// ***************************************************************************
//               Copyright (C) 2000- Microsoft Corporation.
// @File: sqlsnapi.h
//
// PURPOSE:
//
//		The internal include file for the sql snapshot module
//
// NOTES:
//
// HISTORY:
//
//     @Version: Whistler/Shiloh
//     85581 SRS  08/15/01 Event security
//     76910 SRS  08/08/01 Rollforward from VSS snapshot
//     68228      12/05/00 ntsnap work
//     66601 srs  10/05/00 NTSNAP improvements
//
//
// @EndHeader@
// ***************************************************************************


#include <string>
#include <vector>
#include <list>

#include <oledb.h>
#include <oledberr.h>
#include <sqloledb.h>

#include "vdi.h"        // interface declaration from SQLVDI kit

////////////////////////////////////////////////////////////////////////
//  Standard foo for file name aliasing.  This code block must be after
//  all includes of VSS header files.
//
#ifdef VSS_FILE_ALIAS
#undef VSS_FILE_ALIAS
#endif
#define VSS_FILE_ALIAS "SQLSNPIH"
//
////////////////////////////////////////////////////////////////////////


typedef unsigned long	ULONG;
typedef wchar_t			WCHAR;

#define TRUE 1
#define FALSE 0

class CLogMsg;

// Converting from int to bool "naturally" gives a 4800 warning....
//
inline bool IntToBool (int v)
{
	return v ? true : false;
}

// Unexpected, "internal" errors can be logged with some
// generic international text, like "Internal error: <English servicibility text>"
//
// Situations we expect, for which the user needs to know should
// occur with proper internationalization
//

// Process wide globals used by the sql modules
//
extern IMalloc *	g_pIMalloc;

//-------------------------------------------------------------------------
//
typedef std::wstring					WString;
typedef std::vector<WString>			StringVector;
typedef StringVector::const_iterator	StringVectorIter;
typedef std::list<WString>				StringList;
typedef StringList::const_iterator		StringListIter;

StringVector* EnumerateServers ();

//--------------------------------------------------------------------------------
// database names need special syntactical handling
//
const MaxSysNameLen = 128;
const SysNameBufferLen = MaxSysNameLen * 2; // easily accomodate doubled quotes and delimiters

void
FormStringForName (WCHAR* pString, const WCHAR* pName);
void
FormDelimitedIdentifier (WCHAR* pString, const WCHAR* pName);

//-------------------------------------------------------------------------
// Handle our simple needs for DB services.
//
// Useage:
//    - Connect :		establish a connection to a given server
//    - SetCommand:		setup the SQL text to send
//    - ExecCommand:	execute some SQL, returns TRUE if a result set
//					is open and ready for retrieval
//	  - Get*:			retrieve info from the result set
//	
// The destructor will automatically disconnect from the server.
//
class SqlConnection
{
public:
	SqlConnection () :
		m_pCommandFactory (NULL),
		m_pCommand (NULL),
		m_pRowset (NULL),
		m_pBuffer (NULL),
		m_BufferSize (0),
		m_hAcc (NULL),
		m_pAccessor (NULL),
		m_pBindings (NULL),
		m_cBindings (0)
	{}

	~SqlConnection ();

	void
	Connect (const std::wstring& serverName);

	void
	Disconnect ();

	void
	ReleaseRowset ();
		
	void	
	SetCommand (const std::wstring& command);

	BOOL	
	ExecCommand ();

	StringVector*
	GetStringColumn ();

	ULONG
	GetServerVersion () {return m_ServerVersion;}

	BOOL
	FetchFirst ();
	
	BOOL
	FetchNext ();
	
	void*
	AccessColumn (int id);

private:
	void LogOledbError
		(
		CVssFunctionTracer &ft,
		CVssDebugInfo &dbgInfo,
		LPCWSTR wszRoutine,
		CLogMsg &msg
		);

	WString						m_ServerName;
	IDBCreateCommand*			m_pCommandFactory;
	ICommandText*				m_pCommand;
	IRowset*					m_pRowset;
	ULONG						m_ServerVersion;

