// heap_record_store_btree.h

/**
*    Copyright (C) 2014 MongoDB Inc.
*
*    This program is free software: you can redistribute it and/or  modify
*    it under the terms of the GNU Affero General Public License, version 3,
*    as published by the Free Software Foundation.
*
*    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 Affero General Public License for more details.
*
*    You should have received a copy of the GNU Affero General Public License
*    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*
*    As a special exception, the copyright holders give permission to link the
*    code of portions of this program with the OpenSSL library under certain
*    conditions as described in each individual source file and distribute
*    linked combinations including the program with the OpenSSL library. You
*    must comply with the GNU Affero General Public License in all respects for
*    all of the code used other than as permitted herein. If you modify file(s)
*    with this exception, you may extend this exception to your version of the
*    file(s), but you are not obligated to do so. If you do not wish to do so,
*    delete this exception statement from your version. If you delete this
*    exception statement from all source files in the program, then also delete
*    it in the license file.
*/

#pragma once

#include <boost/shared_array.hpp>
#include <map>

#include "mongo/db/storage/record_store.h"
#include "mongo/db/storage/recovery_unit.h"

namespace mongo {

/**
 * A RecordStore that stores all data on the heap. This implementation contains only the
 * functionality necessary to test btree.
 */
class HeapRecordStoreBtree : public RecordStore {
    struct Record;

public:
    // RecordId(0,0) isn't valid for records.
    explicit HeapRecordStoreBtree(const StringData& ns) : RecordStore(ns), _nextId(1) {}

    virtual RecordData dataFor(OperationContext* txn, const RecordId& loc) const;

    virtual bool findRecord(OperationContext* txn, const RecordId& loc, RecordData* out) const;

    virtual void deleteRecord(OperationContext* txn, const RecordId& dl);

    virtual StatusWith<RecordId> insertRecord(OperationContext* txn,
                                              const char* data,
                                              int len,
                                              bool enforceQuota);

    virtual StatusWith<RecordId> insertRecord(OperationContext* txn,
                                              const DocWriter* doc,
                                              bool enforceQuota);

    virtual long long numRecords(OperationContext* txn) const {
        return _records.size();
    }

    virtual Status touch(OperationContext* txn, BSONObjBuilder* output) const;

    // public methods below here are not necessary to test btree, and will crash when called.

    // ------------------------------

    virtual StatusWith<RecordId> updateRecord(OperationContext* txn,
                                              const RecordId& oldLocation,
                                              const char* data,
                                              int len,
                                              bool enforceQuota,
                                              UpdateNotifier* notifier) {
        invariant(false);
    }

    virtual bool updateWithDamagesSupported() const {
        return true;
    }

    virtual Status updateWithDamages(OperationContext* txn,
                                     const RecordId& loc,
                                     const RecordData& oldRec,
                                     const char* damageSource,
                                     const mutablebson::DamageVector& damages) {
        invariant(false);
    }

    virtual RecordIterator* getIterator(OperationContext* txn,
                                        const RecordId& start,
                                        const CollectionScanParams::Direction& dir) const {
        invariant(false);
    }

    virtual RecordIterator* getIteratorForRepair(OperationContext* txn) const {
        invariant(false);
    }

    virtual std::vector<RecordIterator*> getManyIterators(OperationContext* txn) const {
        invariant(false);
    }

    virtual Status truncate(OperationContext* txn) {
        invariant(false);
    }

    virtual void temp_cappedTruncateAfter(OperationContext* txn, RecordId end, bool inclusive) {
        invariant(false);
    }

    virtual bool compactSupported() const {
        invariant(false);
    }

    virtual Status validate(OperationContext* txn,
                            bool full,
                            bool scanData,
                            ValidateAdaptor* adaptor,
                            ValidateResults* results,
                            BSONObjBuilder* output) {
        invariant(false);
    }

    virtual void appendCustomStats(OperationContext* txn,
                                   BSONObjBuilder* result,
                                   double scale) const {
        invariant(false);
    }

    virtual void increaseStorageSize(OperationContext* txn, int size, bool enforceQuota) {
        invariant(false);
    }

    virtual int64_t storageSize(OperationContext* txn,
                                BSONObjBuilder* extraInfo = NULL,
                                int infoLevel = 0) const {
        invariant(false);
    }

    virtual long long dataSize(OperationContext* txn) const {
        invariant(false);
    }

    virtual Record* recordFor(const RecordId& loc) const {
        invariant(false);
    }

    virtual bool isCapped() const {
        invariant(false);
    }

    virtual const char* name() const {
        invariant(false);
    }

    virtual void updateStatsAfterRepair(OperationContext* txn,
                                        long long numRecords,
                                        long long dataSize) {
        invariant(false);
    }
    // more things that we actually care about below

private:
    struct Record {
        Record() : dataSize(-1), data() {}
        explicit Record(int size) : dataSize(size), data(new char[size]) {}

        int dataSize;
        boost::shared_array<char> data;
    };

    RecordId allocateLoc();

    typedef std::map<RecordId, HeapRecordStoreBtree::Record> Records;
    Records _records;
    int64_t _nextId;
};

/**
 * A RecoveryUnit for HeapRecordStoreBtree, this is for testing btree only.
 */
class HeapRecordStoreBtreeRecoveryUnit : public RecoveryUnit {
public:
    HeapRecordStoreBtreeRecoveryUnit() {
        _depth = 0;
    }

    virtual ~HeapRecordStoreBtreeRecoveryUnit();

    virtual void beginUnitOfWork(OperationContext* opCtx);
    virtual void commitUnitOfWork();
    virtual void endUnitOfWork();

    virtual bool awaitCommit() {
        return true;
    }

    virtual void commitAndRestart() {}

    virtual void registerChange(Change* change) {
        change->commit();
        delete change;
    }

    virtual void* writingPtr(void* data, size_t len);

    virtual void setRollbackWritesDisabled() {}

    virtual SnapshotId getSnapshotId() const {
        return SnapshotId();
    }

    // -----------------------

    void notifyInsert(HeapRecordStoreBtree* rs, const RecordId& loc);
    static void notifyInsert(OperationContext* ctx, HeapRecordStoreBtree* rs, const RecordId& loc);

private:
    int _depth;
    struct InsertEntry {
        HeapRecordStoreBtree* rs;
        RecordId loc;
    };
    std::vector<InsertEntry> _insertions;

    struct ModEntry {
        void* data;
        size_t len;
        boost::shared_array<char> old;
    };
    std::vector<ModEntry> _mods;
};

}  // namespace mongo