1 /* $Id$ */

     2 

     3 #ifndef  BLOB_HPP

     4 #define  BLOB_HPP

     5 

     6 template <class Titem_>

     7 FORCEINLINE void MemCpyT(Titem_* d, const Titem_* s, int num_items = 1)

     8 {

     9 	memcpy(d, s, num_items * sizeof(Titem_));

    10 }

    11 

    12 

    13 /** Base class for simple binary blobs.

    14     Item is byte.

    15 		The word 'simple' means:

    16 		  - no configurable allocator type (always made from heap)

    17 			- no smart deallocation - deallocation must be called from the same

    18 			    module (DLL) where the blob was allocated

    19 			- no configurable allocation policy (how big blocks should be allocated)

    20 			- no extra ownership policy (i.e. 'copy on write') when blob is copied

    21 			- no thread synchronization at all */

    22 class CBlobBaseSimple {

    23 protected:

    24 	struct CHdr	{

    25 		int    m_size;      // actual blob size in bytes

    26 		int    m_max_size;  // maximum (allocated) size in bytes

    27 	};

    28 

    29 	union {

    30 		int8   *m_pData;

    31 		CHdr   *m_pHdr_1;

    32 	} ptr_u;

    33 

    34 public:

    35 	ST_CONST(int, Ttail_reserve = 4); // four extra bytes will be always allocated and zeroed at the end

    36 

    37 	FORCEINLINE CBlobBaseSimple() { InitEmpty(); }

    38 	FORCEINLINE CBlobBaseSimple(const CBlobBaseSimple& src)

    39 	{

    40 		InitEmpty();

    41 		AppendRaw(src);

    42 	}

    43 	FORCEINLINE ~CBlobBaseSimple() { Free(); }

    44 protected:

    45 	FORCEINLINE void InitEmpty() { static CHdr hdrEmpty[] = {{0, 0}, {0, 0}}; ptr_u.m_pHdr_1 = &hdrEmpty[1]; }

    46 	FORCEINLINE void Init(CHdr* hdr) { ptr_u.m_pHdr_1 = &hdr[1]; }

    47 	FORCEINLINE CHdr& Hdr() { return ptr_u.m_pHdr_1[-1]; }

    48 	FORCEINLINE const CHdr& Hdr() const { return ptr_u.m_pHdr_1[-1]; }

    49 	FORCEINLINE int& RawSizeRef() { return Hdr().m_size; };

    50 

    51 public:

    52 	FORCEINLINE bool IsEmpty() const { return RawSize() == 0; }

    53 	FORCEINLINE int RawSize() const { return Hdr().m_size; };

    54 	FORCEINLINE int MaxRawSize() const { return Hdr().m_max_size; };

    55 	FORCEINLINE int8* RawData() { return ptr_u.m_pData; }

    56 	FORCEINLINE const int8* RawData() const { return ptr_u.m_pData; }

    57 	FORCEINLINE uint32 Crc32() const {return CCrc32::Calc(RawData(), RawSize());}

    58 	FORCEINLINE void Clear() { RawSizeRef() = 0; }

    59 	FORCEINLINE void Free() { if (MaxRawSize() > 0) {RawFree(&Hdr()); InitEmpty();} }

    60 	FORCEINLINE void CopyFrom(const CBlobBaseSimple& src) { Clear(); AppendRaw(src); }

    61 	FORCEINLINE void MoveFrom(CBlobBaseSimple& src) { Free(); ptr_u.m_pData = src.ptr_u.m_pData; src.InitEmpty(); }

    62 	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; }

    63 

    64 	FORCEINLINE void AppendRaw(int8 *p, int num_bytes)

    65 	{

    66 		assert(p != NULL);

    67 		if (num_bytes > 0) {

    68 			memcpy(GrowRawSize(num_bytes), p, num_bytes);

    69 		}	else {

    70 			assert(num_bytes >= 0);

    71 		}

    72 	}

    73 

    74 	FORCEINLINE void AppendRaw(const CBlobBaseSimple& src)

    75 	{

    76 		if (!src.IsEmpty())

    77 			memcpy(GrowRawSize(src.RawSize()), src.RawData(), src.RawSize());

    78 	}

    79 

    80 	/** Reallocate if there is no free space for num_bytes bytes.

    81 	    @return pointer to the new data to be added */

    82 	FORCEINLINE int8* MakeRawFreeSpace(int num_bytes)

    83 	{

    84 		assert(num_bytes >= 0);

    85 		int new_size = RawSize() + num_bytes;

    86 		if (new_size > MaxRawSize()) SmartAlloc(new_size);

    87 		FixTail();

    88 		return ptr_u.m_pData + RawSize();

    89 	}

    90 

    91 	/** Increase RawSize() by num_bytes.

