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1 // © 2016 and later: Unicode, Inc. and others.
2 // License & terms of use: http://www.unicode.org/copyright.html
3 /*
4 ******************************************************************************
5 *
6 *   Copyright (C) 1997-2016, International Business Machines
7 *   Corporation and others.  All Rights Reserved.
8 *
9 ******************************************************************************
10 *
11 * File CMEMORY.H
12 *
13 *  Contains stdlib.h/string.h memory functions
14 *
15 * @author       Bertrand A. Damiba
16 *
17 * Modification History:
18 *
19 *   Date        Name        Description
20 *   6/20/98     Bertrand    Created.
21 *  05/03/99     stephen     Changed from functions to macros.
22 *
23 ******************************************************************************
24 */
25 
26 #ifndef CMEMORY_H
27 #define CMEMORY_H
28 
29 #include "unicode/utypes.h"
30 
31 #include <stddef.h>
32 #include <string.h>
33 #include "unicode/localpointer.h"
34 
35 #if U_DEBUG && defined(UPRV_MALLOC_COUNT)
36 #include <stdio.h>
37 #endif
38 
39 
40 #define uprv_memcpy(dst, src, size) U_STANDARD_CPP_NAMESPACE memcpy(dst, src, size)
41 #define uprv_memmove(dst, src, size) U_STANDARD_CPP_NAMESPACE memmove(dst, src, size)
42 
43 /**
44  * \def UPRV_LENGTHOF
45  * Convenience macro to determine the length of a fixed array at compile-time.
46  * @param array A fixed length array
47  * @return The length of the array, in elements
48  * @internal
49  */
50 #define UPRV_LENGTHOF(array) (int32_t)(sizeof(array)/sizeof((array)[0]))
51 #define uprv_memset(buffer, mark, size) U_STANDARD_CPP_NAMESPACE memset(buffer, mark, size)
52 #define uprv_memcmp(buffer1, buffer2, size) U_STANDARD_CPP_NAMESPACE memcmp(buffer1, buffer2,size)
53 
54 U_CAPI void * U_EXPORT2
55 uprv_malloc(size_t s) U_MALLOC_ATTR U_ALLOC_SIZE_ATTR(1);
56 
57 U_CAPI void * U_EXPORT2
58 uprv_realloc(void *mem, size_t size) U_ALLOC_SIZE_ATTR(2);
59 
60 U_CAPI void U_EXPORT2
61 uprv_free(void *mem);
62 
63 U_CAPI void * U_EXPORT2
64 uprv_calloc(size_t num, size_t size) U_MALLOC_ATTR U_ALLOC_SIZE_ATTR2(1,2);
65 
66 /**
67  * This should align the memory properly on any machine.
68  * This is very useful for the safeClone functions.
69  */
70 typedef union {
71     long    t1;
72     double  t2;
73     void   *t3;
74 } UAlignedMemory;
75 
76 /**
77  * Get the least significant bits of a pointer (a memory address).
78  * For example, with a mask of 3, the macro gets the 2 least significant bits,
79  * which will be 0 if the pointer is 32-bit (4-byte) aligned.
80  *
81  * ptrdiff_t is the most appropriate integer type to cast to.
82  * size_t should work too, since on most (or all?) platforms it has the same
83  * width as ptrdiff_t.
84  */
85 #define U_POINTER_MASK_LSB(ptr, mask) (((ptrdiff_t)(char *)(ptr)) & (mask))
86 
87 /**
88  * Get the amount of bytes that a pointer is off by from
89  * the previous UAlignedMemory-aligned pointer.
90  */
91 #define U_ALIGNMENT_OFFSET(ptr) U_POINTER_MASK_LSB(ptr, sizeof(UAlignedMemory) - 1)
92 
93 /**
94  * Get the amount of bytes to add to a pointer
95  * in order to get the next UAlignedMemory-aligned address.
