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cItemGrid: Allocate storage lazily (#4083) 

* cItemGrid: Allocate storage lazily
* cItemGrid: Fix spelling, Prioritary -> Priority
This commit is contained in:
peterbell10 2018-01-21 18:45:13 +00:00 committed by GitHub
parent cd88a11735
commit ab350d1e43
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GPG Key ID: 4AEE18F83AFDEB23
5 changed files with 262 additions and 92 deletions
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8
Server/Plugins/APIDump/APIDesc.lua
View File

@ -7213,7 +7213,7 @@ This class represents a 2D array of items. It is used as the underlying storage
IsOptional = true,
},
{
Name = "PrioritarySlot",
Name = "PrioritySlot",
Type = "number",
IsOptional = true,
},
@ -7224,7 +7224,7 @@ This class represents a 2D array of items. It is used as the underlying storage
Type = "number",
},
},
Notes = "Adds as many items out of ItemStack as can fit. If AllowNewStacks is set to false, only existing stacks can be topped up. If AllowNewStacks is set to true (default), empty slots can be used for the rest. If PrioritarySlot is set to a non-negative value, then the corresponding slot will be used first (if empty or compatible with added items). If PrioritarySlot is set to -1 (default), regular order applies. Returns the number of items that fit.",
Notes = "Adds as many items out of ItemStack as can fit. If AllowNewStacks is set to false, only existing stacks can be topped up. If AllowNewStacks is set to true (default), empty slots can be used for the rest. If PrioritySlot is set to a non-negative value, then the corresponding slot will be used first (if empty or compatible with added items). If PrioritySlot is set to -1 (default), regular order applies. Returns the number of items that fit.",
},
AddItems =
{
@ -7240,7 +7240,7 @@ This class represents a 2D array of items. It is used as the underlying storage
IsOptional = true,
},
{
Name = "PrioritarySlot",
Name = "PrioritySlot",
Type = "number",
IsOptional = true,
},
@ -7251,7 +7251,7 @@ This class represents a 2D array of items. It is used as the underlying storage
Type = "number",
},
},
Notes = "Same as AddItem, but works on an entire list of item stacks. The a_ItemStackList is modified to reflect the leftover items. If a_AllowNewStacks is set to false, only existing stacks can be topped up. If AllowNewStacks is set to true, empty slots can be used for the rest. If PrioritarySlot is set to a non-negative value, then the corresponding slot will be used first (if empty or compatible with added items). If PrioritarySlot is set to -1 (default), regular order applies. Returns the total number of items that fit.",
Notes = "Same as AddItem, but works on an entire list of item stacks. The a_ItemStackList is modified to reflect the leftover items. If a_AllowNewStacks is set to false, only existing stacks can be topped up. If AllowNewStacks is set to true, empty slots can be used for the rest. If PrioritySlot is set to a non-negative value, then the corresponding slot will be used first (if empty or compatible with added items). If PrioritySlot is set to -1 (default), regular order applies. Returns the total number of items that fit.",
},
ChangeSlotCount =
{

1
src/CMakeLists.txt
View File

@ -118,6 +118,7 @@ SET (HDRS
Inventory.h
