chrome/browser/android/history_report/delta_file_backend_leveldb.h

   1 // Copyright 2015 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CHROME_BROWSER_ANDROID_HISTORY_REPORT_DELTA_FILE_BACKEND_LEVELDB_H_
   6 #define CHROME_BROWSER_ANDROID_HISTORY_REPORT_DELTA_FILE_BACKEND_LEVELDB_H_
   7
   8 #include <vector>
   9
  10 #include "base/files/file_path.h"
  11 #include "base/memory/scoped_ptr.h"
  12
  13 class GURL;
  14
  15 namespace leveldb {
  16 class DB;
  17 }
  18
  19 namespace history_report {
  20
  21 class DeltaFileEntryWithData;
  22
  23 // Backend for delta file.
  24 class DeltaFileBackend {
  25  public:
  26   explicit DeltaFileBackend(const base::FilePath& dir);
  27   ~DeltaFileBackend();
  28
  29   // Adds new addition entry to delta file
  30   void PageAdded(const GURL& url);
  31   // Adds new deletion entry to delta file
  32   void PageDeleted(const GURL& url);
  33   // Removes all delta file entries with
  34   // sequence number <= min(|lower_bound|, max sequence number - 1).
  35   // Returns max sequence number in delta file.
  36   int64 Trim(int64 lower_bound);
  37   // Recreates delta file using given |urls|.
  38   bool Recreate(const std::vector<std::string>& urls);
  39   // Provides up to |limit| delta file entries with
  40   // sequence number > |last_seq_no|.
  41   scoped_ptr<std::vector<DeltaFileEntryWithData> > Query(int64 last_seq_no,
  42                                                          int32 limit);
  43   // Removes all entries from delta file
  44   void Clear();
  45
  46   // Dumps internal state to string. For debuging.
  47   std::string Dump();
  48
  49  private:
  50   // Starts delta file backend.
  51   bool Init();
  52
  53   bool EnsureInitialized();
  54
  55   class DigitsComparator;
  56
  57   base::FilePath path_;
  58   scoped_ptr<leveldb::DB> db_;
  59   scoped_ptr<DigitsComparator> leveldb_cmp_;
  60
  61   DISALLOW_COPY_AND_ASSIGN(DeltaFileBackend);
  62 };
  63
  64 }  // namespace history_report
  65
  66 #endif  // CHROME_BROWSER_ANDROID_HISTORY_REPORT_DELTA_FILE_BACKEND_LEVELDB_H_