public IndexRecord(byte[] bytes, Page page)
: base(page)
{
parseStatusBitsA(new BitArray(new[] { bytes[0] }));
// Index records don't contain fixed length header - it's stored in the page header
FixedLengthData = bytes.Skip(1).Take(Page.Header.Pminlen - 1).ToArray();
PageId = new PagePointer(ArrayHelper.SliceArray(FixedLengthData, FixedLengthData.Length - 6, 6));
var offset = Page.Header.Pminlen;
NumberOfColumns = BitConverter.ToInt16(bytes, offset);
offset += 2;
if (HasNullBitmap)
{
offset = ParseNullBitmap(bytes, ref offset);
}
if (HasVariableLengthColumns)
{
ParseVariableLengthColumns(bytes, ref offset);
}
}
public PageHeader(byte[] header)
{
if (header.Length != 96)
{
throw new ArgumentException("Header length must be 96.");
}
/*
* Bytes Content
* ----- -------
* 00 HeaderVersion (tinyint)
* 01 Type (tinyint)
* 02 TypeFlagBits (tinyint)
* 03 Level (tinyint)
* 04-05 FlagBits (smallint)
* 06-07 IndexID (smallint)
* 08-11 PreviousPageID (int)
* 12-13 PreviousFileID (smallint)
* 14-15 Pminlen (smallint)
* 16-19 NextPageID (int)
* 20-21 NextPageFileID (smallint)
* 22-23 SlotCnt (smallint)
* 24-27 ObjectID (int)
* 28-29 FreeCnt (smallint)
* 30-31 FreeData (smallint)
* 32-35 PageID (int)
* 36-37 FileID (smallint)
* 38-39 ReservedCnt (smallint)
* 40-43 Lsn1 (int)
* 44-47 Lsn2 (int)
* 48-49 Lsn3 (smallint)
* 50-51 XactReserved (smallint)
* 52-55 XdesIDPart2 (int)
* 56-57 XdesIDPart1 (smallint)
* 58-59 GhostRecCnt (smallint)
* 60-63 Checksum/Tornbits (int)
* 64-95 ?
*/
HeaderVersion = header[0];
Type = (PageType)header[1];
TypeFlagBits = header[2];
Level = header[3];
FlagBits = BitConverter.ToInt16(header, 4);
IndexID = BitConverter.ToInt16(header, 6);
PreviousPage = new PagePointer(BitConverter.ToInt16(header, 12), BitConverter.ToInt32(header, 8));
Pminlen = BitConverter.ToInt16(header, 14);
NextPage = new PagePointer(BitConverter.ToInt16(header, 20), BitConverter.ToInt32(header, 16));
SlotCnt = BitConverter.ToInt16(header, 22);
ObjectID = BitConverter.ToInt32(header, 24);
FreeCnt = BitConverter.ToInt16(header, 28);
FreeData = BitConverter.ToInt16(header, 30);
Pointer = new PagePointer(BitConverter.ToInt16(header, 36), BitConverter.ToInt32(header, 32));
ReservedCnt = BitConverter.ToInt16(header, 38);
Lsn = "(" + BitConverter.ToInt32(header, 40) + ":" + BitConverter.ToInt32(header, 44) + ":" + BitConverter.ToInt16(header, 48) + ")";
XactReserved = BitConverter.ToInt16(header, 50);
XdesID = "(" + BitConverter.ToInt16(header, 56) + ":" + BitConverter.ToInt32(header, 52) + ")";
GhostRecCnt = BitConverter.ToInt16(header, 58);
}
public PageHeader(byte[] header)
{
if (header.Length != 96)
throw new ArgumentException("Header length must be 96.");
/*
Bytes Content
----- -------
00 HeaderVersion (tinyint)
01 Type (tinyint)
02 TypeFlagBits (tinyint)
03 Level (tinyint)
04-05 FlagBits (smallint)
06-07 IndexID (smallint)
08-11 PreviousPageID (int)
12-13 PreviousFileID (smallint)
14-15 Pminlen (smallint)
16-19 NextPageID (int)
20-21 NextPageFileID (smallint)
22-23 SlotCnt (smallint)
24-27 ObjectID (int)
28-29 FreeCnt (smallint)
30-31 FreeData (smallint)
32-35 PageID (int)
36-37 FileID (smallint)
38-39 ReservedCnt (smallint)
40-43 Lsn1 (int)
44-47 Lsn2 (int)
48-49 Lsn3 (smallint)
50-51 XactReserved (smallint)
52-55 XdesIDPart2 (int)
56-57 XdesIDPart1 (smallint)
58-59 GhostRecCnt (smallint)
60-63 Checksum/Tornbits (int)
64-95 ?
