From a5d2929220bb08bfdc34505ca4edf5be6d9de94f Mon Sep 17 00:00:00 2001 From: Jane Liu Date: Mon, 24 Jul 2017 11:47:23 -0400 Subject: Added CPDF_NameTree::AddValueAndName() 1. Added CPDF_NameTree::AddValueAndName() for inserting new name and values pairs into a nametree while following nametree order rules. This function will be used for the API for adding embedded files. * Added anonymous helper functions. * Added two unit tests. Bug=pdfium:174 Change-Id: Ic3e2f32f7147ef5c164cf5c2a28e0a652ffed74a Reviewed-on: https://pdfium-review.googlesource.com/8271 Reviewed-by: dsinclair Commit-Queue: Jane Liu --- core/fpdfdoc/cpdf_nametree.cpp | 140 +++++++++++++++++++++++++++++++++++++---- 1 file changed, 127 insertions(+), 13 deletions(-) (limited to 'core/fpdfdoc/cpdf_nametree.cpp') diff --git a/core/fpdfdoc/cpdf_nametree.cpp b/core/fpdfdoc/cpdf_nametree.cpp index f30a27c681..4b4e7e81c2 100644 --- a/core/fpdfdoc/cpdf_nametree.cpp +++ b/core/fpdfdoc/cpdf_nametree.cpp @@ -6,38 +6,96 @@ #include "core/fpdfdoc/cpdf_nametree.h" +#include +#include + #include "core/fpdfapi/parser/cpdf_array.h" #include "core/fpdfapi/parser/cpdf_dictionary.h" #include "core/fpdfapi/parser/cpdf_document.h" +#include "core/fpdfapi/parser/cpdf_string.h" #include "core/fpdfapi/parser/fpdf_parser_decode.h" namespace { const int nMaxRecursion = 32; +// Get the limit arrays that leaf array |pFind| is under in the tree with root +// |pNode|. |pLimits| will hold all the limit arrays from the leaf up to before +// the root. Return true if successful. +bool GetNodeLimits(const CPDF_Dictionary* pNode, + const CPDF_Array* pFind, + int nLevel, + std::vector* pLimits) { + if (nLevel > nMaxRecursion) + return false; + + if (pNode->GetArrayFor("Names") == pFind) { + pLimits->push_back(pNode->GetArrayFor("Limits")); + return true; + } + + CPDF_Array* pKids = pNode->GetArrayFor("Kids"); + if (!pKids) + return false; + + for (size_t i = 0; i < pKids->GetCount(); ++i) { + CPDF_Dictionary* pKid = pKids->GetDictAt(i); + if (!pKid) + continue; + + if (GetNodeLimits(pKid, pFind, nLevel + 1, pLimits)) { + pLimits->push_back(pNode->GetArrayFor("Limits")); + return true; + } + } + return false; +} + +// Search for |csName| in the tree with root |pNode|. If successful, return the +// value that |csName| points to; |nIndex| will be the index of |csName|, +// |ppFind| will be the leaf array that |csName| is found in, and |pFindIndex| +// will be the index of |csName| in |ppFind|. If |csName| is not found, |ppFind| +// will be the leaf array that |csName| should be added to, and |pFindIndex| +// will be the index that it should be added at. CPDF_Object* SearchNameNode(CPDF_Dictionary* pNode, const CFX_WideString& csName, size_t& nIndex, + int nLevel, CPDF_Array** ppFind, - int nLevel = 0) { + int* pFindIndex) { if (nLevel > nMaxRecursion) return nullptr; CPDF_Array* pLimits = pNode->GetArrayFor("Limits"); + CPDF_Array* pNames = pNode->GetArrayFor("Names"); if (pLimits) { CFX_WideString csLeft = pLimits->GetUnicodeTextAt(0); CFX_WideString csRight = pLimits->GetUnicodeTextAt(1); + // If the lower limit is greater than the higher limit, swap them. if (csLeft.Compare(csRight) > 0) { - CFX_WideString csTmp = csRight; - csRight = csLeft; - csLeft = csTmp; + pLimits->SetNewAt(0, csRight); + pLimits->SetNewAt(1, csLeft); + csLeft = pLimits->GetUnicodeTextAt(0); + csRight = pLimits->GetUnicodeTextAt(1); } - if (csName.Compare(csLeft) < 0 || csName.Compare(csRight) > 0) { + // Skip this node if the name to look for is smaller than its lower limit. + if (csName.Compare(csLeft) < 0) + return nullptr; + + // Skip this node if the name to look for is greater than its higher limit, + // and the node itself is a leaf node. + if (csName.Compare(csRight) > 0 && pNames) { + if (ppFind) + *ppFind = pNames; + + if (pFindIndex) + *pFindIndex = pNames->GetCount() / 2 - 1; + return nullptr; } } - CPDF_Array* pNames = pNode->GetArrayFor("Names"); + // If the node is a leaf node, look for the name in its names array. if (pNames) { size_t dwCount = pNames->GetCount() / 2; for (size_t i = 0; i < dwCount; i++) { @@ -48,6 +106,10 @@ CPDF_Object* SearchNameNode(CPDF_Dictionary* pNode, if (ppFind) *ppFind = pNames; + + if (pFindIndex) + *pFindIndex = i; + if (iCompare < 0) continue; @@ -58,6 +120,7 @@ CPDF_Object* SearchNameNode(CPDF_Dictionary* pNode, return nullptr; } + // Search through the node's children. CPDF_Array* pKids = pNode->GetArrayFor("Kids"); if (!pKids) return nullptr; @@ -68,19 +131,22 @@ CPDF_Object* SearchNameNode(CPDF_Dictionary* pNode, continue; CPDF_Object* pFound = - SearchNameNode(pKid, csName, nIndex, ppFind, nLevel + 1); + SearchNameNode(pKid, csName, nIndex, nLevel + 1, ppFind, pFindIndex); if (pFound) return pFound; } return nullptr; } +// Get the key-value pair at |nIndex| in the tree with root |pNode|. If +// successful, return the value object; |csName| will be the key, and |ppFind| +// will be the leaf array that this pair is in. CPDF_Object* SearchNameNode(CPDF_Dictionary* pNode, size_t nIndex, size_t& nCurIndex, + int nLevel, CFX_WideString* csName, - CPDF_Array** ppFind, - int nLevel = 0) { + CPDF_Array** ppFind) { if (nLevel > nMaxRecursion) return nullptr; @@ -104,13 +170,14 @@ CPDF_Object* SearchNameNode(CPDF_Dictionary* pNode, if (!pKid) continue; CPDF_Object* pFound = - SearchNameNode(pKid, nIndex, nCurIndex, csName, ppFind, nLevel + 1); + SearchNameNode(pKid, nIndex, nCurIndex, nLevel + 1, csName, ppFind); if (pFound) return pFound; } return nullptr; } +// Get the total number of key-value pairs in the tree with root |pNode|. size_t CountNames(CPDF_Dictionary* pNode, int nLevel = 0) { if (nLevel > nMaxRecursion) return 0; @@ -163,11 +230,58 @@ int CPDF_NameTree::GetIndex(const CFX_WideString& csName) const { return -1; size_t nIndex = 0; - if (!SearchNameNode(m_pRoot.Get(), csName, nIndex, nullptr)) + if (!SearchNameNode(m_pRoot.Get(), csName, nIndex, 0, nullptr, nullptr)) return -1; return nIndex; } +bool CPDF_NameTree::AddValueAndName(std::unique_ptr pObj, + const CFX_WideString& name) { + if (!m_pRoot) + return false; + + size_t nIndex = 0; + CPDF_Array* pFind = nullptr; + int nFindIndex = -1; + // Fail if the tree already contains this name or if the tree is too deep. + if (SearchNameNode(m_pRoot.Get(), name, nIndex, 0, &pFind, &nFindIndex)) + return false; + + // If the returned |pFind| is a nullptr, then |name| is smaller than all + // existing entries in the tree, and we did not find a leaf array to place + // |name| into. We instead will find the leftmost leaf array in which to place + // |name| and |pObj|. + if (!pFind) { + size_t nCurIndex = 0; + CFX_WideString csName; + SearchNameNode(m_pRoot.Get(), 0, nCurIndex, 0, &csName, &pFind); + } + ASSERT(pFind); + + // Insert the name and the object into the leaf array found. Note that the + // insertion position is right after the key-value pair returned by |index|. + size_t nNameIndex = (nFindIndex + 1) * 2; + size_t nValueIndex = nNameIndex + 1; + pFind->InsertNewAt(nNameIndex, name); + pFind->InsertAt(nValueIndex, std::move(pObj)); + + // Expand the limits that the newly added name is under, if the name falls + // outside of the limits of its leaf array or any arrays above it. + std::vector pLimits; + GetNodeLimits(m_pRoot.Get(), pFind, 0, &pLimits); + for (auto* pLimit : pLimits) { + if (!pLimit) + continue; + + if (name.Compare(pLimit->GetUnicodeTextAt(0)) < 0) + pLimit->SetNewAt(0, name); + + if (name.Compare(pLimit->GetUnicodeTextAt(1)) > 0) + pLimit->SetNewAt(1, name); + } + return true; +} + CPDF_Object* CPDF_NameTree::LookupValueAndName(int nIndex, CFX_WideString* csName) const { csName->clear(); @@ -175,7 +289,7 @@ CPDF_Object* CPDF_NameTree::LookupValueAndName(int nIndex, return nullptr; size_t nCurIndex = 0; - return SearchNameNode(m_pRoot.Get(), nIndex, nCurIndex, csName, nullptr); + return SearchNameNode(m_pRoot.Get(), nIndex, nCurIndex, 0, csName, nullptr); } CPDF_Object* CPDF_NameTree::LookupValue(const CFX_WideString& csName) const { @@ -183,7 +297,7 @@ CPDF_Object* CPDF_NameTree::LookupValue(const CFX_WideString& csName) const { return nullptr; size_t nIndex = 0; - return SearchNameNode(m_pRoot.Get(), csName, nIndex, nullptr); + return SearchNameNode(m_pRoot.Get(), csName, nIndex, 0, nullptr, nullptr); } CPDF_Array* CPDF_NameTree::LookupNamedDest(CPDF_Document* pDoc, -- cgit v1.2.3