/// <summary>
/// Create a new empty database (use synced mode)
/// </summary>
private void Initialize(Stream stream, Collation collation, long initialSize)
{
var buffer = new PageBuffer(new byte[PAGE_SIZE], 0, 0);
var header = new HeaderPage(buffer, 0);
// update collation
header.Pragmas.Set(Pragmas.COLLATION, (collation ?? Collation.Default).ToString(), false);
// update buffer
header.UpdateBuffer();
stream.Write(buffer.Array, buffer.Offset, PAGE_SIZE);
if (initialSize > 0)
{
if (stream is AesStream)
{
throw LiteException.InitialSizeCryptoNotSupported();
}
if (initialSize % PAGE_SIZE != 0)
{
throw LiteException.InvalidInitialSize();
}
stream.SetLength(initialSize);
}
stream.FlushToDisk();
}
/// <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 FileReaderV8(HeaderPage header, DiskService disk)
{
_collections = header.GetCollections().ToDictionary(x => x.Key, x => x.Value);
// using writer stream from pool (no need to return)
_stream = disk.GetPool(FileOrigin.Data).Writer;
}
public FileReaderV8(HeaderPage header, DiskService disk)
{
_collections = header.GetCollections().ToDictionary(x => x.Key, x => x.Value);
// using writer stream from pool (no need to return)
_stream = new ConcurrentStream(disk.Writer);
}
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);
}
}
public EnginePragmas(BufferSlice buffer, HeaderPage headerPage)
: this(headerPage)
{
foreach (var pragma in _pragmas.Values)
{
pragma.Read(buffer);
}
_isDirty = false;
}
/// <summary>
/// Load all confirmed transactions from log file (used only when open datafile)
/// Don't need lock because it's called on ctor of LiteEngine
/// </summary>
public void RestoreIndex(ref HeaderPage header)
{
// get all page positions
var positions = new Dictionary <long, List <PagePosition> >();
var current = 0L;
// read all pages to get confirmed transactions (do not read page content, only page header)
foreach (var buffer in _disk.ReadFull(FileOrigin.Log))
{
// read direct from buffer to avoid create BasePage structure
var pageID = buffer.ReadUInt32(BasePage.P_PAGE_ID);
var isConfirmed = buffer.ReadBool(BasePage.P_IS_CONFIRMED);
var transactionID = buffer.ReadUInt32(BasePage.P_TRANSACTION_ID);
var position = new PagePosition(pageID, current);
if (positions.TryGetValue(transactionID, out var list))
{
list.Add(position);
}
else
{
positions[transactionID] = new List <PagePosition> {
position
};
}
if (isConfirmed)
{
this.ConfirmTransaction(transactionID, positions[transactionID]);
var pageType = (PageType)buffer.ReadByte(BasePage.P_PAGE_TYPE);
// when a header is modified in transaction, must always be the last page inside log file (per transaction)
if (pageType == PageType.Header)
{
// page buffer instance can't change
var headerBuffer = header.Buffer;
// copy this buffer block into original header block
Buffer.BlockCopy(buffer.Array, buffer.Offset, headerBuffer.Array, headerBuffer.Offset, PAGE_SIZE);
// re-load header (using new buffer data)
header = new HeaderPage(headerBuffer);
header.TransactionID = uint.MaxValue;
header.IsConfirmed = false;
}
}
// update last transaction ID
_lastTransactionID = (int)transactionID;
current += PAGE_SIZE;
}
}
public TransactionService(HeaderPage header, DiskService disk, WalIndexService walIndex)
{
// retain instances
_header = header;
_disk = disk;
_walIndex = walIndex;
// create new transactionID
_transactionID = walIndex.NextTransactionID();
_startTime = DateTime.UtcNow;
}
public FileReaderV8(HeaderPage header, DiskService disk)
{
this.UserVersion = header.UserVersion;
_collections = header.GetCollections().ToDictionary(x => x.Key, x => x.Value);
// using writer stream from pool (no need to return)
_stream = disk.GetPool(FileOrigin.Data).Writer;
_buffer = BufferPool.Rent(PAGE_SIZE);
}
public FileReaderV8(HeaderPage header, DiskService disk)
{
// get a copy of pragmas
this.Pragmas = new EnginePragmas(header.UpdateBuffer(), header);
_collections = header.GetCollections().ToDictionary(x => x.Key, x => x.Value);
// using writer stream from pool (no need to return)
_stream = disk.GetPool(FileOrigin.Data).Writer;
_buffer = BufferPool.Rent(PAGE_SIZE);
}
