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vdr/ringbuffer.c
2003-02-15 13:21:50 +01:00

297 lines
6.0 KiB
C

/*
* ringbuffer.c: A 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 1.14 2003/02/15 13:21:50 kls Exp $
*/
#include "ringbuffer.h"
#include <stdlib.h>
#include <unistd.h>
#include "tools.h"
// --- cRingBuffer -----------------------------------------------------------
cRingBuffer::cRingBuffer(int Size, bool Statistics)
{
size = Size;
statistics = Statistics;
maxFill = 0;
lastPercent = 0;
}
cRingBuffer::~cRingBuffer()
{
if (statistics)
dsyslog("buffer stats: %d (%d%%) used", maxFill, maxFill * 100 / (size - 1));
}
void cRingBuffer::WaitForPut(void)
{
putMutex.Lock();
readyForPut.TimedWait(putMutex, 1000);
putMutex.Unlock();
}
void cRingBuffer::WaitForGet(void)
{
getMutex.Lock();
readyForGet.TimedWait(getMutex, 10);
getMutex.Unlock();
}
void cRingBuffer::EnablePut(void)
{
readyForPut.Broadcast();
}
void cRingBuffer::EnableGet(void)
{
readyForGet.Broadcast();
}
// --- cRingBufferLinear -----------------------------------------------------
cRingBufferLinear::cRingBufferLinear(int Size, int Margin, bool Statistics)
:cRingBuffer(Size, Statistics)
{
margin = Margin;
buffer = NULL;
getThreadPid = -1;
if (Size > 1) { // 'Size - 1' must not be 0!
buffer = MALLOC(uchar, Size);
if (!buffer)
esyslog("ERROR: can't allocate ring buffer (size=%d)", Size);
Clear();
}
else
esyslog("ERROR: illegal size for ring buffer (%d)", Size);
}
cRingBufferLinear::~cRingBufferLinear()
{
free(buffer);
}
int cRingBufferLinear::Available(void)
{
Lock();
int diff = head - tail;
Unlock();
return (diff >= 0) ? diff : Size() + diff - margin;
}
void cRingBufferLinear::Clear(void)
{
Lock();
head = tail = margin;
lastGet = -1;
Unlock();
EnablePut();
EnableGet();
}
int cRingBufferLinear::Put(const uchar *Data, int Count)
{
if (Count > 0) {
Lock();
int rest = Size() - head;
int diff = tail - head;
int free = ((tail < margin) ? rest : (diff > 0) ? diff : Size() + diff - margin) - 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) / 5 * 5;
if (abs(lastPercent - percent) >= 5) {
if (percent > 75)
dsyslog("buffer usage: %d%% (pid=%d)", percent, getThreadPid);
lastPercent = percent;
}
}
if (free > 0) {
if (free < Count)
Count = free;
if (Count > maxFill)
maxFill = Count;
if (Count >= rest) {
memcpy(buffer + head, Data, rest);
if (Count - rest)
memcpy(buffer + margin, Data + rest, Count - rest);
head = margin + Count - rest;
}
else {
memcpy(buffer + head, Data, Count);
head += Count;
}
}
else
Count = 0;
Unlock();
EnableGet();
if (Count == 0)
WaitForPut();
}
return Count;
}
const uchar *cRingBufferLinear::Get(int &Count)
{
const uchar *p = NULL;
Lock();
if (getThreadPid < 0)
getThreadPid = getpid();
int rest = Size() - tail;
if (rest < margin && head < tail) {
int t = margin - rest;
memcpy(buffer + t, buffer + tail, rest);
tail = t;
}
int diff = head - tail;
int cont = (diff >= 0) ? diff : Size() + diff - margin;
if (cont > rest)
cont = rest;
if (cont >= margin) {
p = buffer + tail;
Count = lastGet = cont;
}
Unlock();
if (!p)
WaitForGet();
return p;
}
void cRingBufferLinear::Del(int Count)
{
if (Count > 0 && Count <= lastGet) {
Lock();
tail += Count;
lastGet -= Count;
if (tail >= Size())
tail = margin;
Unlock();
EnablePut();
}
else
esyslog("ERROR: invalid Count in cRingBufferLinear::Del: %d", Count);
}
// --- cFrame ----------------------------------------------------------------
cFrame::cFrame(const uchar *Data, int Count, eFrameType Type, int Index)
{
count = abs(Count);
type = Type;
index = Index;
if (Count < 0)
data = (uchar *)Data;
else {
data = MALLOC(uchar, count);
if (data)
memcpy(data, Data, count);
else
esyslog("ERROR: can't allocate frame buffer (count=%d)", count);
}
next = NULL;
}
cFrame::~cFrame()
{
free(data);
}
// --- cRingBufferFrame ------------------------------------------------------
cRingBufferFrame::cRingBufferFrame(int Size, bool Statistics)
:cRingBuffer(Size, Statistics)
{
head = NULL;
currentFill = 0;
}
cRingBufferFrame::~cRingBufferFrame()
{
Clear();
}
void cRingBufferFrame::Clear(void)
{
Lock();
const cFrame *p;
while ((p = Get()) != 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;
}
else {
head = Frame->next = Frame;
}
currentFill += Frame->Count();
Unlock();
EnableGet();
return true;
}
return false;
}
const cFrame *cRingBufferFrame::Get(void)
{
Lock();
cFrame *p = head ? head->next : NULL;
Unlock();
return p;
}
void cRingBufferFrame::Delete(const cFrame *Frame)
{
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("ERROR: attempt to drop wrong frame from ring buffer!");
}
Unlock();
EnablePut();
}
int cRingBufferFrame::Available(void)
{
Lock();
int av = currentFill;
Unlock();
return av;
}