Mercurial > hg > openttd
changeset 7115:0fe66343663e draft
(svn r10388) -Cleanup: coding style (CBlobT & CBlobBaseSimple), removed CStrA
author | KUDr <KUDr@openttd.org> |
---|---|
date | Fri, 29 Jun 2007 22:16:15 +0000 |
parents | 6920273d9132 |
children | 9c23f8eca1c4 |
files | src/misc/blob.hpp |
diffstat | 1 files changed, 294 insertions(+), 114 deletions(-) [+] |
line wrap: on
line diff
--- a/src/misc/blob.hpp +++ b/src/misc/blob.hpp @@ -15,104 +15,196 @@ 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 +* +* Internal member layout: +* 1. The only class member is pointer to the first item (see union ptr_u). +* 2. Allocated block contains the blob header (see CHdr) followed by the raw byte data. +* Always, when it allocates memory the allocated size is: +* sizeof(CHdr) + <data capacity> +* 3. Two 'virtual' members (m_size and m_max_size) are stored in the CHdr at beginning +* of the alloated block. +* 4. The pointter (in ptr_u) pobsize_ts behind the header (to the first data byte). +* When memory block is allocated, the sizeof(CHdr) it added to it. +* 5. Benefits of this layout: +* - items are accessed in the simplest possible way - just dereferencing the pointer, +* which is good for performance (assuming that data are accessed most often). +* - sizeof(blob) is the same as the size of any other pointer +* 6. Drawbacks of this layout: +* - the fact, that pointer to the alocated block is adjusted by sizeof(CHdr) before +* it is stored can lead to several confusions: +* - it is not common pattern so the implementation code is bit harder to read +* - valgrind can generate warning that allocated block is lost (not accessible) +* */ +class CBlobBaseSimple { +public: + typedef ::ptrdiff_t bsize_t; + typedef ::byte bitem_t; -/** 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 - * - * Internal member layout: - * 1. The only class member is pointer to the first item (see union ptr_u). - * 2. Allocated block contains the blob header (see CHdr) followed by the raw byte data. - * Always, when it allocates memory the allocated size is: - * sizeof(CHdr) + <data capacity> - * 3. Two 'virtual' members (m_size and m_max_size) are stored in the CHdr at beginning - * of the alloated block. - * 4. The pointer (in ptr_u) points behind the header (to the first data byte). - * When memory block is allocated, the sizeof(CHdr) it added to it. - * 5. Benefits of this layout: - * - items are accessed in the simplest possible way - just dereferencing the pointer, - * which is good for performance (assuming that data are accessed most often). - * - sizeof(blob) is the same as the size of any other pointer - * 6. Drawbacks of this layout: - * - the fact, that pointer to the alocated block is adjusted by sizeof(CHdr) before - * it is stored can lead to several confusions: - * - it is not common pattern so the implementation code is bit harder to read - * - valgrind can generate warning that allocated block is lost (not accessible) - * */ -class CBlobBaseSimple { protected: /** header of the allocated memory block */ struct CHdr { - int m_size; ///< actual blob size in bytes - int m_max_size; ///< maximum (allocated) size in bytes + bsize_t m_size; ///< actual blob size in bytes + bsize_t m_max_size; ///< maximum (allocated) size in bytes }; /** type used as class member */ union { - int8 *m_pData; ///< pointer to the first byte of data - CHdr *m_pHdr_1; ///< pointer just after the CHdr holding m_size and m_max_size + bitem_t *m_pData; ///< ptr to the first byte of data + wchar_t *m_pwData; ///< ptr to the first byte of data + CHdr *m_pHdr_1; ///< ptr just after the CHdr holding m_size and m_max_size } ptr_u; public: - static const int Ttail_reserve = 4; ///< four extra bytes will be always allocated and zeroed at the end + static