KUDr@5633: /* $Id$ */
KUDr@5633: 
belugas@6481: /** @file blob.hpp */
belugas@6481: 
KUDr@5633: #ifndef  BLOB_HPP
KUDr@5633: #define  BLOB_HPP
KUDr@5633: 
KUDr@5633: /** Type-safe version of memcpy().
KUDr@5633:  * @param d destination buffer
KUDr@5633:  * @param s source buffer
KUDr@5633:  * @param num_items number of items to be copied (!not number of bytes!) */
KUDr@5633: template <class Titem_>
KUDr@5633: FORCEINLINE void MemCpyT(Titem_* d, const Titem_* s, int num_items = 1)
KUDr@5633: {
KUDr@5633: 	memcpy(d, s, num_items * sizeof(Titem_));
KUDr@5633: }
KUDr@5633: 
KUDr@5633: 
KUDr@5633: /** Base class for simple binary blobs.
KUDr@5633:  *  Item is byte.
KUDr@5633:  *  The word 'simple' means:
KUDr@5633:  *    - no configurable allocator type (always made from heap)
KUDr@5633:  *    - no smart deallocation - deallocation must be called from the same
KUDr@5633:  *        module (DLL) where the blob was allocated
KUDr@5633:  *    - no configurable allocation policy (how big blocks should be allocated)
KUDr@5633:  *    - no extra ownership policy (i.e. 'copy on write') when blob is copied
KUDr@5633:  *    - no thread synchronization at all
KUDr@5633:  *
KUDr@5633:  *  Internal member layout:
KUDr@5633:  *  1. The only class member is pointer to the first item (see union ptr_u).
KUDr@5633:  *  2. Allocated block contains the blob header (see CHdr) followed by the raw byte data.
KUDr@5633:  *     Always, when it allocates memory the allocated size is:
KUDr@5633:  *                                                      sizeof(CHdr) + <data capacity>
KUDr@5633:  *  3. Two 'virtual' members (m_size and m_max_size) are stored in the CHdr at beginning
KUDr@5633:  *     of the alloated block.
KUDr@5633:  *  4. The pointer (in ptr_u) points behind the header (to the first data byte).
KUDr@5633:  *     When memory block is allocated, the sizeof(CHdr) it added to it.
KUDr@5633:  *  5. Benefits of this layout:
KUDr@5633:  *     - items are accessed in the simplest possible way - just dereferencing the pointer,
KUDr@5633:  *       which is good for performance (assuming that data are accessed most often).
KUDr@5633:  *     - sizeof(blob) is the same as the size of any other pointer
KUDr@5633:  *  6. Drawbacks of this layout:
KUDr@5633:  *     - the fact, that pointer to the alocated block is adjusted by sizeof(CHdr) before
KUDr@5633:  *       it is stored can lead to several confusions:
KUDr@5633:  *         - it is not common pattern so the implementation code is bit harder to read
KUDr@5633:  *         - valgrind can generate warning that allocated block is lost (not accessible)
KUDr@5633:  * */
KUDr@5633: class CBlobBaseSimple {
KUDr@5633: protected:
KUDr@5633: 	/** header of the allocated memory block */
KUDr@5633: 	struct CHdr {
KUDr@5633: 		int    m_size;      ///< actual blob size in bytes
KUDr@5633: 		int    m_max_size;  ///< maximum (allocated) size in bytes
