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vdr/ringbuffer.c

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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).
*
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* $Id: ringbuffer.c 1.4 2001/08/05 12:17:45 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;
inputThread = NULL;
outputThread = NULL;
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busy = false;
maxFill = 0;
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}
cRingBuffer::~cRingBuffer()
{
delete inputThread;
delete outputThread;
if (statistics)
dsyslog(LOG_INFO, "buffer stats: %d (%d%%) used", maxFill, maxFill * 100 / (size - 1));
}
void cRingBuffer::WaitForPut(void)
{
putMutex.Lock();
readyForPut.Wait(putMutex);
putMutex.Unlock();
}
void cRingBuffer::WaitForGet(void)
{
getMutex.Lock();
readyForGet.Wait(getMutex);
getMutex.Unlock();
}
void cRingBuffer::EnablePut(void)
{
readyForPut.Broadcast();
}
void cRingBuffer::EnableGet(void)
{
readyForGet.Broadcast();
}
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;
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for (time_t t0 = time(NULL) + 3; time(NULL) < t0; ) {
if (!((outputThread && outputThread->Active()) || (inputThread && inputThread->Active())))
break;
}
DELETENULL(inputThread);
DELETENULL(outputThread);
}
// --- cRingBufferLinear ----------------------------------------------------
cRingBufferLinear::cRingBufferLinear(int Size, bool Statistics)
:cRingBuffer(Size, Statistics)
{
buffer = NULL;
if (Size > 1) { // 'Size - 1' must not be 0!
buffer = new uchar[Size];
if (!buffer)
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esyslog(LOG_ERR, "ERROR: can't allocate ring buffer (size=%d)", Size);
Clear();
}
else
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esyslog(LOG_ERR, "ERROR: illegal size for ring buffer (%d)", Size);
}
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cRingBufferLinear::~cRingBufferLinear()
{
delete buffer;
}
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int cRingBufferLinear::Available(void)
{
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Lock();
int diff = head - tail;
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Unlock();
return (diff >= 0) ? diff : Size() + diff;
}
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void cRingBufferLinear::Clear(void)
{
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Lock();
head = tail = 0;
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Unlock();
}
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int cRingBufferLinear::Put(const uchar *Data, int Count)
{
if (Count > 0) {
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Lock();
int rest = Size() - head;
int diff = tail - head;
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Unlock();
int free = (diff > 0) ? diff - 1 : Size() + diff - 1;
if (statistics) {
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int fill = Size() - free - 1 + Count;
if (fill >= Size())
fill = Size() - 1;
if (fill > maxFill) {
maxFill = fill;
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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;
}
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int cRingBufferLinear::Get(uchar *Data, int Count)
{
if (Count > 0) {
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Lock();
int rest = Size() - tail;
int diff = head - tail;
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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;
}
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// --- cFrame ----------------------------------------------------------------
cFrame::cFrame(const uchar *Data, int Count, int Index)
{
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count = Count;
index = Index;
data = new uchar[count];
if (data)
memcpy(data, Data, count);
else
esyslog(LOG_ERR, "ERROR: can't allocate frame buffer (count=%d)", count);
next = NULL;
}
cFrame::~cFrame()
{
delete data;
}
// --- cRingBufferFrame ------------------------------------------------------
cRingBufferFrame::cRingBufferFrame(int Size, bool Statistics = false)
:cRingBuffer(Size, Statistics)
{
head = NULL;
currentFill = 0;
}
cRingBufferFrame::~cRingBufferFrame()
{
Clear();
}
void cRingBufferFrame::Clear(void)
{
Lock();
const cFrame *p;
while ((p = Get(false)) != NULL)
Drop(p);
Unlock();
EnablePut();
EnableGet();
}
bool cRingBufferFrame::Put(cFrame *Frame)
{
if (Frame->Count() <= Free()) {
Lock();
if (head) {
Frame->next = head->next;
head->next = Frame;
head = Frame;
}
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else {
head = Frame->next = Frame;
}
currentFill += Frame->Count();
Unlock();
EnableGet();
return true;
}
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WaitForPut();
return false;
}
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const cFrame *cRingBufferFrame::Get(bool Wait)
{
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Lock();
cFrame *p = head ? head->next : NULL;
Unlock();
if (!p && Wait)
WaitForGet();
return p;
}
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void cRingBufferFrame::Delete(const cFrame *Frame)
{
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currentFill -= Frame->Count();
delete Frame;
}
void cRingBufferFrame::Drop(const cFrame *Frame)
{
Lock();
if (head) {
if (Frame == head->next) {
if (head->next != head) {
head->next = Frame->next;
Delete(Frame);
}
else {
Delete(head);
head = NULL;
}
}
else
esyslog(LOG_ERR, "ERROR: attempt to drop wrong frame from ring buffer!");
}
Unlock();
EnablePut();
}
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int cRingBufferFrame::Available(void)
{
Lock();
int av = currentFill;
Unlock();
return av;
}