| // © 2016 and later: Unicode, Inc. and others. |
| // License & terms of use: http://www.unicode.org/copyright.html |
| /* |
| ****************************************************************************** |
| * |
| * Copyright (C) 1997-2016, International Business Machines |
| * Corporation and others. All Rights Reserved. |
| * |
| ****************************************************************************** |
| * |
| * File CMEMORY.H |
| * |
| * Contains stdlib.h/string.h memory functions |
| * |
| * @author Bertrand A. Damiba |
| * |
| * Modification History: |
| * |
| * Date Name Description |
| * 6/20/98 Bertrand Created. |
| * 05/03/99 stephen Changed from functions to macros. |
| * |
| ****************************************************************************** |
| */ |
| |
| #ifndef CMEMORY_H |
| #define CMEMORY_H |
| |
| #include "unicode/utypes.h" |
| |
| #include <stddef.h> |
| #include <string.h> |
| #include "unicode/localpointer.h" |
| #include "uassert.h" |
| |
| #if U_DEBUG && defined(UPRV_MALLOC_COUNT) |
| #include <stdio.h> |
| #endif |
| |
| // uprv_memcpy and uprv_memmove |
| #if defined(__clang__) |
| #define uprv_memcpy(dst, src, size) UPRV_BLOCK_MACRO_BEGIN { \ |
| /* Suppress warnings about addresses that will never be NULL */ \ |
| _Pragma("clang diagnostic push") \ |
| _Pragma("clang diagnostic ignored \"-Waddress\"") \ |
| U_ASSERT(dst != NULL); \ |
| U_ASSERT(src != NULL); \ |
| _Pragma("clang diagnostic pop") \ |
| U_STANDARD_CPP_NAMESPACE memcpy(dst, src, size); \ |
| } UPRV_BLOCK_MACRO_END |
| #define uprv_memmove(dst, src, size) UPRV_BLOCK_MACRO_BEGIN { \ |
| /* Suppress warnings about addresses that will never be NULL */ \ |
| _Pragma("clang diagnostic push") \ |
| _Pragma("clang diagnostic ignored \"-Waddress\"") \ |
| U_ASSERT(dst != NULL); \ |
| U_ASSERT(src != NULL); \ |
| _Pragma("clang diagnostic pop") \ |
| U_STANDARD_CPP_NAMESPACE memmove(dst, src, size); \ |
| } UPRV_BLOCK_MACRO_END |
| #elif defined(__GNUC__) |
| #define uprv_memcpy(dst, src, size) UPRV_BLOCK_MACRO_BEGIN { \ |
| /* Suppress warnings about addresses that will never be NULL */ \ |
| _Pragma("GCC diagnostic push") \ |
| _Pragma("GCC diagnostic ignored \"-Waddress\"") \ |
| U_ASSERT(dst != NULL); \ |
| U_ASSERT(src != NULL); \ |
| _Pragma("GCC diagnostic pop") \ |
| U_STANDARD_CPP_NAMESPACE memcpy(dst, src, size); \ |
| } UPRV_BLOCK_MACRO_END |
| #define uprv_memmove(dst, src, size) UPRV_BLOCK_MACRO_BEGIN { \ |
| /* Suppress warnings about addresses that will never be NULL */ \ |
| _Pragma("GCC diagnostic push") \ |
| _Pragma("GCC diagnostic ignored \"-Waddress\"") \ |
| U_ASSERT(dst != NULL); \ |
| U_ASSERT(src != NULL); \ |
| _Pragma("GCC diagnostic pop") \ |
| U_STANDARD_CPP_NAMESPACE memmove(dst, src, size); \ |
| } UPRV_BLOCK_MACRO_END |
| #else |
| #define uprv_memcpy(dst, src, size) UPRV_BLOCK_MACRO_BEGIN { \ |
| U_ASSERT(dst != NULL); \ |
| U_ASSERT(src != NULL); \ |
| U_STANDARD_CPP_NAMESPACE memcpy(dst, src, size); \ |
| } UPRV_BLOCK_MACRO_END |
| #define uprv_memmove(dst, src, size) UPRV_BLOCK_MACRO_BEGIN { \ |
| U_ASSERT(dst != NULL); \ |
| U_ASSERT(src != NULL); \ |
| U_STANDARD_CPP_NAMESPACE memmove(dst, src, size); \ |
| } UPRV_BLOCK_MACRO_END |
| #endif |
| |
| /** |
| * \def UPRV_LENGTHOF |
| * Convenience macro to determine the length of a fixed array at compile-time. |
| * @param array A fixed length array |
| * @return The length of the array, in elements |
| * @internal |
| */ |
| #define UPRV_LENGTHOF(array) (int32_t)(sizeof(array)/sizeof((array)[0])) |
| #define uprv_memset(buffer, mark, size) U_STANDARD_CPP_NAMESPACE memset(buffer, mark, size) |
| #define uprv_memcmp(buffer1, buffer2, size) U_STANDARD_CPP_NAMESPACE memcmp(buffer1, buffer2,size) |
