chromium/third_party/abseil-cpp/absl/strings/internal/cord_rep_btree_navigator.h

// Copyright 2021 The Abseil Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#ifndef ABSL_STRINGS_INTERNAL_CORD_REP_BTREE_NAVIGATOR_H_
#define ABSL_STRINGS_INTERNAL_CORD_REP_BTREE_NAVIGATOR_H_

#include <cassert>
#include <iostream>

#include "absl/strings/internal/cord_internal.h"
#include "absl/strings/internal/cord_rep_btree.h"

namespace absl {
ABSL_NAMESPACE_BEGIN
namespace cord_internal {

// CordRepBtreeNavigator is a bi-directional navigator allowing callers to
// navigate all the (leaf) data edges in a CordRepBtree instance.
//
// A CordRepBtreeNavigator instance is by default empty. Callers initialize a
// navigator instance by calling one of `InitFirst()`, `InitLast()` or
// `InitOffset()`, which establishes a current position. Callers can then
// navigate using the `Next`, `Previous`, `Skip` and `Seek` methods.
//
// The navigator instance does not take or adopt a reference on the provided
// `tree` on any of the initialization calls. Callers are responsible for
// guaranteeing the lifecycle of the provided tree. A navigator instance can
// be reset to the empty state by calling `Reset`.
//
// A navigator only keeps positional state on the 'current data edge', it does
// explicitly not keep any 'offset' state. The class does accept and return
// offsets in the `Read()`, `Skip()` and 'Seek()` methods as these would
// otherwise put a big burden on callers. Callers are expected to maintain
// (returned) offset info if they require such granular state.
class CordRepBtreeNavigator { … };

// Returns true if this instance is not empty.
operator bool()

inline CordRepBtree* CordRepBtreeNavigator::btree() const { … }

inline CordRep* CordRepBtreeNavigator::Current() const { … }

inline void CordRepBtreeNavigator::Reset() { … }

inline CordRep* CordRepBtreeNavigator::InitFirst(CordRepBtree* tree) { … }

inline CordRep* CordRepBtreeNavigator::InitLast(CordRepBtree* tree) { … }

template <CordRepBtree::EdgeType edge_type>
inline CordRep* CordRepBtreeNavigator::Init(CordRepBtree* tree) { … }

inline CordRepBtreeNavigator::Position CordRepBtreeNavigator::Seek(
    size_t offset) { … }

inline CordRepBtreeNavigator::Position CordRepBtreeNavigator::InitOffset(
    CordRepBtree* tree, size_t offset) { … }

inline CordRep* CordRepBtreeNavigator::Next() { … }

inline CordRep* CordRepBtreeNavigator::Previous() { … }

inline CordRep* CordRepBtreeNavigator::NextUp() { … }

inline CordRep* CordRepBtreeNavigator::PreviousUp() { … }

}  // namespace cord_internal
ABSL_NAMESPACE_END
}  // namespace absl

#endif  // ABSL_STRINGS_INTERNAL_CORD_REP_BTREE_NAVIGATOR_H_