*/
HeaderVersion = header[0];
Type = (PageType)header[1];
TypeFlagBits = header[2];
Level = header[3];
FlagBits = BitConverter.ToInt16(header, 4);
IndexID = BitConverter.ToInt16(header, 6);
PreviousPage = new PagePointer(BitConverter.ToInt16(header, 12), BitConverter.ToInt32(header, 8));
Pminlen = BitConverter.ToInt16(header, 14);
NextPage = new PagePointer(BitConverter.ToInt16(header, 20), BitConverter.ToInt32(header, 16));
SlotCnt = BitConverter.ToInt16(header, 22);
ObjectID = BitConverter.ToInt32(header, 24);
FreeCnt = BitConverter.ToInt16(header, 28);
FreeData = BitConverter.ToInt16(header, 30);
Pointer = new PagePointer(BitConverter.ToInt16(header, 36), BitConverter.ToInt32(header, 32));
ReservedCnt = BitConverter.ToInt16(header, 38);
Lsn = "(" + BitConverter.ToInt32(header, 40) + ":" + BitConverter.ToInt32(header, 44) + ":" + BitConverter.ToInt16(header, 48) + ")";
XactReserved = BitConverter.ToInt16(header, 50);
XdesID = "(" + BitConverter.ToInt16(header, 56) + ":" + BitConverter.ToInt32(header, 52) + ")";
GhostRecCnt = BitConverter.ToInt16(header, 58);
}
public ClusteredIndexRecord(byte[] bytes, Page page)
: base(page)
{
parseStatusBitsA(new BitArray(new[] { bytes[0] }));
// Index records don't contain fixed length header - it's stored in the page header
FixedLengthData = bytes.Skip(1).Take(Page.Header.Pminlen - 1).ToArray();
PageId = new PagePointer(ArrayHelper.SliceArray(FixedLengthData, FixedLengthData.Length - 6, 6));
}
private void parseHeader()
{
/*
* Bytes Content
* ----- -------
* 00-03 SequenceNumber (int)
* 04-13 ?
* 14-15 Status (smallint)
* 16-27 ?
* 28-31 ObjectID (int)
* 32-33 IndexID (smallint)
* 34 PageCount (tinyint)
* 35 ?
* 36-39 StartPage PageID (int)
* 40-41 StartPage FileID (smallint)
* 42-45 Slot0 PageID (int)
* 46-47 Slot0 FileID (smallint)
* 48-51 Slot1 PageID (int)
* 52-53 Slot1 FileID (smallint)
* 54-57 Slot2 PageID (v)
* 58-59 Slot2 FileID (smallint)
* 60-63 Slot3 PageID (int)
* 64-65 Slot3 FileID (smallint)
* 66-69 Slot4 PageID (int)
* 70-71 Slot4 FileID (smallint)
* 72-75 Slot5 PageID (int)
* 76-77 Slot5 FileID (smallint)
* 78-81 Slot6 PageID (int)
* 82-83 Slot6 FileID (smallint)
* 84-87 Slot7 PageID (int)
* 88-89 Slot7 FileID (smallint)
*/
byte[] header = Records[0].FixedLengthData;
// Read iam header
SequenceNumber = BitConverter.ToUInt32(header, 0);
Status = BitConverter.ToInt16(header, 14);
ObjectID = BitConverter.ToInt32(header, 28);
IndexID = BitConverter.ToInt16(header, 32);
PageCount = header[34];
StartPage = new PagePointer(BitConverter.ToInt16(header, 40), BitConverter.ToInt32(header, 36));
// Read single page slot allocations
Slot0 = new PagePointer(BitConverter.ToInt16(header, 46), BitConverter.ToInt32(header, 42));
Slot1 = new PagePointer(BitConverter.ToInt16(header, 52), BitConverter.ToInt32(header, 48));
Slot2 = new PagePointer(BitConverter.ToInt16(header, 58), BitConverter.ToInt32(header, 54));
Slot3 = new PagePointer(BitConverter.ToInt16(header, 64), BitConverter.ToInt32(header, 60));
Slot4 = new PagePointer(BitConverter.ToInt16(header, 70), BitConverter.ToInt32(header, 66));
Slot5 = new PagePointer(BitConverter.ToInt16(header, 76), BitConverter.ToInt32(header, 72));
