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| 1 | |
| 2 /* | |
| 3 * Copyright 2006 The Android Open Source Project | |
| 4 * | |
| 5 * Use of this source code is governed by a BSD-style license that can be | |
| 6 * found in the LICENSE file. | |
| 7 */ | |
| 8 | |
| 9 | |
| 10 #ifndef SkTemplates_DEFINED | |
| 11 #define SkTemplates_DEFINED | |
| 12 | |
| 13 #include "../private/SkTLogic.h" | |
| 14 #include "SkMath.h" | |
| 15 #include "SkTypes.h" | |
| 16 #include <limits.h> | |
| 17 #include <new> | |
| 18 | |
| 19 /** \file SkTemplates.h | |
| 20 | |
| 21 This file contains light-weight template classes for type-safe and exception
-safe | |
| 22 resource management. | |
| 23 */ | |
| 24 | |
| 25 /** | |
| 26 * Marks a local variable as known to be unused (to avoid warnings). | |
| 27 * Note that this does *not* prevent the local variable from being optimized aw
ay. | |
| 28 */ | |
| 29 template<typename T> inline void sk_ignore_unused_variable(const T&) { } | |
| 30 | |
| 31 namespace skstd { | |
| 32 | |
| 33 template <typename T> inline remove_reference_t<T>&& move(T&& t) { | |
| 34 return static_cast<remove_reference_t<T>&&>(t); | |
| 35 } | |
| 36 | |
| 37 template <typename T> inline T&& forward(remove_reference_t<T>& t) /*noexcept*/
{ | |
| 38 return static_cast<T&&>(t); | |
| 39 } | |
| 40 template <typename T> inline T&& forward(remove_reference_t<T>&& t) /*noexcept*/
{ | |
| 41 static_assert(!is_lvalue_reference<T>::value, | |
| 42 "Forwarding an rvalue reference as an lvalue reference is not
allowed."); | |
| 43 return static_cast<T&&>(t); | |
| 44 } | |
| 45 | |
| 46 } // namespace skstd | |
| 47 | |
| 48 ///@{ | |
| 49 /** SkTConstType<T, CONST>::type will be 'const T' if CONST is true, 'T' otherwi
se. */ | |
| 50 template <typename T, bool CONST> struct SkTConstType { | |
| 51 typedef T type; | |
| 52 }; | |
| 53 template <typename T> struct SkTConstType<T, true> { | |
| 54 typedef const T type; | |
| 55 }; | |
| 56 ///@} | |
| 57 | |
| 58 /** | |
| 59 * Returns a pointer to a D which comes immediately after S[count]. | |
| 60 */ | |
| 61 template <typename D, typename S> static D* SkTAfter(S* ptr, size_t count = 1) { | |
| 62 return reinterpret_cast<D*>(ptr + count); | |
| 63 } | |
| 64 | |
| 65 /** | |
| 66 * Returns a pointer to a D which comes byteOffset bytes after S. | |
| 67 */ | |
| 68 template <typename D, typename S> static D* SkTAddOffset(S* ptr, size_t byteOffs
et) { | |
| 69 // The intermediate char* has the same const-ness as D as this produces bett
er error messages. | |
| 70 // This relies on the fact that reinterpret_cast can add constness, but cann
ot remove it. | |
| 71 return reinterpret_cast<D*>( | |
| 72 reinterpret_cast<typename SkTConstType<char, SkTIsConst<D>::value>::type
*>(ptr) + byteOffset | |
| 73 ); | |
| 74 } | |
| 75 | |
| 76 /** \class SkAutoTCallVProc | |
| 77 | |
| 78 Call a function when this goes out of scope. The template uses two | |
| 79 parameters, the object, and a function that is to be called in the destructo
r. | |
| 80 If detach() is called, the object reference is set to null. If the object | |
