Deduplicate code in CPDF_Parser and rename some methods
- Refactor common code into FindAllCrossReferenceTablesAndStream()
- Rename LoadAllCrossRefTable() to LoadAllCrossRefTables()
- Rename LoadAllCrossRefStream() to LoadAllCrossRefStreams()
Change-Id: Iced6b5b84f4c9a1a013975738f1d47fe0fc2cd3c
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/118331
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Reviewed-by: Thomas Sepez <tsepez@google.com>
diff --git a/core/fpdfapi/parser/cpdf_data_avail.cpp b/core/fpdfapi/parser/cpdf_data_avail.cpp
index 5c1fb43..0850f7e 100644
--- a/core/fpdfapi/parser/cpdf_data_avail.cpp
+++ b/core/fpdfapi/parser/cpdf_data_avail.cpp
@@ -195,9 +195,9 @@
return false;
}
- if (!m_parser.LoadAllCrossRefTable(
+ if (!m_parser.LoadAllCrossRefTables(
m_pCrossRefAvail->last_crossref_offset()) &&
- !m_parser.LoadAllCrossRefStream(
+ !m_parser.LoadAllCrossRefStreams(
m_pCrossRefAvail->last_crossref_offset())) {
m_internalStatus = InternalStatus::kLoadAllFile;
return false;
diff --git a/core/fpdfapi/parser/cpdf_parser.cpp b/core/fpdfapi/parser/cpdf_parser.cpp
index dcdcb7b..61861de 100644
--- a/core/fpdfapi/parser/cpdf_parser.cpp
+++ b/core/fpdfapi/parser/cpdf_parser.cpp
@@ -250,8 +250,8 @@
m_LastXRefOffset = ParseStartXRef();
if (m_LastXRefOffset >= kPDFHeaderSize) {
- if (!LoadAllCrossRefTable(m_LastXRefOffset) &&
- !LoadAllCrossRefStream(m_LastXRefOffset)) {
+ if (!LoadAllCrossRefTables(m_LastXRefOffset) &&
+ !LoadAllCrossRefStreams(m_LastXRefOffset)) {
if (!RebuildCrossRef())
return FORMAT_ERROR;
@@ -372,7 +372,7 @@
return true;
}
-bool CPDF_Parser::LoadAllCrossRefTable(FX_FILESIZE xref_offset) {
+bool CPDF_Parser::LoadAllCrossRefTables(FX_FILESIZE xref_offset) {
if (!LoadCrossRefTable(xref_offset, /*skip=*/true)) {
return false;
}
@@ -400,39 +400,11 @@
}
// Otherwise, follow the /Prev from the trailer.
- std::vector<FX_FILESIZE> xref_stream_list{xref_stm};
std::vector<FX_FILESIZE> xref_list{xref_offset};
- std::set<FX_FILESIZE> seen_xref_offset{xref_offset};
-
- // When the trailer doesn't have Prev entry or Prev entry value is not
- // numerical, GetDirectInteger() returns 0. Loading will end.
- xref_offset = GetTrailer()->GetDirectIntegerFor("Prev");
- while (xref_offset > 0) {
- // Check for circular references.
- if (pdfium::Contains(seen_xref_offset, xref_offset)) {
- return false;
- }
-
- seen_xref_offset.insert(xref_offset);
- xref_list.insert(xref_list.begin(), xref_offset);
-
- // SLOW ...
- LoadCrossRefTable(xref_offset, /*skip=*/true);
-
- RetainPtr<CPDF_Dictionary> trailer_dict = LoadTrailer();
- if (!trailer_dict) {
- return false;
- }
-
- xref_offset = trailer_dict->GetDirectIntegerFor("Prev");
- xref_stm = trailer_dict->GetIntegerFor("XRefStm");
- xref_stream_list.insert(xref_stream_list.begin(), xref_stm);
-
- // SLOW ...
- m_CrossRefTable = CPDF_CrossRefTable::MergeUp(
- std::make_unique<CPDF_CrossRefTable>(std::move(trailer_dict),
- kNoTrailerObjectNumber),
- std::move(m_CrossRefTable));
+ std::vector<FX_FILESIZE> xref_stream_list{xref_stm};
+ if (!FindAllCrossReferenceTablesAndStream(xref_offset, xref_list,
+ xref_stream_list)) {
+ return false;
}
for (size_t i = 0; i < xref_list.size(); ++i) {
@@ -469,11 +441,11 @@
// first-page trailer, as the caller already did that and passed it in as
// |main_xref_offset|.
FX_FILESIZE xref_stm = GetTrailer()->GetDirectIntegerFor("XRefStm");
- std::vector<FX_FILESIZE> xref_stream_list{xref_stm};
std::vector<FX_FILESIZE> xref_list{main_xref_offset};
- std::set<FX_FILESIZE> seen_xref_offset{main_xref_offset};
+ std::vector<FX_FILESIZE> xref_stream_list{xref_stm};
- // Merge the trailers.
+ // Merge the trailers. Now GetTrailer() returns the merged trailer, where
+ // /Prev is from the main-trailer.
m_CrossRefTable = CPDF_CrossRefTable::MergeUp(
std::make_unique<CPDF_CrossRefTable>(std::move(main_trailer),
kNoTrailerObjectNumber),
@@ -482,35 +454,9 @@
// Ignore /Prev for hybrid-reference files.
