676 lines
16 KiB
C
676 lines
16 KiB
C
/*++ BUILD Version: 0000 // Increment this if a change has global effects
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Copyright (c) 1989 Microsoft Corporation
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Module Name:
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LfsStruc.h
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Abstract:
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This module defines the data structures that make up the major internal
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part of the Log File Service.
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Author:
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Brian Andrew [BrianAn] 13-June-1991
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Revision History:
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*/
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#ifndef _LFSSTRUC_
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#define _LFSSTRUC_
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typedef PVOID PBCB; //**** Bcb's are now part of the cache module
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// Log Context Block. A pointer to this structure is returned to the user
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// when a client is reading a particular set of log records from the log
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// file.
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typedef struct _LCB {
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// The type and size of this record (must be LFS_NTC_LCB)
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NODE_TYPE_CODE NodeTypeCode;
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NODE_BYTE_SIZE NodeByteSize;
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// Log record header. This is the mapped log record header and bcb
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// for the record header of the current Lsn.
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struct _LFS_RECORD_HEADER *RecordHeader;
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PBCB RecordHeaderBcb;
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// Context Mode. This is the mode governing the log record lookup. We
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// can look backwards via the ClientUndoNextLsn or ClientPreviousLsn.
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// We can also look forwards by walking through all the log records and
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// comparing ClientId fields.
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LFS_CONTEXT_MODE ContextMode;
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// Client Id. This is the client ID for the log records being returned.
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LFS_CLIENT_ID ClientId;
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// Log record pointer. This is the address returned to the user as the
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// log record referred to by CurrentLsn. If we allocated a buffer to
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// hold the record, we need to deallocate it as necessary.
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// This field is either the actual mapped log record or a pointer to
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// an auxilary buffer allocated by the Lfs.
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PVOID CurrentLogRecord;
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BOOLEAN AuxilaryBuffer;
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} LCB, *PLCB;
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// Lfcb synchronization. This is the synchronization structure used by the Lfcb.
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typedef struct _LFCB_SYNC {
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// Principal Lfcb Resource.
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ERESOURCE Resource;
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// Notification Event. This event is set to the Signalled state when
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// pages are flushed to the cache file. Any waiters will then check
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// to see if the Lsn they're waiting for made it to disk.
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KEVENT Event;
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// User Count. Number of clients using this structure. We will deallocate
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// when all clients are gone.
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ULONG UserCount;
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// Mutant to guard Lcb spare list
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FAST_MUTEX SpareListMutex;
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} LFCB_SYNC, *PLFCB_SYNC;
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// Log Client Structure. The Lfs allocates one of these for each active
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// client. The address of this structure will be returned to the user
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// as a log handle.
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typedef struct _LCH {
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// The type and size of this record (must be LFS_NTC_LCH)
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NODE_TYPE_CODE NodeTypeCode;
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NODE_BYTE_SIZE NodeByteSize;
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// Links for all the client handles on an Lfcb.
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LIST_ENTRY LchLinks;
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// Log File Control Block. This is the log file for this log handle.
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struct _LFCB *Lfcb;
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// Client Id. This refers to the client record for this client in the
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// Lfs restart area.
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LFS_CLIENT_ID ClientId;
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// The following is the number of bytes this client has asked to
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// have reserved in the log file. It includes the space
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// for the log record headers.
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LONGLONG ClientUndoCommitment;
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// Byte offset in the client array.
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ULONG ClientArrayByteOffset;
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// Pointer to the resource in the Lfcb. We access the resource with
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// this pointer for the times when the lfcb has been deleted.
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PLFCB_SYNC Sync;
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} LCH, *PLCH;
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// Log Buffer Control Block. A buffer control block is associated with
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// each of the log buffers. They are used to serialize access to the
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// log file.
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typedef struct _LBCB {
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// The type and size of this record (must be LFS_NTC_LBCB)
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NODE_TYPE_CODE NodeTypeCode;
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NODE_BYTE_SIZE NodeByteSize;
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// Buffer Block Links. These fields are used to link the buffer blocks
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// together.
