Files
UnrealEngine/Engine/Source/Runtime/PakFile/Private/PakIntervalTree.inl
2025-05-18 13:04:45 +08:00

643 lines
18 KiB
C++

// Copyright Epic Games, Inc. All Rights Reserved.
#pragma once
enum
{
IntervalTreeInvalidIndex = 0
};
typedef uint32 TIntervalTreeIndex; // this is the arg type of TSparseArray::operator[]
typedef uint64 FJoinedOffsetAndPakIndex;
static FORCEINLINE uint16 GetRequestPakIndexLow(FJoinedOffsetAndPakIndex Joined)
{
return uint16((Joined >> 48) & 0xffff);
}
static FORCEINLINE int64 GetRequestOffset(FJoinedOffsetAndPakIndex Joined)
{
return int64(Joined & 0xffffffffffffll);
}
static FORCEINLINE FJoinedOffsetAndPakIndex MakeJoinedRequest(uint16 PakIndex, int64 Offset)
{
check(Offset >= 0);
return (FJoinedOffsetAndPakIndex(PakIndex) << 48) | Offset;
}
static uint32 GNextSalt = 1;
// This is like TSparseArray, only a bit safer and I needed some restrictions on resizing.
template<class TItem>
class TIntervalTreeAllocator
{
TArray<TItem> Items;
TArray<int32> FreeItems; //@todo make this into a linked list through the existing items
uint32 Salt;
uint32 SaltMask;
public:
TIntervalTreeAllocator()
{
check(GNextSalt < 4);
Salt = (GNextSalt++) << 30;
SaltMask = MAX_uint32 << 30;
verify((Alloc() & ~SaltMask) == IntervalTreeInvalidIndex); // we want this to always have element zero so we can figure out an index from a pointer
}
inline TIntervalTreeIndex Alloc()
{
int32 Result;
if (FreeItems.Num())
{
Result = FreeItems.Pop();
}
else
{
Result = Items.Num();
Items.AddUninitialized();
}
new ((void*)&Items[Result]) TItem();
return Result | Salt;;
}
void EnsureNoRealloc(int32 NeededNewNum)
{
if (FreeItems.Num() + Items.GetSlack() < NeededNewNum)
{
Items.Reserve(Items.Num() + NeededNewNum);
}
}
FORCEINLINE TItem& Get(TIntervalTreeIndex InIndex)
{
TIntervalTreeIndex Index = InIndex & ~SaltMask;
check((InIndex & SaltMask) == Salt && Index != IntervalTreeInvalidIndex && Index >= 0 && Index < (uint32)Items.Num()); //&& !FreeItems.Contains(Index));
return Items[Index];
}
FORCEINLINE void Free(TIntervalTreeIndex InIndex)
{
TIntervalTreeIndex Index = InIndex & ~SaltMask;
check((InIndex & SaltMask) == Salt && Index != IntervalTreeInvalidIndex && Index >= 0 && Index < (uint32)Items.Num()); //&& !FreeItems.Contains(Index));
Items[Index].~TItem();
FreeItems.Push(Index);
if (FreeItems.Num() + 1 == Items.Num())
{
// get rid everything to restore memory coherence
Items.Empty();
FreeItems.Empty();
verify((Alloc() & ~SaltMask) == IntervalTreeInvalidIndex); // we want this to always have element zero so we can figure out an index from a pointer
}
}
FORCEINLINE void CheckIndex(TIntervalTreeIndex InIndex)
{
TIntervalTreeIndex Index = InIndex & ~SaltMask;
check((InIndex & SaltMask) == Salt && Index != IntervalTreeInvalidIndex && Index >= 0 && Index < (uint32)Items.Num()); // && !FreeItems.Contains(Index));
