-
-
Notifications
You must be signed in to change notification settings - Fork 727
/
cmemory.h
900 lines (847 loc) · 30 KB
/
cmemory.h
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
// © 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=nullptr) : LocalPointerBase<T>(p) {}
/**
* Move constructor, leaves src with isNull().
* @param src source smart pointer
*/
LocalMemory(LocalMemory<T> &&src) noexcept : LocalPointerBase<T>(src.ptr) {
src.ptr=nullptr;
}
/**
* 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) noexcept {
uprv_free(LocalPointerBase<T>::ptr);
LocalPointerBase<T>::ptr=src.ptr;
src.ptr=nullptr;
return *this;
}
/**
* Swap pointers.
* @param other other smart pointer
*/
void swap(LocalMemory<T> &other) 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) 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 nullptr.
* @param newCapacity must be >0
* @return the allocated array pointer, or nullptr 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 nullptr.
* @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 nullptr 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!=nullptr) {
uprv_memset(p, 0, newCapacity*sizeof(T));
uprv_free(LocalPointerBase<T>::ptr);
LocalPointerBase<T>::ptr=p;
}
return p;
} else {
return nullptr;
}
}
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!=nullptr) {
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 nullptr;
}
}
/**
* 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) noexcept = delete;
static void* U_EXPORT2 operator new[](size_t) noexcept = delete;
#if U_HAVE_PLACEMENT_NEW
static void* U_EXPORT2 operator new(size_t, void*) 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) noexcept;
/**
* Move assignment: transfers ownership or copies the stack array.
*/
MaybeStackArray<T, stackCapacity> &operator=(MaybeStackArray<T, stackCapacity> &&src) 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 nullptr
* @param otherCapacity must be >0
*/
void aliasInstead(T *otherArray, int32_t otherCapacity) {
if(otherArray!=nullptr && 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 nullptr.
* @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 nullptr 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 nullptr 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) == nullptr) {
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) 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) 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!=nullptr) {
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 nullptr;
}
}
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 nullptr;
} 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==nullptr) {
return nullptr;
}
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) noexcept = delete;
static void* U_EXPORT2 operator new[](size_t) noexcept = delete;
#if U_HAVE_PLACEMENT_NEW
static void* U_EXPORT2 operator new(size_t, void*) 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 nullptr
* @param otherCapacity must be >0
*/
void aliasInstead(H *otherMemory, int32_t otherCapacity) {
if(otherMemory!=nullptr && 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 nullptr.
* @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 nullptr 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 nullptr 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!=nullptr) {
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 nullptr;
}
}
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==nullptr) {
return nullptr;
}
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) noexcept : fCount(other.fCount),
fPool(std::move(other.fPool)) {
other.fCount = 0;
}
MemoryPool& operator=(MemoryPool&& other) 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 */