| #define uprv_memchr(ptr, value, num) U_STANDARD_CPP_NAMESPACE memchr(ptr, value, num) |
| |
| U_CAPI void * U_EXPORT2 |
| uprv_malloc(size_t s) U_MALLOC_ATTR U_ALLOC_SIZE_ATTR(1); |
| |
| U_CAPI void * U_EXPORT2 |
| uprv_realloc(void *mem, size_t size) U_ALLOC_SIZE_ATTR(2); |
| |
| U_CAPI void U_EXPORT2 |
| uprv_free(void *mem); |
| |
| U_CAPI void * U_EXPORT2 |
| uprv_calloc(size_t num, size_t size) U_MALLOC_ATTR U_ALLOC_SIZE_ATTR2(1,2); |
| |
| /** |
| * Get the least significant bits of a pointer (a memory address). |
| * For example, with a mask of 3, the macro gets the 2 least significant bits, |
| * which will be 0 if the pointer is 32-bit (4-byte) aligned. |
| * |
| * uintptr_t is the most appropriate integer type to cast to. |
| */ |
| #define U_POINTER_MASK_LSB(ptr, mask) ((uintptr_t)(ptr) & (mask)) |
| |
| /** |
| * Create & return an instance of "type" in statically allocated storage. |
| * e.g. |
| * static std::mutex *myMutex = STATIC_NEW(std::mutex); |
| * To destroy an object created in this way, invoke the destructor explicitly, e.g. |
| * myMutex->~mutex(); |
| * DO NOT use delete. |
| * DO NOT use with class UMutex, which has specific support for static instances. |
| * |
| * STATIC_NEW is intended for use when |
| * - We want a static (or global) object. |
| * - We don't want it to ever be destructed, or to explicitly control destruction, |
| * to avoid use-after-destruction problems. |
| * - We want to avoid an ordinary heap allocated object, |
| * to avoid the possibility of memory allocation failures, and |
| * to avoid memory leak reports, from valgrind, for example. |
| * This is defined as a macro rather than a template function because each invocation |
| * must define distinct static storage for the object being returned. |
| */ |
| #define STATIC_NEW(type) [] () { \ |
| alignas(type) static char storage[sizeof(type)]; \ |
| return new(storage) type();} () |
| |
| /** |
| * Heap clean up function, called from u_cleanup() |
| * Clears any user heap functions from u_setMemoryFunctions() |
| * Does NOT deallocate any remaining allocated memory. |
| */ |
| U_CFUNC UBool |
| cmemory_cleanup(void); |
| |
| /** |
| * A function called by <TT>uhash_remove</TT>, |
| * <TT>uhash_close</TT>, or <TT>uhash_put</TT> to delete |
| * an existing key or value. |
| * @param obj A key or value stored in a hashtable |
| * @see uprv_deleteUObject |
| */ |
| typedef void U_CALLCONV UObjectDeleter(void* obj); |
| |
| /** |
| * Deleter for UObject instances. |
| * Works for all subclasses of UObject because it has a virtual destructor. |
| */ |
| U_CAPI void U_EXPORT2 |
| uprv_deleteUObject(void *obj); |
| |
| #ifdef __cplusplus |
| |
| #include <utility> |
| #include "unicode/uobject.h" |
| |
| U_NAMESPACE_BEGIN |
| |
| /** |
| * "Smart pointer" class, deletes memory via uprv_free(). |
| * For most methods see the LocalPointerBase base class. |
| * Adds operator[] for array item access. |
| * |
| * @see LocalPointerBase |
| */ |
| template<typename T> |
| class LocalMemory : public LocalPointerBase<T> { |
| public: |
| using LocalPointerBase<T>::operator*; |
| using LocalPointerBase<T>::operator->; |
| /** |
| * Constructor takes ownership. |
| * @param p simple pointer to an array of T items that is adopted |
| */ |
| explicit LocalMemory(T *p=NULL) : LocalPointerBase<T>(p) {} |
| /** |
| * Move constructor, leaves src with isNull(). |
| * @param src source smart pointer |
| */ |
| LocalMemory(LocalMemory<T> &&src) U_NOEXCEPT : LocalPointerBase<T>(src.ptr) { |
| src.ptr=NULL; |
| } |
| /** |
| * Destructor deletes the memory it owns. |
| */ |
| ~LocalMemory() { |
| uprv_free(LocalPointerBase<T>::ptr); |
| } |
| /** |
| * Move assignment operator, leaves src with isNull(). |