// See ISO 32000-1:2008 spec, table 17.
if (!xref_stm) {
- // Now GetTrailer() returns the merged trailer, where /Prev is from the
- // main-trailer.
- FX_FILESIZE xref_offset = GetTrailer()->GetDirectIntegerFor("Prev");
- while (xref_offset > 0) {
- // Check for circular references.
- if (pdfium::Contains(seen_xref_offset, xref_offset)) {
- return false;
- }
-
- seen_xref_offset.insert(xref_offset);
- xref_list.insert(xref_list.begin(), xref_offset);
-
- // SLOW ...
- LoadCrossRefTable(xref_offset, /*skip=*/true);
-
- RetainPtr<CPDF_Dictionary> trailer_dict = LoadTrailer();
- if (!trailer_dict) {
- return false;
- }
-
- xref_offset = trailer_dict->GetDirectIntegerFor("Prev");
- xref_stm = trailer_dict->GetIntegerFor("XRefStm");
- xref_stream_list.insert(xref_stream_list.begin(), xref_stm);
-
- // SLOW ...
- m_CrossRefTable = CPDF_CrossRefTable::MergeUp(
- std::make_unique<CPDF_CrossRefTable>(std::move(trailer_dict),
- kNoTrailerObjectNumber),
- std::move(m_CrossRefTable));
+ if (!FindAllCrossReferenceTablesAndStream(main_xref_offset, xref_list,
+ xref_stream_list)) {
+ return false;
}
}
@@ -689,7 +635,7 @@
}
}
-bool CPDF_Parser::LoadAllCrossRefStream(FX_FILESIZE xref_offset) {
+bool CPDF_Parser::LoadAllCrossRefStreams(FX_FILESIZE xref_offset) {
if (!LoadCrossRefStream(&xref_offset, /*is_main_xref=*/true)) {
return false;
}
@@ -732,6 +678,45 @@
return true;
}
+bool CPDF_Parser::FindAllCrossReferenceTablesAndStream(
+ FX_FILESIZE main_xref_offset,
+ std::vector<FX_FILESIZE>& xref_list,
+ std::vector<FX_FILESIZE>& xref_stream_list) {
+ std::set<FX_FILESIZE> seen_xref_offset{main_xref_offset};
+
+ // When the trailer doesn't have Prev entry or Prev entry value is not
+ // numerical, GetDirectInteger() returns 0. Loading will end.
+ FX_FILESIZE xref_offset = GetTrailer()->GetDirectIntegerFor("Prev");
+ while (xref_offset > 0) {
+ // Check for circular references.
+ if (pdfium::Contains(seen_xref_offset, xref_offset)) {
+ return false;
+ }
+
+ seen_xref_offset.insert(xref_offset);
+ xref_list.insert(xref_list.begin(), xref_offset);
+
+ // SLOW ...
+ LoadCrossRefTable(xref_offset, /*skip=*/true);
+
+ RetainPtr<CPDF_Dictionary> trailer_dict = LoadTrailer();
+ if (!trailer_dict) {
+ return false;
+ }
+
+ xref_offset = trailer_dict->GetDirectIntegerFor("Prev");
+ xref_stream_list.insert(xref_stream_list.begin(),
+ trailer_dict->GetIntegerFor("XRefStm"));
+
+ // SLOW ...
+ m_CrossRefTable = CPDF_CrossRefTable::MergeUp(
+ std::make_unique<CPDF_CrossRefTable>(std::move(trailer_dict),
+ kNoTrailerObjectNumber),
+ std::move(m_CrossRefTable));
+ }
+ return true;
+}
+
bool CPDF_Parser::RebuildCrossRef() {
auto cross_ref_table = std::make_unique<CPDF_CrossRefTable>();
diff --git a/core/fpdfapi/parser/cpdf_parser.h b/core/fpdfapi/parser/cpdf_parser.h
index aaed8bc..26abc7d 100644
--- a/core/fpdfapi/parser/cpdf_parser.h
+++ b/core/fpdfapi/parser/cpdf_parser.h
@@ -143,9 +143,13 @@
CPDF_CrossRefTable::ObjectInfo info;
};
- bool LoadAllCrossRefTable(FX_FILESIZE xref_offset);
- bool LoadAllCrossRefStream(FX_FILESIZE xref_offset);
+ bool LoadAllCrossRefTables(FX_FILESIZE xref_offset);
+ bool LoadAllCrossRefStreams(FX_FILESIZE xref_offset);
bool LoadAllSecondaryCrossRefStreams(FX_FILESIZE xref_offset);
+ bool FindAllCrossReferenceTablesAndStream(
+ FX_FILESIZE main_xref_offset,
+ std::vector<FX_FILESIZE>& xref_list,
+ std::vector<FX_FILESIZE>& xref_stream_list);
bool LoadCrossRefStream(FX_FILESIZE* pos, bool is_main_xref);
void ProcessCrossRefStreamEntry(pdfium::span<const uint8_t> entry_span,
pdfium::span<const uint32_t> field_widths,