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, $"Datafile collation '{_header.Pragmas.Collation}' is different from engine settings. Use Rebuild database to change collation.");
}
// initialize locker service
_locker = new LockService(_header.Pragmas);
// initialize wal-index service
_walIndex = new WalIndexService(_disk, _locker);
// restore wal index references, if exists
_walIndex.RestoreIndex(_header);
// initialize sort temp disk
_sortDisk = new SortDisk(settings.CreateTempFactory(), CONTAINER_SORT_SIZE, _header.Pragmas);
// initialize transaction monitor as last service
_monitor = new TransactionMonitor(_header, _settings, _locker, _disk, _walIndex);
// register system collections
this.InitializeSystemCollections();
LOG("initialization completed", "ENGINE");
}
catch (Exception ex)
{
LOG(ex.Message, "ERROR");
// explicit dispose (but do not run shutdown operation)
this.Dispose(true);
throw;
}
}
/// <summary>
/// Check collection name if is valid (and fit on header)
/// Throw correct message error if not valid name or not fit on header page
/// </summary>
public static void CheckName(string name, HeaderPage header)
{
if (Encoding.UTF8.GetByteCount(name) > header.GetAvaiableCollectionSpace())
{
throw LiteException.InvalidCollectionName(name, "There is no space in header this collection name");
}
if (!name.IsWord())
{
throw LiteException.InvalidCollectionName(name, "Use only [a-Z$_]");
}
if (name.StartsWith("$"))
{
throw LiteException.InvalidCollectionName(name, "Collection can't starts with `$` (reserved for system collections)");
}
}
/// <summary>
/// Create a new empty database (use synced mode)
/// </summary>
private void Initialize(Stream stream, long initialSize)
{
var buffer = new PageBuffer(new byte[PAGE_SIZE], 0, 0);
var header = new HeaderPage(buffer, 0);
// update buffer
header.UpdateBuffer();
stream.Write(buffer.Array, 0, PAGE_SIZE);
if (initialSize > 0)
{
stream.SetLength(initialSize);
}
stream.FlushToDisk();
}
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();
}
/// <summary>
/// Initialize database
/// </summary>
public async Task OpenAsync()
{
LOG("start initializing", "ENGINE");
try
{
// open async stream
if (_stream is IAsyncInitialize s)
{
await s.InitializeAsync();
}
// initialize disk service (will create database if needed)
_disk = await DiskService.CreateAsync(_stream, _collation, MEMORY_SEGMENT_SIZES, MAX_EXTENDS);
// get header page from disk service
_header = _disk.Header;
// test for same collation
if (_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 wal-index service
_walIndex = new WalIndexService(_disk);
// restore wal index references, if exists
await _walIndex.RestoreIndex(_header);
// register system collections
// this.InitializeSystemCollections();
_disposed = false;
LOG("initialization completed", "ENGINE");
}
catch (Exception ex)
{
LOG(ex.Message, "ERROR");
// explicit dispose (but do not run shutdown operation)
await this.DisposeAsync();
throw;
}
}
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();
}
/// <summary>
/// Create a new empty database (use synced mode)
/// </summary>
private void Initialize(Stream stream, Collation collation, long initialSize)
{
var buffer = new PageBuffer(new byte[PAGE_SIZE], 0, 0);
var header = new HeaderPage(buffer, 0);
// update collation
header.Pragmas.Set(Pragmas.COLLATION, (collation ?? Collation.Default).ToString(), false);
// update buffer
header.UpdateBuffer();
stream.Write(buffer.Array, buffer.Offset, PAGE_SIZE);
if (initialSize > 0)
{
stream.SetLength(initialSize);
}
stream.FlushToDisk();
}
public EnginePragmas(HeaderPage headerPage)
{
_headerPage = headerPage;
_pragmas = new Dictionary <string, Pragma>(StringComparer.OrdinalIgnoreCase)
{
["USER_VERSION"] = new Pragma
{
Name = "USER_VERSION",
Get = () => this.UserVersion,
Set = (v) => this.UserVersion = v.AsInt32,
Read = (b) => this.UserVersion = b.ReadInt32(P_USER_VERSION),
Validate = (v, h) => { },
Write = (b) => b.Write(this.UserVersion, P_USER_VERSION)
},
["COLLATION"] = new Pragma
{
Name = "COLLATION",
Get = () => this.Collation.ToString(),
Set = (v) => this.Collation = new Collation(v.AsString),