| * The behavior is undefined if *this and src are the same object. |
| * @param src source smart pointer |
| * @return *this |
| */ |
| LocalMemory<T> &operator=(LocalMemory<T> &&src) U_NOEXCEPT { |
| uprv_free(LocalPointerBase<T>::ptr); |
| LocalPointerBase<T>::ptr=src.ptr; |
| src.ptr=NULL; |
| return *this; |
| } |
| /** |
| * Swap pointers. |
| * @param other other smart pointer |
| */ |
| void swap(LocalMemory<T> &other) U_NOEXCEPT { |
| T *temp=LocalPointerBase<T>::ptr; |
| LocalPointerBase<T>::ptr=other.ptr; |
| other.ptr=temp; |
| } |
| /** |
| * Non-member LocalMemory swap function. |
| * @param p1 will get p2's pointer |
| * @param p2 will get p1's pointer |
| */ |
| friend inline void swap(LocalMemory<T> &p1, LocalMemory<T> &p2) U_NOEXCEPT { |
| p1.swap(p2); |
| } |
| /** |
| * Deletes the array it owns, |
| * and adopts (takes ownership of) the one passed in. |
| * @param p simple pointer to an array of T items that is adopted |
| */ |
| void adoptInstead(T *p) { |
| uprv_free(LocalPointerBase<T>::ptr); |
| LocalPointerBase<T>::ptr=p; |
| } |
| /** |
| * Deletes the array it owns, allocates a new one and reset its bytes to 0. |
| * Returns the new array pointer. |
| * If the allocation fails, then the current array is unchanged and |
| * this method returns NULL. |
| * @param newCapacity must be >0 |
| * @return the allocated array pointer, or NULL if the allocation failed |
| */ |
| inline T *allocateInsteadAndReset(int32_t newCapacity=1); |
| /** |
| * Deletes the array it owns and allocates a new one, copying length T items. |
| * Returns the new array pointer. |
| * If the allocation fails, then the current array is unchanged and |
| * this method returns NULL. |
| * @param newCapacity must be >0 |
| * @param length number of T items to be copied from the old array to the new one; |
| * must be no more than the capacity of the old array, |
| * which the caller must track because the LocalMemory does not track it |
| * @return the allocated array pointer, or NULL if the allocation failed |
| */ |
| inline T *allocateInsteadAndCopy(int32_t newCapacity=1, int32_t length=0); |
| /** |
| * Array item access (writable). |
| * No index bounds check. |
| * @param i array index |
| * @return reference to the array item |
| */ |
| T &operator[](ptrdiff_t i) const { return LocalPointerBase<T>::ptr[i]; } |
| }; |
| |
| template<typename T> |
| inline T *LocalMemory<T>::allocateInsteadAndReset(int32_t newCapacity) { |
| if(newCapacity>0) { |
| T *p=(T *)uprv_malloc(newCapacity*sizeof(T)); |
| if(p!=NULL) { |
| uprv_memset(p, 0, newCapacity*sizeof(T)); |
| uprv_free(LocalPointerBase<T>::ptr); |
| LocalPointerBase<T>::ptr=p; |
| } |
| return p; |
| } else { |
| return NULL; |
| } |
| } |
| |
| |
| template<typename T> |
| inline T *LocalMemory<T>::allocateInsteadAndCopy(int32_t newCapacity, int32_t length) { |
| if(newCapacity>0) { |
| T *p=(T *)uprv_malloc(newCapacity*sizeof(T)); |
| if(p!=NULL) { |
| if(length>0) { |
| if(length>newCapacity) { |
| length=newCapacity; |
| } |
| uprv_memcpy(p, LocalPointerBase<T>::ptr, (size_t)length*sizeof(T)); |
| } |
| uprv_free(LocalPointerBase<T>::ptr); |
| LocalPointerBase<T>::ptr=p; |
| } |
| return p; |
| } else { |
| return NULL; |
| } |
| } |
| |
| /** |
| * Simple array/buffer management class using uprv_malloc() and uprv_free(). |
| * Provides an internal array with fixed capacity. Can alias another array |
| * or allocate one. |
| * |
| * The array address is properly aligned for type T. It might not be properly |
| * aligned for types larger than T (or larger than the largest subtype of T). |
| * |
| * Unlike LocalMemory and LocalArray, this class never adopts |
| * (takes ownership of) another array. |
| * |
| * WARNING: MaybeStackArray only works with primitive (plain-old data) types. |