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LIST_ENTRY WorkqueLinks;
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LIST_ENTRY ActiveLinks;
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// Log file position and length. This is the location in the log file to write
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// out this buffer.
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LONGLONG FileOffset;
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LONGLONG Length;
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// Sequence number. This is the sequence number for log records which
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// begin on this page.
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LONGLONG SeqNumber;
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// Next Offset. This is the next offset to write a log record in the
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// this log page. Stored as a large integer to facilitate large
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// integer operations.
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LONGLONG BufferOffset;
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// Buffer. This field points to the buffer containing the log page
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// for this block. For a log record page this is a pointer to
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// a pinned cache buffer, for a log restart page, this is a pointer
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// to an auxilary buffer.
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PVOID PageHeader;
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// Bcb for Log Page Block. This is the Bcb for the pinned data.
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// If this buffer block describes an Lfs restart area, this field is NULL.
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PBCB LogPageBcb;
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// Last Lsn. This is the Lsn for the last log record on this page. We delay
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// writing it until the page is flushed, storing it here instead.
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LSN LastLsn;
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// Last complete Lsn. This is the Lsn for the last log record which ends
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// on this page.
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LSN LastEndLsn;
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// Page Flags. These are the flags associated with this log page.
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// We store them in the Lbcb until the page is written. They flags
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// to use are the same as in the log record page header.
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// LOG_PAGE_LOG_RECORD_END - Page contains the end of a log record
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// LOG_PAGE_PACKED - Page contains packed log records
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// LOG_PAGE_TAIL_COPY - Page is a copy of the log file end
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ULONG Flags;
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// Lbcb flags. These are flags used to describe this Lbcb.
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// LBCB_LOG_WRAPPED - Lbcb has wrapped the log file
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// LBCB_ON_ACTIVE_QUEUE - Lbcb is on the active queue
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// LBCB_NOT_EMPTY - Page has existing log record
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// LBCB_FLUSH_COPY - Write copy of this page first
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// LBCB_RESTART_LBCB - This Lbcb contains a restart page
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ULONG LbcbFlags;
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// This is the thread which has locked the log page.
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ERESOURCE_THREAD ResourceThread;
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} LBCB, *PLBCB;
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#define LBCB_LOG_WRAPPED (0x00000001)
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#define LBCB_ON_ACTIVE_QUEUE (0x00000002)
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#define LBCB_NOT_EMPTY (0x00000004)
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#define LBCB_FLUSH_COPY (0x00000008)
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#define LBCB_RESTART_LBCB (0x00000020)
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// Log file data. This data structure is used on a per-log file basis.
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typedef enum _LFS_IO_STATE {
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LfsNoIoInProgress = 0,
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LfsClientThreadIo
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} LFS_IO_STATE;
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typedef struct _LFCB {
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// The type and size of this record (must be LFS_NTC_LFCB)
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NODE_TYPE_CODE NodeTypeCode;
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NODE_BYTE_SIZE NodeByteSize;
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// Lfcb Links. The following links the file control blocks to the
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// global data structure.
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LIST_ENTRY LfcbLinks;
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// Lch Links. The following links all of the handles for the Lfcb.
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LIST_ENTRY LchLinks;
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// File Object. This is the file object for the log file.
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PFILE_OBJECT FileObject;
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// Log File Size. This is the size of the log file.
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// The second value is the size proposed by this open.
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LONGLONG FileSize;
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// System page size and masks.
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LONGLONG SystemPageSize;
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ULONG SystemPageMask;
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LONG SystemPageInverseMask;
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// Log page size, masks and shift count to do multiplication and division
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// of log pages.
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LONGLONG LogPageSize;
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ULONG LogPageMask;
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LONG LogPageInverseMask;
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ULONG LogPageShift;
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// First log page. This is the offset in the file of the first
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// log page with log records.
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LONGLONG FirstLogPage;
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// Next log page offset. This is the offset of the next log page to use.
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// If we are reusing this page we store the offset to begin with.
