OpenVDB: openvdb/util/PagedArray.h Source File

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PagedArray.h
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1// Copyright Contributors to the OpenVDB Project
2// SPDX-License-Identifier: MPL-2.0
3///
4/// @file PagedArray.h
5///
6/// @author Ken Museth
7///
8/// @brief Concurrent, page-based, dynamically-sized linear data
9/// structure with O(1) random access and STL-compliant
10/// iterators. It is primarily intended for applications
11/// that involve multi-threading push_back of (a possibly
12/// unkown number of) elements into a dynamically growing
13/// linear array, and fast random access to said elements.
14
15#ifndef OPENVDB_UTIL_PAGED_ARRAY_HAS_BEEN_INCLUDED
16#define OPENVDB_UTIL_PAGED_ARRAY_HAS_BEEN_INCLUDED
17
18#include <openvdb/version.h>
19#include <openvdb/Types.h>// SharedPtr
20#include <deque>
21#include <cassert>
22#include <iostream>
23#include <algorithm>// std::swap
24#include <atomic>
25#include <tbb/spin_mutex.h>
26#include <tbb/parallel_for.h>
27#include <tbb/parallel_sort.h>
28
29namespace openvdb {
30 OPENVDB_USE_VERSION_NAMESPACE
31namespace OPENVDB_VERSION_NAME {
32namespace util {
33
34////////////////////////////////////////
35
36
37/// @brief Concurrent, page-based, dynamically-sized linear data structure
38/// with O(1) random access and STL-compliant iterators. It is
39/// primarily intended for applications that concurrently insert
40/// (a possibly unkown number of) elements into a dynamically
41/// growing linear array, and fast random access to said elements.
42///
43/// @note Multiple threads can grow the page-table and push_back
44/// new elements concurrently. A ValueBuffer provides accelerated
45/// and threadsafe push_back at the cost of potentially re-ordering
46/// elements (when multiple instances are used).
47///
48/// @details This data structure employes contiguous pages of elements
49/// (a std::deque) which avoids moving data when the
50/// capacity is out-grown and new pages are allocated. The
51/// size of the pages can be controlled with the Log2PageSize
52/// template parameter (defaults to 1024 elements of type ValueT).
53///
54/// There are three fundamentally different ways to insert elements to
55/// this container - each with different advanteges and disadvanteges.
56///
57/// The simplest way to insert elements is to use PagedArray::push_back_unsafe
58/// which is @a not thread-safe:
59/// @code
60/// PagedArray<size_t> array;
61/// for (size_t i=0; i<100000; ++i) array.push_back_unsafe(i);
62/// @endcode
63///
64/// The fastest way (by far) to insert elements is by means of a PagedArray::ValueBuffer:
65/// @code
66/// PagedArray<size_t> array;
67/// auto buffer = array.getBuffer();
68/// for (size_t i=0; i<100000; ++i) buffer.push_back(i);
69/// buffer.flush();
70/// @endcode
71/// or
72/// @code
73/// PagedArray<size_t> array;
74/// {
75/// //local scope of a single thread
76/// auto buffer = array.getBuffer();
77/// for (size_t i=0; i<100000; ++i) buffer.push_back(i);
78/// }
79/// @endcode
80/// or with TBB task-based multi-threading:
81/// @code
82/// PagedArray<size_t> array;
83/// tbb::parallel_for(
84/// tbb::blocked_range<size_t>(0, 10000, array.pageSize()),
85/// [&array](const tbb::blocked_range<size_t>& range) {
86/// auto buffer = array.getBuffer();
87/// for (size_t i=range.begin(); i!=range.end(); ++i) buffer.push_back(i);
88/// }
89/// );
90/// @endcode
91/// or with TBB thread-local storage for even better performance (due
92/// to fewer concurrent instantiations of partially full ValueBuffers)
93/// @code
94/// PagedArray<size_t> array;
95/// auto exemplar = array.getBuffer();//dummy used for initialization
96/// tbb::enumerable_thread_specific<PagedArray<size_t>::ValueBuffer>
97/// pool(exemplar);//thread local storage pool of ValueBuffers
98/// tbb::parallel_for(
99/// tbb::blocked_range<size_t>(0, 10000, array.pageSize()),
100/// [&pool](const tbb::blocked_range<size_t>& range) {
101/// auto &buffer = pool.local();
102/// for (size_t i=range.begin(); i!=range.end(); ++i) buffer.push_back(i);
103/// }
104/// );
105/// for (auto i=pool.begin(); i!=pool.end(); ++i) i->flush();
106/// @endcode
107/// This technique generally outperforms PagedArray::push_back_unsafe,
108/// std::vector::push_back, std::deque::push_back and even
109/// tbb::concurrent_vector::push_back. Additionally it
110/// is thread-safe as long as each thread has it's own instance of a
111/// PagedArray::ValueBuffer. The only disadvantage is the ordering of
112/// the elements is undefined if multiple instance of a
113/// PagedArray::ValueBuffer are employed. This is typically the case
114/// in the context of multi-threading, where the
115/// ordering of inserts are undefined anyway. Note that a local scope
116/// can be used to guarentee that the ValueBuffer has inserted all its
117/// elements by the time the scope ends. Alternatively the ValueBuffer
118/// can be explicitly flushed by calling ValueBuffer::flush.
119///
120/// The third way to insert elements is to resize the container and use
121/// random access, e.g.
122/// @code
123/// PagedArray<int> array;
124/// array.resize(100000);
125/// for (int i=0; i<100000; ++i) array[i] = i;
126/// @endcode
127/// or in terms of the random access iterator
128/// @code
129/// PagedArray<int> array;
130/// array.resize(100000);
131/// for (auto i=array.begin(); i!=array.end(); ++i) *i = i.pos();
132/// @endcode
133/// While this approach is both fast and thread-safe it suffers from the
134/// major disadvantage that the problem size, i.e. number of elements, needs to
135/// be known in advance. If that's the case you might as well consider
136/// using std::vector or a raw c-style array! In other words the
137/// PagedArray is most useful in the context of applications that
138/// involve multi-threading of dynamically growing linear arrays that
139/// require fast random access.