| * It does NOT know how to call a destructor! If you work with classes with |
| * destructors, consider: |
| * |
| * - LocalArray in localpointer.h if you know the length ahead of time |
| * - MaybeStackVector if you know the length at runtime |
| */ |
| template<typename T, int32_t stackCapacity> |
| class MaybeStackArray { |
| public: |
| // No heap allocation. Use only on the stack. |
| static void* U_EXPORT2 operator new(size_t) U_NOEXCEPT = delete; |
| static void* U_EXPORT2 operator new[](size_t) U_NOEXCEPT = delete; |
| #if U_HAVE_PLACEMENT_NEW |
| static void* U_EXPORT2 operator new(size_t, void*) U_NOEXCEPT = delete; |
| #endif |
| |
| /** |
| * Default constructor initializes with internal T[stackCapacity] buffer. |
| */ |
| MaybeStackArray() : ptr(stackArray), capacity(stackCapacity), needToRelease(false) {} |
| /** |
| * Automatically allocates the heap array if the argument is larger than the stack capacity. |
| * Intended for use when an approximate capacity is known at compile time but the true |
| * capacity is not known until runtime. |
| */ |
| MaybeStackArray(int32_t newCapacity, UErrorCode status) : MaybeStackArray() { |
| if (U_FAILURE(status)) { |
| return; |
| } |
| if (capacity < newCapacity) { |
| if (resize(newCapacity) == nullptr) { |
| status = U_MEMORY_ALLOCATION_ERROR; |
| } |
| } |
| } |
| /** |
| * Destructor deletes the array (if owned). |
| */ |
| ~MaybeStackArray() { releaseArray(); } |
| /** |
| * Move constructor: transfers ownership or copies the stack array. |
| */ |
| MaybeStackArray(MaybeStackArray<T, stackCapacity> &&src) U_NOEXCEPT; |
| /** |
| * Move assignment: transfers ownership or copies the stack array. |
| */ |
| MaybeStackArray<T, stackCapacity> &operator=(MaybeStackArray<T, stackCapacity> &&src) U_NOEXCEPT; |
| /** |
| * Returns the array capacity (number of T items). |
| * @return array capacity |
| */ |
| int32_t getCapacity() const { return capacity; } |
| /** |
| * Access without ownership change. |
| * @return the array pointer |
| */ |
| T *getAlias() const { return ptr; } |
| /** |
| * Returns the array limit. Simple convenience method. |
| * @return getAlias()+getCapacity() |
| */ |
| T *getArrayLimit() const { return getAlias()+capacity; } |
| // No "operator T *() const" because that can make |
| // expressions like mbs[index] ambiguous for some compilers. |
| /** |
| * Array item access (const). |
| * No index bounds check. |
| * @param i array index |
| * @return reference to the array item |
| */ |
| const T &operator[](ptrdiff_t i) const { return ptr[i]; } |
| /** |
| * Array item access (writable). |
| * No index bounds check. |
| * @param i array index |
| * @return reference to the array item |
| */ |
| T &operator[](ptrdiff_t i) { return ptr[i]; } |
| /** |
| * Deletes the array (if owned) and aliases another one, no transfer of ownership. |
| * If the arguments are illegal, then the current array is unchanged. |
| * @param otherArray must not be NULL |
| * @param otherCapacity must be >0 |
| */ |
| void aliasInstead(T *otherArray, int32_t otherCapacity) { |
| if(otherArray!=NULL && otherCapacity>0) { |
| releaseArray(); |
| ptr=otherArray; |
| capacity=otherCapacity; |
| needToRelease=false; |
| } |
| } |
| /** |
| * Deletes the array (if owned) and allocates a new one, copying length T items. |
| * Returns the new array pointer. |
| * If the allocation fails, then the current array is unchanged and |
| * this method returns NULL. |
| * @param newCapacity can be less than or greater than the current capacity; |
| * must be >0 |
| * @param length number of T items to be copied from the old array to the new one |
| * @return the allocated array pointer, or NULL if the allocation failed |
| */ |
