Unify some code

core/fpdfapi/parser/cpdf_parser.cpp

 // Copyright 2016 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #include "core/fpdfapi/parser/cpdf_parser.h"
 
 #include <vector>
 
 #include "core/fpdfapi/parser/cpdf_array.h"
 #include "core/fpdfapi/parser/cpdf_crypto_handler.h"
 #include "core/fpdfapi/parser/cpdf_dictionary.h"
 #include "core/fpdfapi/parser/cpdf_document.h"
+#include "core/fpdfapi/parser/cpdf_linearized.h"
 #include "core/fpdfapi/parser/cpdf_number.h"
 #include "core/fpdfapi/parser/cpdf_reference.h"
 #include "core/fpdfapi/parser/cpdf_security_handler.h"
 #include "core/fpdfapi/parser/cpdf_stream.h"
 #include "core/fpdfapi/parser/cpdf_stream_acc.h"
 #include "core/fpdfapi/parser/cpdf_syntax_parser.h"
 #include "core/fpdfapi/parser/fpdf_parser_utility.h"
 #include "core/fxcrt/fx_ext.h"
 #include "core/fxcrt/fx_safe_types.h"
 #include "third_party/base/stl_util.h"
@@ skipping 22 matching lines @@
 }  // namespace
 
 CPDF_Parser::CPDF_Parser()
     : m_pDocument(nullptr),
       m_bHasParsed(false),
       m_bOwnFileRead(true),
       m_FileVersion(0),
       m_pTrailer(nullptr),
       m_pEncryptDict(nullptr),
       m_bVersionUpdated(false),
-      m_pLinearized(nullptr),
-      m_dwFirstPageNo(0),
       m_dwXrefStartObjNum(0) {
   m_pSyntax.reset(new CPDF_SyntaxParser);
 }
 
 CPDF_Parser::~CPDF_Parser() {
   if (m_pTrailer)
     m_pTrailer->Release();
 
   ReleaseEncryptHandler();
   SetEncryptDictionary(nullptr);
 
   if (m_bOwnFileRead && m_pSyntax->m_pFileAccess) {
     m_pSyntax->m_pFileAccess->Release();
     m_pSyntax->m_pFileAccess = nullptr;
   }
 
   for (CPDF_Dictionary* trailer : m_Trailers) {
     if (trailer)
       trailer->Release();
   }
-
-  if (m_pLinearized)
-    m_pLinearized->Release();
 }
 
 uint32_t CPDF_Parser::GetLastObjNum() const {
   return m_ObjectInfo.empty() ? 0 : m_ObjectInfo.rbegin()->first;
 }
 
 bool CPDF_Parser::IsValidObjectNumber(uint32_t objnum) const {
   return !m_ObjectInfo.empty() && objnum <= m_ObjectInfo.rbegin()->first;
 }
 
@@ skipping 1315 matching lines @@
   }
 
   CPDF_Object* pObj = m_pSyntax->GetObjectForStrict(pObjList, objnum, gennum);
   if (pResultPos)
     *pResultPos = m_pSyntax->m_Pos;
 
   m_pSyntax->RestorePos(SavedPos);
   return pObj;
 }
 
+uint32_t CPDF_Parser::GetFirstPageNo() const {
+  return m_pLinearized ? m_pLinearized->GetFirstPageNo() : 0;
+}
+
 CPDF_Dictionary* CPDF_Parser::LoadTrailerV4() {
   if (m_pSyntax->GetKeyword() != "trailer")
     return nullptr;
 
   std::unique_ptr<CPDF_Object, ReleaseDeleter<CPDF_Object>> pObj(
       m_pSyntax->GetObject(m_pDocument, 0, 0, true));
   if (!ToDictionary(pObj.get()))
     return nullptr;
   return pObj.release()->AsDictionary();
 }
@@ skipping 26 matching lines @@
   word = m_pSyntax->GetNextWord(&bIsNumber);
   if (!bIsNumber)
     return FALSE;
 
   uint32_t gennum = FXSYS_atoui(word.c_str());
   if (m_pSyntax->GetKeyword() != "obj") {
     m_pSyntax->RestorePos(SavedPos);
     return FALSE;
   }
 
-  m_pLinearized = m_pSyntax->GetObject(nullptr, objnum, gennum, true);
-  if (!m_pLinearized)
+  auto pLinearized = CPDF_Linearized::CreateForObject(

[Lei Zhang, 2016/11/03 00:46:26]

Do we want to directly assign to |m_pLinearized| here?

[snake, 2016/11/03 01:39:27]

What do you mean?
If we have not valid CPDF_Linearized we should not store it.

[Lei Zhang, 2016/11/03 01:59:31]

But with the IsValid() check that we just added, CreateForObject() will either
return something valid or nullptr. So if |m_pLinearized| starts out as nullptr,
and you assign nullptr to it, there is no harm.

