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/*
* ringbuffer.c: A threaded ring buffer
*
* See the main source file 'vdr.c' for copyright information and
* how to reach the author.
*
* Parts of this file were inspired by the 'ringbuffy.c' from the
* LinuxDVB driver (see linuxtv.org).
*
* $Id: ringbuffer.c 1.3 2001/08/02 13:48:38 kls Exp $
*/
#include "ringbuffer.h"
#include "tools.h"
// --- cRingBufferInputThread -------------------------------------------------
class cRingBufferInputThread : public cThread {
private:
cRingBuffer *ringBuffer;
protected:
virtual void Action(void) { ringBuffer->Input(); }
public:
cRingBufferInputThread(cRingBuffer *RingBuffer) { ringBuffer = RingBuffer; }
};
// --- cRingBufferOutputThread ------------------------------------------------
class cRingBufferOutputThread : public cThread {
private:
cRingBuffer *ringBuffer;
protected:
virtual void Action(void) { ringBuffer->Output(); }
public:
cRingBufferOutputThread(cRingBuffer *RingBuffer) { ringBuffer = RingBuffer; }
};
// --- cRingBuffer ------------------------------------------------------------
cRingBuffer::cRingBuffer(int Size, bool Statistics)
{
size = Size;
statistics = Statistics;
buffer = NULL;
inputThread = NULL;
outputThread = NULL;
maxFill = 0;
busy = false;
if (size > 1) { // 'size - 1' must not be 0!
buffer = new uchar[size];
if (!buffer)
esyslog(LOG_ERR, "ERROR: can't allocate ring buffer (size=%d)", size);
Clear();
}
else
esyslog(LOG_ERR, "ERROR: illegal size for ring buffer (%d)", size);
}
cRingBuffer::~cRingBuffer()
{
delete inputThread;
delete outputThread;
delete buffer;
if (statistics)
dsyslog(LOG_INFO, "buffer stats: %d (%d%%) used", maxFill, maxFill * 100 / (size - 1));
}
int cRingBuffer::Available(void)
{
mutex.Lock();
int diff = head - tail;
mutex.Unlock();
return (diff >= 0) ? diff : size + diff;
}
void cRingBuffer::Clear(void)
{
mutex.Lock();
head = tail = 0;
mutex.Unlock();
}
int cRingBuffer::Put(const uchar *Data, int Count)
{
if (Count > 0) {
mutex.Lock();
int rest = size - head;
int diff = tail - head;
mutex.Unlock();
int free = (diff > 0) ? diff - 1 : size + diff - 1;
if (statistics) {
int fill = size - free - 1 + Count;
if (fill >= size)
fill = size - 1;
if (fill > maxFill) {
maxFill = fill;
int percent = maxFill * 100 / (size - 1);
if (percent > 75)
dsyslog(LOG_INFO, "buffer usage: %d%%", percent);
}
}
if (free <= 0)
return 0;
if (free < Count)
Count = free;
if (Count > maxFill)
maxFill = Count;
if (Count >= rest) {
memcpy(buffer + head, Data, rest);
if (Count - rest)
memcpy(buffer, Data + rest, Count - rest);
head = Count - rest;
}
else {
memcpy(buffer + head, Data, Count);
head += Count;
}
}
return Count;
}
int cRingBuffer::Get(uchar *Data, int Count)
{
if (Count > 0) {
mutex.Lock();
int rest = size - tail;
int diff = head - tail;
mutex.Unlock();
int cont = (diff >= 0) ? diff : size + diff;
if (rest <= 0)
return 0;
if (cont < Count)
Count = cont;
if (Count >= rest) {
memcpy(Data, buffer + tail, rest);
if (Count - rest)
memcpy(Data + rest, buffer, Count - rest);
tail = Count - rest;
}
else {
memcpy(Data, buffer + tail, Count);
tail += Count;
}
}
return Count;
}
bool cRingBuffer::Start(void)
{
if (!busy) {
busy = true;
outputThread = new cRingBufferOutputThread(this);
if (!outputThread->Start())
DELETENULL(outputThread);
inputThread = new cRingBufferInputThread(this);
if (!inputThread->Start()) {
DELETENULL(inputThread);
DELETENULL(outputThread);
}
busy = outputThread && inputThread;
}
return busy;
}
bool cRingBuffer::Active(void)
{
return outputThread && outputThread->Active() && inputThread && inputThread->Active();
}
void cRingBuffer::Stop(void)
{
busy = false;
for (time_t t0 = time(NULL) + 3; time(NULL) < t0; ) {
if (!((outputThread && outputThread->Active()) || (inputThread && inputThread->Active())))
break;
}
DELETENULL(inputThread);
DELETENULL(outputThread);
}
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