Slot6 = new PagePointer(BitConverter.ToInt16(header, 82), BitConverter.ToInt32(header, 78));
Slot7 = new PagePointer(BitConverter.ToInt16(header, 88), BitConverter.ToInt32(header, 84));
}
private void parseSysrowsets()
{
// Using a fixed allocation unit ID, we can look up the hobt AU and scan it
var pageLoc = new PagePointer(
sysallocunits
.Where(x => x.auid == FixedSystemObjectAllocationUnits.sysrowsets)
.Single()
.pgfirst
);
sysrowsets = scanner.ScanLinkedDataPages <sysrowset>(pageLoc, CompressionContext.NoCompression).ToList();
}
private void parseSyssingleobjrefs()
{
// Using a fixed object ID, we can look up the partition for sysscalartypes and scan the hobt AU from there
long rowsetID = sysrowsets
.Where(x => x.idmajor == (int)SystemObject.syssingleobjrefs && x.idminor == 1)
.Single()
.rowsetid;
var pageLoc = new PagePointer(
sysallocunits
.Where(x => x.auid == rowsetID && x.type == 1)
.Single()
.pgfirst
);
syssingleobjrefs = scanner.ScanLinkedDataPages <syssingleobjref>(pageLoc, CompressionContext.NoCompression).ToList();
}
internal static RecordEntityParser CreateEntityParserForPage(PagePointer loc, CompressionContext compression, Database database)
{
switch (compression.CompressionLevel)
{
case CompressionLevel.Page:
throw new NotImplementedException("Page compression not yet supported.");
case CompressionLevel.Row:
return new CompressedRecordEntityParser(database.GetCompressedRecordPage(loc, compression));
case CompressionLevel.None:
return new PrimaryRecordEntityParser(database.GetPrimaryRecordPage(loc, compression), compression);
default:
throw new ArgumentException("Unsupported compression level: " + compression.CompressionLevel);
}
}
private void parseSyscolpars()
{
// Using a fixed object ID, we can look up the partition for syscolpars and scan the hobt AU from there
long rowsetID = SysRowsets
.Where(x => x.idmajor == (int)SystemObject.syscolpars && x.idminor == 1)
.Single()
.rowsetid;
var pageLoc = new PagePointer(
SysAllocUnits
.Where(x => x.auid == rowsetID && x.type == 1)
.Single()
.pgfirst
);
SysColPars = _scanner.ScanLinkedDataPages <syscolpar>(pageLoc, CompressionContext.NoCompression).ToList();
}
internal static RecordEntityParser CreateEntityParserForPage(PagePointer loc, CompressionContext compression, Database database)
{
switch (compression.CompressionLevel)
{
case CompressionLevel.Page:
throw new NotImplementedException("Page compression not yet supported.");
case CompressionLevel.Row:
return(new CompressedRecordEntityParser(database.GetCompressedRecordPage(loc, compression)));
case CompressionLevel.None:
return(new PrimaryRecordEntityParser(database.GetPrimaryRecordPage(loc, compression), compression));
default:
throw new ArgumentException("Unsupported compression level: " + compression.CompressionLevel);
}
}
private void parseBootRecord()
{
/*
* Bytes Content
* ----- -------
* 0-1 Version (smallint)
* 2-3 CreateVersion (smallint)
* 4-31 ?
* 32-35 Status (int)
* 36-39 NextID (int)
* 40-47 ?
* 48-303 DatabaseName (nchar(128))
* 304-307 ?
* 308-309 DBID (smallint)
* 310-311 ?
* 312-319 MaxDBTimeStamp (bigint)
* 320-383 ?
* 384-388 CollationId(long)
* 389-511 ?
* 512-515 FirstSysIndexes PageID (int)
* 516-517 FirstSysIndexes FileID (smallint)
* 518-1440 ?
