| // Copyright 2016 The PDFium Authors |
| // 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 |
| |
| #ifndef CORE_FPDFDOC_CPDF_NUMBERTREE_H_ |
| #define CORE_FPDFDOC_CPDF_NUMBERTREE_H_ |
| |
| #include <optional> |
| |
| #include "core/fxcrt/retain_ptr.h" |
| |
| class CPDF_Dictionary; |
| class CPDF_Object; |
| |
| // Represents a number tree that allows for sub-linear lookups of tree nodes. |
| // See ISO 32000-1:2008 spec, section 7.9.7. |
| class CPDF_NumberTree { |
| public: |
| struct KeyValue { |
| KeyValue(int key, RetainPtr<const CPDF_Object> value); |
| KeyValue(const KeyValue&) = delete; |
| KeyValue& operator=(const KeyValue&) = delete; |
| KeyValue(KeyValue&&) noexcept; |
| KeyValue& operator=(KeyValue&&) noexcept; |
| ~KeyValue(); |
| |
| int key; |
| RetainPtr<const CPDF_Object> value; |
| }; |
| |
| explicit CPDF_NumberTree(RetainPtr<const CPDF_Dictionary> root); |
| ~CPDF_NumberTree(); |
| |
| // Finds the object in the number tree whose key is `num`. Returns nullptr in |
| // there is no `num` key in the tree. |
| RetainPtr<const CPDF_Object> LookupValue(int num) const; |
| |
| // Finds the object in the number tree with the largest key, such that |
| // `num` >= key. Returns the key/value pair if such a key exists, or |
| // std::nullopt otherwise. |
| // Note that this is similar to, but not exactly the same as |
| // std::lower_bound(). |
| std::optional<KeyValue> GetLowerBound(int num) const; |
| |
| protected: |
| RetainPtr<const CPDF_Dictionary> const root_; |
| }; |
| |
| #endif // CORE_FPDFDOC_CPDF_NUMBERTREE_H_ |