140
141template<typename ValueT, size_t Log2PageSize = 10UL>
142 class PagedArray
143{
144private:
145 static_assert(Log2PageSize > 1UL, "Expected Log2PageSize > 1");
146 class Page;
147
148 // must allow mutiple threads to call operator[] as long as only one thread calls push_back
149 using PageTableT = std::deque<Page*>;
150
151public:
152 using ValueType = ValueT;
153 using Ptr = SharedPtr<PagedArray>;
154
155 /// @brief Default constructor
156 PagedArray() : mCapacity{0} { mSize = 0; }
157
158 /// @brief Destructor removed all allocated pages
159 ~PagedArray() { this->clear(); }
160
161 // Disallow copy construction and assignment
162 PagedArray(const PagedArray&) = delete;
163 PagedArray& operator=(const PagedArray&) = delete;
164
165 /// @brief Return a shared pointer to a new instance of this class
166 static Ptr create() { return Ptr(new PagedArray); }
167
168 /// @brief Caches values into a local memory Page to improve
169 /// performance of push_back into a PagedArray.
170 ///
171 /// @note The ordering of inserted elements is undefined when
172 /// multiple ValueBuffers are used!
173 ///
174 /// @warning By design this ValueBuffer is not threadsafe so
175 /// make sure to create an instance per thread!
176 class ValueBuffer;
177
178 /// @return a new instance of a ValueBuffer which supports thread-safe push_back!
179 ValueBuffer getBuffer() { return ValueBuffer(*this); }
180
181 /// Const std-compliant iterator
182 class ConstIterator;
183
184 /// Non-const std-compliant iterator
185 class Iterator;
186
187 /// @param value value to be added to this PagedArray
188 ///
189 /// @note For best performance consider using the ValueBuffer!
190 ///
191 /// @warning Not thread-safe and mostly intended for debugging!
192 size_t push_back_unsafe(const ValueType& value)
193 {
194 const size_t index = mSize.fetch_add(1);
195 if (index >= mCapacity) {
196 mPageTable.push_back( new Page() );
197 mCapacity += Page::Size;
198 }
199 (*mPageTable[index >> Log2PageSize])[index] = value;
200 return index;
201 }
202
203 /// @brief Reduce the page table to fix the current size.
204 ///
205 /// @warning Not thread-safe!
206 void shrink_to_fit();
207
208 /// @brief Return a reference to the value at the specified offset
209 ///
210 /// @param i linear offset of the value to be accessed.
211 ///
212 /// @note This random access has constant time complexity.
213 ///
214 /// @warning It is assumed that the i'th element is already allocated!
215 ValueType& operator[](size_t i)
216 {
217 assert(i<mCapacity);
218 return (*mPageTable[i>>Log2PageSize])[i];
219 }
220
221 /// @brief Return a const-reference to the value at the specified offset
222 ///
223 /// @param i linear offset of the value to be accessed.
224 ///
225 /// @note This random access has constant time complexity.
226 ///
227 /// @warning It is assumed that the i'th element is already allocated!
228 const ValueType& operator[](size_t i) const
229 {
230 assert(i<mCapacity);
231 return (*mPageTable[i>>Log2PageSize])[i];
232 }
233
234 /// @brief Set all elements in the page table to the specified value
235 ///
236 /// @param v value to be filled in all the existing pages of this PagedArray.
237 ///
238 /// @note Multi-threaded
239 void fill(const ValueType& v)
240 {
241 auto op = [&](const tbb::blocked_range<size_t>& r){
242 for(size_t i=r.begin(); i!=r.end(); ++i) mPageTable[i]->fill(v);
243 };
244 tbb::parallel_for(tbb::blocked_range<size_t>(0, this->pageCount()), op);
245 }
246
247 /// @brief Copy the first @a count values in this PageArray into
248 /// a raw c-style array, assuming it to be at least @a count
249 /// elements long.
250 ///
251 /// @param p pointer to an array that will used as the destination of the copy.
252 /// @param count number of elements to be copied.
253 ///
254 bool copy(ValueType *p, size_t count) const
255 {
256 size_t last_page = count >> Log2PageSize;
257 if (last_page >= this->pageCount()) return false;
258 auto op = [&](const tbb::blocked_range<size_t>& r){
259 for (size_t i=r.begin(); i!=r.end(); ++i) {
260 mPageTable[i]->copy(p+i*Page::Size, Page::Size);
261 }
262 };
263 if (size_t m = count & Page::Mask) {//count is not divisible by page size
264 tbb::parallel_for(tbb::blocked_range<size_t>(0, last_page, 32), op);
265 mPageTable[last_page]->copy(p+last_page*Page::Size, m);
266 } else {
267 tbb::parallel_for(tbb::blocked_range<size_t>(0, last_page+1, 32), op);
268 }
269 return true;
270 }
271 void copy(ValueType *p) const { this->copy(p, mSize); }
272
273 /// @brief Resize this array to the specified size.
274 ///
275 /// @param size number of elements that this PageArray will contain.
276 ///
277 /// @details Will grow or shrink the page table to contain
278 /// the specified number of elements. It will affect the size(),
279 /// iteration will go over all those elements, push_back will
280 /// insert after them and operator[] can be used directly access
281 /// them.
282 ///
283 /// @note No reserve method is implemented due to efficiency concerns
284 /// (especially for the ValueBuffer) from having to deal with empty pages.
285 ///
286 /// @warning Not thread-safe!