*/
byte[] bootRecord = Records[0].FixedLengthData;
Version = BitConverter.ToInt16(bootRecord, 0);
CreateVersion = BitConverter.ToInt16(bootRecord, 2);
Status = BitConverter.ToInt32(bootRecord, 32);
NextID = BitConverter.ToInt32(bootRecord, 36);
// Truncate name at first 0x2020 char
DatabaseName = Encoding.Unicode.GetString(bootRecord, 48, 256);
if (DatabaseName.IndexOf('†') > 0)
{
DatabaseName = DatabaseName.Substring(0, DatabaseName.IndexOf('†'));
}
DBID = BitConverter.ToInt16(bootRecord, 308);
MaxDBTimeStamp = BitConverter.ToInt64(bootRecord, 312);
CollationId = BitConverter.ToInt64(bootRecord, 384);
FirstSysIndexes = new PagePointer(BitConverter.ToInt16(bootRecord, 516), BitConverter.ToInt32(bootRecord, 512));
}
public string CreateRestoreScriptWithRollback(string connectionString, PagePointer pagePointer)
{
using (var connection = new SqlConnection(connectionString))
{
connection.Open();
using (var command = connection.CreateCommand())
{
command.CommandText = "DBCC READPAGE (@dbName, @fileId, @pageId, 'V8192', 1)";
command.Parameters.AddWithValue("@dbName", connection.Database);
command.Parameters.AddWithValue("@fileId", pagePointer.FileID);
command.Parameters.AddWithValue("@pageId", pagePointer.PageID);
var reader = command.ExecuteReader();
reader.Read();
var pageBytes = (byte[])reader["ValueDump"];
var backupPage = _database.GetPage(pagePointer).RawBytes;
var rolloutScript =
"-- PAGE UPDATE SCRIPT\r\n\r\n" +
$"DBCC WRITEPAGE('{connection.Database}', {pagePointer.FileID}, {pagePointer.PageID}, 0, 8000, 0x{BitConverter.ToString(backupPage.Take(8000).ToArray()).Replace("-", string.Empty)}, 1);\r\n" +
$"DBCC WRITEPAGE('{connection.Database}', {pagePointer.FileID}, {pagePointer.PageID}, 8000, 192, 0x{BitConverter.ToString(backupPage.Skip(8000).ToArray()).Replace("-", string.Empty)}, 1);";
var rollBackScript =
"-- ROLLBACK SCRIPT\r\n\r\n" +
$"-- DBCC WRITEPAGE('{connection.Database}', {pagePointer.FileID}, {pagePointer.PageID}, 0, 8000, 0x{BitConverter.ToString(pageBytes.Take(8000).ToArray()).Replace("-", string.Empty)}, 1);\r\n" +
$"-- DBCC WRITEPAGE('{connection.Database}', {pagePointer.FileID}, {pagePointer.PageID}, 8000, 192, 0x{BitConverter.ToString(pageBytes.Skip(8000).ToArray()).Replace("-", string.Empty)}, 1);";
var resultScript =
$"\r\nUSE [{connection.Database}]\r\nGO\r\nALTER DATABASE [{connection.Database}] SET SINGLE_USER WITH ROLLBACK IMMEDIATE;\r\nGO\r\n" +
rolloutScript + "\r\n\r\n" + rollBackScript +
$"\r\n\r\nALTER DATABASE [{connection.Database}] SET MULTI_USER\r\nGO";
return(resultScript);
}
}
}
public static PagePointer GetGamPointerForPage(PagePointer loc)
{
// First gam page is at index 2 and every 511232 pages hereafter
return(new PagePointer(loc.FileID, Math.Max(loc.PageID / 511232 * 511232, 2)));
}
private void parseBootRecord()
{
/*
Bytes Content
----- -------
0-1 Version (smallint)
2-3 CreateVersion (smallint)
4-31 ?
32-35 Status (int)
36-39 NextID (int)
40-47 ?
48-303 DatabaseName (nchar(128))
304-307 ?
308-309 DBID (smallint)
310-311 ?
312-319 MaxDBTimeStamp (bigint)
320-511 ?
512-515 FirstSysIndexes PageID (int)
516-517 FirstSysIndexes FileID (smallint)
518-1440 ?