KUDr@5633: 	};
KUDr@5633: 
KUDr@5633: 	/** type used as class member */
KUDr@5633: 	union {
KUDr@5633: 		int8   *m_pData;    ///< pointer to the first byte of data
KUDr@5633: 		CHdr   *m_pHdr_1;   ///< pointer just after the CHdr holding m_size and m_max_size
KUDr@5633: 	} ptr_u;
KUDr@5633: 
KUDr@5633: public:
KUDr@5633: 	static const int Ttail_reserve = 4; ///< four extra bytes will be always allocated and zeroed at the end
KUDr@5633: 
KUDr@5633: 	/** default constructor - initializes empty blob */
KUDr@5633: 	FORCEINLINE CBlobBaseSimple() { InitEmpty(); }
KUDr@5633: 	/** copy constructor */
KUDr@5633: 	FORCEINLINE CBlobBaseSimple(const CBlobBaseSimple& src)
KUDr@5633: 	{
KUDr@5633: 		InitEmpty();
KUDr@5633: 		AppendRaw(src);
KUDr@5633: 	}
KUDr@5633: 	/** destructor */
KUDr@5633: 	FORCEINLINE ~CBlobBaseSimple() { Free(); }
KUDr@5633: protected:
KUDr@5633: 	/** initialize the empty blob by setting the ptr_u.m_pHdr_1 pointer to the static CHdr with
KUDr@5633: 	 *  both m_size and m_max_size containing zero */
KUDr@5633: 	FORCEINLINE void InitEmpty() { static CHdr hdrEmpty[] = {{0, 0}, {0, 0}}; ptr_u.m_pHdr_1 = &hdrEmpty[1]; }
KUDr@5633: 	/** initialize blob by attaching it to the given header followed by data */
KUDr@5633: 	FORCEINLINE void Init(CHdr* hdr) { ptr_u.m_pHdr_1 = &hdr[1]; }
KUDr@5633: 	/** blob header accessor - use it rather than using the pointer arithmetics directly - non-const version */
KUDr@5633: 	FORCEINLINE CHdr& Hdr() { return ptr_u.m_pHdr_1[-1]; }
KUDr@5633: 	/** blob header accessor - use it rather than using the pointer arithmetics directly - const version */
KUDr@5633: 	FORCEINLINE const CHdr& Hdr() const { return ptr_u.m_pHdr_1[-1]; }
KUDr@5633: 	/** return reference to the actual blob size - used when the size needs to be modified */
KUDr@5633: 	FORCEINLINE int& RawSizeRef() { return Hdr().m_size; };
KUDr@5633: 
KUDr@5633: public:
KUDr@5633: 	/** return true if blob doesn't contain valid data */
KUDr@5633: 	FORCEINLINE bool IsEmpty() const { return RawSize() == 0; }
KUDr@5633: 	/** return the number of valid data bytes in the blob */
KUDr@5633: 	FORCEINLINE int RawSize() const { return Hdr().m_size; };
KUDr@5633: 	/** return the current blob capacity in bytes */
KUDr@5633: 	FORCEINLINE int MaxRawSize() const { return Hdr().m_max_size; };
KUDr@5633: 	/** return pointer to the first byte of data - non-const version */
KUDr@5633: 	FORCEINLINE int8* RawData() { return ptr_u.m_pData; }
KUDr@5633: 	/** return pointer to the first byte of data - const version */
KUDr@5633: 	FORCEINLINE const int8* RawData() const { return ptr_u.m_pData; }
KUDr@5633: #if 0 // reenable when needed
KUDr@5633: 	/** return the 32 bit CRC of valid data in the blob */
KUDr@5633: 	FORCEINLINE uint32 Crc32() const {return CCrc32::Calc(RawData(), RawSize());}
KUDr@5633: #endif //0