Read = (b) => this.Collation = new Collation(b.ReadInt32(P_COLLATION_LCID), (CompareOptions)b.ReadInt32(P_COLLATION_SORT)),
Validate = (v, h) => { throw new LiteException(0, "Pragma COLLATION is read only"); },
Write = (b) =>
{
b.Write(this.Collation.LCID, P_COLLATION_LCID);
b.Write((int)this.Collation.SortOptions, P_COLLATION_SORT);
}
},
["TIMEOUT"] = new Pragma
{
Name = "TIMEOUT",
Get = () => (int)this.Timeout.TotalSeconds,
Set = (v) => this.Timeout = TimeSpan.FromSeconds(v.AsInt32),
Read = (b) => this.Timeout = TimeSpan.FromSeconds(b.ReadInt32(P_TIMEOUT)),
Validate = (v, h) => { if (v <= 0)
{
throw new LiteException(0, "Pragma TIMEOUT must be greater than zero");
}
},
Write = (b) => b.Write((int)this.Timeout.TotalSeconds, P_TIMEOUT)
},
["LIMIT_SIZE"] = new Pragma
{
Name = "LIMIT_SIZE",
Get = () => this.LimitSize,
Set = (v) => this.LimitSize = v.AsInt64,
Read = (b) => this.LimitSize = b.ReadInt64(P_LIMIT_SIZE),
Validate = (v, h) =>
{
if (v < 4 * PAGE_SIZE)
{
throw new LiteException(0, "Pragma LIMIT_SIZE must be at least 4 pages (32768 bytes)");
}
if (h != null && v.AsInt64 < (h.LastPageID + 1) * Constants.PAGE_SIZE)
{
throw new LiteException(0, "Pragma LIMIT_SIZE must be greater or equal to the current file size");
}
},
Write = (b) => b.Write(this.LimitSize, P_LIMIT_SIZE)
},
["UTC_DATE"] = new Pragma
{
Name = "UTC_DATE",
Get = () => this.UtcDate,
Set = (v) => this.UtcDate = v.AsBoolean,
Read = (b) => this.UtcDate = b.ReadBool(P_UTC_DATE),
Validate = (v, h) => { },
Write = (b) => b.Write(this.UtcDate, P_UTC_DATE)
},
["CHECKPOINT"] = new Pragma
{
Name = "CHECKPOINT",
Get = () => this.Checkpoint,
Set = (v) => this.Checkpoint = v.AsInt32,
Read = (b) => this.Checkpoint = b.ReadInt32(P_CHECKPOINT),
Validate = (v, h) => { if (v < 0)
{
throw new LiteException(0, "Pragma CHECKPOINT must be greater or equal to zero");
}
},
Write = (b) => b.Write(this.Checkpoint, P_CHECKPOINT)
}
};
_isDirty = true;
}
public DiskService(EngineSettings settings, int[] memorySegmentSizes)
{
_cache = new MemoryCache(memorySegmentSizes);
// get new stream factory based on settings
_streamFactory = settings.CreateDataFactory();
// create stream pool
_streamPool = new StreamPool(_streamFactory, settings.ReadOnly);
// create async writer queue for log file
_queue = new DiskWriterQueue(_streamPool.Writer);
// checks if is a new file
var isNew = settings.ReadOnly == false && _streamPool.Writer.Length == 0;
// create new database if not exist yet
if (isNew)
{
LOG($"creating new database: '{Path.GetFileName(_streamFactory.Name)}'", "DISK");
_header = this.Initialize(_streamPool.Writer, settings.Collation, settings.InitialSize);
}
else
{
// load header page from position 0 from file
var stream = _streamPool.Rent();
var buffer = new PageBuffer(new byte[PAGE_SIZE], 0, 0)
{
Position = 0
};
try
{
stream.Position = 0;
stream.Read(buffer.Array, 0, PAGE_SIZE);
// 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);
_streamPool.Return(stream);
}
catch
{
// return to pool before dispose
_streamPool.Return(stream);
this.Dispose();
throw;
}
}
// define start/end position for log content
_logStartPosition = (_header.LastPageID + 1) * PAGE_SIZE;
_logEndPosition = _logStartPosition; // will be updated by RestoreIndex
}
public CollectionService(HeaderPage header, Snapshot snapshot, TransactionPages transPages)
{
_snapshot = snapshot;
_header = header;
_transPages = transPages;
}
/// <summary>
/// Load all confirmed transactions from log file (used only when open datafile)
/// Don't need lock because it's called on ctor of LiteEngine
/// Update _disk instance with last log position
/// </summary>
public void RestoreIndex(HeaderPage header)
{
// get all page positions
var positions = new Dictionary <long, List <PagePosition> >();
var last = 0L;
// read all pages to get confirmed transactions (do not read page content, only page header)
foreach (var buffer in _disk.ReadLog(true))
{
// read direct from buffer to avoid create BasePage structure
var pageID = buffer.ReadUInt32(BasePage.P_PAGE_ID);
var isConfirmed = buffer.ReadBool(BasePage.P_IS_CONFIRMED);
var transactionID = buffer.ReadUInt32(BasePage.P_TRANSACTION_ID);
