Revert 202215 "Migrate the IndexedDB backend from Blink to Chromium"

trunk/src/content/browser/indexed_db/leveldb/leveldb_transaction.h

-// Copyright (c) 2013 The Chromium 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 CONTENT_BROWSER_INDEXED_DB_LEVELDB_LEVELDB_TRANSACTION_H_
-#define CONTENT_BROWSER_INDEXED_DB_LEVELDB_LEVELDB_TRANSACTION_H_
-
-#include <set>
-#include <vector>
-
-#include "base/memory/ref_counted.h"
-#include "base/memory/scoped_ptr.h"
-#include "content/browser/indexed_db/leveldb/avltree.h"
-#include "content/browser/indexed_db/leveldb/leveldb_comparator.h"
-#include "content/browser/indexed_db/leveldb/leveldb_database.h"
-#include "content/browser/indexed_db/leveldb/leveldb_iterator.h"
-#include "content/browser/indexed_db/leveldb/leveldb_slice.h"
-
-namespace content {
-
-class LevelDBWriteBatch;
-
-class CONTENT_EXPORT LevelDBTransaction
-    : public base::RefCounted<LevelDBTransaction> {
- public:
-  static scoped_refptr<LevelDBTransaction> Create(LevelDBDatabase* db);
-
-  void Put(const LevelDBSlice& key, const std::vector<char>& value);
-  void Remove(const LevelDBSlice& key);
-  bool Get(const LevelDBSlice& key, std::vector<char>& value, bool& found);
-  bool Commit();
-  void Rollback();
-
-  scoped_ptr<LevelDBIterator> CreateIterator();
-
- private:
-  LevelDBTransaction(LevelDBDatabase* db);
-  virtual ~LevelDBTransaction();
-  friend class base::RefCounted<LevelDBTransaction>;
-
-  struct AVLTreeNode {
-    AVLTreeNode();
-    ~AVLTreeNode();
-    std::vector<char> key;
-    std::vector<char> value;
-    bool deleted;
-
-    AVLTreeNode* less;
-    AVLTreeNode* greater;
-    int balance_factor;
-    DISALLOW_COPY_AND_ASSIGN(AVLTreeNode);
-  };
-
-  struct AVLTreeAbstractor {
-    typedef AVLTreeNode* handle;
-    typedef size_t size;
-    typedef LevelDBSlice key;
-
-    handle get_less(handle h) { return h->less; }
-    void set_less(handle h, handle less) { h->less = less; }
-    handle get_greater(handle h) { return h->greater; }
-    void set_greater(handle h, handle greater) { h->greater = greater; }
-
-    int get_balance_factor(handle h) { return h->balance_factor; }
-    void set_balance_factor(handle h, int bf) { h->balance_factor = bf; }
-
-    int compare_key_key(const key& ka, const key& kb) {
-      return comparator_->Compare(ka, kb);
-    }
-    int compare_key_node(const key& k, handle h) {
-      return compare_key_key(k, key(h->key));
-    }
-    int compare_node_node(handle ha, handle hb) {
-      return compare_key_key(key(ha->key), key(hb->key));
-    }
-
-    static handle null() { return 0; }
-
-    const LevelDBComparator* comparator_;
-  };
-
-  typedef AVLTree<AVLTreeAbstractor> TreeType;
-
-  class TreeIterator : public LevelDBIterator {
-   public:
-    static scoped_ptr<TreeIterator> Create(LevelDBTransaction* transaction);
-    virtual ~TreeIterator();
-
-    virtual bool IsValid() const OVERRIDE;
-    virtual void SeekToLast() OVERRIDE;
-    virtual void Seek(const LevelDBSlice& slice) OVERRIDE;
-    virtual void Next() OVERRIDE;
-    virtual void Prev() OVERRIDE;
-    virtual LevelDBSlice Key() const OVERRIDE;
-    virtual LevelDBSlice Value() const OVERRIDE;
-    bool IsDeleted() const;
-    void Reset();
-
-   private:
-    TreeIterator(LevelDBTransaction* transaction);
-    mutable TreeType::Iterator iterator_;  // Dereferencing this is non-const.
-    TreeType* tree_;
-    LevelDBTransaction* transaction_;
-    std::vector<char> key_;
-  };
-
-  class TransactionIterator : public LevelDBIterator {
-   public:
-    virtual ~TransactionIterator();
-    static scoped_ptr<TransactionIterator> Create(
-        scoped_refptr<LevelDBTransaction> transaction);
-
-    virtual bool IsValid() const OVERRIDE;
-    virtual void SeekToLast() OVERRIDE;
-    virtual void Seek(const LevelDBSlice& target) OVERRIDE;
-    virtual void Next() OVERRIDE;
-    virtual void Prev() OVERRIDE;
-    virtual LevelDBSlice Key() const OVERRIDE;
-    virtual LevelDBSlice Value() const OVERRIDE;
-    void TreeChanged();
-
-   private:
-    TransactionIterator(scoped_refptr<LevelDBTransaction> transaction);
-    void HandleConflictsAndDeletes();
-    void SetCurrentIteratorToSmallestKey();
-    void SetCurrentIteratorToLargestKey();
-    void RefreshTreeIterator() const;
-    bool TreeIteratorIsLower() const;
-    bool TreeIteratorIsHigher() const;
-
-    scoped_refptr<LevelDBTransaction> transaction_;
-    const LevelDBComparator* comparator_;
-    mutable scoped_ptr<TreeIterator> tree_iterator_;
-    scoped_ptr<LevelDBIterator> db_iterator_;
-    LevelDBIterator* current_;
-
-    enum Direction {
-      FORWARD,
-      REVERSE
-    };
-    Direction direction_;
-    mutable bool tree_changed_;
-  };
-
-  void Set(const LevelDBSlice& key,
-           const std::vector<char>& value,
-           bool deleted);
-  void ClearTree();
-  void RegisterIterator(TransactionIterator* iterator);
-  void UnregisterIterator(TransactionIterator* iterator);
-  void NotifyIteratorsOfTreeChange();
-
-  LevelDBDatabase* db_;
-  const LevelDBSnapshot snapshot_;
-  const LevelDBComparator* comparator_;
-  TreeType tree_;
-  bool finished_;
-  std::set<TransactionIterator*> iterators_;
-};
-
-class LevelDBWriteOnlyTransaction {
- public:
-  static scoped_ptr<LevelDBWriteOnlyTransaction> Create(LevelDBDatabase* db);
-
-  ~LevelDBWriteOnlyTransaction();
-  void Remove(const LevelDBSlice& key);
-  bool Commit();
-
- private:
-  LevelDBWriteOnlyTransaction(LevelDBDatabase* db);
-
-  LevelDBDatabase* db_;
-  scoped_ptr<LevelDBWriteBatch> write_batch_;
-  bool finished_;
-};
-
-}  // namespace content
-
-#endif  // CONTENT_BROWSER_INDEXED_DB_LEVELDB_LEVELDB_TRANSACTION_H_