/// <inheritdoc />
public IScorer CreateIndexScorer(IIndexSnapshot indexSnapshot)
{
if (indexSnapshot is null)
{
throw new ArgumentNullException(nameof(indexSnapshot));
}
return(new OkapiBm25Scorer(this.k1, this.b, indexSnapshot.Items));
}
public async Task WriteAsync(IIndexSnapshot <TKey> snapshot)
{
await this.WriteHeaderAsync(snapshot).ConfigureAwait(false);
await this.WriteItemsAsync(snapshot).ConfigureAwait(false);
await this.WriteNodeAsync(snapshot.Root).ConfigureAwait(false);
await this.WriteTerminatorAsync().ConfigureAwait(false);
}
public async Task SerializeAsync(IIndexSnapshot <TKey> snapshot, Stream stream, bool disposeStream = true)
{
if (snapshot is null)
{
throw new ArgumentNullException(nameof(snapshot));
}
using (var writer = new IndexWriter <TKey>(stream, disposeStream, this.keySerializer))
{
await writer.WriteAsync(snapshot).ConfigureAwait(false);
}
}
public IIndexNavigator Create(IIndexSnapshot indexSnapshot)
{
var node = indexSnapshot.Root;
if (!this.pool.TryTake(out var navigator))
{
navigator = new IndexNavigator();
}
navigator.Initialize(node, this, this.scorer.CreateIndexScorer(indexSnapshot));
return(navigator);
}
/// <inheritdoc />
public IEnumerable <SearchResult <TKey> > Execute <TKey>(IIndexSnapshot <TKey> index)
{
if (index is null)
{
throw new ArgumentNullException(nameof(index));
}
if (this.Root == EmptyQueryPart.Instance)
{
return(Enumerable.Empty <SearchResult <TKey> >());
}
var idLookup = index.Items;
var fieldLookup = index.FieldLookup;
var evaluationResult = this.Root.Evaluate(index.CreateNavigator, QueryContext.Empty);
var matches = evaluationResult.Matches;
var results = new Dictionary <int, List <ScoredFieldMatch> >();
foreach (var match in matches)
{
if (!results.TryGetValue(match.ItemId, out var itemResults))
{
itemResults = new List <ScoredFieldMatch>();
results[match.ItemId] = itemResults;
}
itemResults.AddRange(match.FieldMatches);
}
var searchResults = new List <SearchResult <TKey> >(matches.Count);
foreach (var itemResults in matches)
{
var item = idLookup.GetMetadata(itemResults.ItemId);
searchResults.Add(
new SearchResult <TKey>(
item.Item,
itemResults.FieldMatches.Select(m => new FieldSearchResult(
fieldLookup.GetFieldForId(m.FieldId),
m.Score,
m.FieldMatch.GetTokenLocations()))
.ToList()));
}
return(searchResults.OrderByDescending(r => r.Score));
}
public IEnumerable <SearchResult <TKey> > Execute <TKey>(IIndexSnapshot <TKey> index)
{
if (index is null)
{
throw new ArgumentNullException(nameof(index));
}
if (this.Root == EmptyQueryPart.Instance)
{
yield break;
}
var idLookup = index.IdLookup;
var fieldLookup = index.FieldLookup;
var matches = this.Root.Evaluate(index.CreateNavigator, QueryContext.Empty).Matches;
var results = new Dictionary <int, List <FieldMatch> >();
foreach (var match in matches)
{
if (!results.TryGetValue(match.ItemId, out var itemResults))
{
itemResults = new List <FieldMatch>();
results[match.ItemId] = itemResults;
}
itemResults.AddRange(match.FieldMatches);
}
foreach (var itemResults in matches)
{
var item = idLookup.GetItemForId(itemResults.ItemId);
yield return(new SearchResult <TKey>(
item,
itemResults.FieldMatches.Select(m => new FieldSearchResult(
fieldLookup.GetFieldForId(m.FieldId),
m.GetWordLocations()))
.ToList()));
}
}
