Fulltext implementation incl. config (#2480)

This adds the main component of the fulltext search.
This PR doesn't do anything yet, besides creating an empty fulltextindex
folder if enabled. Indexing events is done in a separate PR.

3 files changed, 479 insertions, 0 deletions

diff --git a/internal/fulltext/bleve.go b/internal/fulltext/bleve.go
new file mode 100644
index 00000000..b07c0e51
--- /dev/null
+++ b/internal/fulltext/bleve.go
@@ -0,0 +1,164 @@
+// Copyright 2022 The Matrix.org Foundation C.I.C.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build !wasm
+// +build !wasm
+
+package fulltext
+
+import (
+	"strings"
+
+	"github.com/blevesearch/bleve/v2"
+	"github.com/blevesearch/bleve/v2/mapping"
+	"github.com/matrix-org/dendrite/setup/config"
+	"github.com/matrix-org/gomatrixserverlib"
+)
+
+// Search contains all existing bleve.Index
+type Search struct {
+	FulltextIndex bleve.Index
+}
+
+// IndexElement describes the layout of an element to index
+type IndexElement struct {
+	EventID        string
+	RoomID         string
+	Content        string
+	ContentType    string
+	StreamPosition int64
+}
+
+// SetContentType sets i.ContentType given an identifier
+func (i *IndexElement) SetContentType(v string) {
+	switch v {
+	case "m.room.message":
+		i.ContentType = "content.body"
+	case gomatrixserverlib.MRoomName:
+		i.ContentType = "content.name"
+	case gomatrixserverlib.MRoomTopic:
+		i.ContentType = "content.topic"
+	}
+}
+
+// New opens a new/existing fulltext index
+func New(cfg config.Fulltext) (fts *Search, err error) {
+	fts = &Search{}
+	fts.FulltextIndex, err = openIndex(cfg)
+	if err != nil {
+		return nil, err
+	}
+	return fts, nil
+}
+
+// Close closes the fulltext index
+func (f *Search) Close() error {
+	return f.FulltextIndex.Close()
+}
+
+// Index indexes the given elements
+func (f *Search) Index(elements ...IndexElement) error {
+	batch := f.FulltextIndex.NewBatch()
+
+	for _, element := range elements {
+		err := batch.Index(element.EventID, element)
+		if err != nil {
+			return err
+		}
+	}
+	return f.FulltextIndex.Batch(batch)
+}
+
+// Delete deletes an indexed element by the eventID
+func (f *Search) Delete(eventID string) error {
+	return f.FulltextIndex.Delete(eventID)
+}
+
+// Search searches the index given a search term, roomIDs and keys.
+func (f *Search) Search(term string, roomIDs, keys []string, limit, from int, orderByStreamPos bool) (*bleve.SearchResult, error) {
+	qry := bleve.NewConjunctionQuery()
+	termQuery := bleve.NewBooleanQuery()
+
+	terms := strings.Split(term, " ")
+	for _, term := range terms {
+		matchQuery := bleve.NewMatchQuery(term)
+		matchQuery.SetField("Content")
+		termQuery.AddMust(matchQuery)
+	}
+	qry.AddQuery(termQuery)
+
+	roomQuery := bleve.NewBooleanQuery()
+	for _, roomID := range roomIDs {
+		roomSearch := bleve.NewMatchQuery(roomID)
+		roomSearch.SetField("RoomID")
+		roomQuery.AddShould(roomSearch)
+	}
+	if len(roomIDs) > 0 {
+		qry.AddQuery(roomQuery)
+	}
+	keyQuery := bleve.NewBooleanQuery()
+	for _, key := range keys {
+		keySearch := bleve.NewMatchQuery(key)
+		keySearch.SetField("ContentType")
+		keyQuery.AddShould(keySearch)
+	}
+	if len(keys) > 0 {
+		qry.AddQuery(keyQuery)
+	}
+
+	s := bleve.NewSearchRequestOptions(qry, limit, from, false)
+	s.Fields = []string{"*"}
+	s.SortBy([]string{"_score"})
+	if orderByStreamPos {
+		s.SortBy([]string{"-StreamPosition"})
+	}
+
+	return f.FulltextIndex.Search(s)
+}
+
+func openIndex(cfg config.Fulltext) (bleve.Index, error) {
+	m := getMapping(cfg)
+	if cfg.InMemory {
+		return bleve.NewMemOnly(m)
+	}
+	if index, err := bleve.Open(string(cfg.IndexPath)); err == nil {
+		return index, nil
+	}
+
+	index, err := bleve.New(string(cfg.IndexPath), m)
+	if err != nil {
+		return nil, err
+	}
+	return index, nil
+}
+
+func getMapping(cfg config.Fulltext) *mapping.IndexMappingImpl {