}
};
class FIntervalTreeNode
{
public:
TIntervalTreeIndex LeftChildOrRootOfLeftList;
TIntervalTreeIndex RootOfOnList;
TIntervalTreeIndex RightChildOrRootOfRightList;
FIntervalTreeNode()
: LeftChildOrRootOfLeftList(IntervalTreeInvalidIndex)
, RootOfOnList(IntervalTreeInvalidIndex)
, RightChildOrRootOfRightList(IntervalTreeInvalidIndex)
{
}
~FIntervalTreeNode()
{
check(LeftChildOrRootOfLeftList == IntervalTreeInvalidIndex && RootOfOnList == IntervalTreeInvalidIndex && RightChildOrRootOfRightList == IntervalTreeInvalidIndex); // this routine does not handle recursive destruction
}
};
static TIntervalTreeAllocator<FIntervalTreeNode> GIntervalTreeNodeNodeAllocator;
static FORCEINLINE uint64 HighBit(uint64 x)
{
return x & (1ull << 63);
}
static FORCEINLINE bool IntervalsIntersect(uint64 Min1, uint64 Max1, uint64 Min2, uint64 Max2)
{
return !(Max2 < Min1 || Max1 < Min2);
}
template<typename TItem>
// this routine assume that the pointers remain valid even though we are reallocating
static void AddToIntervalTree_Dangerous(
TIntervalTreeIndex* RootNode,
TIntervalTreeAllocator<TItem>& Allocator,
TIntervalTreeIndex Index,
uint64 MinInterval,
uint64 MaxInterval,
uint32 CurrentShift,
uint32 MaxShift
)
{
while (true)
{
if (*RootNode == IntervalTreeInvalidIndex)
{
*RootNode = GIntervalTreeNodeNodeAllocator.Alloc();
}
int64 MinShifted = HighBit(MinInterval << CurrentShift);
int64 MaxShifted = HighBit(MaxInterval << CurrentShift);
FIntervalTreeNode& Root = GIntervalTreeNodeNodeAllocator.Get(*RootNode);
if (MinShifted == MaxShifted && CurrentShift < MaxShift)
{
CurrentShift++;
RootNode = (!MinShifted) ? &Root.LeftChildOrRootOfLeftList : &Root.RightChildOrRootOfRightList;
}
else
{
TItem& Item = Allocator.Get(Index);
if (MinShifted != MaxShifted) // crosses middle
{
Item.Next = Root.RootOfOnList;
Root.RootOfOnList = Index;
}
else // we are at the leaf
{
if (!MinShifted)
{
Item.Next = Root.LeftChildOrRootOfLeftList;
Root.LeftChildOrRootOfLeftList = Index;
}
else
{
Item.Next = Root.RightChildOrRootOfRightList;
Root.RightChildOrRootOfRightList = Index;
}
}
return;
}
}
}
template<typename TItem>
static void AddToIntervalTree(
TIntervalTreeIndex* RootNode,
TIntervalTreeAllocator<TItem>& Allocator,
TIntervalTreeIndex Index,
uint32 StartShift,
uint32 MaxShift
)
{
GIntervalTreeNodeNodeAllocator.EnsureNoRealloc(1 + MaxShift - StartShift);
TItem& Item = Allocator.Get(Index);
check(Item.Next == IntervalTreeInvalidIndex);
uint64 MinInterval = GetRequestOffset(Item.OffsetAndPakIndex);
uint64 MaxInterval = MinInterval + Item.Size - 1;
AddToIntervalTree_Dangerous(RootNode, Allocator, Index, MinInterval, MaxInterval, StartShift, MaxShift);
}
template<typename TItem>
static FORCEINLINE bool ScanNodeListForRemoval(
TIntervalTreeIndex* Iter,
TIntervalTreeAllocator<TItem>& Allocator,
TIntervalTreeIndex Index,
