C++ DamageVector::begin方法代码示例

    StatusWith<RecordData> KVRecordStore::updateWithDamages( OperationContext* txn,
                                                             const RecordId& id,
                                                             const RecordData& oldRec,
                                                             const char* damageSource,
                                                             const mutablebson::DamageVector& damages ) {
        const KeyString key(id);

        const Slice oldValue(oldRec.data(), oldRec.size());
        const KVUpdateWithDamagesMessage message(damageSource, damages);

        // updateWithDamages can't change the number or size of records, so we don't need to update
        // stats.

        const Status s = _db->update(txn, Slice::of(key), oldValue, message);
        if (!s.isOK()) {
            return StatusWith<RecordData>(s);
        }

        // We also need to reach in and screw with the old doc's data so that the update system gets
        // the new image, because the update system is assuming mmapv1's behavior.  Sigh.
        for (mutablebson::DamageVector::const_iterator it = damages.begin(); it != damages.end(); it++) {
            const mutablebson::DamageEvent &event = *it;
            invariant(event.targetOffset + event.size < static_cast<uint32_t>(oldRec.size()));
            std::copy(damageSource + event.sourceOffset, damageSource + event.sourceOffset + event.size,
                      /* eek */
                      const_cast<char *>(oldRec.data()) + event.targetOffset);
        }

        return StatusWith<RecordData>(oldRec);
    }

    Status HeapRecordStore::updateWithDamages( OperationContext* txn,
                                               const DiskLoc& loc,
                                               const RecordData& oldRec,
                                               const char* damageSource,
                                               const mutablebson::DamageVector& damages ) {
        HeapRecord* oldRecord = recordFor( loc );
        const int len = oldRecord->size;

        HeapRecord newRecord(len);
        memcpy(newRecord.data.get(), oldRecord->data.get(), len);

        txn->recoveryUnit()->registerChange(new RemoveChange(_data, loc, *oldRecord));
        *oldRecord = newRecord;

        cappedDeleteAsNeeded(txn);

        char* root = newRecord.data.get();
        mutablebson::DamageVector::const_iterator where = damages.begin();
        const mutablebson::DamageVector::const_iterator end = damages.end();
        for( ; where != end; ++where ) {
            const char* sourcePtr = damageSource + where->sourceOffset;
            char* targetPtr = root + where->targetOffset;
            std::memcpy(targetPtr, sourcePtr, where->size);
        }

        *oldRecord = newRecord;

        return Status::OK();
    }

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

    stdx::lock_guard<stdx::recursive_mutex> lock(_data->recordsMutex);

    EphemeralForTestRecord* oldRecord = recordFor(loc);
    const int len = oldRecord->size;

    EphemeralForTestRecord newRecord(len);
    memcpy(newRecord.data.get(), oldRecord->data.get(), len);

    opCtx->recoveryUnit()->registerChange(new RemoveChange(opCtx, _data, loc, *oldRecord));
    *oldRecord = newRecord;

    cappedDeleteAsNeeded_inlock(opCtx);

    char* root = newRecord.data.get();
    mutablebson::DamageVector::const_iterator where = damages.begin();
    const mutablebson::DamageVector::const_iterator end = damages.end();
    for (; where != end; ++where) {
        const char* sourcePtr = damageSource + where->sourceOffset;
        char* targetPtr = root + where->targetOffset;
        std::memcpy(targetPtr, sourcePtr, where->size);
    }

    *oldRecord = newRecord;

    return newRecord.toRecordData();
}

    Status HeapRecordStore::updateWithDamages( OperationContext* txn,
                                               const DiskLoc& loc,
                                               const char* damangeSource,
                                               const mutablebson::DamageVector& damages ) {
        HeapRecord* rec = recordFor( loc );
        char* root = rec->data();

        // All updates were in place. Apply them via durability and writing pointer.
        mutablebson::DamageVector::const_iterator where = damages.begin();
        const mutablebson::DamageVector::const_iterator end = damages.end();
        for( ; where != end; ++where ) {
            const char* sourcePtr = damangeSource + where->sourceOffset;
            char* targetPtr = root + where->targetOffset;
            std::memcpy(targetPtr, sourcePtr, where->size);
        }

        return Status::OK();
    }

StatusWith<RecordData> RecordStoreV1Base::updateWithDamages(
    OperationContext* txn,
    const RecordId& loc,
    const RecordData& oldRec,
    const char* damageSource,
    const mutablebson::DamageVector& damages) {
    MmapV1RecordHeader* rec = recordFor(DiskLoc::fromRecordId(loc));
    char* root = rec->data();

    // All updates were in place. Apply them via durability and writing pointer.
    mutablebson::DamageVector::const_iterator where = damages.begin();
    const mutablebson::DamageVector::const_iterator end = damages.end();
    for (; where != end; ++where) {
        const char* sourcePtr = damageSource + where->sourceOffset;
        void* targetPtr = txn->recoveryUnit()->writingPtr(root + where->targetOffset, where->size);
        std::memcpy(targetPtr, sourcePtr, where->size);
    }

    return rec->toRecordData();
}