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LONGLONG NextLogPage;
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ULONG ReusePageOffset;
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// Data Offset. This is the offset within a log page of the data that
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// appears on that page. This will be the actual restart data for
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// an Lfs restart page, or the beginning of log record data for a log
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// record page.
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ULONG RestartDataOffset;
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LONGLONG LogPageDataOffset;
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// Data Size. This is the amount of data that may be stored on a
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// log page. It is included here because it is frequently used. It
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// is simply the log page size minus the data offset.
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ULONG RestartDataSize;
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LONGLONG LogPageDataSize;
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// Record header size. This is the size to use for the record headers
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// when reading the log file.
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USHORT RecordHeaderLength;
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// Sequence number. This is the number of times we have cycled through
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// the log file. The wrap sequence number is used to confirm that we
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// have gone through the entire file at least once. When we write a
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// log record page for an Lsn with this sequence number, then we have
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// cycled through the file.
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LONGLONG SeqNumber;
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LONGLONG SeqNumberForWrap;
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ULONG SeqNumberBits;
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ULONG FileDataBits;
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// Buffer Block Links. The following links the buffer blocks for this
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// log file.
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LIST_ENTRY LbcbWorkque;
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LIST_ENTRY LbcbActive;
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PLBCB ActiveTail;
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PLBCB PrevTail;
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// The enumerated type indicates if there is an active write for
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// this log file and whether it is being done by an Lfs or
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// client thread.
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LFS_IO_STATE LfsIoState;
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// Current Restart Area. The following is the in-memory image of the
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// next restart area. We also store a pointer to the client data
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// array in the restart area. The client array offset is from the start of
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// the restart area.
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PLFS_RESTART_AREA RestartArea;
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PLFS_CLIENT_RECORD ClientArray;
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USHORT ClientArrayOffset;
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USHORT ClientNameOffset;
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// Restart Area size. This is the usable size of the restart area.
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ULONG RestartAreaSize;
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USHORT LogClients;
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// Initial Restart area. If true, then the in-memory restart area is to
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// be written to the first position on the disk.
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BOOLEAN InitialRestartArea;
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// The following pseudo Lsn's are used to track when restart areas
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// are flushed to the disk.
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LSN NextRestartLsn;
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LSN LastFlushedRestartLsn;
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// The following is the earliest Lsn we will guarantee is still in the
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// log file.
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LSN OldestLsn;
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// The following is the file offset of the oldest Lsn in the system.
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// We redundantly store it in this form since we will be constantly
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// checking if a new log record will write over part of the file
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// we are trying to maintain.
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LONGLONG OldestLsnOffset;
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// Last Flushed Lsn. The following is the last Lsn guaranteed to
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// be flushed to the disk.
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LSN LastFlushedLsn;
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// The following fields are used to track current usage in the log file.
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// TotalAvailable - is the total number of bytes available for
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// log records. It is the number of log pages times the
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// data size of each page.
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// TotalAvailInPages - is the total number of bytes in the log
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// pages for log records. This is TotalAvailable without
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// subtracting the size of the page headers.
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// TotalUndoCommitment - is the number of bytes reserved for
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// possible abort operations. This includes space for
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// log record headers as well.
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// MaxCurrentAvail - is the maximum available in all pages
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// subtracting the page header and any reserved tail.
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// CurrentAvailable - is the total number of bytes available in
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// unused pages in the log file.
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// ReservedLogPageSize - is the number of bytes on a page available
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// for reservation.
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LONGLONG TotalAvailable;
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LONGLONG TotalAvailInPages;
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LONGLONG TotalUndoCommitment;
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LONGLONG MaxCurrentAvail;
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LONGLONG CurrentAvailable;
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LONGLONG ReservedLogPageSize;
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// The following fields are used to store information about the
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// update sequence arrays.
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USHORT RestartUsaOffset;
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USHORT RestartUsaArraySize;
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USHORT LogRecordUsaOffset;
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USHORT LogRecordUsaArraySize;
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// Major and minor version numbers.