uint64 MinInterval,
uint64 MaxInterval
)
{
while (*Iter != IntervalTreeInvalidIndex)
{
TItem& Item = Allocator.Get(*Iter);
if (*Iter == Index)
{
*Iter = Item.Next;
Item.Next = IntervalTreeInvalidIndex;
return true;
}
Iter = &Item.Next;
}
return false;
}
template<typename TItem>
static bool RemoveFromIntervalTree(
TIntervalTreeIndex* RootNode,
TIntervalTreeAllocator<TItem>& Allocator,
TIntervalTreeIndex Index,
uint64 MinInterval,
uint64 MaxInterval,
uint32 CurrentShift,
uint32 MaxShift
)
{
bool bResult = false;
if (*RootNode != IntervalTreeInvalidIndex)
{
int64 MinShifted = HighBit(MinInterval << CurrentShift);
int64 MaxShifted = HighBit(MaxInterval << CurrentShift);
FIntervalTreeNode& Root = GIntervalTreeNodeNodeAllocator.Get(*RootNode);
if (!MinShifted && !MaxShifted)
{
if (CurrentShift == MaxShift)
{
bResult = ScanNodeListForRemoval(&Root.LeftChildOrRootOfLeftList, Allocator, Index, MinInterval, MaxInterval);
}
else
{
bResult = RemoveFromIntervalTree(&Root.LeftChildOrRootOfLeftList, Allocator, Index, MinInterval, MaxInterval, CurrentShift + 1, MaxShift);
}
}
else if (!MinShifted && MaxShifted)
{
bResult = ScanNodeListForRemoval(&Root.RootOfOnList, Allocator, Index, MinInterval, MaxInterval);
}
else
{
if (CurrentShift == MaxShift)
{
bResult = ScanNodeListForRemoval(&Root.RightChildOrRootOfRightList, Allocator, Index, MinInterval, MaxInterval);
}
else
{
bResult = RemoveFromIntervalTree(&Root.RightChildOrRootOfRightList, Allocator, Index, MinInterval, MaxInterval, CurrentShift + 1, MaxShift);
}
}
if (bResult)
{
if (Root.LeftChildOrRootOfLeftList == IntervalTreeInvalidIndex && Root.RootOfOnList == IntervalTreeInvalidIndex && Root.RightChildOrRootOfRightList == IntervalTreeInvalidIndex)
{
check(&Root == &GIntervalTreeNodeNodeAllocator.Get(*RootNode));
GIntervalTreeNodeNodeAllocator.Free(*RootNode);
*RootNode = IntervalTreeInvalidIndex;
}
}
}
return bResult;
}
template<typename TItem>
static bool RemoveFromIntervalTree(
TIntervalTreeIndex* RootNode,
TIntervalTreeAllocator<TItem>& Allocator,
TIntervalTreeIndex Index,
uint32 StartShift,
uint32 MaxShift
)
{
TItem& Item = Allocator.Get(Index);
uint64 MinInterval = GetRequestOffset(Item.OffsetAndPakIndex);
uint64 MaxInterval = MinInterval + Item.Size - 1;
return RemoveFromIntervalTree(RootNode, Allocator, Index, MinInterval, MaxInterval, StartShift, MaxShift);
}
template<typename TItem>
static FORCEINLINE void ScanNodeListForRemovalFunc(
TIntervalTreeIndex* Iter,
TIntervalTreeAllocator<TItem>& Allocator,
uint64 MinInterval,
uint64 MaxInterval,
TFunctionRef<bool(TIntervalTreeIndex)> Func
)
{
while (*Iter != IntervalTreeInvalidIndex)
{
TItem& Item = Allocator.Get(*Iter);
uint64 Offset = uint64(GetRequestOffset(Item.OffsetAndPakIndex));
uint64 LastByte = Offset + uint64(Item.Size) - 1;
// save the value and then clear it.
