OpenTTD-patches/yapf/blob.hpp

266 lines
8.6 KiB
C++

/* $Id$ */
#ifndef BLOB_HPP
#define BLOB_HPP
template <class Titem_>
FORCEINLINE void MemCpyT(Titem_* d, const Titem_* s, int num_items = 1)
{
memcpy(d, s, num_items * sizeof(Titem_));
}
/** Base class for simple binary blobs.
* Item is byte.
* The word 'simple' means:
* - no configurable allocator type (always made from heap)
* - no smart deallocation - deallocation must be called from the same
* module (DLL) where the blob was allocated
* - no configurable allocation policy (how big blocks should be allocated)
* - no extra ownership policy (i.e. 'copy on write') when blob is copied
* - no thread synchronization at all */
class CBlobBaseSimple {
protected:
struct CHdr {
int m_size; // actual blob size in bytes
int m_max_size; // maximum (allocated) size in bytes
};
union {
int8 *m_pData;
CHdr *m_pHdr_1;
} ptr_u;
public:
static const int Ttail_reserve = 4; // four extra bytes will be always allocated and zeroed at the end
FORCEINLINE CBlobBaseSimple() { InitEmpty(); }
FORCEINLINE CBlobBaseSimple(const CBlobBaseSimple& src)
{
InitEmpty();
AppendRaw(src);
}
FORCEINLINE ~CBlobBaseSimple() { Free(); }
protected:
FORCEINLINE void InitEmpty() { static CHdr hdrEmpty[] = {{0, 0}, {0, 0}}; ptr_u.m_pHdr_1 = &hdrEmpty[1]; }
FORCEINLINE void Init(CHdr* hdr) { ptr_u.m_pHdr_1 = &hdr[1]; }
FORCEINLINE CHdr& Hdr() { return ptr_u.m_pHdr_1[-1]; }
FORCEINLINE const CHdr& Hdr() const { return ptr_u.m_pHdr_1[-1]; }
FORCEINLINE int& RawSizeRef() { return Hdr().m_size; };
public:
FORCEINLINE bool IsEmpty() const { return RawSize() == 0; }
FORCEINLINE int RawSize() const { return Hdr().m_size; };
FORCEINLINE int MaxRawSize() const { return Hdr().m_max_size; };
FORCEINLINE int8* RawData() { return ptr_u.m_pData; }
FORCEINLINE const int8* RawData() const { return ptr_u.m_pData; }
FORCEINLINE uint32 Crc32() const {return CCrc32::Calc(RawData(), RawSize());}
FORCEINLINE void Clear() { RawSizeRef() = 0; }
FORCEINLINE void Free() { if (MaxRawSize() > 0) {RawFree(&Hdr()); InitEmpty();} }
FORCEINLINE void CopyFrom(const CBlobBaseSimple& src) { Clear(); AppendRaw(src); }
FORCEINLINE void MoveFrom(CBlobBaseSimple& src) { Free(); ptr_u.m_pData = src.ptr_u.m_pData; src.InitEmpty(); }
FORCEINLINE void Swap(CBlobBaseSimple& src) { int8 *tmp = ptr_u.m_pData; ptr_u.m_pData = src.ptr_u.m_pData; src.ptr_u.m_pData = tmp; }
FORCEINLINE void AppendRaw(int8 *p, int num_bytes)
{
assert(p != NULL);
if (num_bytes > 0) {
memcpy(GrowRawSize(num_bytes), p, num_bytes);
} else {
assert(num_bytes >= 0);
}
}
FORCEINLINE void AppendRaw(const CBlobBaseSimple& src)
{
if (!src.IsEmpty())
memcpy(GrowRawSize(src.RawSize()), src.RawData(), src.RawSize());
}
/** Reallocate if there is no free space for num_bytes bytes.
* @return pointer to the new data to be added */
FORCEINLINE int8* MakeRawFreeSpace(int num_bytes)
{
assert(num_bytes >= 0);
int new_size = RawSize() + num_bytes;
if (new_size > MaxRawSize()) SmartAlloc(new_size);
FixTail();
return ptr_u.m_pData + RawSize();
}
/** Increase RawSize() by num_bytes.