Item.h
ItemGrid.h
LazyArray.h
LightingThread.h
LineBlockTracer.h
LinearInterpolation.h

190
src/ItemGrid.cpp
View File

@ -12,11 +12,10 @@
cItemGrid::cItemGrid(int a_Width, int a_Height) :
cItemGrid::cItemGrid(int a_Width, int a_Height):
m_Width(a_Width),
m_Height(a_Height),
m_NumSlots(a_Width * a_Height),
m_Slots(new cItem[a_Width * a_Height]),
m_Slots(a_Width * a_Height),
m_IsInTriggerListeners(false)
{
}
@ -25,19 +24,9 @@ cItemGrid::cItemGrid(int a_Width, int a_Height) :
cItemGrid::~cItemGrid()
{
delete[] m_Slots;
m_Slots = nullptr;
}
bool cItemGrid::IsValidSlotNum(int a_SlotNum) const
{
return ((a_SlotNum >= 0) && (a_SlotNum < m_NumSlots));
return ((a_SlotNum >= 0) && (a_SlotNum < m_Slots.size()));
}
@ -77,7 +66,7 @@ void cItemGrid::GetSlotCoords(int a_SlotNum, int & a_X, int & a_Y) const
if (!IsValidSlotNum(a_SlotNum))
{
LOGWARNING("%s: SlotNum out of range: %d in grid of range %d",
__FUNCTION__, a_SlotNum, m_NumSlots
__FUNCTION__, a_SlotNum, m_Slots.size()
);
a_X = -1;
a_Y = -1;
@ -93,12 +82,9 @@ void cItemGrid::GetSlotCoords(int a_SlotNum, int & a_X, int & a_Y) const
void cItemGrid::CopyFrom(const cItemGrid & a_Src)
{
ASSERT(m_Width == a_Src.m_Width);
ASSERT(m_Height == a_Src.m_Height);
for (int i = m_NumSlots - 1; i >= 0; --i)
{
m_Slots[i] = a_Src.m_Slots[i];
}
m_Width = a_Src.m_Width;
m_Height = a_Src.m_Height;
m_Slots = a_Src.m_Slots;
// The listeners are not copied
}
@ -121,11 +107,11 @@ const cItem & cItemGrid::GetSlot(int a_SlotNum) const
if (!IsValidSlotNum(a_SlotNum))
{
LOGWARNING("%s: Invalid slot number, %d out of %d slots",
__FUNCTION__, a_SlotNum, m_NumSlots
__FUNCTION__, a_SlotNum, m_Slots.size()
);
return m_Slots[0];
a_SlotNum = 0;
}
return m_Slots[a_SlotNum];
return m_Slots.GetAt(a_SlotNum);
}
@ -155,11 +141,15 @@ void cItemGrid::SetSlot(int a_SlotNum, const cItem & a_Item)
if (!IsValidSlotNum(a_SlotNum))
{
LOGWARNING("%s: Invalid slot number %d out of %d slots",
__FUNCTION__, a_SlotNum, m_NumSlots
__FUNCTION__, a_SlotNum, m_Slots.size()
);
return;
}
m_Slots[a_SlotNum] = a_Item;
if (!a_Item.IsEmpty() || m_Slots.IsStorageAllocated())
{
m_Slots[a_SlotNum] = a_Item;
}
TriggerListeners(a_SlotNum);
}
@ -190,13 +180,13 @@ void cItemGrid::EmptySlot(int a_SlotNum)
if (!IsValidSlotNum(a_SlotNum))
{
LOGWARNING("%s: Invalid slot number %d out of %d slots",
__FUNCTION__, a_SlotNum, m_NumSlots
__FUNCTION__, a_SlotNum, m_Slots.size()
);
return;
}
// Check if already empty:
if (m_Slots[a_SlotNum].IsEmpty())
if (m_Slots.GetAt(a_SlotNum).IsEmpty())
{
return;
}
@ -215,11 +205,11 @@ bool cItemGrid::IsSlotEmpty(int a_SlotNum) const
if (!IsValidSlotNum(a_SlotNum))
{
LOGWARNING("%s: Invalid slot number %d out of %d slots",
__FUNCTION__, a_SlotNum, m_NumSlots
__FUNCTION__, a_SlotNum, m_Slots.size()
);
return true;
}
return m_Slots[a_SlotNum].IsEmpty();
return m_Slots.GetAt(a_SlotNum).IsEmpty();
}
@ -237,7 +227,12 @@ bool cItemGrid::IsSlotEmpty(int a_X, int a_Y) const
void cItemGrid::Clear(void)
{
for (int i = 0; i < m_NumSlots; i++)
if (!m_Slots.IsStorageAllocated())
{
return; // Already clear
}
for (int i = 0; i < m_Slots.size(); i++)
{
m_Slots[i].Empty();
TriggerListeners(i);
@ -250,27 +245,34 @@ void cItemGrid::Clear(void)
int cItemGrid::HowManyCanFit(const cItem & a_ItemStack, bool a_AllowNewStacks)
{
char NumLeft = a_ItemStack.m_ItemCount;