TIntervalTreeIndex NextIndex = Item.Next;
if (IntervalsIntersect(MinInterval, MaxInterval, Offset, LastByte) && Func(*Iter))
{
*Iter = NextIndex; // this may have already be deleted, so cannot rely on the memory block
}
else
{
Iter = &Item.Next;
}
}
}
template<typename TItem>
static void MaybeRemoveOverlappingNodesInIntervalTree(
TIntervalTreeIndex* RootNode,
TIntervalTreeAllocator<TItem>& Allocator,
uint64 MinInterval,
uint64 MaxInterval,
uint64 MinNode,
uint64 MaxNode,
uint32 CurrentShift,
uint32 MaxShift,
TFunctionRef<bool(TIntervalTreeIndex)> Func
)
{
if (*RootNode != IntervalTreeInvalidIndex)
{
int64 MinShifted = HighBit(MinInterval << CurrentShift);
int64 MaxShifted = HighBit(MaxInterval << CurrentShift);
FIntervalTreeNode& Root = GIntervalTreeNodeNodeAllocator.Get(*RootNode);
uint64 Center = (MinNode + MaxNode + 1) >> 1;
//UE_LOG(LogTemp, Warning, TEXT("Exploring Node %X [%d, %d] %d%d interval %llX %llX node interval %llX %llX center %llX "), *RootNode, CurrentShift, MaxShift, !!MinShifted, !!MaxShifted, MinInterval, MaxInterval, MinNode, MaxNode, Center);
if (!MinShifted)
{
if (CurrentShift == MaxShift)
{
//UE_LOG(LogTemp, Warning, TEXT("LeftBottom %X [%d, %d] %d%d"), *RootNode, CurrentShift, MaxShift, !!MinShifted, !!MaxShifted);
ScanNodeListForRemovalFunc(&Root.LeftChildOrRootOfLeftList, Allocator, MinInterval, MaxInterval, Func);
}
else
{
//UE_LOG(LogTemp, Warning, TEXT("LeftRecur %X [%d, %d] %d%d"), *RootNode, CurrentShift, MaxShift, !!MinShifted, !!MaxShifted);
MaybeRemoveOverlappingNodesInIntervalTree(&Root.LeftChildOrRootOfLeftList, Allocator, MinInterval, FMath::Min(MaxInterval, Center - 1), MinNode, Center - 1, CurrentShift + 1, MaxShift, Func);
}
}
//UE_LOG(LogTemp, Warning, TEXT("Center %X [%d, %d] %d%d"), *RootNode, CurrentShift, MaxShift, !!MinShifted, !!MaxShifted);
ScanNodeListForRemovalFunc(&Root.RootOfOnList, Allocator, MinInterval, MaxInterval, Func);
if (MaxShifted)
{
if (CurrentShift == MaxShift)
{
//UE_LOG(LogTemp, Warning, TEXT("RightBottom %X [%d, %d] %d%d"), *RootNode, CurrentShift, MaxShift, !!MinShifted, !!MaxShifted);
ScanNodeListForRemovalFunc(&Root.RightChildOrRootOfRightList, Allocator, MinInterval, MaxInterval, Func);
}
else
{
//UE_LOG(LogTemp, Warning, TEXT("RightRecur %X [%d, %d] %d%d"), *RootNode, CurrentShift, MaxShift, !!MinShifted, !!MaxShifted);
MaybeRemoveOverlappingNodesInIntervalTree(&Root.RightChildOrRootOfRightList, Allocator, FMath::Max(MinInterval, Center), MaxInterval, Center, MaxNode, CurrentShift + 1, MaxShift, Func);
}
}
//UE_LOG(LogTemp, Warning, TEXT("Done Exploring Node %X [%d, %d] %d%d interval %llX %llX node interval %llX %llX center %llX "), *RootNode, CurrentShift, MaxShift, !!MinShifted, !!MaxShifted, MinInterval, MaxInterval, MinNode, MaxNode, Center);
if (Root.LeftChildOrRootOfLeftList == IntervalTreeInvalidIndex && Root.RootOfOnList == IntervalTreeInvalidIndex && Root.RightChildOrRootOfRightList == IntervalTreeInvalidIndex)
{
check(&Root == &GIntervalTreeNodeNodeAllocator.Get(*RootNode));
GIntervalTreeNodeNodeAllocator.Free(*RootNode);
*RootNode = IntervalTreeInvalidIndex;
}
}
}
template<typename TItem>
static FORCEINLINE bool ScanNodeList(
TIntervalTreeIndex Iter,
TIntervalTreeAllocator<TItem>& Allocator,