KUDr@5633: 	/** invalidate blob's data - doesn't free buffer */
KUDr@5633: 	FORCEINLINE void Clear() { RawSizeRef() = 0; }
KUDr@5633: 	/** free the blob's memory */
KUDr@5633: 	FORCEINLINE void Free() { if (MaxRawSize() > 0) {RawFree(&Hdr()); InitEmpty();} }
KUDr@5633: 	/** copy data from another blob - replaces any existing blob's data */
KUDr@5633: 	FORCEINLINE void CopyFrom(const CBlobBaseSimple& src) { Clear(); AppendRaw(src); }
KUDr@5633: 	/** overtake ownership of data buffer from the source blob - source blob will become empty */
KUDr@5633: 	FORCEINLINE void MoveFrom(CBlobBaseSimple& src) { Free(); ptr_u.m_pData = src.ptr_u.m_pData; src.InitEmpty(); }
KUDr@5633: 	/** swap buffers (with data) between two blobs (this and source blob) */
KUDr@5633: 	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; }
KUDr@5633: 
KUDr@5633: 	/** append new bytes at the end of existing data bytes - reallocates if necessary */
KUDr@5633: 	FORCEINLINE void AppendRaw(int8 *p, int num_bytes)
KUDr@5633: 	{
KUDr@5633: 		assert(p != NULL);
KUDr@5633: 		if (num_bytes > 0) {
KUDr@5633: 			memcpy(GrowRawSize(num_bytes), p, num_bytes);
KUDr@5633: 		} else {
KUDr@5633: 			assert(num_bytes >= 0);
KUDr@5633: 		}
KUDr@5633: 	}
KUDr@5633: 
KUDr@5633: 	/** append bytes from given source blob to the end of existing data bytes - reallocates if necessary */
KUDr@5633: 	FORCEINLINE void AppendRaw(const CBlobBaseSimple& src)
KUDr@5633: 	{
KUDr@5633: 		if (!src.IsEmpty())
KUDr@5633: 			memcpy(GrowRawSize(src.RawSize()), src.RawData(), src.RawSize());
KUDr@5633: 	}
KUDr@5633: 
KUDr@5633: 	/** Reallocate if there is no free space for num_bytes bytes.
KUDr@5633: 	 *  @return pointer to the new data to be added */
KUDr@5633: 	FORCEINLINE int8* MakeRawFreeSpace(int num_bytes)
KUDr@5633: 	{
KUDr@5633: 		assert(num_bytes >= 0);
KUDr@5633: 		int new_size = RawSize() + num_bytes;
KUDr@5633: 		if (new_size > MaxRawSize()) SmartAlloc(new_size);
KUDr@5633: 		FixTail();
KUDr@5633: 		return ptr_u.m_pData + RawSize();
KUDr@5633: 	}
KUDr@5633: 
KUDr@5633: 	/** Increase RawSize() by num_bytes.
KUDr@5633: 	 *  @return pointer to the new data added */
KUDr@5633: 	FORCEINLINE int8* GrowRawSize(int num_bytes)
KUDr@5633: 	{
KUDr@5633: 		int8* pNewData = MakeRawFreeSpace(num_bytes);
KUDr@5633: 		RawSizeRef() += num_bytes;
KUDr@5633: 		return pNewData;
KUDr@5633: 	}
KUDr@5633: 
KUDr@5633: 	/** Decrease RawSize() by num_bytes. */
KUDr@5633: 	FORCEINLINE void ReduceRawSize(int num_bytes)
KUDr@5633: 	{
KUDr@5633: 		if (MaxRawSize() > 0 && num_bytes > 0) {
KUDr@5633: 			assert(num_bytes <= RawSize());
KUDr@5633: 			if (num_bytes < RawSize()) RawSizeRef() -= num_bytes;
KUDr@5633: 			else RawSizeRef() = 0;
KUDr@5633: 		}
KUDr@5633: 	}
KUDr@5633: 	/** reallocate blob data if needed */
KUDr@5633: 	void SmartAlloc(int new_size)
KUDr@5633: 	{
KUDr@5633: 		int old_max_size = MaxRawSize();
