windows-xp/Source/XPSP1/NT/base/fs/rdr2/inc/fcbtable.h

/*++

Copyright (c) 1989  Microsoft Corporation

Module Name:

    fcbtable.h

Abstract:

    This module defines the data structures that facilitate management of the
    collection of FCB's associated with a NET_ROOT

Author:

    Balan Sethu Raman (SethuR)    10/17/96

Revision History:

    This was derived from the original implementation of prefix tables done
    by Joe Linn.

--*/


#ifndef _RXFCBTABLE_
#define _RXFCBTABLE_

typedef struct _RX_FCB_TABLE_ENTRY {

    // Normal Header for Refcounted Structure
    NODE_TYPE_CODE NodeTypeCode;
    NODE_BYTE_SIZE NodeByteSize;

    // the computed hash value
    ULONG      HashValue;

    // the path associated with the FCB
    UNICODE_STRING Path;

    // the threaded list of all entries in a bucket.
    LIST_ENTRY HashLinks;

    // Statistics for amortising lookup costs
    LONG       Lookups;
} RX_FCB_TABLE_ENTRY, *PRX_FCB_TABLE_ENTRY;


#define RX_FCB_TABLE_NUMBER_OF_HASH_BUCKETS 32

typedef struct _RX_FCB_TABLE {

    // Normal Header for refcounted data structures
    NODE_TYPE_CODE NodeTypeCode;
    NODE_BYTE_SIZE NodeByteSize;

    // version stamp changes on each insertion/removal
    ULONG Version;

    BOOLEAN CaseInsensitiveMatch;
    USHORT  NumberOfBuckets;

    // Statistics for table maintenance
    LONG    Lookups;
    LONG    FailedLookups;
    LONG    Compares;

    // Resource used to control table access
    ERESOURCE TableLock;

    // TableEntry for the Null string
    PRX_FCB_TABLE_ENTRY pTableEntryForNull;

    // the hash buckets
    LIST_ENTRY HashBuckets[RX_FCB_TABLE_NUMBER_OF_HASH_BUCKETS];
} RX_FCB_TABLE, *PRX_FCB_TABLE;

extern VOID
RxInitializeFcbTable(
    IN OUT PRX_FCB_TABLE pFcbTable,
    IN     BOOLEAN       CaseInsensitiveMatch);

extern VOID
RxFinalizeFcbTable(
    IN OUT PRX_FCB_TABLE pFcbTable);

extern PFCB
RxFcbTableLookupFcb(
    IN  PRX_FCB_TABLE    pFcbTable,
    IN  PUNICODE_STRING  pPath);

extern NTSTATUS
RxFcbTableInsertFcb (
    IN OUT PRX_FCB_TABLE pFcbTable,
    IN OUT PFCB          pFcb);

extern NTSTATUS
RxFcbTableRemoveFcb (
    IN OUT PRX_FCB_TABLE pFcbTable,
    IN OUT PFCB          pFcb);

#define RxAcquireFcbTableLockShared(pFcbTable,Wait) \
        ExAcquireResourceSharedLite(&(pFcbTable)->TableLock,Wait)

#define RxAcquireFcbTableLockExclusive(pFcbTable,Wait) \
        ExAcquireResourceExclusiveLite(&(pFcbTable)->TableLock,Wait)

#define RxReleaseFcbTableLock(pFcbTable)  \
        ExReleaseResourceLite(&(pFcbTable)->TableLock)

#define RxIsFcbTableLockExclusive(PTABLE) ExIsResourceAcquiredExclusiveLite(&(PTABLE)->TableLock)

#define RxIsFcbTableLockAcquired(PTABLE) ( ExIsResourceAcquiredSharedLite(&(PTABLE)->TableLock) || \
                                              ExIsResourceAcquiredExclusiveLite(&(PTABLE)->TableLock) )


#endif