uint64 MinInterval,
uint64 MaxInterval,
TFunctionRef<bool(TIntervalTreeIndex)> Func
)
{
while (Iter != IntervalTreeInvalidIndex)
{
TItem& Item = Allocator.Get(Iter);
uint64 Offset = uint64(GetRequestOffset(Item.OffsetAndPakIndex));
uint64 LastByte = Offset + uint64(Item.Size) - 1;
if (IntervalsIntersect(MinInterval, MaxInterval, Offset, LastByte))
{
if (!Func(Iter))
{
return false;
}
}
Iter = Item.Next;
}
return true;
}
template<typename TItem>
static bool OverlappingNodesInIntervalTree(
TIntervalTreeIndex RootNode,
TIntervalTreeAllocator<TItem>& Allocator,
uint64 MinInterval,
uint64 MaxInterval,
uint64 MinNode,
uint64 MaxNode,
uint32 CurrentShift,
uint32 MaxShift,
TFunctionRef<bool(TIntervalTreeIndex)> Func
)
{
if (RootNode != IntervalTreeInvalidIndex)
{
int64 MinShifted = HighBit(MinInterval << CurrentShift);
int64 MaxShifted = HighBit(MaxInterval << CurrentShift);
FIntervalTreeNode& Root = GIntervalTreeNodeNodeAllocator.Get(RootNode);
uint64 Center = (MinNode + MaxNode + 1) >> 1;
if (!MinShifted)
{
if (CurrentShift == MaxShift)
{
if (!ScanNodeList(Root.LeftChildOrRootOfLeftList, Allocator, MinInterval, MaxInterval, Func))
{
return false;
}
}
else
{
if (!OverlappingNodesInIntervalTree(Root.LeftChildOrRootOfLeftList, Allocator, MinInterval, FMath::Min(MaxInterval, Center - 1), MinNode, Center - 1, CurrentShift + 1, MaxShift, Func))
{
return false;
}
}
}
if (!ScanNodeList(Root.RootOfOnList, Allocator, MinInterval, MaxInterval, Func))
{
return false;
}
if (MaxShifted)
{
if (CurrentShift == MaxShift)
{
if (!ScanNodeList(Root.RightChildOrRootOfRightList, Allocator, MinInterval, MaxInterval, Func))
{
return false;
}
}
else
{
if (!OverlappingNodesInIntervalTree(Root.RightChildOrRootOfRightList, Allocator, FMath::Max(MinInterval, Center), MaxInterval, Center, MaxNode, CurrentShift + 1, MaxShift, Func))
{
return false;
}
}
}
}
return true;
}
template<typename TItem>
static bool ScanNodeListWithShrinkingInterval(
TIntervalTreeIndex Iter,
TIntervalTreeAllocator<TItem>& Allocator,
uint64 MinInterval,
uint64& MaxInterval,
TFunctionRef<bool(TIntervalTreeIndex)> Func
)
{
while (Iter != IntervalTreeInvalidIndex)
{
TItem& Item = Allocator.Get(Iter);
uint64 Offset = uint64(GetRequestOffset(Item.OffsetAndPakIndex));
uint64 LastByte = Offset + uint64(Item.Size) - 1;
//UE_LOG(LogTemp, Warning, TEXT("Test Overlap %llu %llu %llu %llu"), MinInterval, MaxInterval, Offset, LastByte);
if (IntervalsIntersect(MinInterval, MaxInterval, Offset, LastByte))
{
//UE_LOG(LogTemp, Warning, TEXT("Overlap %llu %llu %llu %llu"), MinInterval, MaxInterval, Offset, LastByte);
if (!Func(Iter))
{
return false;
}
}
Iter = Item.Next;
}
return true;
}
template<typename TItem>
static bool OverlappingNodesInIntervalTreeWithShrinkingInterval(
TIntervalTreeIndex RootNode,
TIntervalTreeAllocator<TItem>& Allocator,
uint64 MinInterval,
uint64& MaxInterval,
uint64 MinNode,
uint64 MaxNode,
uint32 CurrentShift,
uint32 MaxShift,
TFunctionRef<bool(TIntervalTreeIndex)> Func
)
{
if (RootNode != IntervalTreeInvalidIndex)
{
int64 MinShifted = HighBit(MinInterval << CurrentShift);
int64 MaxShifted = HighBit(FMath::Min(MaxInterval, MaxNode) << CurrentShift); // since MaxInterval is changing, we cannot clamp it during recursion.