	// used for the generic findfirst/findnext
	DBBINDING*					m_pBindings;
	ULONG						m_cBindings;
	BYTE*						m_pBuffer;
	ULONG						m_BufferSize;
	HACCESSOR					m_hAcc;
	IAccessor*					m_pAccessor;
};

BOOL
IsServerOnline (const WCHAR*	serverName);

//-------------------------------------------------------------------------
// Provide a simple container for BACKUP metadata.
//
class MetaData
{
public:
	MetaData ();
	~MetaData ();

	// Data is appended until complete
	//
	void
	Append (const BYTE* pData, UINT length);

	// At completion, a checksum is appended
	//
	void
	Finalize ();

	// The buffer and its length are made available.
	//
	const BYTE*
	GetImage (UINT*	pLength);

	// Verify the checksum
	//
	static
	BOOL
	IsValidImage (const BYTE* pData, UINT length);

private:
	static 
	UINT
	Checksum (const BYTE* pData, UINT length);

	BYTE*					m_pData;
	UINT					m_AllocatedLength;
	UINT					m_UsedLength;
};

class Freeze2000;
class FrozenServer;

//-------------------------------------------------------------------------
// Handle a single frozen database (>=SQL2000 only).
//
class FrozenDatabase
{
	friend Freeze2000;
	friend FrozenServer;
	
//protected:
	enum VDState
	{
		Unknown=0, 
		Created, 
		Open, 
		PreparedToFreeze,
		Frozen
	};

	FrozenDatabase () :
		m_pContext (NULL),
		m_hThread (NULL),
		m_pIVDSet (NULL),
		m_pIVD (NULL),
		m_pSnapshotCmd (NULL),
		m_VDState (Unknown),
		m_SuccessDetected (FALSE)
	{}

	Freeze2000*					m_pContext;
	HANDLE						m_hThread;
	IClientVirtualDeviceSet2*   m_pIVDSet;
	IClientVirtualDevice*       m_pIVD;
	WString						m_DbName;
	VDC_Command*				m_pSnapshotCmd;
	VDState						m_VDState;
	WCHAR						m_SetName [80];
	bool						m_SuccessDetected;
	MetaData					m_MetaData;
//	bool						m_IsSimpleModel; // true if recovery model is simple
	bool						m_IsMaster;		 // true if this is the "master" database
};

//-------------------------------------------------------------------------
//
// Handle a SQL2000 server.
//
// In SQL2000 we'll use VDI snapshots to avoid bug 58266: thaw fails.
//
//  We'll prepare each database by starting a BACKUP WITH SNAPSHOT.
//  This will require one thread per database.
//  The backups will stall waiting for the VDI client to pull metadata.
//  When the "freeze" message comes along, the controlling thread will
//  pull all the BACKUPs to the frozen state.
//  Later the "thaw" message results in gathering the "success" report
//  from each thread.
//
//
class Snapshot;
class Freeze2000
{
	friend Snapshot;
	friend FrozenServer;

public:
	Freeze2000 (
		const WString&	serverName,
		ULONG			maxDatabases);

	~Freeze2000 ();

	void
	PrepareDatabase (
		const WString&	dbName);
	
	const BYTE*
	GetMetaData (
		const WString&	dbName,
		UINT*			pDataLength);
	
	void
	WaitForPrepare ();

	void
	Freeze ();

	BOOL
	Thaw () throw ();

	static DWORD
	DatabaseThreadStart (LPVOID	pContext);

private:
	enum State {
		Unprepared,
		Preparing,
		Prepared,
		Frozen,
		Complete,
		Aborted
	};

