storage/browser/database/vfs_backend.cc

   1 // Copyright (c) 2011 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 #include "storage/browser/database/vfs_backend.h"
   6
   7 #include "base/files/file_path.h"
   8 #include "base/files/file_util.h"
   9 #include "base/logging.h"
  10 #include "third_party/sqlite/sqlite3.h"
  11
  12 namespace storage {
  13
  14 static const int kFileTypeMask = 0x00007F00;
  15
  16 // static
  17 bool VfsBackend::OpenTypeIsReadWrite(int desired_flags) {
  18   return (desired_flags & SQLITE_OPEN_READWRITE) != 0;
  19 }
  20
  21 // static
  22 bool VfsBackend::OpenFileFlagsAreConsistent(int desired_flags) {
  23   const int file_type = desired_flags & kFileTypeMask;
  24   const bool is_exclusive = (desired_flags & SQLITE_OPEN_EXCLUSIVE) != 0;
  25   const bool is_delete = (desired_flags & SQLITE_OPEN_DELETEONCLOSE) != 0;
  26   const bool is_create = (desired_flags & SQLITE_OPEN_CREATE) != 0;
  27   const bool is_read_only = (desired_flags & SQLITE_OPEN_READONLY) != 0;
  28   const bool is_read_write = (desired_flags & SQLITE_OPEN_READWRITE) != 0;
  29
  30   // All files should be opened either read-write or read-only, but not both.
  31   if (is_read_only == is_read_write)
  32     return false;
  33
  34   // If a new file is created, it must also be writable.
  35   if (is_create && !is_read_write)
  36     return false;
  37
  38   // If we're accessing an existing file, we cannot give exclusive access, and
  39   // we can't delete it.
  40   // Normally, we'd also check that 'is_delete' is false for a main DB, main
  41   // journal or master journal file; however, when in incognito mode, we use
  42   // the SQLITE_OPEN_DELETEONCLOSE flag when opening those files too and keep
  43   // an open handle to them for as long as the incognito profile is around.
  44   if ((is_exclusive || is_delete) && !is_create)
  45     return false;
  46
  47   // Make sure we're opening the DB directory or that a file type is set.
  48   return (file_type == SQLITE_OPEN_MAIN_DB) ||
  49          (file_type == SQLITE_OPEN_TEMP_DB) ||
  50          (file_type == SQLITE_OPEN_MAIN_JOURNAL) ||
  51          (file_type == SQLITE_OPEN_TEMP_JOURNAL) ||
  52          (file_type == SQLITE_OPEN_SUBJOURNAL) ||
  53          (file_type == SQLITE_OPEN_MASTER_JOURNAL) ||
  54          (file_type == SQLITE_OPEN_TRANSIENT_DB);
  55 }
  56
  57 // static
  58 base::File VfsBackend::OpenFile(const base::FilePath& file_path,
  59                                 int desired_flags) {
  60   DCHECK(!file_path.empty());
  61
  62   // Verify the flags for consistency and create the database
  63   // directory if it doesn't exist.
  64   if (!OpenFileFlagsAreConsistent(desired_flags) ||
  65       !base::CreateDirectory(file_path.DirName())) {
  66     return base::File();
  67   }
  68
  69   int flags = 0;
  70   flags |= base::File::FLAG_READ;
  71   if (desired_flags & SQLITE_OPEN_READWRITE)
  72     flags |= base::File::FLAG_WRITE;
  73
  74   if (!(desired_flags & SQLITE_OPEN_MAIN_DB))
  75     flags |= base::File::FLAG_EXCLUSIVE_READ | base::File::FLAG_EXCLUSIVE_WRITE;
  76
  77   flags |= ((desired_flags & SQLITE_OPEN_CREATE) ?
  78            base::File::FLAG_OPEN_ALWAYS : base::File::FLAG_OPEN);
  79
  80   if (desired_flags & SQLITE_OPEN_EXCLUSIVE)
  81     flags |= base::File::FLAG_EXCLUSIVE_READ | base::File::FLAG_EXCLUSIVE_WRITE;
  82
  83   if (desired_flags & SQLITE_OPEN_DELETEONCLOSE) {
  84     flags |= base::File::FLAG_TEMPORARY | base::File::FLAG_HIDDEN |
  85              base::File::FLAG_DELETE_ON_CLOSE;
  86   }
  87
  88   // This flag will allow us to delete the file later on from the browser
  89   // process.
  90   flags |= base::File::FLAG_SHARE_DELETE;
  91
  92   // Try to open/create the DB file.
  93   return base::File(file_path, flags);
  94 }
  95
  96 // static
  97 base::File VfsBackend::OpenTempFileInDirectory(const base::FilePath& dir_path,
  98                                                int desired_flags) {
  99   // We should be able to delete temp files when they're closed
 100   // and create them as needed
 101   if (!(desired_flags & SQLITE_OPEN_DELETEONCLOSE) ||
 102       !(desired_flags & SQLITE_OPEN_CREATE)) {
 103     return base::File();
 104   }
 105
 106   // Get a unique temp file name in the database directory.
 107   base::FilePath temp_file_path;
 108   if (!base::CreateTemporaryFileInDir(dir_path, &temp_file_path))
 109     return base::File();
 110
 111   return OpenFile(temp_file_path, desired_flags);
 112 }
 113
 114 // static
 115 int VfsBackend::DeleteFile(const base::FilePath& file_path, bool sync_dir) {
 116   if (!base::PathExists(file_path))
 117     return SQLITE_OK;
 118   if (!base::DeleteFile(file_path, false))
 119     return SQLITE_IOERR_DELETE;
 120
 121   int error_code = SQLITE_OK;
 122 #if defined(OS_POSIX)
 123   if (sync_dir) {
 124     base::File dir(file_path.DirName(), base::File::FLAG_READ);
 125     if (dir.IsValid()) {
 126       if (!dir.Flush())
 127         error_code = SQLITE_IOERR_DIR_FSYNC;
 128     } else {
 129       error_code = SQLITE_CANTOPEN;
 130     }
 131   }
 132 #endif
 133   return error_code;
 134 }
 135
 136 // static
 137 uint32 VfsBackend::GetFileAttributes(const base::FilePath& file_path) {
 138 #if defined(OS_WIN)
 139   uint32 attributes = ::GetFileAttributes(file_path.value().c_str());
 140 #elif defined(OS_POSIX)
 141   uint32 attributes = 0;
 142   if (!access(file_path.value().c_str(), R_OK))
 143     attributes |= static_cast<uint32>(R_OK);
 144   if (!access(file_path.value().c_str(), W_OK))
 145     attributes |= static_cast<uint32>(W_OK);
 146   if (!attributes)
 147     attributes = -1;
 148 #endif
 149   return attributes;
 150 }
 151
 152 // static
 153 int64 VfsBackend::GetFileSize(const base::FilePath& file_path) {
 154   int64 size = 0;
 155   return (base::GetFileSize(file_path, &size) ? size : 0);
 156 }
 157
 158 }  // namespace storage