| """Small deterministic real-time DAC clock for synthetic WebSocket checks. |
| |
| Chunk arrival is not playback completion. No physical device is simulated; |
| timestamps/position tags follow the browser wire contract, including gaps. |
| """ |
| class SyntheticPlayback: |
| def __init__(self,lead16=640): |
| self.lead16=lead16;self.until=0;self.segments=[];self.sent={};self.stopped={} |
| def add(self,rid,n24,now16): |
| if not rid or rid in self.stopped:return |
| offset=self.sent.get(rid,0);self.sent[rid]=offset+n24 |
| start=max(now16+self.lead16,self.until);end=start+round(n24*2/3) |
| self.segments.append((start,end,rid,offset,n24));self.until=end |
| def pieces(self,start16,n): |
| active=[];cuts={0,n};end16=start16+n |
| for a,b,rid,p,count in self.segments: |
| b=min(b,self.stopped.get(rid,b)) |
| if b<=start16 or a>=end16:continue |
| lo=max(a,start16)-start16;hi=min(b,end16)-start16 |
| active.append((lo,hi,rid,p+round((start16+lo-a)*1.5)));cuts.update((lo,hi)) |
| edges=sorted(cuts);parts=[] |
| for a,b in zip(edges,edges[1:]): |
| value=next(((rid,p+round((a-lo)*1.5)) for lo,hi,rid,p in active if lo<=a<hi),(0,-1)) |
| parts.append((a,b,*value)) |
| return parts |
| def acknowledgments(self,now16): |
| positions={} |
| for a,b,rid,p,count in self.segments: |
| if rid in self.stopped or now16<a:continue |
| positions[rid]=max(positions.get(rid,0),min(p+count,p+round((min(now16,b)-a)*1.5))) |
| return positions |
| def cancel(self,now16): |
| for rid in self.sent:self.stopped[rid]=min(self.stopped.get(rid,now16),now16) |
| self.until=now16 |
|
|