	DWORD
	DatabaseThread (
		FrozenDatabase*	pDbContext);

	void
	WaitForThreads ();

	void
	AdvanceVDState (
		FrozenDatabase::VDState	targetState);

	void		// race-free method to persist an abort condition
	SetAbort ()
	{
		InterlockedIncrement (&m_AbortCount);
	}

	bool		// return true if the freeze is aborting
	CheckAbort ()
	{
		return 0 != InterlockedCompareExchange (
#ifdef DOWNLEVEL_WINBASE
			(void**)
#endif
			&m_AbortCount, 0, 0);
	}

	void
	Abort () throw ();

	void
	Lock ()
	{
		EnterCriticalSection (&m_Latch);
	}
	void
	Unlock ()
	{	
		LeaveCriticalSection (&m_Latch);
	}
	BOOL	// return TRUE if we got the lock
	TryLock ()
	{
		return TryEnterCriticalSection (&m_Latch);
	}

	LONG				m_AbortCount;
	CRITICAL_SECTION	m_Latch;		
	State				m_State;
	WString				m_ServerName;
	GUID				m_BackupId;
	UINT				m_NumDatabases;
	UINT				m_MaxDatabases;
	FrozenDatabase*		m_pDBContext;
};

//-------------------------------------------------------------------------
// Represent a server which can be frozen.
//
class FrozenServer
{
	friend Snapshot;

public:
	FrozenServer (const std::wstring& serverName) :
		m_Name (serverName),
		m_pFreeze2000 (NULL)
	{}

	~FrozenServer ()
	{
		if (m_pFreeze2000)
		{
			delete m_pFreeze2000;
			m_pFreeze2000 = NULL;
		}
	}

	const std::wstring& GetName () const
	{ return m_Name; }

	BOOL
	FindDatabasesToFreeze (
		CCheckPath*		checker);

	BOOL
	Prepare ();

	BOOL
	Freeze ();

	BOOL
	Thaw () throw ();

#if 0
	void
	GetServerInfo (ServerInfo* pSrv);

	UINT
	GetDatabaseCount ();
#endif

	void
	GetDatabaseInfo (UINT dbIndex, FrozenDatabaseInfo* pInfo);

private:
	BOOL
	FindDatabases2000 (
		CCheckPath*		checker);

	void
	GetDatabaseProperties70 (const WString& dbName,
		BOOL*	pSimple,
		BOOL*	pOnline);

private:
	std::wstring	m_Name;
	SqlConnection	m_Connection;
	StringList		m_FrozenDatabases;
	Freeze2000*		m_pFreeze2000;
};


//-------------------------------------------------------------------------
//
class Snapshot : public CSqlSnapshot
{
	enum Status {
		NotInitialized,
		Enumerated,
		Prepared,
		Frozen };

public:
	HRESULT Prepare (
		CCheckPath*		checker) throw ();

	HRESULT Freeze () throw ();

	HRESULT Thaw () throw ();

	Snapshot () {m_Status = NotInitialized;}

	~Snapshot () throw ();

#if 0
	CSqlEnumerator* GetEnumerator () throw ()
	{return (CSqlEnumerator*)this;}

	// Call this at "Post-snapshot" time, after all databases are frozen and MD is complete.
	//
	HRESULT GetBackupMetadata (
		const WCHAR*		pInstance,
		const WCHAR*		pDatabase,
		BYTE**				ppData,		// returns a pointer to the string of metadata
		unsigned int*		pDataLen)	// length of the metadata (in bytes)
							throw ();

	// The enumeration interface
	//
	HRESULT FirstServer (
		ServerInfo*			pServer) throw ();

	HRESULT NextServer (
		ServerInfo*			pServer) throw ();

	HRESULT FirstDatabase (
		const WCHAR*		pServerName,
		DatabaseInfo*		pDbInfo) throw ()
	{return E_NOTIMPL;}

	HRESULT FirstDatabase (
		DatabaseInfo*		pDbInfo) throw ();

	HRESULT NextDatabase (
		DatabaseInfo*		pDbInfo) throw ();

	HRESULT FirstFile (
		const WCHAR*		pServerName,
		const WCHAR*		pDbName,
		DatabaseFileInfo*	pDbInfo) throw ()
	{return E_NOTIMPL;}

