c = n;
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while (c)
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{
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int f;
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while ((f = free()) == 0) // wait for space
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{
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if (!t) return n - c; // no more space and not blocking
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/* nothing / just wait */;
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}
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// check free space
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if (c < f) f = c;
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int w = _w;
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int m = N - w;
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// check wrap
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if (f > m) f = m;
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memcpy(&_b[w], p, f);
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_w = _inc(w, f);
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c -= f;
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p += f;
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}
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return n - c;
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}
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// reading thread/context API
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// --------------------------------------------------------
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bool readable(void)
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{
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return (_r != _w);
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}
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size_t size(void)
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{
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int s = _w - _r;
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if (s < 0)
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s += N;
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return s;
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}
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bool get(T* p)
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{
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int r = _r;
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if (r == _w) // !readable()
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return false;
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*p = _b[r];
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_r = _inc(r);
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return true;
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}
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int get(T* p, int n, bool t = false)
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{
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int c = n;
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while (c)
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{
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int f;
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for (;;) // wait for data
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{
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f = size();
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if (f) break; // free space
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if (!t) return n - c; // no space and not blocking
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/* nothing / just wait */;
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}
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// check available data
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if (c < f) f = c;
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int r = _r;
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int m = N - r;
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// check wrap
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if (f > m) f = m;
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memcpy(p, &_b[r], f);
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_r = _inc(r, f);
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c -= f;
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p += f;
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}
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return n - c;
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}
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private:
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int _inc(int i, int n = 1)
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{
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return (i + n) % N;
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}
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T _b[N];
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int _w;
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int _r;
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};
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#endif
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