287 void resize(size_t size)
288 {
289 mSize = size;
290 if (size > mCapacity) {
291 this->grow(size-1);
292 } else {
293 this->shrink_to_fit();
294 }
295 }
296
297 /// @brief Resize this array to the specified size and initialize
298 /// all values to @a v.
299 ///
300 /// @param size number of elements that this PageArray will contain.
301 /// @param v value of all the @a size values.
302 ///
303 /// @details Will grow or shrink the page table to contain
304 /// the specified number of elements. It will affect the size(),
305 /// iteration will go over all those elements, push_back will
306 /// insert after them and operator[] can be used directly access them.
307 ///
308 /// @note No reserve method is implemented due to efficiency concerns
309 /// (especially for the ValueBuffer) from having to deal with empty pages.
310 ///
311 /// @warning Not thread-safe!
312 void resize(size_t size, const ValueType& v)
313 {
314 this->resize(size);
315 this->fill(v);
316 }
317
318 /// @brief Return the number of elements in this array.
319 size_t size() const { return mSize; }
320
321 /// @brief Return the maximum number of elements that this array
322 /// can contain without allocating more memory pages.
323 size_t capacity() const { return mCapacity; }
324
325 /// @brief Return the number of additional elements that can be
326 /// added to this array without allocating more memory pages.
327 size_t freeCount() const { return mCapacity - mSize; }
328
329 /// @brief Return the number of allocated memory pages.
330 size_t pageCount() const { return mPageTable.size(); }
331
332 /// @brief Return the number of elements per memory page.
333 static size_t pageSize() { return Page::Size; }
334
335 /// @brief Return log2 of the number of elements per memory page.
336 static size_t log2PageSize() { return Log2PageSize; }
337
338 /// @brief Return the memory footprint of this array in bytes.
339 size_t memUsage() const
340 {
341 return sizeof(*this) + mPageTable.size() * Page::memUsage();
342 }
343
344 /// @brief Return true if the container contains no elements.
345 bool isEmpty() const { return mSize == 0; }
346
347 /// @brief Return true if the page table is partially full, i.e. the
348 /// last non-empty page contains less than pageSize() elements.
349 ///
350 /// @details When the page table is partially full calling merge()
351 /// or using a ValueBuffer will rearrange the ordering of
352 /// existing elements.
353 bool isPartiallyFull() const { return (mSize & Page::Mask) > 0; }
354
355 /// @brief Removes all elements from the array and delete all pages.
356 ///
357 /// @warning Not thread-safe!
358 void clear()
359 {
360 for (size_t i=0, n=mPageTable.size(); i<n; ++i) delete mPageTable[i];
361 PageTableT().swap(mPageTable);
362 mSize = 0;
363 mCapacity = 0;
364 }
365
366 /// @brief Return a non-const iterator pointing to the first element
367 Iterator begin() { return Iterator(*this, 0); }
368
369 /// @brief Return a non-const iterator pointing to the
370 /// past-the-last element.
371 ///
372 /// @warning Iterator does not point to a valid element and should not
373 /// be dereferenced!
374 Iterator end() { return Iterator(*this, mSize); }
375
376 //@{
377 /// @brief Return a const iterator pointing to the first element
378 ConstIterator cbegin() const { return ConstIterator(*this, 0); }
379 ConstIterator begin() const { return ConstIterator(*this, 0); }
380 //@}
381
382 //@{
383 /// @brief Return a const iterator pointing to the
384 /// past-the-last element.
385 ///
386 /// @warning Iterator does not point to a valid element and should not
387 /// be dereferenced!
388 ConstIterator cend() const { return ConstIterator(*this, mSize); }
389 ConstIterator end() const { return ConstIterator(*this, mSize); }
390 //@}
391
392 /// @brief Parallel sort of all the elements in ascending order.
393 void sort() { tbb::parallel_sort(this->begin(), this->end(), std::less<ValueT>() ); }
394
395 /// @brief Parallel sort of all the elements in descending order.
396 void invSort() { tbb::parallel_sort(this->begin(), this->end(), std::greater<ValueT>()); }
397
398 //@{
399 /// @brief Parallel sort of all the elements based on a custom
400 /// functor with the api:
401 /// @code bool operator()(const ValueT& a, const ValueT& b) @endcode
402 /// which returns true if a comes before b.
403 template <typename Functor>
404 void sort(Functor func) { tbb::parallel_sort(this->begin(), this->end(), func ); }
405 //@}
406
407 /// @brief Transfer all the elements (and pages) from the other array to this array.
408 ///
409 /// @param other non-const reference to the PagedArray that will be merged into this PagedArray.
410 ///
411 /// @note The other PagedArray is empty on return.
412 ///
413 /// @warning The ordering of elements is undefined if this page table is partially full!