| 81 reference is null when the destructor is called, we do not call the | |
| 82 function. | |
| 83 */ | |
| 84 template <typename T, void (*P)(T*)> class SkAutoTCallVProc : SkNoncopyable { | |
| 85 public: | |
| 86 SkAutoTCallVProc(T* obj): fObj(obj) {} | |
| 87 ~SkAutoTCallVProc() { if (fObj) P(fObj); } | |
| 88 | |
| 89 operator T*() const { return fObj; } | |
| 90 T* operator->() const { SkASSERT(fObj); return fObj; } | |
| 91 | |
| 92 T* detach() { T* obj = fObj; fObj = NULL; return obj; } | |
| 93 void reset(T* obj = NULL) { | |
| 94 if (fObj != obj) { | |
| 95 if (fObj) { | |
| 96 P(fObj); | |
| 97 } | |
| 98 fObj = obj; | |
| 99 } | |
| 100 } | |
| 101 private: | |
| 102 T* fObj; | |
| 103 }; | |
| 104 | |
| 105 /** \class SkAutoTCallIProc | |
| 106 | |
| 107 Call a function when this goes out of scope. The template uses two | |
| 108 parameters, the object, and a function that is to be called in the destructor. | |
| 109 If detach() is called, the object reference is set to null. If the object | |
| 110 reference is null when the destructor is called, we do not call the | |
| 111 function. | |
| 112 */ | |
| 113 template <typename T, int (*P)(T*)> class SkAutoTCallIProc : SkNoncopyable { | |
| 114 public: | |
| 115 SkAutoTCallIProc(T* obj): fObj(obj) {} | |
| 116 ~SkAutoTCallIProc() { if (fObj) P(fObj); } | |
| 117 | |
| 118 operator T*() const { return fObj; } | |
| 119 T* operator->() const { SkASSERT(fObj); return fObj; } | |
| 120 | |
| 121 T* detach() { T* obj = fObj; fObj = NULL; return obj; } | |
| 122 private: | |
| 123 T* fObj; | |
| 124 }; | |
| 125 | |
| 126 /** \class SkAutoTDelete | |
| 127 An SkAutoTDelete<T> is like a T*, except that the destructor of SkAutoTDelete<
T> | |
| 128 automatically deletes the pointer it holds (if any). That is, SkAutoTDelete<T
> | |
| 129 owns the T object that it points to. Like a T*, an SkAutoTDelete<T> may hold | |
| 130 either NULL or a pointer to a T object. Also like T*, SkAutoTDelete<T> is | |
| 131 thread-compatible, and once you dereference it, you get the threadsafety | |
| 132 guarantees of T. | |
| 133 | |
| 134 The size of a SkAutoTDelete is small: sizeof(SkAutoTDelete<T>) == sizeof(T*) | |
| 135 */ | |
| 136 template <typename T> class SkAutoTDelete : SkNoncopyable { | |
| 137 public: | |
| 138 SkAutoTDelete(T* obj = NULL) : fObj(obj) {} | |
| 139 ~SkAutoTDelete() { SkDELETE(fObj); } | |
| 140 | |
| 141 T* get() const { return fObj; } | |
| 142 operator T*() const { return fObj; } | |
| 143 T& operator*() const { SkASSERT(fObj); return *fObj; } | |
| 144 T* operator->() const { SkASSERT(fObj); return fObj; } | |
| 145 | |
| 146 void reset(T* obj) { | |
| 147 if (fObj != obj) { | |
| 148 SkDELETE(fObj); | |
| 149 fObj = obj; | |
| 150 } | |
| 151 } | |
| 152 | |
| 153 /** | |
| 154 * Delete the owned object, setting the internal pointer to NULL. | |
| 155 */ | |
| 156 void free() { | |
| 157 SkDELETE(fObj); | |
| 158 fObj = NULL; | |
| 159 } | |
| 160 | |
| 161 /** | |
| 162 * Transfer ownership of the object to the caller, setting the internal | |
| 163 * pointer to NULL. Note that this differs from get(), which also returns | |