	HRESULT NextFile (
		DatabaseFileInfo*	pDbInfo) throw ()
	{return E_NOTIMPL;}
#endif

	HRESULT GetFirstDatabase (
		FrozenDatabaseInfo*	pInfo)	throw ();
	HRESULT GetNextDatabase (
		FrozenDatabaseInfo*	pInfo)	throw ();

private:
	void
	Deinitialize ();

	Status						m_Status;
	std::list<FrozenServer*>	m_FrozenServers;

	typedef std::list<FrozenServer*>::iterator ServerIter;

	ServerIter					m_ServerIter;	// iterate over the frozen servers
	UINT						m_DbIndex;		// iterate over databases within a server
};

//-------------------------------------------------------------------------
//
class RestoreHandler : public CSqlRestore
{
public:
	RestoreHandler ();

	// Inform SQLServer that data laydown is desired on the full database.
	// Performs a DETACH, preventing SQLServer from touching the files.
	//
	virtual HRESULT	PrepareToRestore (
		const WCHAR*		pInstance,
		const WCHAR*		pDatabase)
							throw ();

	// After data is laid down, this performs RESTORE WITH SNAPSHOT[,NORECOVERY]
	//
	virtual HRESULT	FinalizeRestore (
		const WCHAR*		pInstance,
		const WCHAR*		pDatabase,
		bool				compositeRestore,	// true if WITH NORECOVERY desired
		const BYTE*			pMetadata,			// metadata obtained from BACKUP
		unsigned int		dataLen)			// size of metadata (in bytes)
							throw ();

	// Internal use only. Called from the thread proc wrapper.
	//
	void
	RestoreVD ();

private:
	SqlConnection				m_Connection;
	HANDLE						m_hThread;
	IClientVirtualDeviceSet2*   m_pIVDSet;
	IClientVirtualDevice*       m_pIVD;
	WCHAR						m_SetName [80];
	GUID						m_VDSId;
	const BYTE*					m_pMetaData;
	UINT						m_MetaDataSize;
};


// We'll use very simple exception handling.
//
#define THROW_GENERIC  throw exception ();

//----------------------------------------------------------
// Implement our simple enumeration service
//
class SqlEnumerator : public CSqlEnumerator
{
	enum Status {
		Unknown = 0,
		DatabaseQueryActive,
		FileQueryActive
	};

public:
	~SqlEnumerator () throw ();

	SqlEnumerator () :
		m_State (Unknown),
		m_pServers (NULL)
	{}

	HRESULT FirstServer (
		ServerInfo*			pServer) throw ();

	HRESULT NextServer (
		ServerInfo*			pServer) throw ();

	HRESULT FirstDatabase (
		const WCHAR*		pServerName,
		DatabaseInfo*		pDbInfo) throw ();

	HRESULT NextDatabase (
		DatabaseInfo*		pDbInfo) throw ();

	HRESULT FirstFile (
		const WCHAR*		pServerName,
		const WCHAR*		pDbName,
		DatabaseFileInfo*	pDbInfo) throw ();

	HRESULT NextFile (
		DatabaseFileInfo*	pDbInfo) throw ();

private:
	void 
	SetupDatabaseInfo (
		DatabaseInfo*	pDbInfo);

	Status			m_State;
	SqlConnection	m_Connection;
	StringVector*	m_pServers;
	UINT			m_CurrServer;
};

#if defined (DEBUG)

// Type of assertion passed through to utassert_fail function.
//


#define DBG_ASSERT(exp)  BS_ASSERT(exp)

// Allow for noop 64 bit asserts on win32 for things like
// overflowing 32 bit long, etc.
//
#ifdef _WIN64
 #define DBG64_ASSERT(exp) BS_ASSERT(exp)
#else
 #define DBG64_ASSERT(exp)
#endif

#else
 #define DBG_ASSERT(exp)
 #define DBG64_ASSERT(exp)
 #define DBG_ASSERTSZ(exp, txt)
#endif