96  */
97 #define U_ALIGNMENT_OFFSET_UP(ptr) (sizeof(UAlignedMemory) - U_ALIGNMENT_OFFSET(ptr))
98 
99 /**
100   *  Heap clean up function, called from u_cleanup()
101   *    Clears any user heap functions from u_setMemoryFunctions()
102   *    Does NOT deallocate any remaining allocated memory.
103   */
104 U_CFUNC UBool
105 cmemory_cleanup(void);
106 
107 /**
108  * A function called by <TT>uhash_remove</TT>,
109  * <TT>uhash_close</TT>, or <TT>uhash_put</TT> to delete
110  * an existing key or value.
111  * @param obj A key or value stored in a hashtable
112  * @see uprv_deleteUObject
113  */
114 typedef void U_CALLCONV UObjectDeleter(void* obj);
115 
116 /**
117  * Deleter for UObject instances.
118  * Works for all subclasses of UObject because it has a virtual destructor.
119  */
120 U_CAPI void U_EXPORT2
121 uprv_deleteUObject(void *obj);
122 
123 #ifdef __cplusplus
124 
125 U_NAMESPACE_BEGIN
126 
127 /**
128  * "Smart pointer" class, deletes memory via uprv_free().
129  * For most methods see the LocalPointerBase base class.
130  * Adds operator[] for array item access.
131  *
132  * @see LocalPointerBase
133  */
134 template<typename T>
135 class LocalMemory : public LocalPointerBase<T> {
136 public:
137     using LocalPointerBase<T>::operator*;
138     using LocalPointerBase<T>::operator->;
139     /**
140      * Constructor takes ownership.
141      * @param p simple pointer to an array of T items that is adopted
142      */
143     explicit LocalMemory(T *p=NULL) : LocalPointerBase<T>(p) {}
144     /**
145      * Move constructor, leaves src with isNull().
146      * @param src source smart pointer
147      */
LocalMemory(LocalMemory<T> && src)148     LocalMemory(LocalMemory<T> &&src) U_NOEXCEPT : LocalPointerBase<T>(src.ptr) {
149         src.ptr=NULL;
150     }
151     /**
152      * Destructor deletes the memory it owns.
153      */
~LocalMemory()154     ~LocalMemory() {
155         uprv_free(LocalPointerBase<T>::ptr);
156     }
157     /**
158      * Move assignment operator, leaves src with isNull().
159      * The behavior is undefined if *this and src are the same object.
160      * @param src source smart pointer
161      * @return *this
162      */
163     LocalMemory<T> &operator=(LocalMemory<T> &&src) U_NOEXCEPT {
164         return moveFrom(src);
165     }
166     /**
167      * Move assignment, leaves src with isNull().
168      * The behavior is undefined if *this and src are the same object.
169      *
170      * Can be called explicitly, does not need C++11 support.
171      * @param src source smart pointer
172      * @return *this
173      */
moveFrom(LocalMemory<T> & src)174     LocalMemory<T> &moveFrom(LocalMemory<T> &src) U_NOEXCEPT {
175         uprv_free(LocalPointerBase<T>::ptr);
176         LocalPointerBase<T>::ptr=src.ptr;
177         src.ptr=NULL;
178         return *this;
179     }
180     /**
181      * Swap pointers.
182      * @param other other smart pointer
183      */
swap(LocalMemory<T> & other)184     void swap(LocalMemory<T> &other) U_NOEXCEPT {
185         T *temp=LocalPointerBase<T>::ptr;
186         LocalPointerBase<T>::ptr=other.ptr;
187         other.ptr=temp;
188     }
189     /**
190      * Non-member LocalMemory swap function.
191      * @param p1 will get p2's pointer
192      * @param p2 will get p1's pointer
193      */
swap(LocalMemory<T> & p1,LocalMemory<T> & p2)194     friend inline void swap(LocalMemory<T> &p1, LocalMemory<T> &p2) U_NOEXCEPT {
195         p1.swap(p2);
196     }
197     /**
198      * Deletes the array it owns,
199      * and adopts (takes ownership of) the one passed in.