| inline T *resize(int32_t newCapacity, int32_t length=0); |
| /** |
| * Gives up ownership of the array if owned, or else clones it, |
| * copying length T items; resets itself to the internal stack array. |
| * Returns NULL if the allocation failed. |
| * @param length number of T items to copy when cloning, |
| * and capacity of the clone when cloning |
| * @param resultCapacity will be set to the returned array's capacity (output-only) |
| * @return the array pointer; |
| * caller becomes responsible for deleting the array |
| */ |
| inline T *orphanOrClone(int32_t length, int32_t &resultCapacity); |
| |
| protected: |
| // Resizes the array to the size of src, then copies the contents of src. |
| void copyFrom(const MaybeStackArray &src, UErrorCode &status) { |
| if (U_FAILURE(status)) { |
| return; |
| } |
| if (this->resize(src.capacity, 0) == NULL) { |
| status = U_MEMORY_ALLOCATION_ERROR; |
| return; |
| } |
| uprv_memcpy(this->ptr, src.ptr, (size_t)capacity * sizeof(T)); |
| } |
| |
| private: |
| T *ptr; |
| int32_t capacity; |
| UBool needToRelease; |
| T stackArray[stackCapacity]; |
| void releaseArray() { |
| if(needToRelease) { |
| uprv_free(ptr); |
| } |
| } |
| void resetToStackArray() { |
| ptr=stackArray; |
| capacity=stackCapacity; |
| needToRelease=false; |
| } |
| /* No comparison operators with other MaybeStackArray's. */ |
| bool operator==(const MaybeStackArray & /*other*/) = delete; |
| bool operator!=(const MaybeStackArray & /*other*/) = delete; |
| /* No ownership transfer: No copy constructor, no assignment operator. */ |
| MaybeStackArray(const MaybeStackArray & /*other*/) = delete; |
| void operator=(const MaybeStackArray & /*other*/) = delete; |
| }; |
| |
| template<typename T, int32_t stackCapacity> |
| icu::MaybeStackArray<T, stackCapacity>::MaybeStackArray( |
| MaybeStackArray <T, stackCapacity>&& src) U_NOEXCEPT |
| : ptr(src.ptr), capacity(src.capacity), needToRelease(src.needToRelease) { |
| if (src.ptr == src.stackArray) { |
| ptr = stackArray; |
| uprv_memcpy(stackArray, src.stackArray, sizeof(T) * src.capacity); |
| } else { |
| src.resetToStackArray(); // take ownership away from src |
| } |
| } |
| |
| template<typename T, int32_t stackCapacity> |
| inline MaybeStackArray <T, stackCapacity>& |
| MaybeStackArray<T, stackCapacity>::operator=(MaybeStackArray <T, stackCapacity>&& src) U_NOEXCEPT { |
| releaseArray(); // in case this instance had its own memory allocated |
| capacity = src.capacity; |
| needToRelease = src.needToRelease; |
| if (src.ptr == src.stackArray) { |
| ptr = stackArray; |
| uprv_memcpy(stackArray, src.stackArray, sizeof(T) * src.capacity); |
| } else { |
| ptr = src.ptr; |
| src.resetToStackArray(); // take ownership away from src |
| } |
| return *this; |
| } |
| |
| template<typename T, int32_t stackCapacity> |
| inline T *MaybeStackArray<T, stackCapacity>::resize(int32_t newCapacity, int32_t length) { |
| if(newCapacity>0) { |
| #if U_DEBUG && defined(UPRV_MALLOC_COUNT) |
| ::fprintf(::stderr, "MaybeStackArray (resize) alloc %d * %lu\n", newCapacity, sizeof(T)); |
| #endif |
| T *p=(T *)uprv_malloc(newCapacity*sizeof(T)); |
| if(p!=NULL) { |
| if(length>0) { |
| if(length>capacity) { |
| length=capacity; |
| } |
| if(length>newCapacity) { |
| length=newCapacity; |
| } |
| uprv_memcpy(p, ptr, (size_t)length*sizeof(T)); |
| } |
| releaseArray(); |
| ptr=p; |
| capacity=newCapacity; |
| needToRelease=true; |
| } |
| return p; |
| } else { |
| return NULL; |
| } |
| } |
| |
| template<typename T, int32_t stackCapacity> |
| inline T *MaybeStackArray<T, stackCapacity>::orphanOrClone(int32_t length, int32_t &resultCapacity) { |
| T *p; |
| if(needToRelease) { |
| p=ptr; |
| } else if(length<=0) { |
| return NULL; |
| } else { |