KUDr@5633: 		if (old_max_size >= new_size) return;
KUDr@5633: 		// calculate minimum block size we need to allocate
KUDr@5633: 		int min_alloc_size = sizeof(CHdr) + new_size + Ttail_reserve;
KUDr@5633: 		// ask allocation policy for some reasonable block size
KUDr@5633: 		int alloc_size = AllocPolicy(min_alloc_size);
KUDr@5633: 		// allocate new block
KUDr@5633: 		CHdr* pNewHdr = RawAlloc(alloc_size);
KUDr@5633: 		// setup header
KUDr@5633: 		pNewHdr->m_size = RawSize();
KUDr@5633: 		pNewHdr->m_max_size = alloc_size - (sizeof(CHdr) + Ttail_reserve);
KUDr@5633: 		// copy existing data
KUDr@5633: 		if (RawSize() > 0)
KUDr@5633: 			memcpy(pNewHdr + 1, ptr_u.m_pData, pNewHdr->m_size);
KUDr@5633: 		// replace our block with new one
KUDr@5633: 		CHdr* pOldHdr = &Hdr();
KUDr@5633: 		Init(pNewHdr);
KUDr@5633: 		if (old_max_size > 0)
KUDr@5633: 			RawFree(pOldHdr);
KUDr@5633: 	}
KUDr@5633: 	/** simple allocation policy - can be optimized later */
KUDr@5633: 	FORCEINLINE static int AllocPolicy(int min_alloc)
KUDr@5633: 	{
KUDr@5633: 		if (min_alloc < (1 << 9)) {
KUDr@5633: 			if (min_alloc < (1 << 5)) return (1 << 5);
KUDr@5633: 			return (min_alloc < (1 << 7)) ? (1 << 7) : (1 << 9);
KUDr@5633: 		}
KUDr@5633: 		if (min_alloc < (1 << 15)) {
KUDr@5633: 			if (min_alloc < (1 << 11)) return (1 << 11);
KUDr@5633: 			return (min_alloc < (1 << 13)) ? (1 << 13) : (1 << 15);
KUDr@5633: 		}
KUDr@5633: 		if (min_alloc < (1 << 20)) {
KUDr@5633: 			if (min_alloc < (1 << 17)) return (1 << 17);
KUDr@5633: 			return (min_alloc < (1 << 19)) ? (1 << 19) : (1 << 20);
KUDr@5633: 		}
KUDr@5633: 		min_alloc = (min_alloc | ((1 << 20) - 1)) + 1;
KUDr@5633: 		return min_alloc;
KUDr@5633: 	}
KUDr@5633: 
KUDr@5633: 	/** all allocation should happen here */
KUDr@5633: 	static FORCEINLINE CHdr* RawAlloc(int num_bytes) { return (CHdr*)malloc(num_bytes); }
KUDr@5633: 	/** all deallocations should happen here */
KUDr@5633: 	static FORCEINLINE void RawFree(CHdr* p) { free(p); }
KUDr@5633: 	/** fixing the four bytes at the end of blob data - useful when blob is used to hold string */
KUDr@5633: 	FORCEINLINE void FixTail()
KUDr@5633: 	{
KUDr@5633: 		if (MaxRawSize() > 0) {
KUDr@5633: 			int8 *p = &ptr_u.m_pData[RawSize()];
KUDr@5633: 			for (int i = 0; i < Ttail_reserve; i++) p[i] = 0;
KUDr@5633: 		}
KUDr@5633: 	}
KUDr@5633: };
KUDr@5633: 
KUDr@5633: /** Blob - simple dynamic Titem_ array. Titem_ (template argument) is a placeholder for any type.
KUDr@5633:  *  Titem_ can be any integral type, pointer, or structure. Using Blob instead of just plain C array
KUDr@5633:  *  simplifies the resource management in several ways:
KUDr@5633:  *  1. When adding new item(s) it automatically grows capacity if needed.
KUDr@5633:  *  2. When variable of type Blob comes out of scope it automatically frees the data buffer.
KUDr@5633:  *  3. Takes care about the actual data size (number of used items).