200      * @param p simple pointer to an array of T items that is adopted
201      */
adoptInstead(T * p)202     void adoptInstead(T *p) {
203         uprv_free(LocalPointerBase<T>::ptr);
204         LocalPointerBase<T>::ptr=p;
205     }
206     /**
207      * Deletes the array it owns, allocates a new one and reset its bytes to 0.
208      * Returns the new array pointer.
209      * If the allocation fails, then the current array is unchanged and
210      * this method returns NULL.
211      * @param newCapacity must be >0
212      * @return the allocated array pointer, or NULL if the allocation failed
213      */
214     inline T *allocateInsteadAndReset(int32_t newCapacity=1);
215     /**
216      * Deletes the array it owns and allocates a new one, copying length T items.
217      * Returns the new array pointer.
218      * If the allocation fails, then the current array is unchanged and
219      * this method returns NULL.
220      * @param newCapacity must be >0
221      * @param length number of T items to be copied from the old array to the new one;
222      *               must be no more than the capacity of the old array,
223      *               which the caller must track because the LocalMemory does not track it
224      * @return the allocated array pointer, or NULL if the allocation failed
225      */
226     inline T *allocateInsteadAndCopy(int32_t newCapacity=1, int32_t length=0);
227     /**
228      * Array item access (writable).
229      * No index bounds check.
230      * @param i array index
231      * @return reference to the array item
232      */
233     T &operator[](ptrdiff_t i) const { return LocalPointerBase<T>::ptr[i]; }
234 };
235 
236 template<typename T>
allocateInsteadAndReset(int32_t newCapacity)237 inline T *LocalMemory<T>::allocateInsteadAndReset(int32_t newCapacity) {
238     if(newCapacity>0) {
239         T *p=(T *)uprv_malloc(newCapacity*sizeof(T));
240         if(p!=NULL) {
241             uprv_memset(p, 0, newCapacity*sizeof(T));
242             uprv_free(LocalPointerBase<T>::ptr);
243             LocalPointerBase<T>::ptr=p;
244         }
245         return p;
246     } else {
247         return NULL;
248     }
249 }
250 
251 
252 template<typename T>
allocateInsteadAndCopy(int32_t newCapacity,int32_t length)253 inline T *LocalMemory<T>::allocateInsteadAndCopy(int32_t newCapacity, int32_t length) {
254     if(newCapacity>0) {
255         T *p=(T *)uprv_malloc(newCapacity*sizeof(T));
256         if(p!=NULL) {
257             if(length>0) {
258                 if(length>newCapacity) {
259                     length=newCapacity;
260                 }
261                 uprv_memcpy(p, LocalPointerBase<T>::ptr, (size_t)length*sizeof(T));
262             }
263             uprv_free(LocalPointerBase<T>::ptr);
264             LocalPointerBase<T>::ptr=p;
265         }
266         return p;
267     } else {
268         return NULL;
269     }
270 }
271 
272 /**
273  * Simple array/buffer management class using uprv_malloc() and uprv_free().
274  * Provides an internal array with fixed capacity. Can alias another array
275  * or allocate one.
276  *
277  * The array address is properly aligned for type T. It might not be properly
278  * aligned for types larger than T (or larger than the largest subtype of T).
279  *
280  * Unlike LocalMemory and LocalArray, this class never adopts
281  * (takes ownership of) another array.
282  *
283  * WARNING: MaybeStackArray only works with primitive (plain-old data) types.
284  * It does NOT know how to call a destructor! If you work with classes with
285  * destructors, consider LocalArray in localpointer.h.
286  */
287 template<typename T, int32_t stackCapacity>
288 class MaybeStackArray {
289 public:
290     /**
291      * Default constructor initializes with internal T[stackCapacity] buffer.
292      */
MaybeStackArray()293     MaybeStackArray() : ptr(stackArray), capacity(stackCapacity), needToRelease(FALSE) {}
294     /**
295      * Automatically allocates the heap array if the argument is larger than the stack capacity.
296      * Intended for use when an approximate capacity is known at compile time but the true
297      * capacity is not known until runtime.