const bsize_t Ttail_reserve = 4; ///< four extra bytes will be always allocated and zeroed at the end /** default constructor - initializes empty blob */ FORCEINLINE CBlobBaseSimple() { InitEmpty(); } + /** constructor - create blob with data */ + FORCEINLINE CBlobBaseSimple(const bitem_t *p, bsize_t num_bytes) + { + InitEmpty(); + AppendRaw(p, num_bytes); + } + /** copy constructor */ FORCEINLINE CBlobBaseSimple(const CBlobBaseSimple& src) { InitEmpty(); AppendRaw(src); } + + /** move constructor - take ownership of blob data */ + FORCEINLINE CBlobBaseSimple(CHdr * const & pHdr_1) + { + assert(pHdr_1 != NULL); + ptr_u.m_pHdr_1 = pHdr_1; + *(CHdr**)&pHdr_1 = NULL; + } + /** destructor */ - FORCEINLINE ~CBlobBaseSimple() { Free(); } + FORCEINLINE ~CBlobBaseSimple() + { + Free(); + } + protected: /** initialize the empty blob by setting the ptr_u.m_pHdr_1 pointer to the static CHdr with - * both m_size and m_max_size containing zero */ - FORCEINLINE void InitEmpty() { static CHdr hdrEmpty[] = {{0, 0}, {0, 0}}; ptr_u.m_pHdr_1 = &hdrEmpty[1]; } + * both m_size and m_max_size containing zero */ + FORCEINLINE void InitEmpty() + { + static CHdr hdrEmpty[] = {{0, 0}, {0, 0}}; + ptr_u.m_pHdr_1 = &hdrEmpty[1]; + } + /** initialize blob by attaching it to the given header followed by data */ - FORCEINLINE void Init(CHdr* hdr) { ptr_u.m_pHdr_1 = &hdr[1]; } + FORCEINLINE void Init(CHdr* hdr) + { + ptr_u.m_pHdr_1 = &hdr[1]; + } + /** blob header accessor - use it rather than using the pointer arithmetics directly - non-const version */ - FORCEINLINE CHdr& Hdr() { return ptr_u.m_pHdr_1[-1]; } + FORCEINLINE CHdr& Hdr() + { + return ptr_u.m_pHdr_1[-1]; + } + /** blob header accessor - use it rather than using the pointer arithmetics directly - const version */ - FORCEINLINE const CHdr& Hdr() const { return ptr_u.m_pHdr_1[-1]; } + FORCEINLINE const CHdr& Hdr() const + { + return ptr_u.m_pHdr_1[-1]; + } + /** return reference to the actual blob size - used when the size needs to be modified */ - FORCEINLINE int& RawSizeRef() { return Hdr().m_size; }; + FORCEINLINE bsize_t& RawSizeRef() + { + return Hdr().m_size; + }; public: /** return true if blob doesn't contain valid data */ - FORCEINLINE bool IsEmpty() const { return RawSize() == 0; } + FORCEINLINE bool IsEmpty() const + { + return RawSize() == 0; + } + /** return the number of valid data bytes in the blob */ - FORCEINLINE int RawSize() const { return Hdr().m_size; }; + FORCEINLINE bsize_t RawSize() const + { + return Hdr().m_size; + }; + /** return the current blob capacity in bytes */ - FORCEINLINE int MaxRawSize() const { return Hdr().m_max_size; }; + FORCEINLINE bsize_t MaxRawSize() const + { + return Hdr().m_max_size; + }; + /** return pointer to the first byte of data - non-const version */ - FORCEINLINE int8* RawData() { return ptr_u.m_pData; } + FORCEINLINE bitem_t* RawData() + { + return ptr_u.m_pData; + } + /** return pointer to the first byte of data - const version */ - FORCEINLINE const int8* RawData() const { return ptr_u.m_pData; } -#if 0 // reenable when needed + FORCEINLINE const bitem_t* RawData() const + { + return ptr_u.m_pData; + } + /** return the 32 bit CRC of valid data in the blob */ - FORCEINLINE uint32 Crc32() const {return CCrc32::Calc(RawData(), RawSize());} -#endif //0 + //FORCEINLINE bsize_t Crc32() const + //{ + // return CCrc32::Calc(RawData(), RawSize()); + //} + /** invalidate blob's data - doesn't free buffer */ - FORCEINLINE void Clear() { RawSizeRef() = 0; } + FORCEINLINE void Clear() + { + RawSizeRef() = 0; + } + /** free the blob's memory */ - FORCEINLINE void Free() { if (MaxRawSize() > 0) {RawFree(&Hdr()); InitEmpty();} } + FORCEINLINE void Free() + { + if (MaxRawSize() > 0) { + RawFree(&Hdr()); + InitEmpty(); + } + } + /** copy data from