storage/browser/fileapi/sandbox_directory_database.h

   1 // Copyright (c) 2012 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 STORAGE_BROWSER_FILEAPI_SANDBOX_DIRECTORY_DATABASE_H_
   6 #define STORAGE_BROWSER_FILEAPI_SANDBOX_DIRECTORY_DATABASE_H_
   7
   8 #include <string>
   9 #include <vector>
  10
  11 #include "base/files/file.h"
  12 #include "base/files/file_path.h"
  13 #include "base/memory/scoped_ptr.h"
  14 #include "base/time/time.h"
  15 #include "storage/browser/storage_browser_export.h"
  16
  17 namespace content {
  18 class SandboxDirectoryDatabaseTest;
  19 }
  20
  21 namespace tracked_objects {
  22 class Location;
  23 }
  24
  25 namespace leveldb {
  26 class DB;
  27 class Env;
  28 class Status;
  29 class WriteBatch;
  30 }
  31
  32 namespace storage {
  33
  34 // This class WILL NOT protect you against producing directory loops, giving an
  35 // empty directory a backing data file, giving two files the same backing file,
  36 // or pointing to a nonexistent backing file.  It does no file IO other than
  37 // that involved with talking to its underlying database.  It does not create or
  38 // in any way touch real files; it only creates path entries in its database.
  39
  40 // TODO(ericu): Safe mode, which does more checks such as the above on debug
  41 // builds.
  42 // TODO(ericu): Add a method that will give a unique filename for a data file.
  43 class STORAGE_EXPORT_PRIVATE SandboxDirectoryDatabase {
  44  public:
  45   typedef int64 FileId;
  46
  47   struct STORAGE_EXPORT_PRIVATE FileInfo {
  48     FileInfo();
  49     ~FileInfo();
  50
  51     bool is_directory() const {
  52       return data_path.empty();
  53     }
  54
  55     FileId parent_id;
  56     base::FilePath data_path;
  57     base::FilePath::StringType name;
  58     // This modification time is valid only for directories, not files, as
  59     // FileWriter will get the files out of sync.
  60     // For files, look at the modification time of the underlying data_path.
  61     base::Time modification_time;
  62   };
  63
  64   SandboxDirectoryDatabase(
  65       const base::FilePath& filesystem_data_directory,
  66       leveldb::Env* env_override);
  67   ~SandboxDirectoryDatabase();
  68
  69   bool GetChildWithName(
  70       FileId parent_id,
  71       const base::FilePath::StringType& name,
  72       FileId* child_id);
  73   bool GetFileWithPath(const base::FilePath& path, FileId* file_id);
  74   // ListChildren will succeed, returning 0 children, if parent_id doesn't
  75   // exist.
  76   bool ListChildren(FileId parent_id, std::vector<FileId>* children);
  77   bool GetFileInfo(FileId file_id, FileInfo* info);
  78   base::File::Error AddFileInfo(const FileInfo& info, FileId* file_id);
  79   bool RemoveFileInfo(FileId file_id);
  80   // This does a full update of the FileInfo, and is what you'd use for moves
  81   // and renames.  If you just want to update the modification_time, use
  82   // UpdateModificationTime.
  83   bool UpdateFileInfo(FileId file_id, const FileInfo& info);
  84   bool UpdateModificationTime(
  85       FileId file_id, const base::Time& modification_time);
  86   // This is used for an overwriting move of a file [not a directory] on top of
  87   // another file [also not a directory]; we need to alter two files' info in a
  88   // single transaction to avoid weird backing file references in the event of a
  89   // partial failure.
  90   bool OverwritingMoveFile(FileId src_file_id, FileId dest_file_id);
  91
  92   // This produces the series 0, 1, 2..., starting at 0 when the underlying
  93   // filesystem is first created, and maintaining state across
  94   // creation/destruction of SandboxDirectoryDatabase objects.
  95   bool GetNextInteger(int64* next);
  96
  97   bool IsDirectory(FileId file_id);
  98
  99   // Returns true if the database looks consistent with local filesystem.
 100   bool IsFileSystemConsistent();
 101
 102   // Completely deletes contents of the database.
 103   bool DestroyDatabase();
 104
 105  private:
 106   enum RecoveryOption {
 107     DELETE_ON_CORRUPTION,
 108     REPAIR_ON_CORRUPTION,
 109     FAIL_ON_CORRUPTION,
 110   };
 111
 112   friend class content::SandboxDirectoryDatabaseTest;
 113   friend class ObfuscatedFileUtil;
 114
 115   bool Init(RecoveryOption recovery_option);
 116   bool RepairDatabase(const std::string& db_path);
 117   void ReportInitStatus(const leveldb::Status& status);
 118   bool StoreDefaultValues();
 119   bool GetLastFileId(FileId* file_id);
 120   bool AddFileInfoHelper(
 121       const FileInfo& info, FileId file_id, leveldb::WriteBatch* batch);
 122   bool RemoveFileInfoHelper(FileId file_id, leveldb::WriteBatch* batch);
 123   void HandleError(const tracked_objects::Location& from_here,
 124                    const leveldb::Status& status);
 125
 126   const base::FilePath filesystem_data_directory_;
 127   leveldb::Env* env_override_;
 128   scoped_ptr<leveldb::DB> db_;
 129   base::Time last_reported_time_;
 130   DISALLOW_COPY_AND_ASSIGN(SandboxDirectoryDatabase);
 131 };
 132
 133 }  // namespace storage
 134
 135 #endif  // STORAGE_BROWSER_FILEAPI_SANDBOX_DIRECTORY_DATABASE_H_