int NumLeft = a_ItemStack.m_ItemCount;
int MaxStack = ItemHandler(a_ItemStack.m_ItemType)->GetMaxStackSize();
for (int i = m_NumSlots - 1; i >= 0; i--)
if (!m_Slots.IsStorageAllocated())
{
if (m_Slots[i].IsEmpty())
// Grid is empty, all slots are available
return a_AllowNewStacks ? std::min(NumLeft, m_Slots.size() * MaxStack) : 0;
}
for (const auto & Slot : m_Slots)
{
if (Slot.IsEmpty())
{
if (a_AllowNewStacks)
{
NumLeft -= MaxStack;
}
}
else if (m_Slots[i].IsEqual(a_ItemStack))
else if (Slot.IsEqual(a_ItemStack))
{
NumLeft -= MaxStack - m_Slots[i].m_ItemCount;
NumLeft -= MaxStack - Slot.m_ItemCount;
}
if (NumLeft <= 0)
{
// All items fit
return a_ItemStack.m_ItemCount;
}
} // for i - m_Slots[]
} // for Slot - m_Slots[]
return a_ItemStack.m_ItemCount - NumLeft;
}
@ -283,7 +285,7 @@ int cItemGrid::AddItemToSlot(const cItem & a_ItemStack, int a_Slot, int a_Num, i
if (!IsValidSlotNum(a_Slot))
{
LOGWARNING("%s: Invalid slot number %d out of %d slots",
__FUNCTION__, a_Slot, m_NumSlots
__FUNCTION__, a_Slot, m_Slots.size()
);
return 0;
}
@ -308,33 +310,38 @@ int cItemGrid::AddItemToSlot(const cItem & a_ItemStack, int a_Slot, int a_Num, i
int cItemGrid::AddItem(cItem & a_ItemStack, bool a_AllowNewStacks, int a_PrioritarySlot)
int cItemGrid::AddItem(cItem & a_ItemStack, bool a_AllowNewStacks, int a_PrioritySlot)
{
int NumLeft = a_ItemStack.m_ItemCount;
int MaxStack = a_ItemStack.GetMaxStackSize();
if ((a_PrioritarySlot != -1) && !IsValidSlotNum(a_PrioritarySlot))
if ((a_PrioritySlot != -1) && !IsValidSlotNum(a_PrioritySlot))
{
LOGWARNING("%s: Invalid slot number %d out of %d slots",
__FUNCTION__, a_PrioritarySlot, m_NumSlots
__FUNCTION__, a_PrioritySlot, m_Slots.size()
);
a_PrioritarySlot = -1;
a_PrioritySlot = -1;
}
// Try prioritarySlot first:
if (!a_AllowNewStacks && !m_Slots.IsStorageAllocated())
{
return 0; // No existing stacks to add to
}
// Try prioritySlot first:
if (
(a_PrioritarySlot != -1) &&
(a_PrioritySlot != -1) &&
(
m_Slots[a_PrioritarySlot].IsEmpty() ||
m_Slots[a_PrioritarySlot].IsEqual(a_ItemStack)
m_Slots[a_PrioritySlot].IsEmpty() ||
m_Slots[a_PrioritySlot].IsEqual(a_ItemStack)
)
)
{
NumLeft -= AddItemToSlot(a_ItemStack, a_PrioritarySlot, NumLeft, MaxStack);
NumLeft -= AddItemToSlot(a_ItemStack, a_PrioritySlot, NumLeft, MaxStack);
}
// Scan existing stacks:
for (int i = 0; i < m_NumSlots; i++)
for (int i = 0; i < m_Slots.size(); i++)
{
if (m_Slots[i].IsEqual(a_ItemStack))
{
@ -352,7 +359,7 @@ int cItemGrid::AddItem(cItem & a_ItemStack, bool a_AllowNewStacks, int a_Priorit
return (a_ItemStack.m_ItemCount - NumLeft);
}
for (int i = 0; i < m_NumSlots; i++)
for (int i = 0; i < m_Slots.size(); i++)
{
if (m_Slots[i].IsEmpty())
{
@ -371,12 +378,12 @@ int cItemGrid::AddItem(cItem & a_ItemStack, bool a_AllowNewStacks, int a_Priorit
int cItemGrid::AddItems(cItems & a_ItemStackList, bool a_AllowNewStacks, int a_PrioritarySlot)
int cItemGrid::AddItems(cItems & a_ItemStackList, bool a_AllowNewStacks, int a_PrioritySlot)
{
int TotalAdded = 0;
for (cItems::iterator itr = a_ItemStackList.begin(); itr != a_ItemStackList.end();)
{
int NumAdded = AddItem(*itr, a_AllowNewStacks, a_PrioritarySlot);
int NumAdded = AddItem(*itr, a_AllowNewStacks, a_PrioritySlot);
if (itr->m_ItemCount == NumAdded)
{
itr = a_ItemStackList.erase(itr);
