heap_record_store_btree.h

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// heap_record_store_btree.h

#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 {

class HeapRecordStoreBtree : public RecordStore {
    struct MmapV1RecordHeader;

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

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

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

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

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

    virtual Status insertRecordsWithDocWriter(OperationContext* opCtx,
                                              const DocWriter* const* docs,
                                              const Timestamp*,
                                              size_t nDocs,
                                              RecordId* idsOut);

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

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

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

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

    virtual Status updateRecord(OperationContext* opCtx,
                                const RecordId& oldLocation,
                                const char* data,
                                int len,
                                bool enforceQuota,
                                UpdateNotifier* notifier) {
        MONGO_UNREACHABLE;
    }

    virtual bool updateWithDamagesSupported() const {
        return true;
    }

    virtual StatusWith<RecordData> updateWithDamages(OperationContext* opCtx,
                                                     const RecordId& loc,
                                                     const RecordData& oldRec,
                                                     const char* damageSource,
                                                     const mutablebson::DamageVector& damages) {
        MONGO_UNREACHABLE;
    }

    std::unique_ptr<SeekableRecordCursor> getCursor(OperationContext* opCtx,
                                                    bool forward) const final {
        MONGO_UNREACHABLE;
    }


    virtual Status truncate(OperationContext* opCtx) {
        MONGO_UNREACHABLE;
    }

    virtual void cappedTruncateAfter(OperationContext* opCtx, RecordId end, bool inclusive) {
        MONGO_UNREACHABLE;
    }

    virtual bool compactSupported() const {
        MONGO_UNREACHABLE;
    }

    virtual Status validate(OperationContext* opCtx,
                            ValidateCmdLevel level,
                            ValidateAdaptor* adaptor,
                            ValidateResults* results,
                            BSONObjBuilder* output) {
        MONGO_UNREACHABLE;
    }

    virtual void appendCustomStats(OperationContext* opCtx,
                                   BSONObjBuilder* result,
                                   double scale) const {
        MONGO_UNREACHABLE;
    }

    virtual void increaseStorageSize(OperationContext* opCtx, int size, bool enforceQuota) {
        MONGO_UNREACHABLE;
    }

    virtual int64_t storageSize(OperationContext* opCtx,
                                BSONObjBuilder* extraInfo = NULL,
                                int infoLevel = 0) const {
        MONGO_UNREACHABLE;
    }

    virtual long long dataSize(OperationContext* opCtx) const {
        MONGO_UNREACHABLE;
    }

    virtual MmapV1RecordHeader* recordFor(const RecordId& loc) const {
        MONGO_UNREACHABLE;
    }

    virtual bool isCapped() const {
        MONGO_UNREACHABLE;
    }

    virtual const char* name() const {
        MONGO_UNREACHABLE;
    }

    void waitForAllEarlierOplogWritesToBeVisible(OperationContext* opCtx) const override {
        MONGO_UNREACHABLE;
    }

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

private:
    struct MmapV1RecordHeader {
        MmapV1RecordHeader() : dataSize(-1), data() {}
        explicit MmapV1RecordHeader(int size) : dataSize(size), data(new char[size]) {}

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

    RecordId allocateLoc();

    typedef std::map<RecordId, HeapRecordStoreBtree::MmapV1RecordHeader> Records;
    Records _records;
    int64_t _nextId;
};

class HeapRecordStoreBtreeRecoveryUnit : public RecoveryUnit {
public:
    void beginUnitOfWork(OperationContext* opCtx) final{};
    void commitUnitOfWork() final;
    void abortUnitOfWork() final;

    virtual bool waitUntilDurable() {
        return true;
    }

    virtual void abandonSnapshot() {}

    virtual void registerChange(Change* change) {
        change->commit(boost::none);
        delete change;
    }

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

    virtual void setRollbackWritesDisabled() {}

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

    virtual void setOrderedCommit(bool orderedCommit) {}

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

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

private:
    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