| if(length>capacity) { |
| length=capacity; |
| } |
| p=(T *)uprv_malloc(length*sizeof(T)); |
| #if U_DEBUG && defined(UPRV_MALLOC_COUNT) |
| ::fprintf(::stderr,"MaybeStacArray (orphan) alloc %d * %lu\n", length,sizeof(T)); |
| #endif |
| if(p==NULL) { |
| return NULL; |
| } |
| uprv_memcpy(p, ptr, (size_t)length*sizeof(T)); |
| } |
| resultCapacity=length; |
| resetToStackArray(); |
| return p; |
| } |
| |
| /** |
| * Variant of MaybeStackArray that allocates a header struct and an array |
| * in one contiguous memory block, using uprv_malloc() and uprv_free(). |
| * Provides internal memory with fixed array capacity. Can alias another memory |
| * block or allocate one. |
| * The stackCapacity is the number of T items in the internal memory, |
| * not counting the H header. |
| * Unlike LocalMemory and LocalArray, this class never adopts |
| * (takes ownership of) another memory block. |
| */ |
| template<typename H, typename T, int32_t stackCapacity> |
| class MaybeStackHeaderAndArray { |
| public: |
| // No heap allocation. Use only on the stack. |
| static void* U_EXPORT2 operator new(size_t) U_NOEXCEPT = delete; |
| static void* U_EXPORT2 operator new[](size_t) U_NOEXCEPT = delete; |
| #if U_HAVE_PLACEMENT_NEW |
| static void* U_EXPORT2 operator new(size_t, void*) U_NOEXCEPT = delete; |
| #endif |
| |
| /** |
| * Default constructor initializes with internal H+T[stackCapacity] buffer. |
| */ |
| MaybeStackHeaderAndArray() : ptr(&stackHeader), capacity(stackCapacity), needToRelease(false) {} |
| /** |
| * Destructor deletes the memory (if owned). |
| */ |
| ~MaybeStackHeaderAndArray() { releaseMemory(); } |
| /** |
| * Returns the array capacity (number of T items). |
| * @return array capacity |
| */ |
| int32_t getCapacity() const { return capacity; } |
| /** |
| * Access without ownership change. |
| * @return the header pointer |
| */ |
| H *getAlias() const { return ptr; } |
| /** |
| * Returns the array start. |
| * @return array start, same address as getAlias()+1 |
| */ |
| T *getArrayStart() const { return reinterpret_cast<T *>(getAlias()+1); } |
| /** |
| * Returns the array limit. |
| * @return array limit |
| */ |
| T *getArrayLimit() const { return getArrayStart()+capacity; } |
| /** |
| * Access without ownership change. Same as getAlias(). |
| * A class instance can be used directly in expressions that take a T *. |
| * @return the header pointer |
| */ |
| operator H *() const { return ptr; } |
| /** |
| * Array item access (writable). |
| * No index bounds check. |
| * @param i array index |
| * @return reference to the array item |
| */ |
| T &operator[](ptrdiff_t i) { return getArrayStart()[i]; } |
| /** |
| * Deletes the memory block (if owned) and aliases another one, no transfer of ownership. |
| * If the arguments are illegal, then the current memory is unchanged. |
| * @param otherArray must not be NULL |
| * @param otherCapacity must be >0 |
| */ |
| void aliasInstead(H *otherMemory, int32_t otherCapacity) { |
| if(otherMemory!=NULL && otherCapacity>0) { |
| releaseMemory(); |
| ptr=otherMemory; |
| capacity=otherCapacity; |
| needToRelease=false; |
| } |
| } |
| /** |
| * Deletes the memory block (if owned) and allocates a new one, |
| * copying the header and length T array items. |
| * Returns the new header pointer. |
| * If the allocation fails, then the current memory is unchanged and |
| * this method returns NULL. |
| * @param newCapacity can be less than or greater than the current capacity; |
| * must be >0 |
| * @param length number of T items to be copied from the old array to the new one |
| * @return the allocated pointer, or NULL if the allocation failed |
| */ |
| inline H *resize(int32_t newCapacity, int32_t length=0); |
| /** |