if (transactionID == 0 || transactionID == uint.MaxValue)
{
continue;
}
var position = new PagePosition(pageID, buffer.Position);
if (positions.TryGetValue(transactionID, out var list))
{
list.Add(position);
}
else
{
positions[transactionID] = new List <PagePosition> {
position
};
}
if (isConfirmed)
{
// update last IsConfirmed page
last = buffer.Position;
this.ConfirmTransaction(transactionID, positions[transactionID]);
var pageType = (PageType)buffer.ReadByte(BasePage.P_PAGE_TYPE);
// when a header is modified in transaction, must always be the last page inside log file (per transaction)
if (pageType == PageType.Header)
{
// copy this buffer block into original header block
Buffer.BlockCopy(buffer.Array, buffer.Offset, header.Buffer.Array, header.Buffer.Offset, PAGE_SIZE);
header.LoadPage();
}
}
// update last transaction ID
_lastTransactionID = (int)transactionID;
}
// update last log position acording with last IsConfirmed on log
if (last > 0)
{
_disk.LogEndPosition = last + PAGE_SIZE;
}
}
public SysDump(HeaderPage header, TransactionMonitor monitor, DiskService disk) : base("$dump")
{
_header = header;
_monitor = monitor;
_disk = disk;
}
/// <summary>
/// Run Commit event
/// </summary>
public void OnCommit(HeaderPage header)
{
this.Commit?.Invoke(header);
}
public SysDump(HeaderPage header, TransactionMonitor monitor) : base("$dump")
{
_header = header;
_monitor = monitor;
}
private IEnumerable <BsonDocument> SysDump(FileOrigin origin)
{
var collections = _header.GetCollections().ToDictionary(x => x.Value, x => x.Key);
foreach (var buffer in _disk.ReadFull(origin))
{
var page = new BasePage(buffer);
var pageID = page.PageID;
if (origin == FileOrigin.Data && buffer.Position > 0 && pageID == 0)
{
// this will fix print PageID in data file bubbles pages
pageID = (uint)(buffer.Position / PAGE_SIZE);
}
var doc = new BsonDocument();
doc["_position"] = (int)buffer.Position;
doc["pageID"] = (int)pageID;
doc["pageType"] = page.PageType.ToString();
doc["nextPageID"] = dumpPageID(page.NextPageID);
doc["prevPageID"] = dumpPageID(page.PrevPageID);
doc["collection"] = collections.GetOrDefault(page.ColID, "-");
doc["transactionID"] = (int)page.TransactionID;
doc["isConfirmed"] = page.IsConfirmed;
doc["itemsCount"] = (int)page.ItemsCount;
doc["freeBytes"] = page.FreeBytes;
doc["usedBytes"] = (int)page.UsedBytes;
doc["fragmentedBytes"] = (int)page.FragmentedBytes;
doc["nextFreePosition"] = (int)page.NextFreePosition;
doc["highestIndex"] = (int)page.HighestIndex;
if (page.PageType == PageType.Header)
{
var header = new HeaderPage(buffer);
doc["freeEmptyPageID"] = dumpPageID(header.FreeEmptyPageID);
doc["lastPageID"] = (int)header.LastPageID;
doc["creationTime"] = header.CreationTime;
doc["userVersion"] = header.UserVersion;
doc["collections"] = new BsonDocument(header.GetCollections().ToDictionary(x => x.Key, x => new BsonValue((int)x.Value)));
}
else if (page.PageType == PageType.Collection)
{
var collection = new CollectionPage(buffer);
doc["lastAnalyzed"] = collection.LastAnalyzed;
doc["creationTime"] = collection.CreationTime;
doc["freeDataPageID"] = new BsonArray(collection.FreeDataPageID.Select(x => dumpPageID(x)));
doc["freeIndexPageID"] = new BsonArray(collection.FreeIndexPageID.Select(x => dumpPageID(x)));
doc["indexes"] = new BsonArray(collection.GetCollectionIndexes().Select(x => new BsonDocument
{
["name"] = x.Name,
["expression"] = x.Expression,
["unique"] = x.Unique,
["headPageID"] = dumpPageID(x.Head.PageID),
["tailPageID"] = dumpPageID(x.Tail.PageID),
["maxLevel"] = (int)x.MaxLevel,
["keyCount"] = (int)x.KeyCount,
["uniqueKeyCount"] = (int)x.UniqueKeyCount
}));
}
yield return(doc);
}
BsonValue dumpPageID(uint pageID)
{
return(pageID == uint.MaxValue ? BsonValue.Null : new BsonValue((int)pageID));
}
}
public SysPageList(HeaderPage header, TransactionMonitor monitor) : base("$page_list")
{
_header = header;
_monitor = monitor;
}
public SysDump(HeaderPage header, LiteEngine engine) : base("$dump")
{
_header = header;
_engine = engine;
}
public SysPageList(HeaderPage header, LiteEngine engine) : base("$page_list")
{
_header = header;
_engine = engine;
}