*/
byte[] bootRecord = Records[0].FixedLengthData;
Version = BitConverter.ToInt16(bootRecord, 0);
CreateVersion = BitConverter.ToInt16(bootRecord, 2);
Status = BitConverter.ToInt32(bootRecord, 32);
NextID = BitConverter.ToInt32(bootRecord, 36);
// Truncate name at first 0x2020 char
DatabaseName = Encoding.Unicode.GetString(bootRecord, 48, 256);
if (DatabaseName.IndexOf('†') > 0)
DatabaseName = DatabaseName.Substring(0, DatabaseName.IndexOf('†'));
DBID = BitConverter.ToInt16(bootRecord, 308);
MaxDBTimeStamp = BitConverter.ToInt64(bootRecord, 312);
FirstSysIndexes = new PagePointer(BitConverter.ToInt16(bootRecord, 516), BitConverter.ToInt32(bootRecord, 512));
}
public static PagePointer GetSgamPointerForPage(PagePointer loc)
{
// First gam page is at index 3 and every 511232 pages hereafter
return new PagePointer(loc.FileID, Math.Max(loc.PageID / 511232 * 511232 + 1, 3));
}
public static PagePointer GetPfsPointerForPage(PagePointer loc)
{
// First pfs page is at index 1 and every 8088 pages hereafter
return(new PagePointer(loc.FileID, Math.Max(loc.PageID / 8088 * 8088, 1)));
}
public static PagePointer GetPfsPointerForPage(PagePointer loc)
{
// First pfs page is at index 1 and every 8088 pages hereafter
return new PagePointer(loc.FileID, Math.Max(loc.PageID / 8088 * 8088, 1));
}
private void parseHeader()
{
/*
Bytes Content
----- -------
00-03 SequenceNumber (int)
04-13 ?
14-15 Status (smallint)
16-27 ?
28-31 ObjectID (int)
32-33 IndexID (smallint)
34 PageCount (tinyint)
35 ?
36-39 StartPage PageID (int)
40-41 StartPage FileID (smallint)
42-45 Slot0 PageID (int)
46-47 Slot0 FileID (smallint)
48-51 Slot1 PageID (int)
52-53 Slot1 FileID (smallint)
54-57 Slot2 PageID (v)
58-59 Slot2 FileID (smallint)
60-63 Slot3 PageID (int)
64-65 Slot3 FileID (smallint)
66-69 Slot4 PageID (int)
70-71 Slot4 FileID (smallint)
72-75 Slot5 PageID (int)
76-77 Slot5 FileID (smallint)
78-81 Slot6 PageID (int)
82-83 Slot6 FileID (smallint)
84-87 Slot7 PageID (int)
88-89 Slot7 FileID (smallint)
*/
byte[] header = Records[0].FixedLengthData;
// Read iam header
SequenceNumber = BitConverter.ToUInt32(header, 0);
Status = BitConverter.ToInt16(header, 14);
ObjectID = BitConverter.ToInt32(header, 28);
IndexID = BitConverter.ToInt16(header, 32);
PageCount = header[34];
StartPage = new PagePointer(BitConverter.ToInt16(header, 40), BitConverter.ToInt32(header, 36));
// Read single page slot allocations
Slot0 = new PagePointer(BitConverter.ToInt16(header, 46), BitConverter.ToInt32(header, 42));
Slot1 = new PagePointer(BitConverter.ToInt16(header, 52), BitConverter.ToInt32(header, 48));
Slot2 = new PagePointer(BitConverter.ToInt16(header, 58), BitConverter.ToInt32(header, 54));
Slot3 = new PagePointer(BitConverter.ToInt16(header, 64), BitConverter.ToInt32(header, 60));
Slot4 = new PagePointer(BitConverter.ToInt16(header, 70), BitConverter.ToInt32(header, 66));
Slot5 = new PagePointer(BitConverter.ToInt16(header, 76), BitConverter.ToInt32(header, 72));
Slot6 = new PagePointer(BitConverter.ToInt16(header, 82), BitConverter.ToInt32(header, 78));
Slot7 = new PagePointer(BitConverter.ToInt16(header, 88), BitConverter.ToInt32(header, 84));
}