| 164 * the pointer, but it does not transfer ownership. | |
| 165 */ | |
| 166 T* detach() { | |
| 167 T* obj = fObj; | |
| 168 fObj = NULL; | |
| 169 return obj; | |
| 170 } | |
| 171 | |
| 172 void swap(SkAutoTDelete* that) { | |
| 173 SkTSwap(fObj, that->fObj); | |
| 174 } | |
| 175 | |
| 176 private: | |
| 177 T* fObj; | |
| 178 }; | |
| 179 | |
| 180 // Calls ~T() in the destructor. | |
| 181 template <typename T> class SkAutoTDestroy : SkNoncopyable { | |
| 182 public: | |
| 183 SkAutoTDestroy(T* obj = NULL) : fObj(obj) {} | |
| 184 ~SkAutoTDestroy() { | |
| 185 if (fObj) { | |
| 186 fObj->~T(); | |
| 187 } | |
| 188 } | |
| 189 | |
| 190 T* get() const { return fObj; } | |
| 191 T& operator*() const { SkASSERT(fObj); return *fObj; } | |
| 192 T* operator->() const { SkASSERT(fObj); return fObj; } | |
| 193 | |
| 194 private: | |
| 195 T* fObj; | |
| 196 }; | |
| 197 | |
| 198 template <typename T> class SkAutoTDeleteArray : SkNoncopyable { | |
| 199 public: | |
| 200 SkAutoTDeleteArray(T array[]) : fArray(array) {} | |
| 201 ~SkAutoTDeleteArray() { SkDELETE_ARRAY(fArray); } | |
| 202 | |
| 203 T* get() const { return fArray; } | |
| 204 void free() { SkDELETE_ARRAY(fArray); fArray = NULL; } | |
| 205 T* detach() { T* array = fArray; fArray = NULL; return array; } | |
| 206 | |
| 207 void reset(T array[]) { | |
| 208 if (fArray != array) { | |
| 209 SkDELETE_ARRAY(fArray); | |
| 210 fArray = array; | |
| 211 } | |
| 212 } | |
| 213 | |
| 214 private: | |
| 215 T* fArray; | |
| 216 }; | |
| 217 | |
| 218 /** Allocate an array of T elements, and free the array in the destructor | |
| 219 */ | |
| 220 template <typename T> class SkAutoTArray : SkNoncopyable { | |
| 221 public: | |
| 222 SkAutoTArray() { | |
| 223 fArray = NULL; | |
| 224 SkDEBUGCODE(fCount = 0;) | |
| 225 } | |
| 226 /** Allocate count number of T elements | |
| 227 */ | |
| 228 explicit SkAutoTArray(int count) { | |
| 229 SkASSERT(count >= 0); | |
| 230 fArray = NULL; | |
| 231 if (count) { | |
| 232 fArray = SkNEW_ARRAY(T, count); | |
| 233 } | |
| 234 SkDEBUGCODE(fCount = count;) | |
| 235 } | |
| 236 | |
| 237 /** Reallocates given a new count. Reallocation occurs even if new count equ
als old count. | |
| 238 */ | |
| 239 void reset(int count) { | |
| 240 SkDELETE_ARRAY(fArray); | |
| 241 SkASSERT(count >= 0); | |
| 242 fArray = NULL; | |
| 243 if (count) { | |
| 244 fArray = SkNEW_ARRAY(T, count); | |
| 245 } | |
| 246 SkDEBUGCODE(fCount = count;) | |
| 247 } | |
| 248 | |
| 249 ~SkAutoTArray() { | |
| 250 SkDELETE_ARRAY(fArray); | |
| 251 } | |
| 252 | |
| 253 /** Return the array of T elements. Will be NULL if count == 0 | |
| 254 */ | |
| 255 T* get() const { return fArray; } | |
| 256 | |
| 257 /** Return the nth element in the array | |
| 258 */ | |
| 259 T& operator[](int index) const { | |
| 260 SkASSERT((unsigned)index < (unsigned)fCount); | |
| 261 return fArray[index]; | |
| 262 } | |
| 263 | |
| 264 void swap(SkAutoTArray& other) { | |
| 265 SkTSwap(fArray, other.fArray); | |
| 266 SkDEBUGCODE(SkTSwap(fCount, other.fCount)); | |
| 267 } | |
| 268 | |
| 269 private: | |
| 270 T* fArray; | |