* @return pointer to the new data added */
FORCEINLINE int8* GrowRawSize(int num_bytes)
{
int8* pNewData = MakeRawFreeSpace(num_bytes);
RawSizeRef() += num_bytes;
return pNewData;
}
/** Decrease RawSize() by num_bytes. */
FORCEINLINE void ReduceRawSize(int num_bytes)
{
if (MaxRawSize() > 0 && num_bytes > 0) {
assert(num_bytes <= RawSize());
if (num_bytes < RawSize()) RawSizeRef() -= num_bytes;
else RawSizeRef() = 0;
}
}
/** reallocate blob data if needed */
void SmartAlloc(int new_size)
{
int old_max_size = MaxRawSize();
if (old_max_size >= new_size) return;
// calculate minimum block size we need to allocate
int min_alloc_size = sizeof(CHdr) + new_size + Ttail_reserve;
// ask allocation policy for some reasonable block size
int alloc_size = AllocPolicy(min_alloc_size);
// allocate new block
CHdr* pNewHdr = RawAlloc(alloc_size);
// setup header
pNewHdr->m_size = RawSize();
pNewHdr->m_max_size = alloc_size - (sizeof(CHdr) + Ttail_reserve);
// copy existing data
if (RawSize() > 0)
memcpy(pNewHdr + 1, ptr_u.m_pData, pNewHdr->m_size);
// replace our block with new one
CHdr* pOldHdr = &Hdr();
Init(pNewHdr);
if (old_max_size > 0)
RawFree(pOldHdr);
}
/** simple allocation policy - can be optimized later */
FORCEINLINE static int AllocPolicy(int min_alloc)
{
if (min_alloc < (1 << 9)) {
if (min_alloc < (1 << 5)) return (1 << 5);
return (min_alloc < (1 << 7)) ? (1 << 7) : (1 << 9);
}
if (min_alloc < (1 << 15)) {
if (min_alloc < (1 << 11)) return (1 << 11);
return (min_alloc < (1 << 13)) ? (1 << 13) : (1 << 15);
}
if (min_alloc < (1 << 20)) {
if (min_alloc < (1 << 17)) return (1 << 17);
return (min_alloc < (1 << 19)) ? (1 << 19) : (1 << 20);
}
min_alloc = (min_alloc | ((1 << 20) - 1)) + 1;
return min_alloc;
}
/** all allocation should happen here */
static FORCEINLINE CHdr* RawAlloc(int num_bytes) { return (CHdr*)malloc(num_bytes); }
/** all deallocations should happen here */
static FORCEINLINE void RawFree(CHdr* p) { free(p); }
/** fixing the four bytes at the end of blob data - useful when blob is used to hold string */
FORCEINLINE void FixTail()
{
if (MaxRawSize() > 0) {
int8 *p = &ptr_u.m_pData[RawSize()];
for (int i = 0; i < Ttail_reserve; i++) p[i] = 0;
}
}
};
template <class Titem_, class Tbase_ = CBlobBaseSimple>
class CBlobT : public CBlobBaseSimple {
// make template arguments public:
public:
typedef Titem_ Titem;
typedef Tbase_ Tbase;
static const int Titem_size = sizeof(Titem);
FORCEINLINE CBlobT() : Tbase() {}
FORCEINLINE CBlobT(const Tbase& src) : Tbase(src) {assert((RawSize() % Titem_size) == 0);}
FORCEINLINE ~CBlobT() { Free(); }
FORCEINLINE void CheckIdx(int idx) { assert(idx >= 0); assert(idx < Size()); }
FORCEINLINE Titem* Data() { return (Titem*)RawData(); }
FORCEINLINE const Titem* Data() const { return (const Titem*)RawData(); }
FORCEINLINE Titem* Data(int idx) { CheckIdx(idx); return (Data() + idx); }
FORCEINLINE const Titem* Data(int idx) const { CheckIdx(idx); return (Data() + idx); }
FORCEINLINE int Size() const { return (RawSize() / Titem_size); }
FORCEINLINE void Free()
{
assert((RawSize() % Titem_size) == 0);
int old_size = Size();
if (old_size > 0) {
// destroy removed items;
Titem* pI_last_to_destroy = Data(0);
for (Titem* pI = Data(old_size - 1); pI >= pI_last_to_destroy; pI--) pI->~Titem_();
}
Tbase::Free();
}
FORCEINLINE Titem* GrowSizeNC(int num_items) { return (Titem*)GrowRawSize(num_items * Titem_size); }
FORCEINLINE Titem* GrowSizeC(int num_items)
{
Titem* pI = GrowSizeNC(num_items);
for (int i = num_items; i > 0; i--, pI++) new (pI) Titem();
}
FORCEINLINE void ReduceSize(int num_items)
{
assert((RawSize() % Titem_size) == 0);
int old_size = Size();
assert(num_items <= old_size);
int new_size = (num_items <= old_size) ? (old_size - num_items) : 0;
// destroy removed items;
Titem* pI_last_to_destroy = Data(new_size);
for (Titem* pI = Data(old_size - 1); pI >= pI_last_to_destroy; pI--) pI->~Titem();
// remove them
ReduceRawSize(num_items * Titem_size);
}
FORCEINLINE Titem* AppendNew()
{
Titem& dst = *GrowSizeNC(1);
Titem* pNewItem = new (&dst) Titem();
return pNewItem;
}
FORCEINLINE Titem* Append(const Titem& src)
{
Titem& dst = *GrowSizeNC(1);
Titem* pNewItem = new (&dst) Titem(src);
return pNewItem;
}
FORCEINLINE Titem* Append(const Titem* pSrc, int num_items)
{
Titem* pDst = GrowSizeNC(num_items);
Titem* pDstOrg = pDst;
Titem* pDstEnd = pDst + num_items;
while (pDst < pDstEnd) new (pDst++) Titem(*(pSrc++));
return pDstOrg;
}
FORCEINLINE void RemoveBySwap(int idx)
{
CheckIdx(idx);
// destroy removed item
Titem* pRemoved = Data(idx);
RemoveBySwap(pRemoved);
}
FORCEINLINE void RemoveBySwap(Titem* pItem)
{
Titem* pLast = Data(Size() - 1);
assert(pItem >= Data() && pItem <= pLast);
// move last item to its new place
if (pItem != pLast) {
pItem->~Titem_();
new (pItem) Titem_(*pLast);
}
// destroy the last item
pLast->~Titem_();
// and reduce the raw blob size
ReduceRawSize(Titem_size);
}
FORCEINLINE Titem* MakeFreeSpace(int num_items) { return (Titem*)MakeRawFreeSpace(num_items * Titem_size); }
};
// simple string implementation
struct CStrA : public CBlobT<char>
{
typedef CBlobT<char> base;
CStrA(const char* str = NULL) {Append(str);}
FORCEINLINE CStrA(const CBlobBaseSimple& src) : base(src) {}
void Append(const char* str) {if (str != NULL && str[0] != '\0') base::Append(str, (int)strlen(str));}
};
#endif /* BLOB_HPP */