// static
void SkPDFPage::GeneratePageTree(const SkTDArray<SkPDFPage*>& pages,
SkPDFCatalog* catalog,
SkTDArray<SkPDFDict*>* pageTree,
SkPDFDict** rootNode) {
// 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;
SkAutoTUnref<SkPDFName> kidsName(new SkPDFName("Kids"));
SkAutoTUnref<SkPDFName> countName(new SkPDFName("Count"));
SkAutoTUnref<SkPDFName> parentName(new SkPDFName("Parent"));
// curNodes takes a reference to its items, which it passes to pageTree.
SkTDArray<SkPDFDict*> curNodes;
curNodes.setReserve(pages.count());
for (int i = 0; i < pages.count(); i++) {
SkSafeRef(pages[i]);
curNodes.push(pages[i]);
}
// nextRoundNodes passes its references to nodes on to curNodes.
SkTDArray<SkPDFDict*> nextRoundNodes;
nextRoundNodes.setReserve((pages.count() + kNodeSize - 1)/kNodeSize);
int treeCapacity = kNodeSize;
do {
for (int i = 0; i < curNodes.count(); ) {
if (i > 0 && i + 1 == curNodes.count()) {
nextRoundNodes.push(curNodes[i]);
break;
}
SkPDFDict* newNode = new SkPDFDict("Pages");
SkAutoTUnref<SkPDFObjRef> newNodeRef(new SkPDFObjRef(newNode));
SkAutoTUnref<SkPDFArray> kids(new SkPDFArray);
kids->reserve(kNodeSize);
int count = 0;
for (; i < curNodes.count() && count < kNodeSize; i++, count++) {
curNodes[i]->insert(parentName.get(), newNodeRef.get());
kids->append(new SkPDFObjRef(curNodes[i]))->unref();
// TODO(vandebo): put the objects in strict access order.
// Probably doesn't matter because they are so small.
if (curNodes[i] != pages[0]) {
pageTree->push(curNodes[i]); // Transfer reference.
catalog->addObject(curNodes[i], false);
} else {
SkSafeUnref(curNodes[i]);
catalog->addObject(curNodes[i], true);
}
}
// 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 = ((pages.count() - 1) % treeCapacity) + 1;
}
newNode->insert(countName.get(), new SkPDFInt(pageCount))->unref();
newNode->insert(kidsName.get(), kids.get());
nextRoundNodes.push(newNode); // Transfer reference.
}
curNodes = nextRoundNodes;
nextRoundNodes.rewind();
treeCapacity *= kNodeSize;
} while (curNodes.count() > 1);
pageTree->push(curNodes[0]); // Transfer reference.
catalog->addObject(curNodes[0], false);
if (rootNode) {
*rootNode = curNodes[0];
}
}
// static
void SkPDFPage::GeneratePageTree(const SkTDArray<SkPDFPage*>& pages,
SkPDFCatalog* catalog,
SkTDArray<SkPDFDict*>* pageTree,
SkPDFDict** rootNode) {
// 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;
SkRefPtr<SkPDFName> kidsName = new SkPDFName("Kids");
kidsName->unref(); // SkRefPtr and new both took a reference.
SkRefPtr<SkPDFName> countName = new SkPDFName("Count");
countName->unref(); // SkRefPtr and new both took a reference.
SkRefPtr<SkPDFName> parentName = new SkPDFName("Parent");
parentName->unref(); // SkRefPtr and new both took a reference.
// curNodes takes a reference to its items, which it passes to pageTree.
SkTDArray<SkPDFDict*> curNodes;
curNodes.setReserve(pages.count());
for (int i = 0; i < pages.count(); i++) {
SkSafeRef(pages[i]);
curNodes.push(pages[i]);
}
// nextRoundNodes passes its references to nodes on to curNodes.
SkTDArray<SkPDFDict*> nextRoundNodes;
nextRoundNodes.setReserve((pages.count() + kNodeSize - 1)/kNodeSize);
int treeCapacity = kNodeSize;
do {
for (int i = 0; i < curNodes.count(); ) {
if (i > 0 && i + 1 == curNodes.count()) {
nextRoundNodes.push(curNodes[i]);
break;
}
SkPDFDict* newNode = new SkPDFDict("Pages");
SkRefPtr<SkPDFObjRef> newNodeRef = new SkPDFObjRef(newNode);
newNodeRef->unref(); // SkRefPtr and new both took a reference.
SkRefPtr<SkPDFArray> kids = new SkPDFArray;
kids->unref(); // SkRefPtr and new both took a reference.
kids->reserve(kNodeSize);
int count = 0;
for (; i < curNodes.count() && count < kNodeSize; i++, count++) {
curNodes[i]->insert(parentName.get(), newNodeRef.get());
kids->append(new SkPDFObjRef(curNodes[i]))->unref();
// TODO(vandebo): put the objects in strict access order.
// Probably doesn't matter because they are so small.
if (curNodes[i] != pages[0]) {
pageTree->push(curNodes[i]); // Transfer reference.
catalog->addObject(curNodes[i], false);
} else {
SkSafeUnref(curNodes[i]);
catalog->addObject(curNodes[i], true);
}
}
newNode->insert(kidsName.get(), kids.get());
int pageCount = treeCapacity;
if (count < kNodeSize) {
pageCount = pages.count() % treeCapacity;
}
newNode->insert(countName.get(), new SkPDFInt(pageCount))->unref();
nextRoundNodes.push(newNode); // Transfer reference.
}
curNodes = nextRoundNodes;
nextRoundNodes.rewind();
treeCapacity *= kNodeSize;
} while (curNodes.count() > 1);
pageTree->push(curNodes[0]); // Transfer reference.
catalog->addObject(curNodes[0], false);
if (rootNode) {
*rootNode = curNodes[0];
}
}
