diff options
Diffstat (limited to 'ringbuffer.c')
| -rw-r--r-- | ringbuffer.c | 82 |
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 ---------------------------------------------------------------- |