Source/WebCore/platform/sql/SQLiteFileSystem.h

/*
 * Copyright (C) 2009 Google Inc. All rights reserved.
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 * modification, are permitted provided that the following conditions are
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 *
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 * notice, this list of conditions and the following disclaimer.
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 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
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#ifndef SQLiteFileSystem_h
#define SQLiteFileSystem_h

#include <wtf/WallTime.h>
#include <wtf/text/WTFString.h>

struct sqlite3;

namespace WebCore {

class SQLiteDatabase;

// A class that abstracts the file system related operations required
// by the WebKit database code.
class SQLiteFileSystem {
public:
    // Creates an absolute file path given a directory and a file name.
    //
    // path - The directory.
    // fileName - The file name.
    WEBCORE_EXPORT static String appendDatabaseFileNameToPath(const String& path, const String& fileName);

    // Makes sure the given directory exists, by creating all missing directories
    // on the given path.
    //
    // path - The directory.
    WEBCORE_EXPORT static bool ensureDatabaseDirectoryExists(const String& path);

    // If 'checkPathOnly' is false, then this method only checks if the given file exists.
    // If 'checkPathOnly' is true, then this method makes sure all directories on the
    // given path exist by creating the missing ones, and does not check if the file
    // itself exists.
    //
    // Sometimes we expect a DB file to exist; other times, we're OK with creating a new
    // DB file, but we want to make sure that the directory in which we want to put the
    // new DB file exists. This method covers both cases.
    //
    // fileName - The file name.
    // checkPathOnly - If true, we only make sure that the given directory exists.
    //                 If false, we only check if the file exists.
    static bool ensureDatabaseFileExists(const String& fileName, bool checkPathOnly);

    // Deletes an empty database directory.
    //
    // path - The directory.
    static bool deleteEmptyDatabaseDirectory(const String& path);

    // Deletes a database file.
    //
    // fileName - The file name.
    WEBCORE_EXPORT static bool deleteDatabaseFile(const String& fileName);

    WEBCORE_EXPORT static String computeHashForFileName(const String& fileName);

#if PLATFORM(IOS_FAMILY)
    // Truncates a database file. Used when MobileSafariSettings deletes a database file,
    // since deleting the file nukes the POSIX file locks which would potentially cause Safari
    // to corrupt the new db if it's running in the background.
    static bool truncateDatabaseFile(sqlite3* database);
#endif
    
    static long long getDatabaseFileSize(const String& fileName);
    WEBCORE_EXPORT static Optional<WallTime> databaseCreationTime(const String& fileName);
    WEBCORE_EXPORT static Optional<WallTime> databaseModificationTime(const String& fileName);

private:
    // do not instantiate this class
    SQLiteFileSystem();
}; // class SQLiteFileSystem

} // namespace WebCore

#endif