FIntervalTreeNode& Root = GIntervalTreeNodeNodeAllocator.Get(RootNode);
uint64 Center = (MinNode + MaxNode + 1) >> 1;
if (!MinShifted)
{
if (CurrentShift == MaxShift)
{
if (!ScanNodeListWithShrinkingInterval(Root.LeftChildOrRootOfLeftList, Allocator, MinInterval, MaxInterval, Func))
{
return false;
}
}
else
{
if (!OverlappingNodesInIntervalTreeWithShrinkingInterval(Root.LeftChildOrRootOfLeftList, Allocator, MinInterval, MaxInterval, MinNode, Center - 1, CurrentShift + 1, MaxShift, Func)) // since MaxInterval is changing, we cannot clamp it during recursion.
{
return false;
}
}
}
if (!ScanNodeListWithShrinkingInterval(Root.RootOfOnList, Allocator, MinInterval, MaxInterval, Func))
{
return false;
}
MaxShifted = HighBit(FMath::Min(MaxInterval, MaxNode) << CurrentShift); // since MaxInterval is changing, we cannot clamp it during recursion.
if (MaxShifted)
{
if (CurrentShift == MaxShift)
{
if (!ScanNodeListWithShrinkingInterval(Root.RightChildOrRootOfRightList, Allocator, MinInterval, MaxInterval, Func))
{
return false;
}
}
else
{
if (!OverlappingNodesInIntervalTreeWithShrinkingInterval(Root.RightChildOrRootOfRightList, Allocator, FMath::Max(MinInterval, Center), MaxInterval, Center, MaxNode, CurrentShift + 1, MaxShift, Func))
{
return false;
}
}
}
}
return true;
}
template<typename TItem>
static void MaskInterval(
TIntervalTreeIndex Index,
TIntervalTreeAllocator<TItem>& Allocator,
uint64 MinInterval,
uint64 MaxInterval,
uint32 BytesToBitsShift,
uint64* Bits
)
{
TItem& Item = Allocator.Get(Index);
uint64 Offset = uint64(GetRequestOffset(Item.OffsetAndPakIndex));
uint64 LastByte = Offset + uint64(Item.Size) - 1;
uint64 InterMinInterval = FMath::Max(MinInterval, Offset);
uint64 InterMaxInterval = FMath::Min(MaxInterval, LastByte);
if (InterMinInterval <= InterMaxInterval)
{
uint32 FirstBit = uint32((InterMinInterval - MinInterval) >> BytesToBitsShift);
uint32 LastBit = uint32((InterMaxInterval - MinInterval) >> BytesToBitsShift);
uint32 FirstQWord = FirstBit >> 6;
uint32 LastQWord = LastBit >> 6;
uint32 FirstBitQWord = FirstBit & 63;
uint32 LastBitQWord = LastBit & 63;
if (FirstQWord == LastQWord)
{
Bits[FirstQWord] |= ((MAX_uint64 << FirstBitQWord) & (MAX_uint64 >> (63 - LastBitQWord)));
}
else
{
Bits[FirstQWord] |= (MAX_uint64 << FirstBitQWord);
for (uint32 QWordIndex = FirstQWord + 1; QWordIndex < LastQWord; QWordIndex++)
{
Bits[QWordIndex] = MAX_uint64;
}
Bits[LastQWord] |= (MAX_uint64 >> (63 - LastBitQWord));
}
}
}
template<typename TItem>
static void OverlappingNodesInIntervalTreeMask(
TIntervalTreeIndex RootNode,
TIntervalTreeAllocator<TItem>& Allocator,
uint64 MinInterval,
uint64 MaxInterval,
uint64 MinNode,
uint64 MaxNode,
uint32 CurrentShift,
uint32 MaxShift,
uint32 BytesToBitsShift,
uint64* Bits
)
{
OverlappingNodesInIntervalTree(
RootNode,
Allocator,
MinInterval,
MaxInterval,
MinNode,
MaxNode,
CurrentShift,
MaxShift,
[&Allocator, MinInterval, MaxInterval, BytesToBitsShift, Bits](TIntervalTreeIndex Index) -> bool
{
MaskInterval(Index, Allocator, MinInterval, MaxInterval, BytesToBitsShift, Bits);
return true;
}
);
}