Hands-On Software Engineering with Golang

Searching the index

The clients of the in-memory indexer submit search queries by invoking the Search method. The implementation of this method is as follows:

func (i *InMemoryBleveIndexer) Search(q index.Query) (index.Iterator, error) {
    var bq query.Query
    switch q.Type {
    case index.QueryTypePhrase:
        bq = bleve.NewMatchPhraseQuery(q.Expression)
    default:
        bq = bleve.NewMatchQuery(q.Expression)
    }

    searchReq := bleve.NewSearchRequest(bq)
    searchReq.SortBy([]string{"-PageRank", "-_score"})
    searchReq.Size = batchSize
    searchReq.From = q.Offset
    rs, err := i.idx.Search(searchReq)
    if err != nil {
        return nil, xerrors.Errorf("search: %w", err)
    }
    return &bleveIterator{idx: i, searchReq: searchReq, rs: rs, cumIdx: q.Offset}, nil
}

The first thing that our ...