414 void merge(PagedArray& other);
415
416 /// @brief Print information for debugging
417 void print(std::ostream& os = std::cout) const
418 {
419 os << "PagedArray:\n"
420 << "\tSize: " << this->size() << " elements\n"
421 << "\tPage table: " << this->pageCount() << " pages\n"
422 << "\tPage size: " << this->pageSize() << " elements\n"
423 << "\tCapacity: " << this->capacity() << " elements\n"
424 << "\tFootprint: " << this->memUsage() << " bytes\n";
425 }
426
427private:
428
429 friend class ValueBuffer;
430
431 void grow(size_t index)
432 {
433 tbb::spin_mutex::scoped_lock lock(mGrowthMutex);
434 while(index >= mCapacity) {
435 mPageTable.push_back( new Page() );
436 mCapacity += Page::Size;
437 }
438 }
439
440 void add_full(Page*& page, size_t size);
441
442 void add_partially_full(Page*& page, size_t size);
443
444 void add(Page*& page, size_t size) {
445 tbb::spin_mutex::scoped_lock lock(mGrowthMutex);
446 if (size == Page::Size) {//page is full
447 this->add_full(page, size);
448 } else if (size>0) {//page is only partially full
449 this->add_partially_full(page, size);
450 }
451 }
452 PageTableT mPageTable;//holds points to allocated pages
453 std::atomic<size_t> mSize;// current number of elements in array
454 size_t mCapacity;//capacity of array given the current page count
455 tbb::spin_mutex mGrowthMutex;//Mutex-lock required to grow pages
456}; // Public class PagedArray
457
458////////////////////////////////////////////////////////////////////////////////
459
460template <typename ValueT, size_t Log2PageSize>
461 void PagedArray<ValueT, Log2PageSize>::shrink_to_fit()
462{
463 if (mPageTable.size() > (mSize >> Log2PageSize) + 1) {
464 tbb::spin_mutex::scoped_lock lock(mGrowthMutex);
465 const size_t pageCount = (mSize >> Log2PageSize) + 1;
466 if (mPageTable.size() > pageCount) {
467 delete mPageTable.back();
468 mPageTable.pop_back();
469 mCapacity -= Page::Size;
470 }
471 }
472}
473
474template <typename ValueT, size_t Log2PageSize>
475 void PagedArray<ValueT, Log2PageSize>::merge(PagedArray& other)
476{
477 if (&other != this && !other.isEmpty()) {
478 tbb::spin_mutex::scoped_lock lock(mGrowthMutex);
479 // extract last partially full page if it exists
480 Page* page = nullptr;
481 const size_t size = mSize & Page::Mask; //number of elements in the last page
482 if ( size > 0 ) {
483 page = mPageTable.back();
484 mPageTable.pop_back();
485 mSize -= size;
486 }
487 // transfer all pages from the other page table
488 mPageTable.insert(mPageTable.end(), other.mPageTable.begin(), other.mPageTable.end());
489 mSize += other.mSize;
490 mCapacity = Page::Size*mPageTable.size();
491 other.mSize = 0;
492 other.mCapacity = 0;
493 PageTableT().swap(other.mPageTable);
494 // add back last partially full page
495 if (page) this->add_partially_full(page, size);
496 }
497}
498
499template <typename ValueT, size_t Log2PageSize>
500void PagedArray<ValueT, Log2PageSize>::add_full(Page*& page, size_t size)
501{
502 assert(size == Page::Size);//page must be full
503 if (mSize & Page::Mask) {//page-table is partially full
504 Page*& tmp = mPageTable.back();
505 std::swap(tmp, page);//swap last table entry with page
506 }
507 mPageTable.push_back(page);
508 mCapacity += Page::Size;
509 mSize += size;
510 page = nullptr;
511}
512
513template <typename ValueT, size_t Log2PageSize>
514void PagedArray<ValueT, Log2PageSize>::add_partially_full(Page*& page, size_t size)
515{
516 assert(size > 0 && size < Page::Size);//page must be partially full
517 if (size_t m = mSize & Page::Mask) {//page table is also partially full
518 ValueT *s = page->data(), *t = mPageTable.back()->data() + m;
519 for (size_t i=std::min(mSize+size, mCapacity)-mSize; i; --i) *t++ = *s++;
520 if (mSize+size > mCapacity) {//grow page table
521 mPageTable.push_back( new Page() );
522 t = mPageTable.back()->data();
523 for (size_t i=mSize+size-mCapacity; i; --i) *t++ = *s++;
524 mCapacity += Page::Size;
525 }
526 } else {//page table is full so simply append page
527 mPageTable.push_back( page );
528 mCapacity += Page::Size;
529 page = nullptr;
530 }
531 mSize += size;
532}
533
534////////////////////////////////////////////////////////////////////////////////
535
536// Public member-class of PagedArray
537template <typename ValueT, size_t Log2PageSize>
538 class PagedArray<ValueT, Log2PageSize>::
539 ValueBuffer
540{
541public:
542 using PagedArrayType = PagedArray<ValueT, Log2PageSize>;
543 /// @brief Constructor from a PageArray
544 ValueBuffer(PagedArray& parent) : mParent(&parent), mPage(new Page()), mSize(0) {}
545 /// @warning This copy-constructor is shallow in the sense that no
546 /// elements are copied, i.e. size = 0.
547 ValueBuffer(const ValueBuffer& other) : mParent(other.mParent), mPage(new Page()), mSize(0) {}
548 /// @brief Destructor that transfers an buffered values to the parent PagedArray.
549 ~ValueBuffer() { mParent->add(mPage, mSize); delete mPage; }
550
551 ValueBuffer& operator=(const ValueBuffer&) = delete;// disallow copy assignment
552
553 /// @brief Add a value to the buffer and increment the size.
554 ///
555 /// @details If the internal memory page is full it will
556 /// automaically flush the page to the parent PagedArray.
557 void push_back(const ValueT& v) {
558 (*mPage)[mSize++] = v;
559 if (mSize == Page::Size) this->flush();
560 }
561 /// @brief Manually transfers the values in this buffer to the parent PagedArray.
562 ///
563 /// @note This method is also called by the destructor and
564 /// push_back so it should only be called if one manually wants to
565 /// sync up the buffer with the array, e.g. during debugging.
566 void flush() {
567 mParent->add(mPage, mSize);
568 if (mPage == nullptr) mPage = new Page();
569 mSize = 0;
570 }
571 /// @brief Return a reference to the parent PagedArray
572 PagedArrayType& parent() const { return *mParent; }
573 /// @brief Return the current number of elements cached in this buffer.