| 271 SkDEBUGCODE(int fCount;) | |
| 272 }; | |
| 273 | |
| 274 /** Wraps SkAutoTArray, with room for up to N elements preallocated | |
| 275 */ | |
| 276 template <int N, typename T> class SkAutoSTArray : SkNoncopyable { | |
| 277 public: | |
| 278 /** Initialize with no objects */ | |
| 279 SkAutoSTArray() { | |
| 280 fArray = NULL; | |
| 281 fCount = 0; | |
| 282 } | |
| 283 | |
| 284 /** Allocate count number of T elements | |
| 285 */ | |
| 286 SkAutoSTArray(int count) { | |
| 287 fArray = NULL; | |
| 288 fCount = 0; | |
| 289 this->reset(count); | |
| 290 } | |
| 291 | |
| 292 ~SkAutoSTArray() { | |
| 293 this->reset(0); | |
| 294 } | |
| 295 | |
| 296 /** Destroys previous objects in the array and default constructs count numb
er of objects */ | |
| 297 void reset(int count) { | |
| 298 T* start = fArray; | |
| 299 T* iter = start + fCount; | |
| 300 while (iter > start) { | |
| 301 (--iter)->~T(); | |
| 302 } | |
| 303 | |
| 304 if (fCount != count) { | |
| 305 if (fCount > N) { | |
| 306 // 'fArray' was allocated last time so free it now | |
| 307 SkASSERT((T*) fStorage != fArray); | |
| 308 sk_free(fArray); | |
| 309 } | |
| 310 | |
| 311 if (count > N) { | |
| 312 const uint64_t size64 = sk_64_mul(count, sizeof(T)); | |
| 313 const size_t size = static_cast<size_t>(size64); | |
| 314 if (size != size64) { | |
| 315 sk_out_of_memory(); | |
| 316 } | |
| 317 fArray = (T*) sk_malloc_throw(size); | |
| 318 } else if (count > 0) { | |
| 319 fArray = (T*) fStorage; | |
| 320 } else { | |
| 321 fArray = NULL; | |
| 322 } | |
| 323 | |
| 324 fCount = count; | |
| 325 } | |
| 326 | |
| 327 iter = fArray; | |
| 328 T* stop = fArray + count; | |
| 329 while (iter < stop) { | |
| 330 SkNEW_PLACEMENT(iter++, T); | |
| 331 } | |
| 332 } | |
| 333 | |
| 334 /** Return the number of T elements in the array | |
| 335 */ | |
| 336 int count() const { return fCount; } | |
| 337 | |
| 338 /** Return the array of T elements. Will be NULL if count == 0 | |
| 339 */ | |
| 340 T* get() const { return fArray; } | |
| 341 | |
| 342 /** Return the nth element in the array | |
| 343 */ | |
| 344 T& operator[](int index) const { | |
| 345 SkASSERT(index < fCount); | |
| 346 return fArray[index]; | |
| 347 } | |
| 348 | |
| 349 private: | |
| 350 int fCount; | |
| 351 T* fArray; | |
| 352 // since we come right after fArray, fStorage should be properly aligned | |
| 353 char fStorage[N * sizeof(T)]; | |
| 354 }; | |
| 355 | |
| 356 /** Manages an array of T elements, freeing the array in the destructor. | |
| 357 * Does NOT call any constructors/destructors on T (T must be POD). | |
| 358 */ | |
| 359 template <typename T> class SkAutoTMalloc : SkNoncopyable { | |
| 360 public: | |
| 361 /** Takes ownership of the ptr. The ptr must be a value which can be passed
to sk_free. */ | |
| 362 explicit SkAutoTMalloc(T* ptr = NULL) { | |
| 363 fPtr = ptr; | |
| 364 } | |
| 365 | |
| 366 /** Allocates space for 'count' Ts. */ | |
| 367 explicit SkAutoTMalloc(size_t count) { | |
| 368 fPtr = (T*)sk_malloc_flags(count * sizeof(T), SK_MALLOC_THROW); | |
| 369 } | |
| 370 | |
| 371 ~SkAutoTMalloc() { | |
