//we are assumed to be in a mutex here
PBYTE DBRead(DWORD ofs,int bytesRequired,int *bytesAvail)
{
int part1sect;
int part2sect;
part1sect = FindSectionForOffset(ofs);
if (ofs%CACHESECTIONSIZE+bytesRequired<CACHESECTIONSIZE) {
//only one section required
if(part1sect==-1) {
part1sect=FindLRUSection();
LoadSection(part1sect,ofs);
}
cacheSectionInfo[part1sect].lastUsed=++lastUseCounter;
if(bytesAvail!=NULL) *bytesAvail=cacheSectionInfo[part1sect].ofsBase+CACHESECTIONSIZE-ofs;
return pDbCache+part1sect*CACHESECTIONSIZE+(ofs-cacheSectionInfo[part1sect].ofsBase);
}
//two sections are required
part2sect=FindSectionForOffset(ofs+CACHESECTIONSIZE);
if(part1sect!=-1) {
if(part2sect==-1) { //first part in cache, but not second part
if(part1sect==CACHESECTIONCOUNT-1) MoveSection(&part1sect,0);
LoadSection(part1sect+1,ofs+CACHESECTIONSIZE);
}
else if(part2sect!=part1sect+1) { //both parts are in cache, but not already consecutive
if(part1sect==CACHESECTIONCOUNT-1) {
//first part is at end, move to before second part
if(part2sect==0) //second part is at start: need to move both
MoveSection(&part2sect,1);
MoveSection(&part1sect,part2sect-1);
}
else //move second part to after first part
MoveSection(&part2sect,part1sect+1);
}
}
else {
if(part2sect==-1) { //neither section is in cache
part1sect=0;
part2sect=1;
LoadSection(part1sect,ofs);
LoadSection(part2sect,ofs+CACHESECTIONSIZE);
}
else { //part 2 is in cache, but not part 1
if(part2sect==0) MoveSection(&part2sect,1);
part1sect=part2sect-1;
LoadSection(part1sect,ofs);
}
}
//both sections are now consecutive, starting at part1sect
cacheSectionInfo[part1sect].lastUsed=++lastUseCounter;
cacheSectionInfo[part1sect+1].lastUsed=++lastUseCounter;
if(bytesAvail!=NULL) *bytesAvail=cacheSectionInfo[part1sect+1].ofsBase+CACHESECTIONSIZE-ofs;
return pDbCache+part1sect*CACHESECTIONSIZE+(ofs-cacheSectionInfo[part1sect].ofsBase);
}
void UMovieSceneSection::InitialPlacement(const TArray<UMovieSceneSection*>& Sections, float InStartTime, float InEndTime, bool bAllowMultipleRows)
{
check(StartTime <= EndTime);
StartTime = InStartTime;
EndTime = InEndTime;
RowIndex = 0;
if (bAllowMultipleRows)
{
while (OverlapsWithSections(Sections) != nullptr)
{
++RowIndex;
}
}
else
{
for (;;)
{
const UMovieSceneSection* OverlappedSection = OverlapsWithSections(Sections);
if (OverlappedSection == nullptr)
{
break;
}
TSet<FKeyHandle> KeyHandles;
MoveSection(OverlappedSection->GetEndTime() - StartTime, KeyHandles);
}
}
}