KUDr@5633:  *  4. Dynamically constructs only used items (as opposite of static array which constructs all items) */
KUDr@5633: template <class Titem_, class Tbase_ = CBlobBaseSimple>
KUDr@5633: class CBlobT : public CBlobBaseSimple {
KUDr@5633: 	// make template arguments public:
KUDr@5633: public:
KUDr@5633: 	typedef Titem_ Titem;
KUDr@5633: 	typedef Tbase_ Tbase;
KUDr@5633: 
KUDr@5633: 	static const int Titem_size = sizeof(Titem);
KUDr@5633: 
KUDr@5633: 	/** Default constructor - makes new Blob ready to accept any data */
KUDr@5633: 	FORCEINLINE CBlobT() : Tbase() {}
KUDr@5633: 	/** Copy constructor - make new blob to become copy of the original (source) blob */
KUDr@5633: 	FORCEINLINE CBlobT(const Tbase& src) : Tbase(src) {assert((RawSize() % Titem_size) == 0);}
KUDr@5633: 	/** Destructor - ensures that allocated memory (if any) is freed */
KUDr@5633: 	FORCEINLINE ~CBlobT() { Free(); }
KUDr@5633: 	/** Check the validity of item index (only in debug mode) */
KUDr@5633: 	FORCEINLINE void CheckIdx(int idx) { assert(idx >= 0); assert(idx < Size()); }
KUDr@5633: 	/** Return pointer to the first data item - non-const version */
KUDr@5633: 	FORCEINLINE Titem* Data() { return (Titem*)RawData(); }
KUDr@5633: 	/** Return pointer to the first data item - const version */
KUDr@5633: 	FORCEINLINE const Titem* Data() const { return (const Titem*)RawData(); }
KUDr@5633: 	/** Return pointer to the idx-th data item - non-const version */
KUDr@5633: 	FORCEINLINE Titem* Data(int idx) { CheckIdx(idx); return (Data() + idx); }
KUDr@5633: 	/** Return pointer to the idx-th data item - const version */
KUDr@5633: 	FORCEINLINE const Titem* Data(int idx) const { CheckIdx(idx); return (Data() + idx); }
KUDr@5633: 	/** Return number of items in the Blob */
KUDr@5633: 	FORCEINLINE int Size() const { return (RawSize() / Titem_size); }
KUDr@5633: 	/** Free the memory occupied by Blob destroying all items */
KUDr@5633: 	FORCEINLINE void Free()
KUDr@5633: 	{
KUDr@5633: 		assert((RawSize() % Titem_size) == 0);
KUDr@5633: 		int old_size = Size();
KUDr@5633: 		if (old_size > 0) {
KUDr@5633: 			// destroy removed items;
KUDr@5633: 			Titem* pI_last_to_destroy = Data(0);
KUDr@5633: 			for (Titem* pI = Data(old_size - 1); pI >= pI_last_to_destroy; pI--) pI->~Titem_();
KUDr@5633: 		}
KUDr@5633: 		Tbase::Free();
KUDr@5633: 	}
KUDr@5633: 	/** Grow number of data items in Blob by given number - doesn't construct items */
KUDr@5633: 	FORCEINLINE Titem* GrowSizeNC(int num_items) { return (Titem*)GrowRawSize(num_items * Titem_size); }
KUDr@5633: 	/** Grow number of data items in Blob by given number - constructs new items (using Titem_'s default constructor) */
KUDr@5633: 	FORCEINLINE Titem* GrowSizeC(int num_items)
KUDr@5633: 	{
KUDr@5633: 		Titem* pI = GrowSizeNC(num_items);
KUDr@5633: 		for (int i = num_items; i > 0; i--, pI++) new (pI) Titem();
KUDr@5633: 	}
KUDr@5633: 	/** Destroy given number of items and reduce the Blob's data size */
KUDr@5633: 	FORCEINLINE void ReduceSize(int num_items)
KUDr@5633: 	{
KUDr@5633: 		assert((RawSize() % Titem_size) == 0);
KUDr@5633: 		int old_size = Size();
KUDr@5633: 		assert(num_items <= old_size);
KUDr@5633: 		int new_size = (num_items <= old_size) ? (old_size - num_items) : 0;