| 372 sk_free(fPtr); | |
| 373 } | |
| 374 | |
| 375 /** Resize the memory area pointed to by the current ptr preserving contents
. */ | |
| 376 void realloc(size_t count) { | |
| 377 fPtr = reinterpret_cast<T*>(sk_realloc_throw(fPtr, count * sizeof(T))); | |
| 378 } | |
| 379 | |
| 380 /** Resize the memory area pointed to by the current ptr without preserving
contents. */ | |
| 381 void reset(size_t count) { | |
| 382 sk_free(fPtr); | |
| 383 fPtr = (T*)sk_malloc_flags(count * sizeof(T), SK_MALLOC_THROW); | |
| 384 } | |
| 385 | |
| 386 T* get() const { return fPtr; } | |
| 387 | |
| 388 operator T*() { | |
| 389 return fPtr; | |
| 390 } | |
| 391 | |
| 392 operator const T*() const { | |
| 393 return fPtr; | |
| 394 } | |
| 395 | |
| 396 T& operator[](int index) { | |
| 397 return fPtr[index]; | |
| 398 } | |
| 399 | |
| 400 const T& operator[](int index) const { | |
| 401 return fPtr[index]; | |
| 402 } | |
| 403 | |
| 404 /** | |
| 405 * Transfer ownership of the ptr to the caller, setting the internal | |
| 406 * pointer to NULL. Note that this differs from get(), which also returns | |
| 407 * the pointer, but it does not transfer ownership. | |
| 408 */ | |
| 409 T* detach() { | |
| 410 T* ptr = fPtr; | |
| 411 fPtr = NULL; | |
| 412 return ptr; | |
| 413 } | |
| 414 | |
| 415 private: | |
| 416 T* fPtr; | |
| 417 }; | |
| 418 | |
| 419 template <size_t N, typename T> class SkAutoSTMalloc : SkNoncopyable { | |
| 420 public: | |
| 421 SkAutoSTMalloc() : fPtr(fTStorage) {} | |
| 422 | |
| 423 SkAutoSTMalloc(size_t count) { | |
| 424 if (count > N) { | |
| 425 fPtr = (T*)sk_malloc_flags(count * sizeof(T), SK_MALLOC_THROW | SK_M
ALLOC_TEMP); | |
| 426 } else { | |
| 427 fPtr = fTStorage; | |
| 428 } | |
| 429 } | |
| 430 | |
| 431 ~SkAutoSTMalloc() { | |
| 432 if (fPtr != fTStorage) { | |
| 433 sk_free(fPtr); | |
| 434 } | |
| 435 } | |
| 436 | |
| 437 // doesn't preserve contents | |
| 438 T* reset(size_t count) { | |
| 439 if (fPtr != fTStorage) { | |
| 440 sk_free(fPtr); | |
| 441 } | |
| 442 if (count > N) { | |
| 443 fPtr = (T*)sk_malloc_throw(count * sizeof(T)); | |
| 444 } else { | |
| 445 fPtr = fTStorage; | |
| 446 } | |
| 447 return fPtr; | |
| 448 } | |
| 449 | |
| 450 T* get() const { return fPtr; } | |
| 451 | |
| 452 operator T*() { | |
| 453 return fPtr; | |
| 454 } | |
| 455 | |
| 456 operator const T*() const { | |
| 457 return fPtr; | |
| 458 } | |
| 459 | |
| 460 T& operator[](int index) { | |
| 461 return fPtr[index]; | |
| 462 } | |
| 463 | |
| 464 const T& operator[](int index) const { | |
| 465 return fPtr[index]; | |
| 466 } | |
| 467 | |
| 468 // Reallocs the array, can be used to shrink the allocation. Makes no attem
pt to be intelligent | |
| 469 void realloc(size_t count) { | |
| 470 if (count > N) { | |
| 471 if (fPtr == fTStorage) { | |
| 472 fPtr = (T*)sk_malloc_throw(count * sizeof(T)); | |
| 473 memcpy(fPtr, fTStorage, N * sizeof(T)); | |
| 474 } else { | |
| 475 fPtr = (T*)sk_realloc_throw(fPtr, count * sizeof(T)); | |
| 476 } | |
| 477 } else if (fPtr != fTStorage) { | |
| 478 fPtr = (T*)sk_realloc_throw(fPtr, count * sizeof(T)); | |