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SHORT MajorVersion;
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SHORT MinorVersion;
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// Log File Flags.
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// LFCB_LOG_WRAPPED - We found an Lbcb which wraps the log file
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// LFCB_MULTIPLE_PAGE_IO - Write multiple pages if possible
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// LFCB_NO_LAST_LSN - There are no log records to return
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// LFCB_PACK_LOG - Pack the records into the pages
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// LFCB_REUSE_TAIL - We will be reusing the tail of the log file after restart
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// LFCB_NO_OLDEST_LSN - There is no oldest page being reserved
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ULONG Flags;
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// The following are the spare Lbcb's for the volume and a field with
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// the count for these.
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ULONG SpareLbcbCount;
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LIST_ENTRY SpareLbcbList;
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// The following are sparse LCB's to be used rather than having to allocate
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// then when reading log records
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ULONG SpareLcbCount;
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LIST_ENTRY SpareLcbList;
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// The following structure synchronizes access to this structure.
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PLFCB_SYNC Sync;
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// Count of waiters wanting access to flush the Lfcb.
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ULONG Waiters;
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// On-disk value for OpenLogCount. This is the value we will stuff into
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// the client handles.
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ULONG CurrentOpenLogCount;
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// Maintain the flush range for this file.
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PLFS_WRITE_DATA UserWriteData;
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PLBCB PageToDirty;
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#ifdef BRIANDBG
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ERESOURCE_THREAD LfsIoThread;
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#endif
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} LFCB, *PLFCB;
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#define LFCB_LOG_WRAPPED (0x00000001)
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#define LFCB_MULTIPLE_PAGE_IO (0x00000002)
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#define LFCB_NO_LAST_LSN (0x00000004)
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#define LFCB_PACK_LOG (0x00000008)
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#define LFCB_REUSE_TAIL (0x00000010)
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#define LFCB_NO_OLDEST_LSN (0x00000020)
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#define LFCB_LOG_FILE_CORRUPT (0x00000040)
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#define LFCB_FINAL_SHUTDOWN (0x00000080)
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#define LFCB_READ_FIRST_RESTART (0x00000100)
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#define LFCB_READ_SECOND_RESTART (0x00000200)
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#define LFCB_RESERVE_LBCB_COUNT (5)
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#define LFCB_MAX_LBCB_COUNT (25)
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#define LFCB_RESERVE_LCB_COUNT (5)
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#define LFCB_MAX_LCB_COUNT (25)
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// Global Log Data. The following structure has only one instance and
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// maintains global information for the entire logging service.
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typedef struct _LFS_DATA {
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// The type and size of this record (must be LFS_NTC_DATA)
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NODE_TYPE_CODE NodeTypeCode;
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NODE_BYTE_SIZE NodeByteSize;
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// The following field links all of the Log File Control Blocks for
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// the logging system.
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LIST_ENTRY LfcbLinks;
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// Flag field.
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ULONG Flags;
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// The following mutex controls access to this structure.
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FAST_MUTEX LfsDataLock;
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// Allocated buffers for reading spanning log records in low memory case.
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// Flags indicate which buffers owned.
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// LFS_BUFFER1_OWNED
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// LFS_BUFFER2_OWNED
|
||
|
||
|
||
PVOID Buffer1;
|
||
PVOID Buffer2;
|
||
ERESOURCE_THREAD BufferOwner;
|
||
ULONG BufferFlags;
|
||
|
||
FAST_MUTEX BufferLock;
|
||
KEVENT BufferNotification;
|
||
|
||
} LFS_DATA, *PLFS_DATA;
|
||
|
||
#define LFS_DATA_INIT_FAILED (0x00000001)
|
||
#define LFS_DATA_INITIALIZED (0x00000002)
|
||
|
||
#define LFS_BUFFER1_OWNED (0x00000001)
|
||
#define LFS_BUFFER2_OWNED (0x00000002)
|
||
|
||
#define LFS_BUFFER_SIZE (0x10000)
|
||
#endif // _LFSSTRUC_
|
||
|