another blob - replaces any existing blob's data */ - FORCEINLINE void CopyFrom(const CBlobBaseSimple& src) { Clear(); AppendRaw(src); } + FORCEINLINE void CopyFrom(const CBlobBaseSimple& src) + { + Clear(); + AppendRaw(src); + } + /** overtake ownership of data buffer from the source blob - source blob will become empty */ - FORCEINLINE void MoveFrom(CBlobBaseSimple& src) { Free(); ptr_u.m_pData = src.ptr_u.m_pData; src.InitEmpty(); } + FORCEINLINE void MoveFrom(CBlobBaseSimple& src) + { + Free(); + ptr_u.m_pData = src.ptr_u.m_pData; + src.InitEmpty(); + } + /** swap buffers (with data) between two blobs (this and source blob) */ - 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 Swap(CBlobBaseSimple& src) + { + bitem_t *tmp = ptr_u.m_pData; ptr_u.m_pData = src.ptr_u.m_pData; + src.ptr_u.m_pData = tmp; + } /** append new bytes at the end of existing data bytes - reallocates if necessary */ - FORCEINLINE void AppendRaw(int8 *p, int num_bytes) + FORCEINLINE void AppendRaw(const void *p, bsize_t num_bytes) { assert(p != NULL); if (num_bytes > 0) { @@ -130,27 +222,26 @@ } /** 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) + * @return pointer to the new data to be added */ + FORCEINLINE bitem_t* MakeRawFreeSpace(bsize_t num_bytes) { assert(num_bytes >= 0); - int new_size = RawSize() + num_bytes; + bsize_t 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) + * @return pointer to the new data added */ + FORCEINLINE bitem_t* GrowRawSize(bsize_t num_bytes) { - int8* pNewData = MakeRawFreeSpace(num_bytes); + bitem_t* pNewData = MakeRawFreeSpace(num_bytes); RawSizeRef() += num_bytes; return pNewData; } /** Decrease RawSize() by num_bytes. */ - FORCEINLINE void ReduceRawSize(int num_bytes) + FORCEINLINE void ReduceRawSize(bsize_t num_bytes) { if (MaxRawSize() > 0 && num_bytes > 0) { assert(num_bytes <= RawSize()); @@ -158,15 +249,16 @@ else RawSizeRef() = 0; } } + /** reallocate blob data if needed */ - void SmartAlloc(int new_size) + void SmartAlloc(bsize_t new_size) { - int old_max_size = MaxRawSize(); + bsize_t 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; + bsize_t min_alloc_size = sizeof(CHdr) + new_size + Ttail_reserve; // ask allocation policy for some reasonable block size - int alloc_size = AllocPolicy(min_alloc_size); + bsize_t alloc_size = AllocPolicy(min_alloc_size); // allocate new block CHdr* pNewHdr = RawAlloc(alloc_size); // setup header @@ -181,8 +273,9 @@ if (old_max_size > 0) RawFree(pOldHdr); } + /** simple allocation policy - can be optimized later */ - FORCEINLINE static int AllocPolicy(int min_alloc) + FORCEINLINE static bsize_t AllocPolicy(bsize_t min_alloc) { if (min_alloc < (1 << 9)) { if (min_alloc < (1 << 5)) return (1 << 5); @@ -201,58 +294,133 @@ } /** all allocation should happen here */ - static FORCEINLINE CHdr* RawAlloc(int num_bytes) { return (CHdr*)malloc(num_bytes); } + static FORCEINLINE CHdr* RawAlloc(bsize_t num_bytes) + { + return (CHdr*)malloc(num_bytes); + } + /** all deallocations should happen here */ - static FORCEINLINE void RawFree(CHdr* p) { free(p); } + 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() + FORCEINLINE void FixTail() const { if (MaxRawSize() > 0) { - int8 *p = &ptr_u.m_pData[RawSize()]; - for (int i = 0; i < Ttail_reserve; i++) p[i] = 0; + bitem_t *p = &ptr_u.m_pData[RawSize()]; + for (bsize_t i = 0; i < Ttail_reserve; i++) { + p[i] = 0; + } } } }; /** Blob - simple dynamic Titem_ array. Titem_ (template argument) is a placeholder for any type. - * Titem_ can be any integral type, pointer, or structure. Using Blob instead of just plain C array - * simplifies the resource management in several ways: - * 1. When adding new item(s) it automatically grows capacity if needed. - * 2. When variable of type Blob comes out of scope it automatically