298      */
MaybeStackArray(int32_t newCapacity)299     MaybeStackArray(int32_t newCapacity) : MaybeStackArray() {
300         if (capacity < newCapacity) { resize(newCapacity); }
301     };
302     /**
303      * Destructor deletes the array (if owned).
304      */
~MaybeStackArray()305     ~MaybeStackArray() { releaseArray(); }
306     /**
307      * Move constructor: transfers ownership or copies the stack array.
308      */
309     MaybeStackArray(MaybeStackArray<T, stackCapacity> &&src) U_NOEXCEPT;
310     /**
311      * Move assignment: transfers ownership or copies the stack array.
312      */
313     MaybeStackArray<T, stackCapacity> &operator=(MaybeStackArray<T, stackCapacity> &&src) U_NOEXCEPT;
314     /**
315      * Returns the array capacity (number of T items).
316      * @return array capacity
317      */
getCapacity()318     int32_t getCapacity() const { return capacity; }
319     /**
320      * Access without ownership change.
321      * @return the array pointer
322      */
getAlias()323     T *getAlias() const { return ptr; }
324     /**
325      * Returns the array limit. Simple convenience method.
326      * @return getAlias()+getCapacity()
327      */
getArrayLimit()328     T *getArrayLimit() const { return getAlias()+capacity; }
329     // No "operator T *() const" because that can make
330     // expressions like mbs[index] ambiguous for some compilers.
331     /**
332      * Array item access (const).
333      * No index bounds check.
334      * @param i array index
335      * @return reference to the array item
336      */
337     const T &operator[](ptrdiff_t i) const { return ptr[i]; }
338     /**
339      * Array item access (writable).
340      * No index bounds check.
341      * @param i array index
342      * @return reference to the array item
343      */
344     T &operator[](ptrdiff_t i) { return ptr[i]; }
345     /**
346      * Deletes the array (if owned) and aliases another one, no transfer of ownership.
347      * If the arguments are illegal, then the current array is unchanged.
348      * @param otherArray must not be NULL
349      * @param otherCapacity must be >0
350      */
aliasInstead(T * otherArray,int32_t otherCapacity)351     void aliasInstead(T *otherArray, int32_t otherCapacity) {
352         if(otherArray!=NULL && otherCapacity>0) {
353             releaseArray();
354             ptr=otherArray;
355             capacity=otherCapacity;
356             needToRelease=FALSE;
357         }
358     }
359     /**
360      * Deletes the array (if owned) and allocates a new one, copying length T items.
361      * Returns the new array pointer.
362      * If the allocation fails, then the current array is unchanged and
363      * this method returns NULL.
364      * @param newCapacity can be less than or greater than the current capacity;
365      *                    must be >0
366      * @param length number of T items to be copied from the old array to the new one
367      * @return the allocated array pointer, or NULL if the allocation failed
368      */
369     inline T *resize(int32_t newCapacity, int32_t length=0);
370     /**
371      * Gives up ownership of the array if owned, or else clones it,
372      * copying length T items; resets itself to the internal stack array.
373      * Returns NULL if the allocation failed.
374      * @param length number of T items to copy when cloning,
375      *        and capacity of the clone when cloning
376      * @param resultCapacity will be set to the returned array's capacity (output-only)
377      * @return the array pointer;
378      *         caller becomes responsible for deleting the array
379      */
380     inline T *orphanOrClone(int32_t length, int32_t &resultCapacity);
381 private:
382     T *ptr;
383     int32_t capacity;
384     UBool needToRelease;
385     T stackArray[stackCapacity];
releaseArray()386     void releaseArray() {
387         if(needToRelease) {
388             uprv_free(ptr);
389         }
390     }
resetToStackArray()391     void resetToStackArray() {
392         ptr=stackArray;
393         capacity=stackCapacity;
394         needToRelease=FALSE;
395     }
396     /* No comparison operators with other MaybeStackArray's. */
397     bool operator==(const MaybeStackArray & /*other*/) {return FALSE;}
398     bool operator!=(const MaybeStackArray & /*other*/) {return TRUE;}
399     /* No ownership transfer: No copy constructor, no assignment operator. */
MaybeStackArray(const MaybeStackArray &)400     MaybeStackArray(const MaybeStackArray & /*other*/) {}
401     void operator=(const MaybeStackArray & /*other*/) {}
402 
403     // No heap allocation. Use only on the stack.