    92 	@return pointer to the new data added */

    93 	FORCEINLINE int8* GrowRawSize(int num_bytes)

    94 	{

    95 		int8* pNewData = MakeRawFreeSpace(num_bytes);

    96 		RawSizeRef() += num_bytes;

    97 		return pNewData;

    98 	}

    99 

   100 	/** Decrease RawSize() by num_bytes. */

   101 	FORCEINLINE void ReduceRawSize(int num_bytes)

   102 	{

   103 		if (MaxRawSize() > 0 && num_bytes > 0) {

   104 			assert(num_bytes <= RawSize());

   105 			if (num_bytes < RawSize()) RawSizeRef() -= num_bytes;

   106 			else RawSizeRef() = 0;

   107 		}

   108 	}

   109 	/** reallocate blob data if needed */

   110 	void SmartAlloc(int new_size)

   111 	{

   112 		int old_max_size = MaxRawSize();

   113 		if (old_max_size >= new_size) return;

   114 		// calculate minimum block size we need to allocate

   115 		int min_alloc_size = sizeof(CHdr) + new_size + Ttail_reserve;

   116 		// ask allocation policy for some reasonable block size

   117 		int alloc_size = AllocPolicy(min_alloc_size);

   118 		// allocate new block

   119 		CHdr* pNewHdr =	RawAlloc(alloc_size);

   120 		// setup header

   121 		pNewHdr->m_size = RawSize();

   122 		pNewHdr->m_max_size = alloc_size - (sizeof(CHdr) + Ttail_reserve);

   123 		// copy existing data

   124 		if (RawSize() > 0)

   125 			memcpy(pNewHdr + 1, ptr_u.m_pData, pNewHdr->m_size);

   126 		// replace our block with new one

   127 		CHdr* pOldHdr = &Hdr();

   128 		Init(pNewHdr);

   129 		if (old_max_size > 0)

   130 			RawFree(pOldHdr);

   131 	}

   132 	/** simple allocation policy - can be optimized later */

   133 	FORCEINLINE static int AllocPolicy(int min_alloc)

   134 	{

   135 		if (min_alloc < (1 << 9)) {

   136 			if (min_alloc < (1 << 5)) return (1 << 5);

   137 			return (min_alloc < (1 << 7)) ? (1 << 7) : (1 << 9);

   138 		}

   139 		if (min_alloc < (1 << 15)) {

   140 			if (min_alloc < (1 << 11)) return (1 << 11);

   141 			return (min_alloc < (1 << 13)) ? (1 << 13) : (1 << 15);

   142 		}

   143 		if (min_alloc < (1 << 20)) {

   144 			if (min_alloc < (1 << 17)) return (1 << 17);

   145 			return (min_alloc < (1 << 19)) ? (1 << 19) : (1 << 20);

   146 		}

   147 		min_alloc = (min_alloc | ((1 << 20) - 1)) + 1;

   148 		return min_alloc;

   149 	}

   150 

   151 	/** all allocation should happen here */

   152 	static FORCEINLINE CHdr* RawAlloc(int num_bytes) { return (CHdr*)malloc(num_bytes); }

   153 	/** all deallocations should happen here */

   154 	static FORCEINLINE void RawFree(CHdr* p) { free(p); }

   155 	/** fixing the four bytes at the end of blob data - useful when blob is used to hold string */

   156 	FORCEINLINE void FixTail()

   157 	{

   158 		if (MaxRawSize() > 0) {

   159 			int8 *p = &ptr_u.m_pData[RawSize()];

   160 			for (int i = 0; i < Ttail_reserve; i++) p[i] = 0;

   161 		}

   162 	}

   163 };

   164 

   165 template <class Titem_, class Tbase_ = CBlobBaseSimple>

   166 class CBlobT : public CBlobBaseSimple {

   167 	// make template arguments public:

   168 public:

   169 	typedef Titem_ Titem;

   170 	typedef Tbase_ Tbase;