@ -399,7 +406,12 @@ int cItemGrid::RemoveItem(const cItem & a_ItemStack)
{
int NumLeft = a_ItemStack.m_ItemCount;
for (int i = 0; i < m_NumSlots; i++)
if (!m_Slots.IsStorageAllocated())
{
return 0; // No items to remove
}
for (int i = 0; i < m_Slots.size(); i++)
{
if (NumLeft <= 0)
{
@ -433,12 +445,12 @@ int cItemGrid::ChangeSlotCount(int a_SlotNum, int a_AddToCount)
if (!IsValidSlotNum(a_SlotNum))
{
LOGWARNING("%s: Invalid slot number %d out of %d slots, ignoring the call, returning -1",
__FUNCTION__, a_SlotNum, m_NumSlots
__FUNCTION__, a_SlotNum, m_Slots.size()
);
return -1;
}
if (m_Slots[a_SlotNum].IsEmpty())
if (m_Slots.GetAt(a_SlotNum).IsEmpty())
{
// The item is empty, it's not gonna change
return 0;
@ -482,13 +494,13 @@ cItem cItemGrid::RemoveOneItem(int a_SlotNum)
if (!IsValidSlotNum(a_SlotNum))
{
LOGWARNING("%s: Invalid slot number %d out of %d slots, ignoring the call, returning empty item",
__FUNCTION__, a_SlotNum, m_NumSlots
__FUNCTION__, a_SlotNum, m_Slots.size()
);
return cItem();
}
// If the slot is empty, return an empty item
if (m_Slots[a_SlotNum].IsEmpty())
if (m_Slots.GetAt(a_SlotNum).IsEmpty())
{
return cItem();
}
@ -526,12 +538,17 @@ cItem cItemGrid::RemoveOneItem(int a_X, int a_Y)
int cItemGrid::HowManyItems(const cItem & a_Item)
{
int res = 0;
for (int i = 0; i < m_NumSlots; i++)
if (!m_Slots.IsStorageAllocated())
{
if (m_Slots[i].IsEqual(a_Item))
return 0;
}
int res = 0;
for (auto & Slot : m_Slots)
{
if (Slot.IsEqual(a_Item))
{
res += m_Slots[i].m_ItemCount;
res += Slot.m_ItemCount;
}
}
return res;
@ -571,9 +588,9 @@ int cItemGrid::GetFirstUsedSlot(void) const
int cItemGrid::GetLastEmptySlot(void) const
{
for (int i = m_NumSlots - 1; i >= 0; i--)
for (int i = m_Slots.size() - 1; i >= 0; i--)
{
if (m_Slots[i].IsEmpty())
if (m_Slots.GetAt(i).IsEmpty())
{
return i;
}
@ -587,9 +604,14 @@ int cItemGrid::GetLastEmptySlot(void) const
int cItemGrid::GetLastUsedSlot(void) const
{
for (int i = m_NumSlots - 1; i >= 0; i--)
if (!m_Slots.IsStorageAllocated())
{
if (!m_Slots[i].IsEmpty())
return -1; // No slots are used
}
for (int i = m_Slots.size() - 1; i >= 0; i--)
{
if (!m_Slots.GetAt(i).IsEmpty())
{
return i;
}
@ -606,14 +628,14 @@ int cItemGrid::GetNextEmptySlot(int a_StartFrom) const
if ((a_StartFrom != -1) && !IsValidSlotNum(a_StartFrom))
{
LOGWARNING("%s: Invalid slot number %d out of %d slots",
__FUNCTION__, a_StartFrom, m_NumSlots
__FUNCTION__, a_StartFrom, m_Slots.size()
);
a_StartFrom = -1;
}
for (int i = a_StartFrom + 1; i < m_NumSlots; i++)
for (int i = a_StartFrom + 1; i < m_Slots.size(); i++)
{
if (m_Slots[i].IsEmpty())
if (m_Slots.GetAt(i).IsEmpty())
{
return i;
}
@ -630,14 +652,19 @@ int cItemGrid::GetNextUsedSlot(int a_StartFrom) const
if ((a_StartFrom != -1) && !IsValidSlotNum(a_StartFrom))
{
LOGWARNING("%s: Invalid slot number %d out of %d slots",
__FUNCTION__, a_StartFrom, m_NumSlots
__FUNCTION__, a_StartFrom, m_Slots.size()
);
a_StartFrom = -1;
}
for (int i = a_StartFrom + 1; i < m_NumSlots; i++)
if (!m_Slots.IsStorageAllocated())
{
if (!m_Slots[i].IsEmpty())
return -1; // No slots are used
}
for (int i = a_StartFrom + 1; i < m_Slots.size(); i++)
{
if (!m_Slots.GetAt(i).IsEmpty())
{
return i;
}
@ -651,13 +678,18 @@ int cItemGrid::GetNextUsedSlot(int a_StartFrom) const
void cItemGrid::CopyToItems(cItems & a_Items) const
{
