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-rw-r--r--core/fpdfapi/parser/cpdf_document.cpp88
-rw-r--r--core/fpdfapi/parser/cpdf_document.h14
-rw-r--r--core/fpdfapi/parser/cpdf_document_unittest.cpp27
3 files changed, 97 insertions, 32 deletions
diff --git a/core/fpdfapi/parser/cpdf_document.cpp b/core/fpdfapi/parser/cpdf_document.cpp
index 64574047e5..8e181de97c 100644
--- a/core/fpdfapi/parser/cpdf_document.cpp
+++ b/core/fpdfapi/parser/cpdf_document.cpp
@@ -336,6 +336,7 @@ CPDF_Document::CPDF_Document(std::unique_ptr<CPDF_Parser> pParser)
m_pParser(std::move(pParser)),
m_pRootDict(nullptr),
m_pInfoDict(nullptr),
+ m_iNextPageToTraverse(0),
m_bLinearized(false),
m_iFirstPageNo(0),
m_dwFirstPageObjNum(0),
@@ -400,40 +401,72 @@ void CPDF_Document::LoadPages() {
m_PageList.SetSize(RetrievePageCount());
}
-CPDF_Dictionary* CPDF_Document::FindPDFPage(CPDF_Dictionary* pPages,
- int iPage,
- int nPagesToGo,
- int level) {
+CPDF_Dictionary* CPDF_Document::TraversePDFPages(int iPage,
+ int* nPagesToGo,
+ size_t level) {
+ if (*nPagesToGo < 0)
+ return nullptr;
+ CPDF_Dictionary* pPages = m_pTreeTraversal[level].first;
CPDF_Array* pKidList = pPages->GetArrayFor("Kids");
- if (!pKidList)
- return nPagesToGo == 0 ? pPages : nullptr;
+ if (!pKidList) {
+ if (*nPagesToGo != 1)
+ return nullptr;
+ m_PageList.SetAt(iPage, pPages->GetObjNum());
+ return pPages;
+ }
- if (level >= FX_MAX_PAGE_LEVEL)
+ if (level >= FX_MAX_PAGE_LEVEL) {
+ m_pTreeTraversal.pop_back();
return nullptr;
+ }
- for (size_t i = 0; i < pKidList->GetCount(); i++) {
+ CPDF_Dictionary* page = nullptr;
+ for (size_t i = m_pTreeTraversal[level].second; i < pKidList->GetCount();
+ i++) {
+ if (*nPagesToGo == 0)
+ break;
CPDF_Dictionary* pKid = pKidList->GetDictAt(i);
if (!pKid) {
- nPagesToGo--;
+ (*nPagesToGo)--;
+ m_pTreeTraversal[level].second++;
continue;
}
- if (pKid == pPages)
+ if (pKid == pPages) {
+ m_pTreeTraversal[level].second++;
continue;
+ }
if (!pKid->KeyExist("Kids")) {
- if (nPagesToGo == 0)
- return pKid;
-
- m_PageList.SetAt(iPage - nPagesToGo, pKid->GetObjNum());
- nPagesToGo--;
+ m_PageList.SetAt(iPage - (*nPagesToGo) + 1, pKid->GetObjNum());
+ (*nPagesToGo)--;
+ m_pTreeTraversal[level].second++;
+ if (*nPagesToGo == 0) {
+ page = pKid;
+ break;
+ }
} else {
- int nPages = pKid->GetIntegerFor("Count");
- if (nPagesToGo < nPages)
- return FindPDFPage(pKid, iPage, nPagesToGo, level + 1);
-
- nPagesToGo -= nPages;
+ // If the vector has size level+1, the child is not in yet
+ if (m_pTreeTraversal.size() == level + 1)
+ m_pTreeTraversal.push_back(std::make_pair(pKid, 0));
+ // Now m_pTreeTraversal[level+1] should exist and be equal to pKid.
+ CPDF_Dictionary* pageKid = TraversePDFPages(iPage, nPagesToGo, level + 1);
+ // Check if child was completely processed, i.e. it popped itself out
+ if (m_pTreeTraversal.size() == level + 1)
+ m_pTreeTraversal[level].second++;
+ // If child did not finish or if no pages to go, we are done
+ if (m_pTreeTraversal.size() != level + 1 || *nPagesToGo == 0) {
+ page = pageKid;
+ break;
+ }
}
}
- return nullptr;
+ if (m_pTreeTraversal[level].second == pKidList->GetCount())
+ m_pTreeTraversal.pop_back();
+ return page;
+}
+
+void CPDF_Document::ResetTraversal() {
+ m_iNextPageToTraverse = 0;
+ m_pTreeTraversal.clear();
}
CPDF_Dictionary* CPDF_Document::GetPagesDict() const {
@@ -460,17 +493,18 @@ CPDF_Dictionary* CPDF_Document::GetPage(int iPage) {
if (objnum) {
if (CPDF_Dictionary* pDict = ToDictionary(GetOrParseIndirectObject(objnum)))
return pDict;
+ return nullptr;
}
CPDF_Dictionary* pPages = GetPagesDict();
if (!pPages)
return nullptr;
- CPDF_Dictionary* pPage = FindPDFPage(pPages, iPage, iPage, 0);
- if (!pPage)
- return nullptr;
-
- m_PageList.SetAt(iPage, pPage->GetObjNum());
+ if (m_pTreeTraversal.empty())
+ m_pTreeTraversal.push_back(std::make_pair(pPages, 0));
+ int nPagesToGo = iPage - m_iNextPageToTraverse + 1;
+ CPDF_Dictionary* pPage = TraversePDFPages(iPage, &nPagesToGo, 0);
+ m_iNextPageToTraverse = iPage + 1;
return pPage;
}
@@ -664,6 +698,7 @@ bool CPDF_Document::InsertDeletePDFPage(CPDF_Dictionary* pPages,
}
pPages->SetIntegerFor(
"Count", pPages->GetIntegerFor("Count") + (bInsert ? 1 : -1));
+ ResetTraversal();
break;
}
int nPages = pKid->GetIntegerFor("Count");
@@ -704,6 +739,7 @@ bool CPDF_Document::InsertNewPage(int iPage, CPDF_Dictionary* pPageDict) {
pPagesList->Add(new CPDF_Reference(this, pPageDict->GetObjNum()));
pPages->SetIntegerFor("Count", nPages + 1);
pPageDict->SetReferenceFor("Parent", this, pPages->GetObjNum());
+ ResetTraversal();
} else {
std::set<CPDF_Dictionary*> stack = {pPages};
if (!InsertDeletePDFPage(pPages, iPage, pPageDict, true, &stack))
diff --git a/core/fpdfapi/parser/cpdf_document.h b/core/fpdfapi/parser/cpdf_document.h
index e1135260ee..0a99e42c3f 100644
--- a/core/fpdfapi/parser/cpdf_document.h
+++ b/core/fpdfapi/parser/cpdf_document.h
@@ -105,10 +105,8 @@ class CPDF_Document : public CPDF_IndirectObjectHolder {
protected:
// Retrieve page count information by getting count value from the tree nodes
int RetrievePageCount() const;
- CPDF_Dictionary* FindPDFPage(CPDF_Dictionary* pPages,
- int iPage,
- int nPagesToGo,
- int level);
+ // When this method is called, m_pTreeTraversal[level] exists.