| * Gives up ownership of the memory if owned, or else clones it, |
| * copying the header and length T array items; resets itself to the internal memory. |
| * Returns NULL if the allocation failed. |
| * @param length number of T items to copy when cloning, |
| * and array capacity of the clone when cloning |
| * @param resultCapacity will be set to the returned array's capacity (output-only) |
| * @return the header pointer; |
| * caller becomes responsible for deleting the array |
| */ |
| inline H *orphanOrClone(int32_t length, int32_t &resultCapacity); |
| private: |
| H *ptr; |
| int32_t capacity; |
| UBool needToRelease; |
| // stackHeader must precede stackArray immediately. |
| H stackHeader; |
| T stackArray[stackCapacity]; |
| void releaseMemory() { |
| if(needToRelease) { |
| uprv_free(ptr); |
| } |
| } |
| /* No comparison operators with other MaybeStackHeaderAndArray's. */ |
| bool operator==(const MaybeStackHeaderAndArray & /*other*/) {return false;} |
| bool operator!=(const MaybeStackHeaderAndArray & /*other*/) {return true;} |
| /* No ownership transfer: No copy constructor, no assignment operator. */ |
| MaybeStackHeaderAndArray(const MaybeStackHeaderAndArray & /*other*/) {} |
| void operator=(const MaybeStackHeaderAndArray & /*other*/) {} |
| }; |
| |
| template<typename H, typename T, int32_t stackCapacity> |
| inline H *MaybeStackHeaderAndArray<H, T, stackCapacity>::resize(int32_t newCapacity, |
| int32_t length) { |
| if(newCapacity>=0) { |
| #if U_DEBUG && defined(UPRV_MALLOC_COUNT) |
| ::fprintf(::stderr,"MaybeStackHeaderAndArray alloc %d + %d * %ul\n", sizeof(H),newCapacity,sizeof(T)); |
| #endif |
| H *p=(H *)uprv_malloc(sizeof(H)+newCapacity*sizeof(T)); |
| if(p!=NULL) { |
| if(length<0) { |
| length=0; |
| } else if(length>0) { |
| if(length>capacity) { |
| length=capacity; |
| } |
| if(length>newCapacity) { |
| length=newCapacity; |
| } |
| } |
| uprv_memcpy(p, ptr, sizeof(H)+(size_t)length*sizeof(T)); |
| releaseMemory(); |
| ptr=p; |
| capacity=newCapacity; |
| needToRelease=true; |
| } |
| return p; |
| } else { |
| return NULL; |
| } |
| } |
| |
| template<typename H, typename T, int32_t stackCapacity> |
| inline H *MaybeStackHeaderAndArray<H, T, stackCapacity>::orphanOrClone(int32_t length, |
| int32_t &resultCapacity) { |
| H *p; |
| if(needToRelease) { |
| p=ptr; |
| } else { |
| if(length<0) { |
| length=0; |
| } else if(length>capacity) { |
| length=capacity; |
| } |
| #if U_DEBUG && defined(UPRV_MALLOC_COUNT) |
| ::fprintf(::stderr,"MaybeStackHeaderAndArray (orphan) alloc %ul + %d * %lu\n", sizeof(H),length,sizeof(T)); |
| #endif |
| p=(H *)uprv_malloc(sizeof(H)+length*sizeof(T)); |
| if(p==NULL) { |
| return NULL; |
| } |
| uprv_memcpy(p, ptr, sizeof(H)+(size_t)length*sizeof(T)); |
| } |
| resultCapacity=length; |
| ptr=&stackHeader; |
| capacity=stackCapacity; |
| needToRelease=false; |
| return p; |
| } |
| |
| /** |
| * A simple memory management class that creates new heap allocated objects (of |
| * any class that has a public constructor), keeps track of them and eventually |
| * deletes them all in its own destructor. |
| * |
| * A typical use-case would be code like this: |
| * |
| * MemoryPool<MyType> pool; |
| * |
| * MyType* o1 = pool.create(); |
| * if (o1 != nullptr) { |
| * foo(o1); |
| * } |
| * |
| * MyType* o2 = pool.create(1, 2, 3); |
| * if (o2 != nullptr) { |
| * bar(o2); |
| * } |
| * |
| * // MemoryPool will take care of deleting the MyType objects. |
| * |
| * It doesn't do anything more than that, and is intentionally kept minimalist. |
| */ |
| template<typename T, int32_t stackCapacity = 8> |
| class MemoryPool : public UMemory { |
| public: |
| MemoryPool() : fCount(0), fPool() {} |
| |
| ~MemoryPool() { |
| for (int32_t i = 0; i < fCount; ++i) { |