404     //   (Declaring these functions private triggers a cascade of problems:
405     //      MSVC insists on exporting an instantiation of MaybeStackArray, which
406     //      requires that all functions be defined.
407     //      An empty implementation of new() is rejected, it must return a value.
408     //      Returning NULL is rejected by gcc for operator new.
409     //      The expedient thing is just not to override operator new.
410     //      While relatively pointless, heap allocated instances will function.
411     // static void * U_EXPORT2 operator new(size_t size);
412     // static void * U_EXPORT2 operator new[](size_t size);
413 #if U_HAVE_PLACEMENT_NEW
414     // static void * U_EXPORT2 operator new(size_t, void *ptr);
415 #endif
416 };
417 
418 template<typename T, int32_t stackCapacity>
MaybeStackArray(MaybeStackArray<T,stackCapacity> && src)419 icu::MaybeStackArray<T, stackCapacity>::MaybeStackArray(
420         MaybeStackArray <T, stackCapacity>&& src) U_NOEXCEPT
421         : ptr(src.ptr), capacity(src.capacity), needToRelease(src.needToRelease) {
422     if (src.ptr == src.stackArray) {
423         ptr = stackArray;
424         uprv_memcpy(stackArray, src.stackArray, sizeof(T) * src.capacity);
425     } else {
426         src.resetToStackArray();  // take ownership away from src
427     }
428 }
429 
430 template<typename T, int32_t stackCapacity>
431 inline MaybeStackArray <T, stackCapacity>&
432 MaybeStackArray<T, stackCapacity>::operator=(MaybeStackArray <T, stackCapacity>&& src) U_NOEXCEPT {
433     releaseArray();  // in case this instance had its own memory allocated
434     capacity = src.capacity;
435     needToRelease = src.needToRelease;
436     if (src.ptr == src.stackArray) {
437         ptr = stackArray;
438         uprv_memcpy(stackArray, src.stackArray, sizeof(T) * src.capacity);
439     } else {
440         ptr = src.ptr;
441         src.resetToStackArray();  // take ownership away from src
442     }
443     return *this;
444 }
445 
446 template<typename T, int32_t stackCapacity>
resize(int32_t newCapacity,int32_t length)447 inline T *MaybeStackArray<T, stackCapacity>::resize(int32_t newCapacity, int32_t length) {
448     if(newCapacity>0) {
449 #if U_DEBUG && defined(UPRV_MALLOC_COUNT)
450       ::fprintf(::stderr,"MaybeStacArray (resize) alloc %d * %lu\n", newCapacity,sizeof(T));
451 #endif
452         T *p=(T *)uprv_malloc(newCapacity*sizeof(T));
453         if(p!=NULL) {
454             if(length>0) {
455                 if(length>capacity) {
456                     length=capacity;
457                 }
458                 if(length>newCapacity) {
459                     length=newCapacity;
460                 }
461                 uprv_memcpy(p, ptr, (size_t)length*sizeof(T));
462             }
463             releaseArray();
464             ptr=p;
465             capacity=newCapacity;
466             needToRelease=TRUE;
467         }
468         return p;
469     } else {
470         return NULL;
471     }
472 }
473 
474 template<typename T, int32_t stackCapacity>
orphanOrClone(int32_t length,int32_t & resultCapacity)475 inline T *MaybeStackArray<T, stackCapacity>::orphanOrClone(int32_t length, int32_t &resultCapacity) {
476     T *p;
477     if(needToRelease) {
478         p=ptr;
479     } else if(length<=0) {
480         return NULL;
481     } else {
482         if(length>capacity) {
483             length=capacity;
484         }
485         p=(T *)uprv_malloc(length*sizeof(T));
486 #if U_DEBUG && defined(UPRV_MALLOC_COUNT)
487       ::fprintf(::stderr,"MaybeStacArray (orphan) alloc %d * %lu\n", length,sizeof(T));
488 #endif
489         if(p==NULL) {
490             return NULL;
491         }
492         uprv_memcpy(p, ptr, (size_t)length*sizeof(T));
493     }
494     resultCapacity=length;
495     resetToStackArray();
496     return p;
497 }
498 
499 /**
500  * Variant of MaybeStackArray that allocates a header struct and an array
501  * in one contiguous memory block, using uprv_malloc() and uprv_free().
