/// <summary>
/// Initialize UltraLiteEngine using custom disk service implementation and full engine options
/// </summary>
public UltraLiteEngine(IDiskService disk, string password = null, TimeSpan?timeout = null, int cacheSize = 5000, Logger log = null, bool utcDate = false)
{
if (disk == null)
{
throw new ArgumentNullException(nameof(disk));
}
_timeout = timeout ?? TimeSpan.FromMinutes(1);
_cacheSize = cacheSize;
_disk = disk;
_log = log ?? new Logger();
try
{
// initialize datafile (create) and set log instance
_disk.Initialize(_log, password);
var buffer = _disk.ReadPage(0);
// create header instance from array bytes
var header = BasePage.ReadPage(buffer) as HeaderPage;
// hash password with sha1 or keep as empty byte[20]
var sha1 = password == null ? new byte[20] : AesEncryption.HashSHA1(password);
// compare header password with user password even if not passed password (datafile can have password)
if (sha1.BinaryCompareTo(header.Password) != 0)
{
throw UltraLiteException.DatabaseWrongPassword();
}
// initialize AES encryptor
if (password != null)
{
_crypto = new AesEncryption(password, header.Salt);
}
// initialize all services
this.InitializeServices();
// if header are marked with recovery, do it now
if (header.Recovery)
{
_trans.Recovery();
}
}
catch (Exception)
{
// explicit dispose
this.Dispose();
throw;
}
}
/// <summary>
/// Initialize new datafile with header page + lock reserved area zone
/// </summary>
public static void CreateDatabase(Stream stream, string password = null, long initialSize = 0)
{
// calculate how many empty pages will be added on disk
var emptyPages = initialSize == 0 ? 0 : (initialSize - (2 * BasePage.PAGE_SIZE)) / BasePage.PAGE_SIZE;
// if too small size (less than 2 pages), assume no initial size
if (emptyPages < 0)
{
emptyPages = 0;
}
// create a new header page in bytes (keep second page empty)
var header = new HeaderPage
{
LastPageID = initialSize == 0 ? 1 : (uint)emptyPages + 1,
FreeEmptyPageID = initialSize == 0 ? uint.MaxValue : 2
};
if (password != null)
{
header.Password = AesEncryption.HashSHA1(password);
header.Salt = AesEncryption.Salt();
}
// point to begin file
stream.Seek(0, SeekOrigin.Begin);
// get header page in bytes
var buffer = header.WritePage();
stream.Write(buffer, 0, BasePage.PAGE_SIZE);
// write second page as an empty AREA (it's not a page) just to use as lock control
stream.Write(new byte[BasePage.PAGE_SIZE], 0, BasePage.PAGE_SIZE);
// create crypto class if has password
var crypto = password != null ? new AesEncryption(password, header.Salt) : null;
// if initial size is defined, lets create empty pages in a linked list
if (emptyPages > 0)
{
stream.SetLength(initialSize);
var pageID = 1u;
while (++pageID < (emptyPages + 2))
{
var empty = new EmptyPage(pageID)
{
PrevPageID = pageID == 2 ? 0 : pageID - 1,
NextPageID = pageID == emptyPages + 1 ? uint.MaxValue : pageID + 1
};
var bytes = empty.WritePage();
if (password != null)
{
bytes = crypto.Encrypt(bytes);
}
stream.Write(bytes, 0, BasePage.PAGE_SIZE);
}
}
if (crypto != null)
{
crypto.Dispose();
}
}