574 size_t size() const { return mSize; }
575 static size_t pageSize() { return 1UL << Log2PageSize; }
576private:
577 PagedArray* mParent;
578 Page* mPage;
579 size_t mSize;
580};// Public class PagedArray::ValueBuffer
581
582////////////////////////////////////////////////////////////////////////////////
583
584// Const std-compliant iterator
585// Public member-class of PagedArray
586template <typename ValueT, size_t Log2PageSize>
587 class PagedArray<ValueT, Log2PageSize>::
588 ConstIterator : public std::iterator<std::random_access_iterator_tag, ValueT>
589{
590public:
591 using BaseT = std::iterator<std::random_access_iterator_tag, ValueT>;
592 using difference_type = typename BaseT::difference_type;
593 // constructors and assignment
594 ConstIterator() : mPos(0), mParent(nullptr) {}
595 ConstIterator(const PagedArray& parent, size_t pos=0) : mPos(pos), mParent(&parent) {}
596 ConstIterator(const ConstIterator& other) : mPos(other.mPos), mParent(other.mParent) {}
597 ConstIterator& operator=(const ConstIterator& other) {
598 mPos=other.mPos;
599 mParent=other.mParent;
600 return *this;
601 }
602 // prefix
603 ConstIterator& operator++() { ++mPos; return *this; }
604 ConstIterator& operator--() { --mPos; return *this; }
605 // postfix
606 ConstIterator operator++(int) { ConstIterator tmp(*this); ++mPos; return tmp; }
607 ConstIterator operator--(int) { ConstIterator tmp(*this); --mPos; return tmp; }
608 // value access
609 const ValueT& operator*() const { return (*mParent)[mPos]; }
610 const ValueT* operator->() const { return &(this->operator*()); }
611 const ValueT& operator[](const difference_type& pos) const { return (*mParent)[mPos+pos]; }
612 // offset
613 ConstIterator& operator+=(const difference_type& pos) { mPos += pos; return *this; }
614 ConstIterator& operator-=(const difference_type& pos) { mPos -= pos; return *this; }
615 ConstIterator operator+(const difference_type &pos) const { return Iterator(*mParent,mPos+pos); }
616 ConstIterator operator-(const difference_type &pos) const { return Iterator(*mParent,mPos-pos); }
617 difference_type operator-(const ConstIterator& other) const { return mPos - other.pos(); }
618 // comparisons
619 bool operator==(const ConstIterator& other) const { return mPos == other.mPos; }
620 bool operator!=(const ConstIterator& other) const { return mPos != other.mPos; }
621 bool operator>=(const ConstIterator& other) const { return mPos >= other.mPos; }
622 bool operator<=(const ConstIterator& other) const { return mPos <= other.mPos; }
623 bool operator< (const ConstIterator& other) const { return mPos < other.mPos; }
624 bool operator> (const ConstIterator& other) const { return mPos > other.mPos; }
625 // non-std methods
626 bool isValid() const { return mParent != nullptr && mPos < mParent->size(); }
627 size_t pos() const { return mPos; }
628private:
629 size_t mPos;
630 const PagedArray* mParent;
631};// Public class PagedArray::ConstIterator
632
633////////////////////////////////////////////////////////////////////////////////
634
635// Non-const std-compliant iterator
636// Public member-class of PagedArray
637template <typename ValueT, size_t Log2PageSize>
638 class PagedArray<ValueT, Log2PageSize>::
639 Iterator : public std::iterator<std::random_access_iterator_tag, ValueT>
640{
641public:
642 using BaseT = std::iterator<std::random_access_iterator_tag, ValueT>;
643 using difference_type = typename BaseT::difference_type;
644 // constructors and assignment
645 Iterator() : mPos(0), mParent(nullptr) {}
646 Iterator(PagedArray& parent, size_t pos=0) : mPos(pos), mParent(&parent) {}
647 Iterator(const Iterator& other) : mPos(other.mPos), mParent(other.mParent) {}
648 Iterator& operator=(const Iterator& other) {
649 mPos=other.mPos;
650 mParent=other.mParent;
651 return *this;
652 }
653 // prefix
654 Iterator& operator++() { ++mPos; return *this; }
655 Iterator& operator--() { --mPos; return *this; }
656 // postfix
657 Iterator operator++(int) { Iterator tmp(*this); ++mPos; return tmp; }
658 Iterator operator--(int) { Iterator tmp(*this); --mPos; return tmp; }
659 // value access
660 ValueT& operator*() const { return (*mParent)[mPos]; }
661 ValueT* operator->() const { return &(this->operator*()); }
662 ValueT& operator[](const difference_type& pos) const { return (*mParent)[mPos+pos]; }
663 // offset
664 Iterator& operator+=(const difference_type& pos) { mPos += pos; return *this; }
665 Iterator& operator-=(const difference_type& pos) { mPos -= pos; return *this; }
666 Iterator operator+(const difference_type &pos) const { return Iterator(*mParent, mPos+pos); }
667 Iterator operator-(const difference_type &pos) const { return Iterator(*mParent, mPos-pos); }
668 difference_type operator-(const Iterator& other) const { return mPos - other.pos(); }
669 // comparisons
670 bool operator==(const Iterator& other) const { return mPos == other.mPos; }
671 bool operator!=(const Iterator& other) const { return mPos != other.mPos; }
672 bool operator>=(const Iterator& other) const { return mPos >= other.mPos; }
673 bool operator<=(const Iterator& other) const { return mPos <= other.mPos; }
674 bool operator< (const Iterator& other) const { return mPos < other.mPos; }
675 bool operator> (const Iterator& other) const { return mPos > other.mPos; }
676 // non-std methods
677 bool isValid() const { return mParent != nullptr && mPos < mParent->size(); }
678 size_t pos() const { return mPos; }
679 private:
680 size_t mPos;
681 PagedArray* mParent;
682};// Public class PagedArray::Iterator
683
684////////////////////////////////////////////////////////////////////////////////
685
686// Private member-class of PagedArray implementing a memory page
687template <typename ValueT, size_t Log2PageSize>
688 class PagedArray<ValueT, Log2PageSize>::
689 Page
690{
691public:
692 static const size_t Size = 1UL << Log2PageSize;
693 static const size_t Mask = Size - 1UL;
694 static size_t memUsage() { return sizeof(ValueT)*Size; }
695 // Raw memory allocation without any initialization
696 Page() : mData(reinterpret_cast<ValueT*>(new char[sizeof(ValueT)*Size])) {}
697 ~Page() { delete [] mData; }
698 Page(const Page&) = delete;//copy construction is not implemented
699 Page& operator=(const Page&) = delete;//copy assignment is not implemented
700 ValueT& operator[](const size_t i) { return mData[i & Mask]; }
701 const ValueT& operator[](const size_t i) const { return mData[i & Mask]; }
702 void fill(const ValueT& v) {
703 ValueT* dst = mData;
704 for (size_t i=Size; i; --i) *dst++ = v;
705 }
706 ValueT* data() { return mData; }
707 // Copy the first n elements of this Page to dst (which is assumed to large
708 // enough to hold the n elements).
