Unify some code

core/fpdfapi/parser/cpdf_hint_tables.cpp

Index: core/fpdfapi/parser/cpdf_hint_tables.cpp
diff --git a/core/fpdfapi/parser/cpdf_hint_tables.cpp b/core/fpdfapi/parser/cpdf_hint_tables.cpp
index 045b94cac5dda7fe7982ad729c3a2662f1a30da7..bbc57dace915abfa17aeb8848a86aa4f027ca31e 100644
--- a/core/fpdfapi/parser/cpdf_hint_tables.cpp
+++ b/core/fpdfapi/parser/cpdf_hint_tables.cpp
@@ -12,6 +12,7 @@
 #include "core/fpdfapi/parser/cpdf_data_avail.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_stream.h"
 #include "core/fpdfapi/parser/cpdf_stream_acc.h"
 #include "core/fxcrt/fx_safe_types.h"
@@ -34,12 +35,12 @@ bool IsValidPageOffsetHintTableBitCount(uint32_t bits) {
 }  // namespace
 
 CPDF_HintTables::CPDF_HintTables(CPDF_DataAvail* pDataAvail,
-                                 CPDF_Dictionary* pLinearized)
+                                 CPDF_Linearized* pLinearized)
     : m_pDataAvail(pDataAvail),
-      m_pLinearizedDict(pLinearized),
+      m_pLinearized(pLinearized),
       m_nFirstPageSharedObjs(0),
       m_szFirstPageObjOffset(0) {
-  ASSERT(m_pLinearizedDict);
+  ASSERT(m_pLinearized);
 }
 
 CPDF_HintTables::~CPDF_HintTables() {}
@@ -487,38 +488,25 @@ bool CPDF_HintTables::LoadHintStream(CPDF_Stream* pHintStream) {
 }
 
 int CPDF_HintTables::GetEndOfFirstPageOffset() const {
-  CPDF_Object* pOffsetE = m_pLinearizedDict->GetDirectObjectFor("E");
-  return pOffsetE ? pOffsetE->GetInteger() : -1;
+  return static_cast<int>(m_pLinearized->GetFirstPageEndOffset());
 }
 
 int CPDF_HintTables::GetNumberOfPages() const {
-  CPDF_Object* pPageNum = m_pLinearizedDict->GetDirectObjectFor("N");
-  return pPageNum ? pPageNum->GetInteger() : 0;
+  return static_cast<int>(m_pLinearized->GetPageCount());
 }
 
 int CPDF_HintTables::GetFirstPageObjectNumber() const {
-  CPDF_Object* pFirstPageObj = m_pLinearizedDict->GetDirectObjectFor("O");
-  return pFirstPageObj ? pFirstPageObj->GetInteger() : -1;
+  return static_cast<int>(m_pLinearized->GetFirstPageObjNum());

[Lei Zhang, 2016/11/03 17:18:00]

There's a subtle difference here: all the callers check for < 0 on failure, but
now this never returns < 0.

Unlike GetEndOfFirstPageOffset() above, CPDF_Linearized::IsValid() does not
check this value.

[snake, 2016/11/03 17:50:34]

This checks not save us from errors value (say 9999999).
If we have any incorrect first page num, we can not parse this page, in
CPDF_Document::GetPage, because we have not this obj-num in ref table or this
object have incorrect format.

Again, I want to update checks like this, and simplify/unify in spearate CLs. As
you see, much of checking in seperate places, with separate conditions. 

[Lei Zhang, 2016/11/04 01:10:15]

Sure, I know it will not save us from other bad values. Hopefully some other
code is doing those checks.

I guess what I'd like is for the 3 callers to check for <= 0, instead of < 0.
Yes, I understand. I agree many improvements can be made in follow up Cls.
Though I do want this CL to be able to stand on its own, so it does not cause a
regression and get reverted.

 }
 
 int CPDF_HintTables::GetFirstPageNumber() const {
-  CPDF_Object* pFirstPageNum = m_pLinearizedDict->GetDirectObjectFor("P");
-  return pFirstPageNum ? pFirstPageNum->GetInteger() : 0;
+  return static_cast<int>(m_pLinearized->GetFirstPageNo());
 }
 
 int CPDF_HintTables::ReadPrimaryHintStreamOffset() const {
-  return ReadPrimaryHintStream(0);
+  return static_cast<int>(m_pLinearized->GetHintStart());
 }
 
 int CPDF_HintTables::ReadPrimaryHintStreamLength() const {
-  return ReadPrimaryHintStream(1);
-}
-
-int CPDF_HintTables::ReadPrimaryHintStream(int index) const {
-  CPDF_Array* pRange = m_pLinearizedDict->GetArrayFor("H");
-  if (!pRange)
-    return -1;
-
-  CPDF_Object* pStreamLen = pRange->GetDirectObjectAt(index);
-  return pStreamLen ? pStreamLen->GetInteger() : -1;
+  return static_cast<int>(m_pLinearized->GetHintLength());
 }