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gecko-dev/intl/icu/source/common/cmemory.h

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// © 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"
#if U_DEBUG && defined(UPRV_MALLOC_COUNT)
#include <stdio.h>
#endif
#if U_DEBUG
/*
* The C++ standard requires that the source pointer for memcpy() & memmove()
* is valid, not NULL, and not at the end of an allocated memory block.
* In debug mode, we read one byte from the source point to verify that it's
* a valid, readable pointer.
*/
U_CAPI void uprv_checkValidMemory(const void *p, size_t n);
#define uprv_memcpy(dst, src, size) ( \
uprv_checkValidMemory(src, 1), \
U_STANDARD_CPP_NAMESPACE memcpy(dst, src, size))
#define uprv_memmove(dst, src, size) ( \
uprv_checkValidMemory(src, 1), \
U_STANDARD_CPP_NAMESPACE memmove(dst, src, size))
#else
#define uprv_memcpy(dst, src, size) U_STANDARD_CPP_NAMESPACE memcpy(dst, src, size)
#define uprv_memmove(dst, src, size) U_STANDARD_CPP_NAMESPACE memmove(dst, src, size)
#endif /* U_DEBUG */
/**
* \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)
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);
/**
* This should align the memory properly on any machine.
* This is very useful for the safeClone functions.
*/
typedef union {
long t1;
double t2;
void *t3;
} UAlignedMemory;
/**
* 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.
*
* ptrdiff_t is the most appropriate integer type to cast to.
* size_t should work too, since on most (or all?) platforms it has the same
* width as ptrdiff_t.
*/
#define U_POINTER_MASK_LSB(ptr, mask) (((ptrdiff_t)(char *)(ptr)) & (mask))
/**
* Get the amount of bytes that a pointer is off by from
* the previous UAlignedMemory-aligned pointer.
*/
#define U_ALIGNMENT_OFFSET(ptr) U_POINTER_MASK_LSB(ptr, sizeof(UAlignedMemory) - 1)
/**
* Get the amount of bytes to add to a pointer
* in order to get the next UAlignedMemory-aligned address.
*/
#define U_ALIGNMENT_OFFSET_UP(ptr) (sizeof(UAlignedMemory) - U_ALIGNMENT_OFFSET(ptr))
/**
* 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
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) {}
#if U_HAVE_RVALUE_REFERENCES
/**
* Move constructor, leaves src with isNull().
* @param src source smart pointer
*/
LocalMemory(LocalMemory<T> &&src) U_NOEXCEPT : LocalPointerBase<T>(src.ptr) {
src.ptr=NULL;
}
#endif
/**
* Destructor deletes the memory it owns.
*/
~LocalMemory() {
uprv_free(LocalPointerBase<T>::ptr);
}
#if U_HAVE_RVALUE_REFERENCES
/**
* 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 {
return moveFrom(src);
}
#endif
/**
* Move assignment, leaves src with isNull().
* The behavior is undefined if *this and src are the same object.
*
* Can be called explicitly, does not need C++11 support.
* @param src source smart pointer
* @return *this
*/
LocalMemory<T> &moveFrom(LocalMemory<T> &src) U_NOEXCEPT {
delete[] 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.
*/
template<typename T, int32_t stackCapacity>
class MaybeStackArray {
public:
/**
* Default constructor initializes with internal T[stackCapacity] buffer.
*/
MaybeStackArray() : ptr(stackArray), capacity(stackCapacity), needToRelease(FALSE) {}
/**
* Destructor deletes the array (if owned).
*/
~MaybeStackArray() { releaseArray(); }
/**
* 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);
private:
T *ptr;
int32_t capacity;
UBool needToRelease;
T stackArray[stackCapacity];
void releaseArray() {
if(needToRelease) {
uprv_free(ptr);
}
}
/* No comparison operators with other MaybeStackArray's. */
bool operator==(const MaybeStackArray & /*other*/) {return FALSE;}
bool operator!=(const MaybeStackArray & /*other*/) {return TRUE;}
/* No ownership transfer: No copy constructor, no assignment operator. */
MaybeStackArray(const MaybeStackArray & /*other*/) {}
void operator=(const MaybeStackArray & /*other*/) {}
// No heap allocation. Use only on the stack.
// (Declaring these functions private triggers a cascade of problems:
// MSVC insists on exporting an instantiation of MaybeStackArray, which
// requires that all functions be defined.
// An empty implementation of new() is rejected, it must return a value.
// Returning NULL is rejected by gcc for operator new.
// The expedient thing is just not to override operator new.
// While relatively pointless, heap allocated instances will function.
// static void * U_EXPORT2 operator new(size_t size);
// static void * U_EXPORT2 operator new[](size_t size);
#if U_HAVE_PLACEMENT_NEW
// static void * U_EXPORT2 operator new(size_t, void *ptr);
#endif
};
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,"MaybeStacArray (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;
ptr=stackArray;
capacity=stackCapacity;
needToRelease=FALSE;
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:
/**
* 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*/) {}
// No heap allocation. Use only on the stack.
// (Declaring these functions private triggers a cascade of problems;
// see the MaybeStackArray class for details.)
// static void * U_EXPORT2 operator new(size_t size);
// static void * U_EXPORT2 operator new[](size_t size);
#if U_HAVE_PLACEMENT_NEW
// static void * U_EXPORT2 operator new(size_t, void *ptr);
#endif
};
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;
}
U_NAMESPACE_END
#endif /* __cplusplus */
#endif /* CMEMORY_H */
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