709 void copy(ValueType *dst, size_t n) const {
710 const ValueT* src = mData;
711 for (size_t i=n; i; --i) *dst++ = *src++;
712 }
713protected:
714 ValueT* mData;
715};// Private class PagedArray::Page
716
717////////////////////////////////////////////////////////////////////////////////
718
719} // namespace util
720} // namespace OPENVDB_VERSION_NAME
721} // namespace openvdb
722
723#endif // OPENVDB_UTIL_PAGED_ARRAY_HAS_BEEN_INCLUDED
value
ValueT value
Definition GridBuilder.h:1290
openvdb::v10_0::util::PagedArray::ConstIterator
Definition PagedArray.h:589
openvdb::v10_0::util::PagedArray::ConstIterator::difference_type
typename BaseT::difference_type difference_type
Definition PagedArray.h:592
openvdb::v10_0::util::PagedArray::ConstIterator::operator==
bool operator==(const ConstIterator &other) const
Definition PagedArray.h:619
openvdb::v10_0::util::PagedArray::ConstIterator::operator[]
const ValueT & operator[](const difference_type &pos) const
Definition PagedArray.h:611
openvdb::v10_0::util::PagedArray::ConstIterator::operator>=
bool operator>=(const ConstIterator &other) const
Definition PagedArray.h:621
openvdb::v10_0::util::PagedArray::ConstIterator::operator+
ConstIterator operator+(const difference_type &pos) const
Definition PagedArray.h:615
openvdb::v10_0::util::PagedArray::ConstIterator::operator+=
ConstIterator & operator+=(const difference_type &pos)
Definition PagedArray.h:613
openvdb::v10_0::util::PagedArray::ConstIterator::operator-
difference_type operator-(const ConstIterator &other) const
Definition PagedArray.h:617
openvdb::v10_0::util::PagedArray::ConstIterator::operator--
ConstIterator & operator--()
Definition PagedArray.h:604
openvdb::v10_0::util::PagedArray::ConstIterator::isValid
bool isValid() const
Definition PagedArray.h:626
openvdb::v10_0::util::PagedArray::ConstIterator::BaseT
std::iterator< std::random_access_iterator_tag, ValueT > BaseT
Definition PagedArray.h:591
openvdb::v10_0::util::PagedArray::ConstIterator::operator-=
ConstIterator & operator-=(const difference_type &pos)
Definition PagedArray.h:614
openvdb::v10_0::util::PagedArray::ConstIterator::operator-
ConstIterator operator-(const difference_type &pos) const
Definition PagedArray.h:616
openvdb::v10_0::util::PagedArray::ConstIterator::operator!=
bool operator!=(const ConstIterator &other) const
Definition PagedArray.h:620
openvdb::v10_0::util::PagedArray::ConstIterator::pos
size_t pos() const
Definition PagedArray.h:627
openvdb::v10_0::util::PagedArray::ConstIterator::operator++
ConstIterator operator++(int)
Definition PagedArray.h:606
openvdb::v10_0::util::PagedArray::ConstIterator::operator*
const ValueT & operator*() const
Definition PagedArray.h:609
openvdb::v10_0::util::PagedArray::ConstIterator::operator->
const ValueT * operator->() const
Definition PagedArray.h:610
openvdb::v10_0::util::PagedArray::ConstIterator::operator<=
bool operator<=(const ConstIterator &other) const
Definition PagedArray.h:622
openvdb::v10_0::util::PagedArray::ConstIterator::operator++
ConstIterator & operator++()
Definition PagedArray.h:603
openvdb::v10_0::util::PagedArray::ConstIterator::ConstIterator
ConstIterator(const PagedArray &parent, size_t pos=0)
Definition PagedArray.h:595
openvdb::v10_0::util::PagedArray::ConstIterator::operator=
ConstIterator & operator=(const ConstIterator &other)
Definition PagedArray.h:597
openvdb::v10_0::util::PagedArray::ConstIterator::ConstIterator
ConstIterator()
Definition PagedArray.h:594
openvdb::v10_0::util::PagedArray::ConstIterator::operator--
ConstIterator operator--(int)
Definition PagedArray.h:607
openvdb::v10_0::util::PagedArray::ConstIterator::ConstIterator
ConstIterator(const ConstIterator &other)
Definition PagedArray.h:596
openvdb::v10_0::util::PagedArray::Iterator
Definition PagedArray.h:640
openvdb::v10_0::util::PagedArray::Iterator::difference_type
typename BaseT::difference_type difference_type
Definition PagedArray.h:643
openvdb::v10_0::util::PagedArray::Iterator::operator>=
bool operator>=(const Iterator &other) const
Definition PagedArray.h:672
openvdb::v10_0::util::PagedArray::Iterator::Iterator
Iterator()
Definition PagedArray.h:645
openvdb::v10_0::util::PagedArray::Iterator::Iterator
Iterator(const Iterator &other)
Definition PagedArray.h:647
openvdb::v10_0::util::PagedArray::Iterator::operator[]
ValueT & operator[](const difference_type &pos) const
Definition PagedArray.h:662
openvdb::v10_0::util::PagedArray::Iterator::Iterator
Iterator(PagedArray &parent, size_t pos=0)
Definition PagedArray.h:646
openvdb::v10_0::util::PagedArray::Iterator::operator->
ValueT * operator->() const
Definition PagedArray.h:661
openvdb::v10_0::util::PagedArray::Iterator::operator+=
