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#ifndef TinyGsmFifo_h
#define TinyGsmFifo_h
template <class T, unsigned N>
class TinyGsmFifo
{
public:
TinyGsmFifo()
{
clear();
}
void clear()
{
_r = 0;
_w = 0;
}
// writing thread/context API
//-------------------------------------------------------------
bool writeable(void)
{
return free() > 0;
}
int free(void)
{
int s = _r - _w;
if (s <= 0)
s += N;
return s - 1;
}
bool put(const T& c)
{
int i = _w;
int j = i;
i = _inc(i);
if (i == _r) // !writeable()
return false;
_b[j] = c;
_w = i;
return true;
}
int put(const T* p, int n, bool t = false)
{
int c = n;
while (c)
{
int f;
while ((f = free()) == 0) // wait for space
{
if (!t) return n - c; // no more space and not blocking
/* nothing / just wait */;
}
// check free space
if (c < f) f = c;
int w = _w;
int m = N - w;
// check wrap
if (f > m) f = m;
memcpy(&_b[w], p, f);
_w = _inc(w, f);
c -= f;
p += f;
}
return n - c;
}
// reading thread/context API
// --------------------------------------------------------
bool readable(void)
{
return (_r != _w);
}
size_t size(void)
{
int s = _w - _r;
if (s < 0)
s += N;
return s;
}
bool get(T* p)
{
int r = _r;
if (r == _w) // !readable()
return false;
*p = _b[r];
_r = _inc(r);
return true;
}
int get(T* p, int n, bool t = false)
{
int c = n;
while (c)
{
int f;
for (;;) // wait for data
{
f = size();
if (f) break; // free space
if (!t) return n - c; // no space and not blocking
/* nothing / just wait */;
}
// check available data
if (c < f) f = c;
int r = _r;
int m = N - r;
// check wrap
if (f > m) f = m;
memcpy(p, &_b[r], f);
_r = _inc(r, f);
c -= f;
p += f;
}
return n - c;
}
uint8_t peek()
{
return _b[_r];
}
private:
int _inc(int i, int n = 1)
{
return (i + n) % N;
}
T _b[N];
int _w;
int _r;
};
#endif