KUDr@5633: 		// destroy removed items;
KUDr@5633: 		Titem* pI_last_to_destroy = Data(new_size);
KUDr@5633: 		for (Titem* pI = Data(old_size - 1); pI >= pI_last_to_destroy; pI--) pI->~Titem();
KUDr@5633: 		// remove them
KUDr@5633: 		ReduceRawSize(num_items * Titem_size);
KUDr@5633: 	}
KUDr@5633: 	/** Append one data item at the end (calls Titem_'s default constructor) */
KUDr@5633: 	FORCEINLINE Titem* AppendNew()
KUDr@5633: 	{
KUDr@5633: 		Titem& dst = *GrowSizeNC(1); // Grow size by one item
KUDr@5633: 		Titem* pNewItem = new (&dst) Titem(); // construct the new item by calling in-place new operator
KUDr@5633: 		return pNewItem;
KUDr@5633: 	}
KUDr@5633: 	/** Append the copy of given item at the end of Blob (using copy constructor) */
KUDr@5633: 	FORCEINLINE Titem* Append(const Titem& src)
KUDr@5633: 	{
KUDr@5633: 		Titem& dst = *GrowSizeNC(1); // Grow size by one item
KUDr@5633: 		Titem* pNewItem = new (&dst) Titem(src); // construct the new item by calling in-place new operator with copy ctor()
KUDr@5633: 		return pNewItem;
KUDr@5633: 	}
KUDr@5633: 	/** Add given items (ptr + number of items) at the end of blob */
KUDr@5633: 	FORCEINLINE Titem* Append(const Titem* pSrc, int num_items)
KUDr@5633: 	{
KUDr@5633: 		Titem* pDst = GrowSizeNC(num_items);
KUDr@5633: 		Titem* pDstOrg = pDst;
KUDr@5633: 		Titem* pDstEnd = pDst + num_items;
KUDr@5633: 		while (pDst < pDstEnd) new (pDst++) Titem(*(pSrc++));
KUDr@5633: 		return pDstOrg;
KUDr@5633: 	}
KUDr@5633: 	/** Remove item with the given index by replacing it by the last item and reducing the size by one */
KUDr@5633: 	FORCEINLINE void RemoveBySwap(int idx)
KUDr@5633: 	{
KUDr@5633: 		CheckIdx(idx);
KUDr@5633: 		// destroy removed item
KUDr@5633: 		Titem* pRemoved = Data(idx);
KUDr@5633: 		RemoveBySwap(pRemoved);
KUDr@5633: 	}
KUDr@5633: 	/** Remove item given by pointer replacing it by the last item and reducing the size by one */
KUDr@5633: 	FORCEINLINE void RemoveBySwap(Titem* pItem)
KUDr@5633: 	{
KUDr@5633: 		Titem* pLast = Data(Size() - 1);
KUDr@5633: 		assert(pItem >= Data() && pItem <= pLast);
KUDr@5633: 		// move last item to its new place
KUDr@5633: 		if (pItem != pLast) {
KUDr@5633: 			pItem->~Titem_();
KUDr@5633: 			new (pItem) Titem_(*pLast);
KUDr@5633: 		}
KUDr@5633: 		// destroy the last item
KUDr@5633: 		pLast->~Titem_();
KUDr@5633: 		// and reduce the raw blob size
KUDr@5633: 		ReduceRawSize(Titem_size);
KUDr@5633: 	}
KUDr@5633: 	/** Ensures that given number of items can be added to the end of Blob. Returns pointer to the
KUDr@5633: 	 *  first free (unused) item */
KUDr@5633: 	FORCEINLINE Titem* MakeFreeSpace(int num_items) { return (Titem*)MakeRawFreeSpace(num_items * Titem_size); }
KUDr@5633: };
KUDr@5633: 
KUDr@5633: // simple string implementation
KUDr@5633: struct CStrA : public CBlobT<char>
KUDr@5633: {
KUDr@5633: 	typedef CBlobT<char> base;
KUDr@5633: 	CStrA(const char* str = NULL) {Append(str);}
KUDr@5633: 	FORCEINLINE CStrA(const CBlobBaseSimple& src) : base(src) {}
KUDr@5633: 	void Append(const char* str) {if (str != NULL && str[0] != '\0') base::Append(str, (int)strlen(str));}
KUDr@5633: };
KUDr@5633: 
KUDr@5633: #endif /* BLOB_HPP */