/// <summary>
/// 附加索引数据
/// </summary>
/// <param name="items">数据列表</param>
/// <param name="columns">需要出列的列</param>
/// <returns></returns>
public async Task AppendIndex(List <dynamic> items, List <Column> columns)
{
List <IndexWord> wordList = new List <IndexWord>();
foreach (var item in items)
{
List <PropertyInfo> fileds = new List <PropertyInfo>();
foreach (var property in (IDictionary <String, Object>)item)
{
var columun = columns.SingleOrDefault(c => c.Name.ToLower() == property.Key.ToLower());
if (columun != null)
{
fileds.Add(new PropertyInfo()
{
Name = columun.Name, Rank = columun.Rank, Value = property.Value.ToString(), Save = columun.Save
});
}
}
var docId = await DocOp.save(fileds);
var words = Tokenizer.GetWords(fileds);
var indexList = Extraction(words, docId);
wordList.AddRange(indexList);
}
;
await AppendIndex(wordList);
}
public async Task <Page <string> > Select(string query, int page, int size)
{
var words = Tokenizer.GetWords(query).Where(w => w.Word.Length > 1).ToList();
int skip = (page - 1) * size;
List <Task <IndexList> > lists = new List <Task <IndexList> >();
foreach (var word in words)
{
lists.Add(IndexOp.GetOrAddIndexList(word));
}
var indexs = await Task.WhenAll(lists);
List <QIndexAtom> atomList = new List <QIndexAtom>(); //查询结果
List <Result> mResults = new List <Result>(); //未排序计算完成结果
if (indexs.Count() > 0)
{
for (int i = 0; i < indexs.Count(); i++)
{
var currentWord = words[i];
foreach (var atom in indexs[i].IndexAtoms)
{
var qAtom = new QIndexAtom();
qAtom.Word = currentWord;
qAtom.DocId = atom.Key;
qAtom.Atom = atom.Value;
atomList.Add(qAtom);
}
}
}
var groups = atomList.GroupBy(a => a.DocId);
foreach (var group in groups)
{
Result r = new Result();
r.DocId = group.Key;
if (group.Count() == 1)
{
var first = group.First();
r.Position = first.Atom.Position;
r.Rank = first.Atom.Rank;
r.Rank += GetFrequencyRank(first.Atom.Frequency);
r.Rank += first.Word.Rank;//把查询权重加到原权重上干扰结果排序
}
else
{
float max = 0, rangeRank = 0;
var list = group.ToList();
for (int i = 0; i < list.Count(); i++)
{
var idata = list[i];
if (idata.Word.Rank > max)
{
max = idata.Word.Rank;
}
r.Rank += GetFrequencyRank(idata.Atom.Frequency);
if (idata.Atom.Position < r.Position)
{
r.Position = idata.Atom.Position;
}
for (int j = i + 1; j < list.Count(); j++)
{
var jdata = list[j];
var wordRange = jdata.Word.Position - idata.Word.Position - idata.Word.Word.Length;
var docRange = jdata.Atom.Position - idata.Atom.Position - idata.Word.Word.Length;
float rank = 3;
if (wordRange != docRange)
{
rank = rank + (wordRange - docRange) / 10.0f;
if (rank < 0.3f)
{
rank = 0.3f;
}
if (rank > 3.3f)
{
rank = 3.3f;
}
}
rangeRank += rank;
}
}
r.Rank += max;//把查询权重加到原权重上干扰结果排序
r.Rank += rangeRank;
}
mResults.Add(r);
}
Page <string> result = new Page <string>();
result.CurrentPage = page;
result.Items = mResults.OrderByDescending(d => d.Rank).OrderBy(d => d.Position).Skip(skip).Take(size).Select(d => d.DocId).ToList();
result.TotalItems = mResults.Count();
result.PageSize = size;
return(result);
}