for (int i = 0; i < m_NumSlots; i++)
if (!m_Slots.IsStorageAllocated())
{
if (!m_Slots[i].IsEmpty())
return; // Nothing to copy
}
for (const auto & Slot : m_Slots)
{
if (!Slot.IsEmpty())
{
a_Items.push_back(m_Slots[i]);
a_Items.push_back(Slot);
}
} // for i - m_Slots[]
} // for Slot - m_Slots[]
}
@ -668,9 +700,15 @@ bool cItemGrid::DamageItem(int a_SlotNum, short a_Amount)
{
if (!IsValidSlotNum(a_SlotNum))
{
LOGWARNING("%s: invalid slot number %d out of %d slots, ignoring.", __FUNCTION__, a_SlotNum, m_NumSlots);
LOGWARNING("%s: invalid slot number %d out of %d slots, ignoring.", __FUNCTION__, a_SlotNum, m_Slots.size());
return false;
}
if (!m_Slots.IsStorageAllocated())
{
return false; // Nothing to damage
}
return m_Slots[a_SlotNum].DamageItem(a_Amount);
}
@ -736,7 +774,7 @@ void cItemGrid::GenerateRandomLootWithBooks(const cLootProbab * a_LootProbabs, s
break;
}
} // for j - a_LootProbabs[]
SetSlot(Rnd % m_NumSlots, CurrentLoot);
SetSlot(Rnd % m_Slots.size(), CurrentLoot);
} // for i - NumSlots
}

21
src/ItemGrid.h
View File

@ -9,6 +9,7 @@
#pragma once
#include "Item.h"
#include "LazyArray.h"
@ -33,12 +34,10 @@ public:
cItemGrid(int a_Width, int a_Height);
~cItemGrid();
// tolua_begin
int GetWidth (void) const { return m_Width; }
int GetHeight (void) const { return m_Height; }
int GetNumSlots(void) const { return m_NumSlots; }
int GetNumSlots(void) const { return m_Slots.size(); }
/** Converts XY coords into slot number; returns -1 on invalid coords */
int GetSlotNum(int a_X, int a_Y) const;
@ -49,7 +48,6 @@ public:
void GetSlotCoords(int a_SlotNum, int & a_X, int & a_Y) const;
/** Copies all items from a_Src to this grid.
Both grids must be the same size (asserts).
Doesn't copy the listeners. */
void CopyFrom(const cItemGrid & a_Src);
@ -84,21 +82,21 @@ public:
/** Adds as many items out of a_ItemStack as can fit.
If a_AllowNewStacks is set to false, only existing stacks can be topped up;
If a_AllowNewStacks is set to true, empty slots can be used for the rest.
If a_PrioritarySlot is set to a positive value, then the corresponding slot will be used first (if empty or compatible with added items).
If a_PrioritarySlot is set to -1, regular order applies.
If a_PrioritySlot is set to a positive value, then the corresponding slot will be used first (if empty or compatible with added items).
If a_PrioritySlot is set to -1, regular order applies.
Returns the number of items that fit.
*/
int AddItem(cItem & a_ItemStack, bool a_AllowNewStacks = true, int a_PrioritarySlot = -1);
int AddItem(cItem & a_ItemStack, bool a_AllowNewStacks = true, int a_PrioritySlot = -1);
/** Same as AddItem, but works on an entire list of item stacks.
The a_ItemStackList is modified to reflect the leftover items.
If a_AllowNewStacks is set to false, only existing stacks can be topped up;
If a_AllowNewStacks is set to true, empty slots can be used for the rest.
If a_PrioritarySlot is set to a positive value, then the corresponding slot will be used first (if empty or compatible with added items).
If a_PrioritarySlot is set to -1, regular order applies.
If a_PrioritySlot is set to a positive value, then the corresponding slot will be used first (if empty or compatible with added items).
If a_PrioritySlot is set to -1, regular order applies.
Returns the total number of items that fit.