502  * Provides internal memory with fixed array capacity. Can alias another memory
503  * block or allocate one.
504  * The stackCapacity is the number of T items in the internal memory,
505  * not counting the H header.
506  * Unlike LocalMemory and LocalArray, this class never adopts
507  * (takes ownership of) another memory block.
508  */
509 template<typename H, typename T, int32_t stackCapacity>
510 class MaybeStackHeaderAndArray {
511 public:
512     /**
513      * Default constructor initializes with internal H+T[stackCapacity] buffer.
514      */
MaybeStackHeaderAndArray()515     MaybeStackHeaderAndArray() : ptr(&stackHeader), capacity(stackCapacity), needToRelease(FALSE) {}
516     /**
517      * Destructor deletes the memory (if owned).
518      */
~MaybeStackHeaderAndArray()519     ~MaybeStackHeaderAndArray() { releaseMemory(); }
520     /**
521      * Returns the array capacity (number of T items).
522      * @return array capacity
523      */
getCapacity()524     int32_t getCapacity() const { return capacity; }
525     /**
526      * Access without ownership change.
527      * @return the header pointer
528      */
getAlias()529     H *getAlias() const { return ptr; }
530     /**
531      * Returns the array start.
532      * @return array start, same address as getAlias()+1
533      */
getArrayStart()534     T *getArrayStart() const { return reinterpret_cast<T *>(getAlias()+1); }
535     /**
536      * Returns the array limit.
537      * @return array limit
538      */
getArrayLimit()539     T *getArrayLimit() const { return getArrayStart()+capacity; }
540     /**
541      * Access without ownership change. Same as getAlias().
542      * A class instance can be used directly in expressions that take a T *.
543      * @return the header pointer
544      */
545     operator H *() const { return ptr; }
546     /**
547      * Array item access (writable).
548      * No index bounds check.
549      * @param i array index
550      * @return reference to the array item
551      */
552     T &operator[](ptrdiff_t i) { return getArrayStart()[i]; }
553     /**
554      * Deletes the memory block (if owned) and aliases another one, no transfer of ownership.
555      * If the arguments are illegal, then the current memory is unchanged.
556      * @param otherArray must not be NULL
557      * @param otherCapacity must be >0
558      */
aliasInstead(H * otherMemory,int32_t otherCapacity)559     void aliasInstead(H *otherMemory, int32_t otherCapacity) {
560         if(otherMemory!=NULL && otherCapacity>0) {
561             releaseMemory();
562             ptr=otherMemory;
563             capacity=otherCapacity;
564             needToRelease=FALSE;
565         }
566     }
567     /**
568      * Deletes the memory block (if owned) and allocates a new one,
569      * copying the header and length T array items.
570      * Returns the new header pointer.
571      * If the allocation fails, then the current memory is unchanged and
572      * this method returns NULL.
573      * @param newCapacity can be less than or greater than the current capacity;
574      *                    must be >0
575      * @param length number of T items to be copied from the old array to the new one
576      * @return the allocated pointer, or NULL if the allocation failed
577      */
578     inline H *resize(int32_t newCapacity, int32_t length=0);
579     /**
580      * Gives up ownership of the memory if owned, or else clones it,
581      * copying the header and length T array items; resets itself to the internal memory.
582      * Returns NULL if the allocation failed.
583      * @param length number of T items to copy when cloning,
584      *        and array capacity of the clone when cloning
585      * @param resultCapacity will be set to the returned array's capacity (output-only)
586      * @return the header pointer;
587      *         caller becomes responsible for deleting the array
588      */
589     inline H *orphanOrClone(int32_t length, int32_t &resultCapacity);
590 private:
591     H *ptr;
592     int32_t capacity;
593     UBool needToRelease;
594     // stackHeader must precede stackArray immediately.
