/*

 * Copyright (c) 2020 Red Hat, Inc.

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version 2

 * of the License, or (at your option) any later version.

 * 

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 * 

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA

 * 02110-1301, USA. 

 *

 * $Id: //eng/vdo-releases/aluminum/src/c++/vdo/base/blockMapInternals.h#12 $

 */

#ifndef BLOCK_MAP_INTERNALS_H

#define BLOCK_MAP_INTERNALS_H

#include "adminState.h"

#include "blockMapEntry.h"

#include "blockMapTree.h"

#include "completion.h"

#include "dirtyLists.h"

#include "header.h"

#include "intMap.h"

#include "ringNode.h"

#include "types.h"

#include "vdoPageCache.h"

#include "vioPool.h"

/**

 * The per-zone fields used by the block map tree.

 **/

struct blockMapTreeZone {

  /** The BlockMapZone which owns this tree zone */

  BlockMapZone        *mapZone;

  /** The lists of dirty tree pages */

  DirtyLists          *dirtyLists;

  /** The number of tree lookups in progress */

  VIOCount             activeLookups;

  /** The map of pages currently being loaded */

  IntMap              *loadingPages;

  /** The pool of VIOs for tree I/O */

  VIOPool             *vioPool;

  /** The tree page which has issued or will be issuing a flush */

  TreePage            *flusher;

  /** The queue of pages waiting for a flush so they can be written out */

  WaitQueue            flushWaiters;

  /** The generation after the most recent flush */

  uint8_t              generation;

  /** The oldest active generation */

  uint8_t              oldestGeneration;

  /** The counts of dirty pages in each generation */

  uint32_t             dirtyPageCounts[256];

};

/**

 * The per-zone fields of the block map.

 **/

struct blockMapZone {

  /** The number of the zone this is */

  ZoneCount         zoneNumber;

  /** The ID of this zone's logical thread */

  ThreadID          threadID;

  /** The BlockMap which owns this BlockMapZone */

  BlockMap         *blockMap;

  /** The ReadOnlyNotifier of the VDO */

  ReadOnlyNotifier *readOnlyNotifier;

  /** The page cache for this zone */

  VDOPageCache     *pageCache;

  /** The per-zone portion of the tree for this zone */

  BlockMapTreeZone  treeZone;

  /** The administrative state of the zone */

  AdminState        state;

};

struct blockMap {

  /** The manager for block map actions */

  ActionManager       *actionManager;

  /** The count of pages in the linear part of the block map */

  BlockCount           flatPageCount;

  /** The absolute PBN of the first root of the tree part of the block map */

  PhysicalBlockNumber  rootOrigin;

  /** The count of root pages of the tree part of the block map */

  BlockCount           rootCount;

  /** The era point we are currently distributing to the zones */

  SequenceNumber       currentEraPoint;

  /** The next era point, not yet distributed to any zone */

  SequenceNumber       pendingEraPoint;

  /** The number of entries in block map */

  BlockCount           entryCount;

  /** The VDO's nonce, for the pages */

  Nonce                nonce;

  /** The recovery journal for this map */

  RecoveryJournal     *journal;

  /** The trees for finding block map pages */

  Forest              *forest;

  /** The expanded trees awaiting growth */

  Forest              *nextForest;

  /** The number of entries after growth */

  BlockCount           nextEntryCount;

  /** The number of logical zones */

  ZoneCount            zoneCount;

  /** The per zone block map structure */

  BlockMapZone         zones[];

};

/**

 * Compute the number of pages required for a block map with the specified

 * parameters.

 *

 * @param entries   The number of block map entries

 *

 * @return The number of pages required

 **/

PageCount computeBlockMapPageCount(BlockCount entries);

/**

 * Compute the number of the block map page on which the entry for a given

 * logical block resides.

 *

 * @param lbn  The logical block number whose page is desired

 *

 * @return The number of the block map page containing the entry for

 *         the given logical block number

 **/

__attribute__((warn_unused_result))

static inline PageNumber computePageNumber(LogicalBlockNumber lbn)

{

  return (lbn / BLOCK_MAP_ENTRIES_PER_PAGE);

}

/**

 * Find the block map page slot in which the entry for a given logical

 * block resides.

 *

 * @param lbn  The logical block number whose slot

 *

 * @return The slot containing the entry for the given logical block number

 **/

__attribute__((warn_unused_result))

static inline SlotNumber computeSlot(LogicalBlockNumber lbn)

{

  return (lbn % BLOCK_MAP_ENTRIES_PER_PAGE);

}

/**

 * Check whether a zone of the block map has drained, and if so, send a

 * notification thereof.

 *

 * @param zone  The zone to check

 **/

void checkForDrainComplete(BlockMapZone *zone);

#endif // BLOCK_MAP_INTERNALS_H