*/
int AddItems(cItems & a_ItemStackList, bool a_AllowNewStacks = true, int a_PrioritarySlot = -1);
int AddItems(cItems & a_ItemStackList, bool a_AllowNewStacks = true, int a_PrioritySlot = -1);
/** Removes the specified item from the grid, as many as possible, up to a_ItemStack.m_ItemCount.
Returns the number of items that were removed. */
@ -185,8 +183,7 @@ public:
protected:
int m_Width;
int m_Height;
int m_NumSlots; // m_Width * m_Height, for easier validity checking in the access functions
cItem * m_Slots; // x + m_Width * y
cLazyArray<cItem> m_Slots;
cListeners m_Listeners; ///< Listeners which should be notified on slot changes; the pointers are not owned by this object
cCriticalSection m_CSListeners; ///< CS that guards the m_Listeners against multi-thread access

134
src/LazyArray.h Normal file
View File

@ -0,0 +1,134 @@
#pragma once
/** A dynamic array that defers allocation to the first modifying access.
Const references from the array before allocation will all be to the same default constructed value.
It is therefore important that default constructed values are indistinguishable from each other. */
template <typename T>
class cLazyArray
{
static_assert((!std::is_reference<T>::value && !std::is_array<T>::value),
"cLazyArray<T>: T must be a value type");
static_assert(std::is_default_constructible<T>::value,
"cLazyArray<T>: T must be default constructible");
public:
using value_type = T;
using pointer = T *;
using const_pointer = const T *;
using reference = T &;
using const_reference = const T &;
using size_type = int;
using iterator = pointer;
using const_iterator = const_pointer;
cLazyArray(size_type a_Size) NOEXCEPT:
m_Size{ a_Size }
{
ASSERT(a_Size > 0);
}
cLazyArray(const cLazyArray & a_Other):
m_Size{ a_Other.m_Size }
{
if (a_Other.IsStorageAllocated())
{
// Note that begin() will allocate the array to copy into
std::copy(a_Other.begin(), a_Other.end(), begin());
}
}
cLazyArray(cLazyArray && a_Other) NOEXCEPT:
m_Array{ std::move(a_Other.m_Array) },
m_Size{ a_Other.m_Size }
{
}
cLazyArray & operator = (const cLazyArray & a_Other)
{
cLazyArray(a_Other).swap(*this);
return *this;
}
cLazyArray & operator = (cLazyArray && a_Other) NOEXCEPT
{
m_Array = std::move(a_Other.m_Array);
m_Size = a_Other.m_Size;
return *this;
}
T & operator [] (size_type a_Idx)
{
ASSERT((0 <= a_Idx) && (a_Idx < m_Size));
return data()[a_Idx];
}
const T & operator [] (size_type a_Idx) const
{
return GetAt(a_Idx);
}
// STL style interface
const_iterator cbegin() const { return data(); }
iterator begin() { return data(); }
const_iterator begin() const { return cbegin(); }
const_iterator cend() const { return data() + m_Size; }
iterator end() { return data() + m_Size; }
const_iterator end() const { return cend(); }
size_type size() const NOEXCEPT { return m_Size; }
const T * data() const
{
if (m_Array == nullptr)
{
m_Array.reset(new T[m_Size]);
}
return m_Array.get();
}
T * data()
{
static_assert(!std::is_const<typename decltype(m_Array)::element_type>::value, "");
const cLazyArray * const_this = this;
return const_cast<T *>(const_this->data());
}
void swap(cLazyArray & a_Other) NOEXCEPT
{
std::swap(m_Array, a_Other.m_Array);
std::swap(m_Size, a_Other.m_Size);
}
friend void swap(cLazyArray & a_Lhs, cLazyArray & a_Rhs) NOEXCEPT
{
a_Lhs.swap(a_Rhs);
}
// Extra functions to help avoid allocation
/** A const view of an element of the array. Never causes the array to allocate. */
const T & GetAt(size_type a_Idx) const
{
ASSERT((0 <= a_Idx) && (a_Idx < m_Size));
if (IsStorageAllocated())
{
return data()[a_Idx];
}
else
{
static const T DefaultValue;
return DefaultValue;
}
}
/** Returns true if the array has already been allocated. */
bool IsStorageAllocated() const NOEXCEPT { return (m_Array != nullptr); }
private:
// Mutable so const data() can allocate the array
mutable std::unique_ptr<T[]> m_Array;
size_type m_Size;
};