[snake, 2016/11/03 02:36:52]

Done.

+      UniqueObject(m_pSyntax->GetObject(nullptr, objnum, gennum, true)));
+  if (!pLinearized || !pLinearized->IsValid())
     return FALSE;
-
-  CPDF_Dictionary* pDict = m_pLinearized->GetDict();
-  if (pDict && pDict->GetObjectFor("Linearized")) {
-    m_pSyntax->GetNextWord(nullptr);
-
-    CPDF_Object* pLen = pDict->GetObjectFor("L");
-    if (!pLen) {
-      m_pLinearized->Release();
-      m_pLinearized = nullptr;
-      return FALSE;
-    }
-
-    if (pLen->GetInteger() != (int)pFileAccess->GetSize())
-      return FALSE;
-
-    if (CPDF_Number* pNo = ToNumber(pDict->GetObjectFor("P")))
-      m_dwFirstPageNo = pNo->GetInteger();
-
-    if (CPDF_Number* pTable = ToNumber(pDict->GetObjectFor("T")))
-      m_LastXRefOffset = pTable->GetInteger();
-
-    return TRUE;
-  }
-  m_pLinearized->Release();
-  m_pLinearized = nullptr;
-  return FALSE;
+  m_pLinearized = std::move(pLinearized);
+  m_LastXRefOffset = m_pLinearized->GetLastXRefOffset();
+  return TRUE;
 }
 
 CPDF_Parser::Error CPDF_Parser::StartLinearizedParse(
     IFX_SeekableReadStream* pFileAccess,
     CPDF_Document* pDocument) {
   ASSERT(!m_bHasParsed);
 
   m_bXRefStream = FALSE;
   m_LastXRefOffset = 0;
   m_bOwnFileRead = true;
 
   int32_t offset = GetHeaderOffset(pFileAccess);
   if (offset == -1)
     return FORMAT_ERROR;
 
   if (!IsLinearizedFile(pFileAccess, offset)) {
     m_pSyntax->m_pFileAccess = nullptr;
     return StartParse(pFileAccess, std::move(pDocument));
   }
   m_bHasParsed = true;
   m_pDocument = pDocument;
 
+  m_pSyntax->GetNextWord(nullptr);
   FX_FILESIZE dwFirstXRefOffset = m_pSyntax->SavePos();
 
   FX_BOOL bXRefRebuilt = FALSE;
   FX_BOOL bLoadV4 = LoadCrossRefV4(dwFirstXRefOffset, 0, FALSE);
   if (!bLoadV4 && !LoadCrossRefV5(&dwFirstXRefOffset, TRUE)) {
     if (!RebuildCrossRef())
       return FORMAT_ERROR;
 
     bXRefRebuilt = TRUE;
     m_LastXRefOffset = 0;
   }
 
   if (bLoadV4) {
     m_pTrailer = LoadTrailerV4();
     if (!m_pTrailer)
       return SUCCESS;
 
     int32_t xrefsize = GetDirectInteger(m_pTrailer, "Size");
     if (xrefsize > 0)
       ShrinkObjectMap(xrefsize);
   }
 
   Error eRet = SetEncryptHandler();
   if (eRet != SUCCESS)
     return eRet;
 
-  m_pDocument->LoadLinearizedDoc(m_pLinearized->GetDict());
+  m_pDocument->LoadLinearizedDoc(m_pLinearized.get());
   if (!m_pDocument->GetRoot() || m_pDocument->GetPageCount() == 0) {
     if (bXRefRebuilt)
       return FORMAT_ERROR;
 
     ReleaseEncryptHandler();
     if (!RebuildCrossRef())
       return FORMAT_ERROR;
 
     eRet = SetEncryptHandler();
     if (eRet != SUCCESS)
       return eRet;
 
-    m_pDocument->LoadLinearizedDoc(m_pLinearized->GetDict());
+    m_pDocument->LoadLinearizedDoc(m_pLinearized.get());
     if (!m_pDocument->GetRoot())
       return FORMAT_ERROR;
   }
 
   if (GetRootObjNum() == 0) {
     ReleaseEncryptHandler();
     if (!RebuildCrossRef() || GetRootObjNum() == 0)
       return FORMAT_ERROR;
 
     eRet = SetEncryptHandler();
@@ skipping 55 matching lines @@
   if (!LoadLinearizedAllCrossRefV4(m_LastXRefOffset, m_dwXrefStartObjNum) &&
       !LoadLinearizedAllCrossRefV5(m_LastXRefOffset)) {
     m_LastXRefOffset = 0;
     m_pSyntax->m_MetadataObjnum = dwSaveMetadataObjnum;
     return FORMAT_ERROR;
   }
 
   m_pSyntax->m_MetadataObjnum = dwSaveMetadataObjnum;
   return SUCCESS;
 }