| 479 } | |
| 480 } | |
| 481 | |
| 482 private: | |
| 483 T* fPtr; | |
| 484 union { | |
| 485 uint32_t fStorage32[(N*sizeof(T) + 3) >> 2]; | |
| 486 T fTStorage[1]; // do NOT want to invoke T::T() | |
| 487 }; | |
| 488 }; | |
| 489 | |
| 490 ////////////////////////////////////////////////////////////////////////////////
////////////////// | |
| 491 | |
| 492 /** | |
| 493 * Pass the object and the storage that was offered during SkInPlaceNewCheck, a
nd this will | |
| 494 * safely destroy (and free if it was dynamically allocated) the object. | |
| 495 */ | |
| 496 template <typename T> void SkInPlaceDeleteCheck(T* obj, void* storage) { | |
| 497 if (storage == obj) { | |
| 498 obj->~T(); | |
| 499 } else { | |
| 500 SkDELETE(obj); | |
| 501 } | |
| 502 } | |
| 503 | |
| 504 /** | |
| 505 * Allocates T, using storage if it is large enough, and allocating on the heap
(via new) if | |
| 506 * storage is not large enough. | |
| 507 * | |
| 508 * obj = SkInPlaceNewCheck<Type>(storage, size); | |
| 509 * ... | |
| 510 * SkInPlaceDeleteCheck(obj, storage); | |
| 511 */ | |
| 512 template <typename T> T* SkInPlaceNewCheck(void* storage, size_t size) { | |
| 513 return (sizeof(T) <= size) ? new (storage) T : SkNEW(T); | |
| 514 } | |
| 515 | |
| 516 template <typename T, typename A1, typename A2, typename A3> | |
| 517 T* SkInPlaceNewCheck(void* storage, size_t size, const A1& a1, const A2& a2, con
st A3& a3) { | |
| 518 return (sizeof(T) <= size) ? new (storage) T(a1, a2, a3) : SkNEW_ARGS(T, (a1
, a2, a3)); | |
| 519 } | |
| 520 | |
| 521 /** | |
| 522 * Reserves memory that is aligned on double and pointer boundaries. | |
| 523 * Hopefully this is sufficient for all practical purposes. | |
| 524 */ | |
| 525 template <size_t N> class SkAlignedSStorage : SkNoncopyable { | |
| 526 public: | |
| 527 size_t size() const { return N; } | |
| 528 void* get() { return fData; } | |
| 529 const void* get() const { return fData; } | |
| 530 | |
| 531 private: | |
| 532 union { | |
| 533 void* fPtr; | |
| 534 double fDouble; | |
| 535 char fData[N]; | |
| 536 }; | |
| 537 }; | |
| 538 | |
| 539 /** | |
| 540 * Reserves memory that is aligned on double and pointer boundaries. | |
| 541 * Hopefully this is sufficient for all practical purposes. Otherwise, | |
| 542 * we have to do some arcane trickery to determine alignment of non-POD | |
| 543 * types. Lifetime of the memory is the lifetime of the object. | |
| 544 */ | |
| 545 template <int N, typename T> class SkAlignedSTStorage : SkNoncopyable { | |
| 546 public: | |
| 547 /** | |
| 548 * Returns void* because this object does not initialize the | |
| 549 * memory. Use placement new for types that require a cons. | |
| 550 */ | |
| 551 void* get() { return fStorage.get(); } | |
| 552 const void* get() const { return fStorage.get(); } | |
| 553 private: | |
| 554 SkAlignedSStorage<sizeof(T)*N> fStorage; | |
| 555 }; | |
| 556 | |
| 557 #endif | |
| OLD | NEW |
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Chromium Code Reviews
Issue 1272293004:
Move SkTemplates.h to private. (Closed)
Base URL: https://skia.googlesource.com/skia.git@master