public Snapshot(LockMode mode, string collectionName, HeaderPage header, uint transactionID, TransactionPages transPages, LockService locker, WalIndexService walIndex, DiskReader reader, bool addIfNotExists)
{
_mode = mode;
_collectionName = collectionName;
_header = header;
_transactionID = transactionID;
_transPages = transPages;
_locker = locker;
_walIndex = walIndex;
_reader = reader;
// enter in lock mode according initial mode
if (mode == LockMode.Read)
{
_locker.EnterRead(_collectionName);
}
else
{
_locker.EnterReserved(_collectionName);
}
// get lastest read version from wal-index
_readVersion = _walIndex.CurrentReadVersion;
var srv = new CollectionService(_header, this, _transPages);
// read collection (create if new - load virtual too)
srv.Get(_collectionName, addIfNotExists, ref _collectionPage);
// clear local pages (will clear _collectionPage link reference)
if (_collectionPage != null)
{
_localPages.Remove(_collectionPage.PageID);
}
}
/// <summary>
/// Initialize LiteEngine using initial engine settings
/// </summary>
public LiteEngine(EngineSettings settings)
{
_settings = settings ?? throw new ArgumentNullException(nameof(settings));
// clear checkpoint if database is readonly
if (_settings.ReadOnly)
{
_settings.Checkpoint = 0;
}
LOG($"start initializing{(_settings.ReadOnly ? " (readonly)" : "")}", "ENGINE");
try
{
// initialize locker service (no dependency)
_locker = new LockService(settings.Timeout, settings.ReadOnly);
// initialize disk service (will create database if needed)
_disk = new DiskService(settings);
// read page with no cache ref (has a own PageBuffer) - do not Release() support
var buffer = _disk.ReadFull(FileOrigin.Data).First();
// if first byte are 1 this datafile are encrypted but has do defined password to open
if (buffer[0] == 1)
{
throw new LiteException(0, "This data file is encrypted and needs a password to open");
}
_header = new HeaderPage(buffer);
// initialize wal-index service
_walIndex = new WalIndexService(_disk, _locker);
// if exists log file, restore wal index references (can update full _header instance)
if (_disk.GetLength(FileOrigin.Log) > 0)
{
_walIndex.RestoreIndex(ref _header);
}
// initialize sort temp disk
_sortDisk = new SortDisk(settings.CreateTempFactory(), CONTAINER_SORT_SIZE, settings.UtcDate);
// initialize transaction monitor as last service
_monitor = new TransactionMonitor(_header, _locker, _disk, _walIndex, _settings);
// register system collections
this.InitializeSystemCollections();
LOG("initialization completed", "ENGINE");
}
catch (Exception ex)
{
LOG(ex.Message, "ERROR");
// explicit dispose (but do not run shutdown operation)
this.Dispose(true);
throw;
}
}
public TransactionMonitor(HeaderPage header, LockService locker, DiskService disk, WalIndexService walIndex)
{
_header = header;
_locker = locker;
_disk = disk;
_walIndex = walIndex;
// initialize free pages with all avaiable pages in memory
_freePages = MAX_TRANSACTION_SIZE;
// initial size
_initialSize = MAX_TRANSACTION_SIZE / MAX_OPEN_TRANSACTIONS;
}
public TransactionMonitor(HeaderPage header, LockService locker, DiskService disk, WalIndexService walIndex, EngineSettings settings)
{
_header = header;
_locker = locker;
_disk = disk;
_walIndex = walIndex;
_settings = settings;
// initialize free pages with all avaiable pages in memory
_freePages = settings.MaxTransactionSize;
// initial size
_initialSize = settings.MaxTransactionSize / MAX_OPEN_TRANSACTIONS;
}
/// <summary>
/// Initialize LiteEngine using initial engine settings
/// </summary>
public LiteEngine(EngineSettings settings)
{
_settings = settings ?? throw new ArgumentNullException(nameof(settings));
LOG($"start initializing{(_settings.ReadOnly ? " (readonly)" : "")}", "ENGINE");
try
{
// initialize disk service (will create database if needed)
_disk = new DiskService(settings, MEMORY_SEGMENT_SIZES);
// get header page from disk service
_header = _disk.Header;
// test for same collation
if (settings.Collation != null && settings.Collation.ToString() != _header.Pragmas.Collation.ToString())
{
throw new LiteException(0, $"Datafile collation '{_header.Pragmas.Collation}' is different from engine settings. Use Rebuild database to change collation.");
}
// initialize locker service
_locker = new LockService(_header.Pragmas);
// initialize wal-index service
_walIndex = new WalIndexService(_disk, _locker);
// restore wal index references, if exists
_walIndex.RestoreIndex(_header);
// initialize sort temp disk
_sortDisk = new SortDisk(settings.CreateTempFactory(), CONTAINER_SORT_SIZE, _header.Pragmas);
// initialize transaction monitor as last service
_monitor = new TransactionMonitor(_header, _settings, _locker, _disk, _walIndex);
// register system collections
this.InitializeSystemCollections();
LOG("initialization completed", "ENGINE");
}
catch (Exception ex)
{
LOG(ex.Message, "ERROR");
// explicit dispose (but do not run shutdown operation)
this.Dispose(true);
throw;
}
}
public TransactionService(HeaderPage header, LockService locker, DiskService disk, WalIndexService walIndex, int maxTransactionSize, TransactionMonitor monitor, bool queryOnly)
{
// retain instances
_header = header;
_locker = locker;
_disk = disk;
_walIndex = walIndex;
_monitor = monitor;
this.QueryOnly = queryOnly;
this.MaxTransactionSize = maxTransactionSize;
// create new transactionID
_transactionID = walIndex.NextTransactionID();
_startTime = DateTime.UtcNow;
_reader = _disk.GetReader();
}
public TransactionService(HeaderPage header, LockService locker, DiskService disk, WalIndexService walIndex, int maxTransactionSize, Action <uint> done)
{
// retain instances
_header = header;
_locker = locker;
_disk = disk;
_walIndex = walIndex;
_maxTransactionSize = maxTransactionSize;
_done = done;
// create new transactionID
_transactionID = walIndex.NextTransactionID();
_startTime = DateTime.UtcNow;
_reader = _disk.GetReader();
// enter transaction locker to avoid 2 transactions in same thread
_locker.EnterTransaction();
}
public WalIndexService(DiskService disk, LockService locker)
{
_disk = disk;
_locker = locker;
}