595     H stackHeader;
596     T stackArray[stackCapacity];
releaseMemory()597     void releaseMemory() {
598         if(needToRelease) {
599             uprv_free(ptr);
600         }
601     }
602     /* No comparison operators with other MaybeStackHeaderAndArray's. */
603     bool operator==(const MaybeStackHeaderAndArray & /*other*/) {return FALSE;}
604     bool operator!=(const MaybeStackHeaderAndArray & /*other*/) {return TRUE;}
605     /* No ownership transfer: No copy constructor, no assignment operator. */
MaybeStackHeaderAndArray(const MaybeStackHeaderAndArray &)606     MaybeStackHeaderAndArray(const MaybeStackHeaderAndArray & /*other*/) {}
607     void operator=(const MaybeStackHeaderAndArray & /*other*/) {}
608 
609     // No heap allocation. Use only on the stack.
610     //   (Declaring these functions private triggers a cascade of problems;
611     //    see the MaybeStackArray class for details.)
612     // static void * U_EXPORT2 operator new(size_t size);
613     // static void * U_EXPORT2 operator new[](size_t size);
614 #if U_HAVE_PLACEMENT_NEW
615     // static void * U_EXPORT2 operator new(size_t, void *ptr);
616 #endif
617 };
618 
619 template<typename H, typename T, int32_t stackCapacity>
resize(int32_t newCapacity,int32_t length)620 inline H *MaybeStackHeaderAndArray<H, T, stackCapacity>::resize(int32_t newCapacity,
621                                                                 int32_t length) {
622     if(newCapacity>=0) {
623 #if U_DEBUG && defined(UPRV_MALLOC_COUNT)
624       ::fprintf(::stderr,"MaybeStackHeaderAndArray alloc %d + %d * %ul\n", sizeof(H),newCapacity,sizeof(T));
625 #endif
626         H *p=(H *)uprv_malloc(sizeof(H)+newCapacity*sizeof(T));
627         if(p!=NULL) {
628             if(length<0) {
629                 length=0;
630             } else if(length>0) {
631                 if(length>capacity) {
632                     length=capacity;
633                 }
634                 if(length>newCapacity) {
635                     length=newCapacity;
636                 }
637             }
638             uprv_memcpy(p, ptr, sizeof(H)+(size_t)length*sizeof(T));
639             releaseMemory();
640             ptr=p;
641             capacity=newCapacity;
642             needToRelease=TRUE;
643         }
644         return p;
645     } else {
646         return NULL;
647     }
648 }
649 
650 template<typename H, typename T, int32_t stackCapacity>
orphanOrClone(int32_t length,int32_t & resultCapacity)651 inline H *MaybeStackHeaderAndArray<H, T, stackCapacity>::orphanOrClone(int32_t length,
652                                                                        int32_t &resultCapacity) {
653     H *p;
654     if(needToRelease) {
655         p=ptr;
656     } else {
657         if(length<0) {
658             length=0;
659         } else if(length>capacity) {
660             length=capacity;
661         }
662 #if U_DEBUG && defined(UPRV_MALLOC_COUNT)
663       ::fprintf(::stderr,"MaybeStackHeaderAndArray (orphan) alloc %ul + %d * %lu\n", sizeof(H),length,sizeof(T));
664 #endif
665         p=(H *)uprv_malloc(sizeof(H)+length*sizeof(T));
666         if(p==NULL) {
667             return NULL;
668         }
669         uprv_memcpy(p, ptr, sizeof(H)+(size_t)length*sizeof(T));
670     }
671     resultCapacity=length;
672     ptr=&stackHeader;
673     capacity=stackCapacity;
674     needToRelease=FALSE;
675     return p;
676 }
677 
678 U_NAMESPACE_END
679 
680 #endif  /* __cplusplus */
681 #endif  /* CMEMORY_H */
682