1 files changed, 52 insertions, 0 deletions
diff --git a/core/fpdfapi/parser/cpdf_object_avail.h b/core/fpdfapi/parser/cpdf_object_avail.h
new file mode 100644
index 0000000000..233d180c94
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+++ b/core/fpdfapi/parser/cpdf_object_avail.h
@@ -0,0 +1,52 @@
+// Copyright 2017 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.
+
+#ifndef CORE_FPDFAPI_PARSER_CPDF_OBJECT_AVAIL_H_
+#define CORE_FPDFAPI_PARSER_CPDF_OBJECT_AVAIL_H_
+
+#include <memory>
+#include <set>
+#include <stack>
+
+#include "core/fpdfapi/parser/cpdf_data_avail.h"
+#include "core/fxcrt/cfx_maybe_owned.h"
+#include "core/fxcrt/cfx_unowned_ptr.h"
+
+class CPDF_Object;
+class CPDF_Reference;
+class CPDF_IndirectObjectHolder;
+class CPDF_ReadValidator;
+
+// Helper for check availability of object tree.
+class CPDF_ObjectAvail {
+ public:
+  CPDF_ObjectAvail(CPDF_ReadValidator* validator,
+                   CPDF_IndirectObjectHolder* holder,
+                   const CPDF_Object* root);
+  CPDF_ObjectAvail(CPDF_ReadValidator* validator,
+                   CPDF_IndirectObjectHolder* holder,
+                   uint32_t obj_num);
+  virtual ~CPDF_ObjectAvail();
+
+  CPDF_DataAvail::DocAvailStatus CheckAvail();
+
+ protected:
+  virtual bool ExcludeObject(const CPDF_Object* object) const;
+
+ private:
+  bool LoadRootObject();
+  bool CheckObjects();
+  bool AppendObjectSubRefs(const CPDF_Object* object,
+                           std::stack<uint32_t>* refs) const;
+  void CleanMemory();
+  bool HasObjectParsed(uint32_t obj_num) const;
+
+  CFX_UnownedPtr<CPDF_ReadValidator> validator_;
+  CFX_UnownedPtr<CPDF_IndirectObjectHolder> holder_;
+  CFX_MaybeOwned<const CPDF_Object> root_;
+  std::set<uint32_t> parsed_objnums_;
+  std::stack<uint32_t> non_parsed_objects_;
+};
+
+#endif  // CORE_FPDFAPI_PARSER_CPDF_OBJECT_AVAIL_H_