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      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
    159