| delete fPool[i]; |
| } |
| } |
| |
| MemoryPool(const MemoryPool&) = delete; |
| MemoryPool& operator=(const MemoryPool&) = delete; |
| |
| MemoryPool(MemoryPool&& other) U_NOEXCEPT : fCount(other.fCount), |
| fPool(std::move(other.fPool)) { |
| other.fCount = 0; |
| } |
| |
| MemoryPool& operator=(MemoryPool&& other) U_NOEXCEPT { |
| // Since `this` may contain instances that need to be deleted, we can't |
| // just throw them away and replace them with `other`. The normal way of |
| // dealing with this in C++ is to swap `this` and `other`, rather than |
| // simply overwrite: the destruction of `other` can then take care of |
| // running MemoryPool::~MemoryPool() over the still-to-be-deallocated |
| // instances. |
| std::swap(fCount, other.fCount); |
| std::swap(fPool, other.fPool); |
| return *this; |
| } |
| |
| /** |
| * Creates a new object of typename T, by forwarding any and all arguments |
| * to the typename T constructor. |
| * |
| * @param args Arguments to be forwarded to the typename T constructor. |
| * @return A pointer to the newly created object, or nullptr on error. |
| */ |
| template<typename... Args> |
| T* create(Args&&... args) { |
| int32_t capacity = fPool.getCapacity(); |
| if (fCount == capacity && |
| fPool.resize(capacity == stackCapacity ? 4 * capacity : 2 * capacity, |
| capacity) == nullptr) { |
| return nullptr; |
| } |
| return fPool[fCount++] = new T(std::forward<Args>(args)...); |
| } |
| |
| template <typename... Args> |
| T* createAndCheckErrorCode(UErrorCode &status, Args &&... args) { |
| if (U_FAILURE(status)) { |
| return nullptr; |
| } |
| T *pointer = this->create(args...); |
| if (U_SUCCESS(status) && pointer == nullptr) { |
| status = U_MEMORY_ALLOCATION_ERROR; |
| } |
| return pointer; |
| } |
| |
| /** |
| * @return Number of elements that have been allocated. |
| */ |
| int32_t count() const { |
| return fCount; |
| } |
| |
| protected: |
| int32_t fCount; |
| MaybeStackArray<T*, stackCapacity> fPool; |
| }; |
| |
| /** |
| * An internal Vector-like implementation based on MemoryPool. |
| * |
| * Heap-allocates each element and stores pointers. |
| * |
| * To append an item to the vector, use emplaceBack. |
| * |
| * MaybeStackVector<MyType> vector; |
| * MyType* element = vector.emplaceBack(); |
| * if (!element) { |
| * status = U_MEMORY_ALLOCATION_ERROR; |
| * } |
| * // do stuff with element |
| * |
| * To loop over the vector, use a for loop with indices: |
| * |
| * for (int32_t i = 0; i < vector.length(); i++) { |
| * MyType* element = vector[i]; |
| * } |
| */ |
| template<typename T, int32_t stackCapacity = 8> |
| class MaybeStackVector : protected MemoryPool<T, stackCapacity> { |
| public: |
| template<typename... Args> |
| T* emplaceBack(Args&&... args) { |
| return this->create(args...); |
| } |
| |
| template <typename... Args> |
| T *emplaceBackAndCheckErrorCode(UErrorCode &status, Args &&... args) { |
| return this->createAndCheckErrorCode(status, args...); |
| } |
| |
| int32_t length() const { |
| return this->fCount; |
| } |
| |
| T** getAlias() { |
| return this->fPool.getAlias(); |
| } |
| |
| const T *const *getAlias() const { |
| return this->fPool.getAlias(); |
| } |
| |
| /** |
| * Array item access (read-only). |
| * No index bounds check. |
| * @param i array index |
| * @return reference to the array item |
| */ |
| const T* operator[](ptrdiff_t i) const { |
| return this->fPool[i]; |
| } |
| |
| /** |
| * Array item access (writable). |
| * No index bounds check. |
| * @param i array index |
| * @return reference to the array item |
| */ |
| T* operator[](ptrdiff_t i) { |
| return this->fPool[i]; |
| } |
| }; |
| |
| |
| U_NAMESPACE_END |
| |
| #endif /* __cplusplus */ |
| #endif /* CMEMORY_H */ |
