Method initializeBucket

kdevplatform/serialization/itemrepository.h:2301–2357

    }

    inline MyBucket* initializeBucket(int bucketNumber) const
    {
        using namespace ItemRepositoryUtils;

        Q_ASSERT(bucketNumber);
#ifdef DEBUG_MONSTERBUCKETS
        // ensure that the previous N buckets are no monster buckets that overlap the requested bucket
        for (int offset = 1; offset < 5; ++offset) {
            int test = bucketNumber - offset;
            if (test >= 0 && m_buckets[test]) {
                Q_ASSERT(m_buckets[test]->monsterBucketExtent() < offset);
            }
        }

#endif

        auto& bucket = m_buckets[bucketNumber];
        if (!bucket) {
            bucket = new MyBucket();

            bool doMMapLoading = ( bool )m_fileMap;

            uint offset = ((bucketNumber - 1) * MyBucket::DataSize);
            if (m_file && offset < m_fileMapSize && doMMapLoading &&
                *reinterpret_cast<uint*>(m_fileMap + offset) == 0) {
//         qDebug() << "loading bucket mmap:" << bucketNumber;
                bucket->initializeFromMap(reinterpret_cast<char*>(m_fileMap + offset));
            } else if (m_file) {
                //Either memory-mapping is disabled, or the item is not in the existing memory-map,
                //so we have to load it the classical way.
                bool res = m_file->open(QFile::ReadOnly);

                if (offset + BucketStartOffset < m_file->size()) {
                    VERIFY(res);
                    offset += BucketStartOffset;
                    m_file->seek(offset);
                    int monsterBucketExtent;
                    readValue(m_file, &monsterBucketExtent);
                    m_file->seek(offset);
                    ///FIXME: use the data here instead of copying it again in prepareChange
                    QByteArray data = m_file->read((1 + monsterBucketExtent) * MyBucket::DataSize);
                    bucket->initializeFromMap(data.data());
                    bucket->prepareChange();
                } else {
                    bucket->initialize(0);
                }

                m_file->close();
            } else {
                bucket->initialize(0);
            }
        } else {
            bucket->initialize(0);
        }

        return bucket;
    }