   171 

   172 	ST_CONST(int, Titem_size = sizeof(Titem));

   173 

   174 	FORCEINLINE CBlobT() : Tbase() {}

   175 	FORCEINLINE CBlobT(const Tbase& src) : Tbase(src) {assert((RawSize() % Titem_size) == 0);}

   176 	FORCEINLINE ~CBlobT() { Free(); }

   177 	FORCEINLINE void CheckIdx(int idx) { assert(idx >= 0); assert(idx < Size()); }

   178 	FORCEINLINE Titem* Data() { return (Titem*)RawData(); }

   179 	FORCEINLINE const Titem* Data() const { return (const Titem*)RawData(); }

   180 	FORCEINLINE Titem* Data(int idx) { CheckIdx(idx); return (Data() + idx); }

   181 	FORCEINLINE const Titem* Data(int idx) const { CheckIdx(idx); return (Data() + idx); }

   182 	FORCEINLINE int Size() const { return (RawSize() / Titem_size); }

   183 	FORCEINLINE void Free()

   184 	{

   185 		assert((RawSize() % Titem_size) == 0);

   186 		int old_size = Size();

   187 		if (old_size > 0) {

   188 			// destroy removed items;

   189 			Titem* pI_last_to_destroy = Data(0);

   190 			for (Titem* pI = Data(old_size - 1); pI >= pI_last_to_destroy; pI--) pI->~Titem_();

   191 		}

   192 		Tbase::Free();

   193 	}

   194 	FORCEINLINE Titem* GrowSizeNC(int num_items) { return (Titem*)GrowRawSize(num_items * Titem_size); }

   195 	FORCEINLINE Titem* GrowSizeC(int num_items)

   196 	{

   197 		Titem* pI = GrowSizeNC(num_items);

   198 		for (int i = num_items; i > 0; i--, pI++) new (pI) Titem();

   199 	}

   200 	FORCEINLINE void ReduceSize(int num_items)

   201 	{

   202 		assert((RawSize() % Titem_size) == 0);

   203 		int old_size = Size();

   204 		assert(num_items <= old_size);

   205 		int new_size = (num_items <= old_size) ? (old_size - num_items) : 0;

   206 		// destroy removed items;

   207 		Titem* pI_last_to_destroy = Data(new_size);

   208 		for (Titem* pI = Data(old_size - 1); pI >= pI_last_to_destroy; pI--) pI->~Titem();

   209 		// remove them

   210 		ReduceRawSize(num_items * Titem_size);

   211 	}

   212 	FORCEINLINE Titem* AppendNew()

   213 	{

   214 		Titem& dst = *GrowSizeNC(1);

   215 		Titem* pNewItem = new (&dst) Titem();

   216 		return pNewItem;

   217 	}

   218 	FORCEINLINE Titem* Append(const Titem& src)

   219 	{

   220 		Titem& dst = *GrowSizeNC(1);

   221 		Titem* pNewItem = new (&dst) Titem(src);

   222 		return pNewItem;

   223 	}

   224 	FORCEINLINE Titem* Append(const Titem* pSrc, int num_items)

   225 	{

   226 		Titem* pDst = GrowSizeNC(num_items);

   227 		Titem* pDstOrg = pDst;

   228 		Titem* pDstEnd = pDst + num_items;

   229 		while (pDst < pDstEnd) new (pDst++) Titem(*(pSrc++));

   230 		return pDstOrg;

   231 	}

   232 	FORCEINLINE void RemoveBySwap(int idx)

   233 	{

   234 		CheckIdx(idx);

   235 		// destroy removed item

   236 		Titem* pRemoved = Data(idx);

   237 		RemoveBySwap(pRemoved);

   238 	}

   239 	FORCEINLINE void RemoveBySwap(Titem* pItem)

   240 	{

   241 		Titem* pLast = Data(Size() - 1);

   242 		assert(pItem >= Data() && pItem <= pLast);

   243 		// move last item to its new place

   244 		if (pItem != pLast) {

   245 			pItem->~Titem_();

   246 			new (pItem) Titem_(*pLast);

   247 		}

   248 		// destroy the last item

   249 		pLast->~Titem_();

   250 		// and reduce the raw blob size

   251 		ReduceRawSize(Titem_size);

   252 	}

   253 	FORCEINLINE Titem* MakeFreeSpace(int num_items) { return (Titem*)MakeRawFreeSpace(num_items * Titem_size); }

   254 };

   255 

   256 // simple string implementation

   257 struct CStrA : public CBlobT<char>

   258 {

   259 	typedef CBlobT<char> base;

   260 	CStrA(const char* str = NULL) {Append(str);}

   261 	FORCEINLINE CStrA(const CBlobBaseSimple& src) : base(src) {}

   262 	void Append(const char* str) {if (str != NULL && str[0] != '\0') base::Append(str, (int)strlen(str));}

   263 };

   264 

   265 #endif /* BLOB_HPP */

   266