public static List <ResultItem> SearchFragments(Db db, /*Db db_post,*/ Db db_words, string query)
{
var results = new List <ResultItem>();
var interm = new List <IntermResult>();
int max_step = db.Table <PostFragment>().LastStep();
int step = 50;
Stopwatch sp = new Stopwatch();
sp.Start();
for (int i = 0; i <= max_step; i += step)
{
var res = db.Table <PostFragment>().Search(f => f.Text, query, i, step)
.Select(f => new { f.Id, f.Text, f.QuestionId })
.Select(f => new IntermResult {
Id = f.Id, Text = f.Text, QuestionId = f.QuestionId
});
interm.AddRange(res);
if (sp.ElapsedMilliseconds > 1000 || interm.GroupBy(f => f.QuestionId).Count() >= 1000)
{
break;
}
}
foreach (var inter in interm)
{
inter.Score += /*5000 +*/ GetFragmentScore(inter.Text, query);
}
//tfidf
var dic = new Dictionary <string, Dictionary <int, short> >();
foreach (var w in query.Split(" ".ToCharArray(), StringSplitOptions.RemoveEmptyEntries))
{
var d = db_words.Table <WordTfIdfData>().Where(f => f.Word == w).SelectEntity().FirstOrDefault();
if (d == null)
{
continue;
}
var data = Utils.TfIdfFromData(d.Data);
dic[w] = data.Item1;
}
foreach (var inter in interm)
{
foreach (var w in query.Split(" ".ToCharArray(), StringSplitOptions.RemoveEmptyEntries))
{
if (dic.ContainsKey(w) && dic[w].ContainsKey(inter.Id))
{
inter.Score += dic[w][inter.Id];
}
}
}
foreach (var r in interm.GroupBy(f => f.QuestionId).OrderByDescending(f => f.OrderByDescending(z => z.Score).First().Score).Take(5))
{
var q = r.OrderByDescending(z => z.Score).First();
var first_id = q.QuestionId;
var item = new ResultItem()
{
Fragment = q.Text,
Id = q.QuestionId,
Title = db.Table <WholePost>().Where(f => f.Id == first_id).Select(f => new { f.Title }).First().Title,
Score = q.Score
};
results.Add(item);
}
if (!results.Any())
{
//return SearchLogic.SearchPosts(db_post, db, query);
return(SearchLogic.SearchSubQueries(db, db_words, query));
}
else
{
return(results);
}
}