Iterator & operator+=(const difference_type &pos)
Definition PagedArray.h:664
openvdb::v10_0::util::PagedArray::Iterator::isValid
bool isValid() const
Definition PagedArray.h:677
openvdb::v10_0::util::PagedArray::Iterator::operator+
Iterator operator+(const difference_type &pos) const
Definition PagedArray.h:666
openvdb::v10_0::util::PagedArray::Iterator::operator*
ValueT & operator*() const
Definition PagedArray.h:660
openvdb::v10_0::util::PagedArray::Iterator::operator!=
bool operator!=(const Iterator &other) const
Definition PagedArray.h:671
openvdb::v10_0::util::PagedArray::Iterator::BaseT
std::iterator< std::random_access_iterator_tag, ValueT > BaseT
Definition PagedArray.h:642
openvdb::v10_0::util::PagedArray::Iterator::operator--
Iterator operator--(int)
Definition PagedArray.h:658
openvdb::v10_0::util::PagedArray::Iterator::operator-=
Iterator & operator-=(const difference_type &pos)
Definition PagedArray.h:665
openvdb::v10_0::util::PagedArray::Iterator::operator<=
bool operator<=(const Iterator &other) const
Definition PagedArray.h:673
openvdb::v10_0::util::PagedArray::Iterator::pos
size_t pos() const
Definition PagedArray.h:678
openvdb::v10_0::util::PagedArray::Iterator::operator-
difference_type operator-(const Iterator &other) const
Definition PagedArray.h:668
openvdb::v10_0::util::PagedArray::Iterator::operator++
Iterator operator++(int)
Definition PagedArray.h:657
openvdb::v10_0::util::PagedArray::Iterator::operator=
Iterator & operator=(const Iterator &other)
Definition PagedArray.h:648
openvdb::v10_0::util::PagedArray::Iterator::operator++
Iterator & operator++()
Definition PagedArray.h:654
openvdb::v10_0::util::PagedArray::Iterator::operator--
Iterator & operator--()
Definition PagedArray.h:655
openvdb::v10_0::util::PagedArray::Iterator::operator==
bool operator==(const Iterator &other) const
Definition PagedArray.h:670
openvdb::v10_0::util::PagedArray::Iterator::operator-
Iterator operator-(const difference_type &pos) const
Definition PagedArray.h:667
openvdb::v10_0::util::PagedArray::Page
Definition PagedArray.h:690
openvdb::v10_0::util::PagedArray::Page::copy
void copy(ValueType *dst, size_t n) const
Definition PagedArray.h:709
openvdb::v10_0::util::PagedArray::Page::operator[]
const ValueT & operator[](const size_t i) const
Definition PagedArray.h:701
openvdb::v10_0::util::PagedArray::Page::operator[]
ValueT & operator[](const size_t i)
Definition PagedArray.h:700
openvdb::v10_0::util::PagedArray::Page::memUsage
static size_t memUsage()
Definition PagedArray.h:694
openvdb::v10_0::util::PagedArray::Page::~Page
~Page()
Definition PagedArray.h:697
openvdb::v10_0::util::PagedArray::Page::mData
ValueT * mData
Definition PagedArray.h:714
openvdb::v10_0::util::PagedArray::Page::Page
Page(const Page &)=delete
openvdb::v10_0::util::PagedArray::Page::data
ValueT * data()
Definition PagedArray.h:706
openvdb::v10_0::util::PagedArray::Page::Page
Page()
Definition PagedArray.h:696
openvdb::v10_0::util::PagedArray::Page::fill
void fill(const ValueT &v)
Definition PagedArray.h:702
openvdb::v10_0::util::PagedArray::Page::operator=
Page & operator=(const Page &)=delete
openvdb::v10_0::util::PagedArray::ValueBuffer
Definition PagedArray.h:540
openvdb::v10_0::util::PagedArray::ValueBuffer::size
size_t size() const
Return the current number of elements cached in this buffer.
Definition PagedArray.h:574
openvdb::v10_0::util::PagedArray::ValueBuffer::~ValueBuffer
~ValueBuffer()
Destructor that transfers an buffered values to the parent PagedArray.
Definition PagedArray.h:549
openvdb::v10_0::util::PagedArray::ValueBuffer::operator=
ValueBuffer & operator=(const ValueBuffer &)=delete
openvdb::v10_0::util::PagedArray::ValueBuffer::push_back
void push_back(const ValueT &v)
Add a value to the buffer and increment the size.
Definition PagedArray.h:557
openvdb::v10_0::util::PagedArray::ValueBuffer::ValueBuffer
ValueBuffer(const ValueBuffer &other)
Definition PagedArray.h:547
openvdb::v10_0::util::PagedArray::ValueBuffer::parent
PagedArrayType & parent() const
Return a reference to the parent PagedArray.
Definition PagedArray.h:572
openvdb::v10_0::util::PagedArray::ValueBuffer::flush
void flush()
Manually transfers the values in this buffer to the parent PagedArray.
Definition PagedArray.h:566
openvdb::v10_0::util::PagedArray::ValueBuffer::ValueBuffer
ValueBuffer(PagedArray &parent)
Constructor from a PageArray.
Definition PagedArray.h:544
openvdb::v10_0::util::PagedArray::ValueBuffer::pageSize
static size_t pageSize()
Definition PagedArray.h:575
openvdb::v10_0::util::PagedArray
Concurrent, page-based, dynamically-sized linear data structure with O(1) random access and STL-compl...