+ CPDF_Dictionary* TraversePDFPages(int iPage, int* nPagesToGo, size_t level);
int FindPageIndex(CPDF_Dictionary* pNode,
uint32_t& skip_count,
uint32_t objnum,
@@ -130,10 +128,18 @@ class CPDF_Document : public CPDF_IndirectObjectHolder {
bool bInsert,
std::set<CPDF_Dictionary*>* pVisited);
bool InsertNewPage(int iPage, CPDF_Dictionary* pPageDict);
+ void ResetTraversal();
std::unique_ptr<CPDF_Parser> m_pParser;
CPDF_Dictionary* m_pRootDict;
CPDF_Dictionary* m_pInfoDict;
+ // Vector of pairs to know current position in the page tree. The index in the
+ // vector corresponds to the level being described. The pair contains a
+ // pointer to the dictionary being processed at the level, and an index of the
+ // of the child being processed within the dictionary's /Kids array.
+ std::vector<std::pair<CPDF_Dictionary*, size_t>> m_pTreeTraversal;
+ // Index of the next page that will be traversed from the page tree.
+ int m_iNextPageToTraverse;
bool m_bLinearized;
int m_iFirstPageNo;
uint32_t m_dwFirstPageObjNum;
diff --git a/core/fpdfapi/parser/cpdf_document_unittest.cpp b/core/fpdfapi/parser/cpdf_document_unittest.cpp
index c09665b716..71716a649e 100644
--- a/core/fpdfapi/parser/cpdf_document_unittest.cpp
+++ b/core/fpdfapi/parser/cpdf_document_unittest.cpp
@@ -95,7 +95,7 @@ TEST_F(cpdf_document_test, GetPages) {
for (int i = 0; i < 7; i++) {
CPDF_Dictionary* page = document->GetPage(i);
ASSERT_TRUE(page);
- ASSERT_TRUE(page->GetObjectFor("PageNumbering"));
+ ASSERT_TRUE(page->KeyExist("PageNumbering"));
EXPECT_EQ(i, page->GetIntegerFor("PageNumbering"));
}
CPDF_Dictionary* page = document->GetPage(7);
@@ -108,13 +108,36 @@ TEST_F(cpdf_document_test, GetPagesReverseOrder) {
for (int i = 6; i >= 0; i--) {
CPDF_Dictionary* page = document->GetPage(i);
ASSERT_TRUE(page);
- ASSERT_TRUE(page->GetObjectFor("PageNumbering"));
+ ASSERT_TRUE(page->KeyExist("PageNumbering"));
EXPECT_EQ(i, page->GetIntegerFor("PageNumbering"));
}
CPDF_Dictionary* page = document->GetPage(7);
EXPECT_FALSE(page);
}
+TEST(cpdf_document, GetPagesInDisorder) {
+ std::unique_ptr<CPDF_TestDocumentForPages> document =
+ pdfium::MakeUnique<CPDF_TestDocumentForPages>();
+
+ CPDF_Dictionary* page = document->GetPage(1);
+ ASSERT_TRUE(page);
+ ASSERT_TRUE(page->KeyExist("PageNumbering"));
+ EXPECT_EQ(1, page->GetIntegerFor("PageNumbering"));
+
+ page = document->GetPage(3);
+ ASSERT_TRUE(page);
+ ASSERT_TRUE(page->KeyExist("PageNumbering"));
+ EXPECT_EQ(3, page->GetIntegerFor("PageNumbering"));
+
+ page = document->GetPage(7);
+ EXPECT_FALSE(page);
+
+ page = document->GetPage(6);
+ ASSERT_TRUE(page);
+ ASSERT_TRUE(page->KeyExist("PageNumbering"));
+ EXPECT_EQ(6, page->GetIntegerFor("PageNumbering"));
+}
+
TEST_F(cpdf_document_test, UseCachedPageObjNumIfHaveNotPagesDict) {
// ObjNum can be added in CPDF_DataAvail::IsPageAvail, and PagesDict
// can be not exists in this case.
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-02 16:20:19 +0000