[vdr] [PATCH] UnbufferedFile improvements v7

[Klaus Schmidinger]

Klaus Schmidinger wrote:
> Artur Skawina wrote:
> 
>> this time with a new approach to read caching. Should make watching 
>> and editing recordings on a non-idle (and/or slow) machine more 
>> comfortable.
>>
>> The difference to previous versions (and stock fadvise-enabled vdr) is 
>> that previously, read data was almost immediately forgotten after it 
>> was used; now a certain amount of recently accessed data (at most 
>> ~16M) is kept around. This means that short seeks (jumps) when 
>> replaying do not cause disk accesses. Things like switching play mode, 
>> FF, setting and moving editing marks shouldn't usually block waiting 
>> for disk IO. The changes are most noticeable when eg. several 
>> recordings are happening in the background.
>>
>> I did very little testing, treat this as beta quality at best. Seems 
>> to work ok, but i won't probably have time to test it further for a 
>> few days; maybe somebody wants to play w/ this, or even better take a 
>> look at the Read() path...
> 
> 
> Attached is the patch as I would add it for the next version.

I just realized that FadviseDrop() should, of course, be
private in cUnbufferedFile. But that doesn't change any
functionality...

Klaus