Definition PagedArray.h:143
openvdb::v10_0::util::PagedArray::cend
ConstIterator cend() const
Return a const iterator pointing to the past-the-last element.
Definition PagedArray.h:388
openvdb::v10_0::util::PagedArray::memUsage
size_t memUsage() const
Return the memory footprint of this array in bytes.
Definition PagedArray.h:339
openvdb::v10_0::util::PagedArray::log2PageSize
static size_t log2PageSize()
Return log2 of the number of elements per memory page.
Definition PagedArray.h:336
openvdb::v10_0::util::PagedArray::begin
Iterator begin()
Return a non-const iterator pointing to the first element.
Definition PagedArray.h:367
openvdb::v10_0::util::PagedArray::size
size_t size() const
Return the number of elements in this array.
Definition PagedArray.h:319
openvdb::v10_0::util::PagedArray::PagedArray
PagedArray(const PagedArray &)=delete
openvdb::v10_0::util::PagedArray::push_back_unsafe
size_t push_back_unsafe(const ValueType &value)
Definition PagedArray.h:192
openvdb::v10_0::util::PagedArray::copy
void copy(ValueType *p) const
Definition PagedArray.h:271
openvdb::v10_0::util::PagedArray::sort
void sort()
Parallel sort of all the elements in ascending order.
Definition PagedArray.h:393
openvdb::v10_0::util::PagedArray::pageCount
size_t pageCount() const
Return the number of allocated memory pages.
Definition PagedArray.h:330
openvdb::v10_0::util::PagedArray::resize
void resize(size_t size)
Resize this array to the specified size.
Definition PagedArray.h:287
openvdb::v10_0::util::PagedArray::sort
void sort(Functor func)
Parallel sort of all the elements based on a custom functor with the api:
Definition PagedArray.h:404
openvdb::v10_0::util::PagedArray::PagedArray
PagedArray()
Default constructor.
Definition PagedArray.h:156
openvdb::v10_0::util::PagedArray::invSort
void invSort()
Parallel sort of all the elements in descending order.
Definition PagedArray.h:396
openvdb::v10_0::util::PagedArray::end
ConstIterator end() const
Definition PagedArray.h:389
openvdb::v10_0::util::PagedArray::fill
void fill(const ValueType &v)
Set all elements in the page table to the specified value.
Definition PagedArray.h:239
openvdb::v10_0::util::PagedArray::freeCount
size_t freeCount() const
Return the number of additional elements that can be added to this array without allocating more memo...
Definition PagedArray.h:327
openvdb::v10_0::util::PagedArray::capacity
size_t capacity() const
Return the maximum number of elements that this array can contain without allocating more memory page...
Definition PagedArray.h:323
openvdb::v10_0::util::PagedArray::isPartiallyFull
bool isPartiallyFull() const
Return true if the page table is partially full, i.e. the last non-empty page contains less than page...
Definition PagedArray.h:353
openvdb::v10_0::util::PagedArray::ValueType
ValueT ValueType
Definition PagedArray.h:152
openvdb::v10_0::util::PagedArray::operator=
PagedArray & operator=(const PagedArray &)=delete
openvdb::v10_0::util::PagedArray::resize
void resize(size_t size, const ValueType &v)
Resize this array to the specified size and initialize all values to v.
Definition PagedArray.h:312
openvdb::v10_0::util::PagedArray::operator[]
ValueType & operator[](size_t i)
Return a reference to the value at the specified offset.
Definition PagedArray.h:215
openvdb::v10_0::util::PagedArray::cbegin
ConstIterator cbegin() const
Return a const iterator pointing to the first element.
Definition PagedArray.h:378
openvdb::v10_0::util::PagedArray::~PagedArray
~PagedArray()
Destructor removed all allocated pages.
Definition PagedArray.h:159
openvdb::v10_0::util::PagedArray::end
Iterator end()
Return a non-const iterator pointing to the past-the-last element.
Definition PagedArray.h:374
openvdb::v10_0::util::PagedArray::copy
bool copy(ValueType *p, size_t count) const
Copy the first count values in this PageArray into a raw c-style array, assuming it to be at least co...
Definition PagedArray.h:254
openvdb::v10_0::util::PagedArray::getBuffer
ValueBuffer getBuffer()
Definition PagedArray.h:179
openvdb::v10_0::util::PagedArray::Ptr
SharedPtr< PagedArray > Ptr
Definition PagedArray.h:153
openvdb::v10_0::util::PagedArray::clear
void clear()
Removes all elements from the array and delete all pages.
Definition PagedArray.h:358
openvdb::v10_0::util::PagedArray::isEmpty
bool isEmpty() const
Return true if the container contains no elements.
Definition PagedArray.h:345
openvdb::v10_0::util::PagedArray::operator[]
const ValueType & operator[](size_t i) const
Return a const-reference to the value at the specified offset.
Definition PagedArray.h:228
openvdb::v10_0::util::PagedArray::begin
ConstIterator begin() const
Definition PagedArray.h:379
openvdb::v10_0::util::PagedArray::create
static Ptr create()
Return a shared pointer to a new instance of this class.
Definition PagedArray.h:166
openvdb::v10_0::util::PagedArray::print
void print(std::ostream &os=std::cout) const
Print information for debugging.
Definition PagedArray.h:417
openvdb::v10_0::util::PagedArray::pageSize
static size_t pageSize()
Return the number of elements per memory page.
Definition PagedArray.h:333
openvdb::v10_0::SharedPtr
std::shared_ptr< T > SharedPtr
Definition Types.h:114
openvdb
Definition Exceptions.h:13
Types.h
OPENVDB_VERSION_NAME
#define OPENVDB_VERSION_NAME
The version namespace name for this library version.
Definition version.h.in:121
OPENVDB_USE_VERSION_NAMESPACE
#define OPENVDB_USE_VERSION_NAMESPACE
Definition version.h.in:212