/*++

Copyright (c) 1991  Microsoft Corporation

Module Name:

    hivefree.c

Abstract:

    Hive free code

Author:

    Bryan M. Willman (bryanwi) 30-Mar-92

Environment:


Revision History:

--*/

#include    "cmp.h"

#ifdef ALLOC_PRAGMA
#pragma alloc_text(PAGE,HvFreeHive)
#pragma alloc_text(PAGE,HvFreeHivePartial)
#endif


VOID
HvFreeHive(
    PHHIVE Hive
    )
/*++

Routine Description:

    Free all of the pieces of a hive.

Arguments:

    Hive - supplies a pointer to hive control structure for hive to free.
            this structure itself will NOT be freed, but everything it
            points to will.

Return Value:

    NONE.

--*/
{
    PHMAP_DIRECTORY Dir;
    PHMAP_ENTRY     Me;
    HCELL_INDEX     Address;
    ULONG           Type;
    ULONG           Length;
    PHBIN           Bin;
    ULONG           Tables;
    PFREE_HBIN      FreeBin;

    ASSERT(Hive->Flat == FALSE);
    ASSERT(Hive->ReadOnly == FALSE);
    ASSERT(Stable == 0);
    ASSERT(Volatile == 1);

    //
    // Iterate through both types of storage
    //
    for (Type = 0; Type <= Volatile; Type++) {

        Address = HCELL_TYPE_MASK * Type;
        Length = Hive->Storage[Type].Length + (HCELL_TYPE_MASK * Type);

        if (Length > (HCELL_TYPE_MASK * Type)) {

            //
            // Sweep through bin set
            //
            do {
                Me = HvpGetCellMap(Hive, Address);
                ASSERT(Me != NULL);
                if (Me->BinAddress & HMAP_DISCARDABLE) {
                    //
                    // hbin is either discarded or discardable, check the tombstone
                    //
                    FreeBin = (PFREE_HBIN)Me->BlockAddress;
                    Address += FreeBin->Size;
                    if (FreeBin->Flags & FREE_HBIN_DISCARDABLE) {
                        CmpFree((PHBIN)(Me->BinAddress & HMAP_BASE), FreeBin->Size);
                    }
                    CmpFree(FreeBin, sizeof(FREE_HBIN));
                } else {
                    Bin = (PHBIN)(Me->BinAddress & HMAP_BASE);
                    Address += Bin->MemAlloc;
#if DBG
                    //
                    // Make sure that the next bin in the list is
                    // actually the start of an alloc before freeing it
                    //
                    if (Address < Length) {
                        Me = HvpGetCellMap(Hive, Address);
                        ASSERT(Me->BinAddress & HMAP_NEWALLOC);
                    }
#endif
                    CmpFree(Bin, Bin->MemAlloc);
                }

            } while (Address < Length);

            //
            // Free map table storage
            //
            ASSERT(Hive->Storage[Type].Length != (HCELL_TYPE_MASK * Type));
            Tables = (((Hive->Storage[Type].Length) / HBLOCK_SIZE)-1) / HTABLE_SLOTS;
            Dir = Hive->Storage[Type].Map;
            HvpFreeMap(Hive, Dir, 0, Tables);

            if (Tables > 0) {
                CmpFree(Hive->Storage[Type].Map, sizeof(HMAP_DIRECTORY));  // free dir if it exists
            }
        }
        Hive->Storage[Type].Length = 0;
    }

    //
    // Free the base block
    //
    (Hive->Free)(Hive->BaseBlock, sizeof(HBASE_BLOCK));
    Hive->BaseBlock = NULL;

    //
    // Free the dirty vector
    //
    if (Hive->DirtyVector.Buffer != NULL) {
        CmpFree((PVOID)(Hive->DirtyVector.Buffer), Hive->DirtyAlloc);
    }

    return;
}


VOID
HvFreeHivePartial(
    PHHIVE      Hive,
    HCELL_INDEX Start,
    HSTORAGE_TYPE Type
    )
/*++

Routine Description:

    Free the memory and associated maps for the end of a hive
    starting at Start.  The baseblock, hive, etc will not be touched.

Arguments:

    Hive - supplies a pointer to hive control structure for hive to
            partially free.

    Start - HCELL_INDEX of first bin to free, will free from this
            bin (inclusive) to the end of the hives stable storage.

    Type - Type of storage (Stable or Volatile) to be freed.

Return Value:

    NONE.

--*/
{
    PHMAP_DIRECTORY Dir;
    PHMAP_ENTRY     Me;
    HCELL_INDEX     Address;
    ULONG           StartTable;
    ULONG           Length;
    PHBIN           Bin;
    ULONG           Tables;
    ULONG           FirstBit;
    ULONG           LastBit;
    PFREE_HBIN      FreeBin;

    ASSERT(Hive->Flat == FALSE);
    ASSERT(Hive->ReadOnly == FALSE);

    Address = Start;
    Length = Hive->Storage[Type].Length;
    ASSERT(Address <= Length);

    if (Address == Length) {
        return;
    }

    //
    // Sweep through bin set
    //
    do {
        Me = HvpGetCellMap(Hive, Address + (Type*HCELL_TYPE_MASK));
        ASSERT(Me != NULL);
        if (Me->BinAddress & HMAP_DISCARDABLE) {
            FreeBin = (PFREE_HBIN)Me->BlockAddress;
            if (FreeBin->Flags & FREE_HBIN_DISCARDABLE) {
                CmpFree((PVOID)(Me->BinAddress & HMAP_BASE), FreeBin->Size);
            } else {
                //
                // The bin has been freed, but quota is still charged.
                // Since the file will now shrink, the quota must be
                // returned here.
                //
                CmpReleaseGlobalQuota(FreeBin->Size);
            }
            RemoveEntryList(&FreeBin->ListEntry);
            Address += FreeBin->Size;
            CmpFree(FreeBin, sizeof(FREE_HBIN));

        } else {
            Bin = (PHBIN)(Me->BinAddress & HMAP_BASE);

            Address += Bin->MemAlloc;
            CmpFree(Bin, Bin->MemAlloc);
        }
    } while (Address < Length);

    //
    // Free map table storage
    //
    Tables = (((Hive->Storage[Type].Length) / HBLOCK_SIZE) - 1) / HTABLE_SLOTS;
    Dir = Hive->Storage[Type].Map;
    if (Start > 0) {
        StartTable = ((Start-1) / HBLOCK_SIZE) / HTABLE_SLOTS;
    } else {
        StartTable = (ULONG)-1;
    }
    HvpFreeMap(Hive, Dir, StartTable+1, Tables);

    Hive->Storage[Type].Length = Start;

    if (Type==Stable) {
        //
        // Clear dirty vector for data past Hive->Storage[Stable].Length
        //
        FirstBit = Start / HSECTOR_SIZE;
        LastBit = Hive->DirtyVector.SizeOfBitMap;
        ASSERT(Hive->DirtyCount == RtlNumberOfSetBits(&Hive->DirtyVector));
        RtlClearBits(&Hive->DirtyVector, FirstBit, LastBit-FirstBit);
        Hive->DirtyCount = RtlNumberOfSetBits(&Hive->DirtyVector);
    }

    return;
}