summaryrefslogtreecommitdiff
path: root/ringbuffer.c
diff options
context:
space:
mode:
Diffstat (limited to 'ringbuffer.c')
-rw-r--r--ringbuffer.c82
1 files changed, 45 insertions, 37 deletions
diff --git a/ringbuffer.c b/ringbuffer.c
index ed92be59..0734c28d 100644
--- a/ringbuffer.c
+++ b/ringbuffer.c
@@ -7,7 +7,7 @@
* Parts of this file were inspired by the 'ringbuffy.c' from the
* LinuxDVB driver (see linuxtv.org).
*
- * $Id: ringbuffer.c 1.11 2003/01/19 15:03:00 kls Exp $
+ * $Id: ringbuffer.c 1.12 2003/01/26 09:39:24 kls Exp $
*/
#include "ringbuffer.h"
@@ -57,13 +57,14 @@ void cRingBuffer::EnableGet(void)
// --- cRingBufferLinear -----------------------------------------------------
-cRingBufferLinear::cRingBufferLinear(int Size, bool Statistics)
+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 = new uchar[Size];
+ buffer = MALLOC(uchar, Size);
if (!buffer)
esyslog("ERROR: can't allocate ring buffer (size=%d)", Size);
Clear();
@@ -74,7 +75,7 @@ cRingBufferLinear::cRingBufferLinear(int Size, bool Statistics)
cRingBufferLinear::~cRingBufferLinear()
{
- delete buffer;
+ free(buffer);
}
int cRingBufferLinear::Available(void)
@@ -82,13 +83,14 @@ int cRingBufferLinear::Available(void)
Lock();
int diff = head - tail;
Unlock();
- return (diff >= 0) ? diff : Size() + diff;
+ return (diff >= 0) ? diff : Size() + diff - margin;
}
void cRingBufferLinear::Clear(void)
{
Lock();
- head = tail = 0;
+ head = tail = margin;
+ lastGet = -1;
Unlock();
EnablePut();
EnableGet();
@@ -100,7 +102,7 @@ int cRingBufferLinear::Put(const uchar *Data, int Count)
Lock();
int rest = Size() - head;
int diff = tail - head;
- int free = (diff > 0) ? diff - 1 : Size() + diff - 1;
+ int free = (diff > 0) ? diff - 1 : Size() + diff - (tail < margin ? -(margin - tail) : margin) - 1;
if (statistics) {
int fill = Size() - free - 1 + Count;
if (fill >= Size())
@@ -122,8 +124,8 @@ int cRingBufferLinear::Put(const uchar *Data, int Count)
if (Count >= rest) {
memcpy(buffer + head, Data, rest);
if (Count - rest)
- memcpy(buffer, Data + rest, Count - rest);
- head = Count - rest;
+ memcpy(buffer + margin, Data + rest, Count - rest);
+ head = margin + Count - rest;
}
else {
memcpy(buffer + head, Data, Count);
@@ -138,36 +140,42 @@ int cRingBufferLinear::Put(const uchar *Data, int Count)
return Count;
}
-int cRingBufferLinear::Get(uchar *Data, int Count)
+const uchar *cRingBufferLinear::Get(int &Count)
{
- if (Count > 0) {
- Lock();
- if (getThreadPid < 0)
- getThreadPid = getpid();
- int rest = Size() - tail;
- int diff = head - tail;
- int cont = (diff >= 0) ? diff : Size() + diff;
- if (rest > 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;
- }
- }
- else
- Count = 0;
- Unlock();
- if (Count == 0)
- WaitForGet();
+ const uchar *p = NULL;
+ Lock();
+ if (getThreadPid < 0)
+ getThreadPid = getpid();
+ int rest = Size() - tail;
+ if (tail > Size() - margin && head < tail) {
+ int t = margin - rest;
+ memcpy(buffer + t, buffer + tail, rest);
+ tail = t;
}
- return Count;
+ 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) {
+ tail += Count;
+ lastGet -= Count;
+ if (tail >= Size())
+ tail = margin;
+ }
+ else
+ esyslog("ERROR: invalid Count in cRingBufferLinear::Del: %d", Count);
}
// --- cFrame ----------------------------------------------------------------