frees the data buffer. - * 3. Takes care about the actual data size (number of used items). - * 4. Dynamically constructs only used items (as opposite of static array which constructs all items) */ +* Titem_ can be any integral type, pointer, or structure. Using Blob instead of just plain C array +* simplifies the resource management in several ways: +* 1. When adding new item(s) it automatically grows capacity if needed. +* 2. When variable of type Blob comes out of scope it automatically frees the data buffer. +* 3. Takes care about the actual data size (number of used items). +* 4. Dynamically constructs only used items (as opposite of static array which constructs all items) */ template <class Titem_, class Tbase_ = CBlobBaseSimple> -class CBlobT : public CBlobBaseSimple { +class CBlobT : public Tbase_ { // make template arguments public: public: typedef Titem_ Titem; typedef Tbase_ Tbase; + typedef typename Tbase::bsize_t bsize_t; - static const int Titem_size = sizeof(Titem); + static const bsize_t Titem_size = sizeof(Titem); + + struct OnTransfer { + typename Tbase_::CHdr *m_pHdr_1; + OnTransfer(const OnTransfer& src) : m_pHdr_1(src.m_pHdr_1) {assert(src.m_pHdr_1 != NULL); *(typename Tbase_::CHdr**)&src.m_pHdr_1 = NULL;} + OnTransfer(CBlobT& src) : m_pHdr_1(src.ptr_u.m_pHdr_1) {src.InitEmpty();} + ~OnTransfer() {assert(m_pHdr_1 == NULL);} + }; /** Default constructor - makes new Blob ready to accept any data */ - FORCEINLINE CBlobT() : Tbase() {} + FORCEINLINE CBlobT() + : Tbase() + {} + + /** Constructor - makes new Blob with data */ + FORCEINLINE CBlobT(const Titem_ *p, bsize_t num_items) + : Tbase((typename Tbase_::bitem_t*)p, num_items * Titem_size) + {} + /** Copy constructor - make new blob to become copy of the original (source) blob */ - FORCEINLINE CBlobT(const Tbase& src) : Tbase(src) {assert((RawSize() % Titem_size) == 0);} + FORCEINLINE CBlobT(const Tbase& src) + : Tbase(src) + { + assert((Tbase::RawSize() % Titem_size) == 0); + } + + /** Take ownership constructor */ + FORCEINLINE CBlobT(const OnTransfer& ot) + : Tbase(ot.m_pHdr_1) + {} + /** Destructor - ensures that allocated memory (if any) is freed */ - FORCEINLINE ~CBlobT() { Free(); } + FORCEINLINE ~CBlobT() + { + Free(); + } + /** Check the validity of item index (only in debug mode) */ - FORCEINLINE void CheckIdx(int idx) { assert(idx >= 0); assert(idx < Size()); } + FORCEINLINE void CheckIdx(bsize_t idx) + { + assert(idx >= 0); assert(idx < Size()); + } + /** Return pointer to the first data item - non-const version */ - FORCEINLINE Titem* Data() { return (Titem*)RawData(); } + FORCEINLINE Titem* Data() + { + return (Titem*)Tbase::RawData(); + } + /** Return pointer to the first data item - const version */ - FORCEINLINE const Titem* Data() const { return (const Titem*)RawData(); } + FORCEINLINE const Titem* Data() const + { + return (const Titem*)Tbase::RawData(); + } + /** Return pointer to the idx-th data item - non-const version */ - FORCEINLINE Titem* Data(int idx) { CheckIdx(idx); return (Data() + idx); } + FORCEINLINE Titem* Data(bsize_t idx) + { + CheckIdx(idx); + return (Data() + idx); + } + /** Return pointer to the idx-th data item - const version */ - FORCEINLINE const Titem* Data(int idx) const { CheckIdx(idx); return (Data() + idx); } + FORCEINLINE const Titem* Data(bsize_t idx) const + { + CheckIdx(idx); return (Data() + idx); + } + /** Return number of items in the Blob */ - FORCEINLINE int Size() const { return (RawSize() / Titem_size); } + FORCEINLINE bsize_t Size() const + { + return (Tbase::RawSize() / Titem_size); + } + + /** Return total number of items that can fit in the Blob without buffer reallocation */ + FORCEINLINE bsize_t MaxSize() const + { + return (Tbase::MaxRawSize() / Titem_size); + } + /** Return