// return root node.
static sk_sp<SkPDFDict> generate_page_tree(SkTArray<sk_sp<SkPDFDict>>* pages) {
// PDF wants a tree describing all the pages in the document. We arbitrary
// choose 8 (kNodeSize) as the number of allowed children. The internal
// nodes have type "Pages" with an array of children, a parent pointer, and
// the number of leaves below the node as "Count." The leaves are passed
// into the method, have type "Page" and need a parent pointer. This method
// builds the tree bottom up, skipping internal nodes that would have only
// one child.
static const int kNodeSize = 8;
// curNodes takes a reference to its items, which it passes to pageTree.
int totalPageCount = pages->count();
SkTArray<sk_sp<SkPDFDict>> curNodes;
curNodes.swap(pages);
// nextRoundNodes passes its references to nodes on to curNodes.
int treeCapacity = kNodeSize;
do {
SkTArray<sk_sp<SkPDFDict>> nextRoundNodes;
for (int i = 0; i < curNodes.count(); ) {
if (i > 0 && i + 1 == curNodes.count()) {
SkASSERT(curNodes[i]);
nextRoundNodes.emplace_back(std::move(curNodes[i]));
break;
}
auto newNode = sk_make_sp<SkPDFDict>("Pages");
auto kids = sk_make_sp<SkPDFArray>();
kids->reserve(kNodeSize);
int count = 0;
for (; i < curNodes.count() && count < kNodeSize; i++, count++) {
SkASSERT(curNodes[i]);
curNodes[i]->insertObjRef("Parent", newNode);
kids->appendObjRef(std::move(curNodes[i]));
}
// treeCapacity is the number of leaf nodes possible for the
// current set of subtrees being generated. (i.e. 8, 64, 512, ...).
// It is hard to count the number of leaf nodes in the current
// subtree. However, by construction, we know that unless it's the
// last subtree for the current depth, the leaf count will be
// treeCapacity, otherwise it's what ever is left over after
// consuming treeCapacity chunks.
int pageCount = treeCapacity;
if (i == curNodes.count()) {
pageCount = ((totalPageCount - 1) % treeCapacity) + 1;
}
newNode->insertInt("Count", pageCount);
newNode->insertObject("Kids", std::move(kids));
nextRoundNodes.emplace_back(std::move(newNode));
}
SkDEBUGCODE( for (const auto& n : curNodes) { SkASSERT(!n); } );
curNodes.swap(&nextRoundNodes);
nextRoundNodes.reset();
treeCapacity *= kNodeSize;
} while (curNodes.count() > 1);
static void test_swap(skiatest::Reporter* reporter) {
typedef SkTArray<int>* (*ArrayMaker)();
ArrayMaker arrayMakers[] = {make, make_s<5>, make_s<10>, make_s<20>};
static int kSizes[] = {0, 1, 5, 10, 15, 20, 25};
for (size_t arrayA = 0; arrayA < SK_ARRAY_COUNT(arrayMakers); ++arrayA) {
for (size_t arrayB = arrayA; arrayB < SK_ARRAY_COUNT(arrayMakers); ++arrayB) {
for (size_t dataSizeA = 0; dataSizeA < SK_ARRAY_COUNT(kSizes); ++dataSizeA) {
for (size_t dataSizeB = 0; dataSizeB < SK_ARRAY_COUNT(kSizes); ++dataSizeB) {
int curr = 0;
SkTArray<int>* a = arrayMakers[arrayA]();
SkTArray<int>* b = arrayMakers[arrayB]();
for (int i = 0; i < kSizes[dataSizeA]; ++i) {
a->push_back(curr++);
}
for (int i = 0; i < kSizes[dataSizeB]; ++i) {
b->push_back(curr++);
}
a->swap(b);
REPORTER_ASSERT(reporter, kSizes[dataSizeA] == b->count());
REPORTER_ASSERT(reporter, kSizes[dataSizeB] == a->count());
curr = 0;
for (int i = 0; i < kSizes[dataSizeA]; ++i) {
REPORTER_ASSERT(reporter, curr++ == (*b)[i]);
}
for (int i = 0; i < kSizes[dataSizeB]; ++i) {
REPORTER_ASSERT(reporter, curr++ == (*a)[i]);
}
delete b;
a->swap(a);
curr = kSizes[dataSizeA];
for (int i = 0; i < kSizes[dataSizeB]; ++i) {
REPORTER_ASSERT(reporter, curr++ == (*a)[i]);
}
delete a;
}
}
}
}
}