number of additional items that can fit in the Blob without buffer reallocation */ + FORCEINLINE bsize_t GetReserve() const + { + return ((Tbase::MaxRawSize() - Tbase::RawSize()) / Titem_size); + } + /** Free the memory occupied by Blob destroying all items */ FORCEINLINE void Free() { - assert((RawSize() % Titem_size) == 0); - int old_size = Size(); + assert((Tbase::RawSize() % Titem_size) == 0); + bsize_t old_size = Size(); if (old_size > 0) { // destroy removed items; Titem* pI_last_to_destroy = Data(0); @@ -260,27 +428,34 @@ } Tbase::Free(); } + /** Grow number of data items in Blob by given number - doesn't construct items */ - FORCEINLINE Titem* GrowSizeNC(int num_items) { return (Titem*)GrowRawSize(num_items * Titem_size); } + FORCEINLINE Titem* GrowSizeNC(bsize_t num_items) + { + return (Titem*)Tbase::GrowRawSize(num_items * Titem_size); + } + /** Grow number of data items in Blob by given number - constructs new items (using Titem_'s default constructor) */ - FORCEINLINE Titem* GrowSizeC(int num_items) + FORCEINLINE Titem* GrowSizeC(bsize_t num_items) { Titem* pI = GrowSizeNC(num_items); - for (int i = num_items; i > 0; i--, pI++) new (pI) Titem(); + for (bsize_t i = num_items; i > 0; i--, pI++) new (pI) Titem(); } + /** Destroy given number of items and reduce the Blob's data size */ - FORCEINLINE void ReduceSize(int num_items) + FORCEINLINE void ReduceSize(bsize_t num_items) { - assert((RawSize() % Titem_size) == 0); - int old_size = Size(); + assert((Tbase::RawSize() % Titem_size) == 0); + bsize_t old_size = Size(); assert(num_items <= old_size); - int new_size = (num_items <= old_size) ? (old_size - num_items) : 0; + bsize_t 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); + Tbase::ReduceRawSize(num_items * Titem_size); } + /** Append one data item at the end (calls Titem_'s default constructor) */ FORCEINLINE Titem* AppendNew() { @@ -288,6 +463,7 @@ Titem* pNewItem = new (&dst) Titem(); // construct the new item by calling in-place new operator return pNewItem; } + /** Append the copy of given item at the end of Blob (using copy constructor) */ FORCEINLINE Titem* Append(const Titem& src) { @@ -295,8 +471,9 @@ Titem* pNewItem = new (&dst) Titem(src); // construct the new item by calling in-place new operator with copy ctor() return pNewItem; } + /** Add given items (ptr + number of items) at the end of blob */ - FORCEINLINE Titem* Append(const Titem* pSrc, int num_items) + FORCEINLINE Titem* Append(const Titem* pSrc, bsize_t num_items) { Titem* pDst = GrowSizeNC(num_items); Titem* pDstOrg = pDst; @@ -304,14 +481,16 @@ while (pDst < pDstEnd) new (pDst++) Titem(*(pSrc++)); return pDstOrg; } + /** Remove item with the given index by replacing it by the last item and reducing the size by one */ - FORCEINLINE void RemoveBySwap(int idx) + FORCEINLINE void RemoveBySwap(bsize_t idx) { CheckIdx(idx); // destroy removed item Titem* pRemoved = Data(idx); RemoveBySwap(pRemoved); } + /** Remove item given by pointer replacing it by the last item and reducing the size by one */ FORCEINLINE void RemoveBySwap(Titem* pItem) { @@ -325,20 +504,21 @@ // destroy the last item pLast->~Titem_(); // and reduce the raw blob size - ReduceRawSize(Titem_size); + Tbase::ReduceRawSize(Titem_size); } + /** Ensures that given number of items can be added to the end of Blob. Returns pointer to the - * first free (unused) item */ - FORCEINLINE Titem* MakeFreeSpace(int num_items) { return (Titem*)MakeRawFreeSpace(num_items * Titem_size); } + * first free (unused) item */ + FORCEINLINE Titem* MakeFreeSpace(bsize_t num_items) + { + return (Titem*)Tbase::MakeRawFreeSpace(num_items * Titem_size); + } + + FORCEINLINE OnTransfer Transfer() + { + return OnTransfer(*this); + }; }; -// 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 */