+	enFieldMapping := bleve.NewTextFieldMapping()
+	enFieldMapping.Analyzer = cfg.Language
+
+	eventMapping := bleve.NewDocumentMapping()
+	eventMapping.AddFieldMappingsAt("Content", enFieldMapping)
+	eventMapping.AddFieldMappingsAt("StreamPosition", bleve.NewNumericFieldMapping())
+
+	// Index entries as is
+	idFieldMapping := bleve.NewKeywordFieldMapping()
+	eventMapping.AddFieldMappingsAt("ContentType", idFieldMapping)
+	eventMapping.AddFieldMappingsAt("RoomID", idFieldMapping)
+	eventMapping.AddFieldMappingsAt("EventID", idFieldMapping)
+
+	indexMapping := bleve.NewIndexMapping()
+	indexMapping.AddDocumentMapping("Event", eventMapping)
+	indexMapping.DefaultType = "Event"
+	return indexMapping
+}
diff --git a/internal/fulltext/bleve_test.go b/internal/fulltext/bleve_test.go
new file mode 100644
index 00000000..84a28242
--- /dev/null
+++ b/internal/fulltext/bleve_test.go
@@ -0,0 +1,250 @@
+// Copyright 2022 The Matrix.org Foundation C.I.C.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package fulltext_test
+
+import (
+	"reflect"
+	"testing"
+
+	"github.com/matrix-org/gomatrixserverlib"
+	"github.com/matrix-org/util"
+
+	"github.com/matrix-org/dendrite/internal/fulltext"
+	"github.com/matrix-org/dendrite/setup/config"
+)
+
+func mustOpenIndex(t *testing.T, tempDir string) *fulltext.Search {
+	t.Helper()
+	cfg := config.Fulltext{}
+	cfg.Defaults(config.DefaultOpts{
+		Generate:   true,
+		Monolithic: true,
+	})
+	if tempDir != "" {
+		cfg.IndexPath = config.Path(tempDir)
+		cfg.InMemory = false
+	}
+	fts, err := fulltext.New(cfg)
+	if err != nil {
+		t.Fatal("failed to open fulltext index:", err)
+	}
+	return fts
+}
+
+func mustAddTestData(t *testing.T, fts *fulltext.Search, firstStreamPos int64) (eventIDs, roomIDs []string) {
+	t.Helper()
+	// create some more random data
+	var batchItems []fulltext.IndexElement
+	streamPos := firstStreamPos
+
+	wantRoomID := util.RandomString(16)
+
+	for i := 0; i < 30; i++ {
+		streamPos++
+		eventID := util.RandomString(16)
+		// Create more data for the first room
+		if i > 15 {
+			wantRoomID = util.RandomString(16)
+		}
+		e := fulltext.IndexElement{
+			EventID:        eventID,
+			RoomID:         wantRoomID,
+			Content:        "lorem ipsum",
+			StreamPosition: streamPos,
+		}
+		e.SetContentType("m.room.message")
+		batchItems = append(batchItems, e)
+		roomIDs = append(roomIDs, wantRoomID)
+		eventIDs = append(eventIDs, eventID)
+	}
+	e := fulltext.IndexElement{
+		EventID:        util.RandomString(16),
+		RoomID:         wantRoomID,
+		Content:        "Roomname testing",
+		StreamPosition: streamPos,
+	}
+	e.SetContentType(gomatrixserverlib.MRoomName)
+	batchItems = append(batchItems, e)
+	e = fulltext.IndexElement{
+		EventID:        util.RandomString(16),
+		RoomID:         wantRoomID,
+		Content:        "Room topic fulltext",
+		StreamPosition: streamPos,
+	}
+	e.SetContentType(gomatrixserverlib.MRoomTopic)
+	batchItems = append(batchItems, e)
+	if err := fts.Index(batchItems...); err != nil {
+		t.Fatalf("failed to batch insert elements: %v", err)
+	}
+	return eventIDs, roomIDs
+}
+
+func TestOpen(t *testing.T) {
+	dataDir := t.TempDir()
+	fts := mustOpenIndex(t, dataDir)
+	if err := fts.Close(); err != nil {
+		t.Fatal("unable to close fulltext index", err)
+	}
+
+	// open existing index
+	fts = mustOpenIndex(t, dataDir)
+	defer fts.Close()
+}
+
+func TestIndex(t *testing.T) {
+	fts := mustOpenIndex(t, "")
+	defer fts.Close()
+
+	// add some data
+	var streamPos int64 = 1
+	roomID := util.RandomString(8)
+	eventID := util.RandomString(16)
+	e := fulltext.IndexElement{
+		EventID:        eventID,
+		RoomID:         roomID,
+		Content:        "lorem ipsum",
+		StreamPosition: streamPos,
+	}
+	e.SetContentType("m.room.message")
+
+	if err := fts.Index(e); err != nil {
+		t.Fatal("failed to index element", err)
+	}
+
+	// create some more random data
+	mustAddTestData(t, fts, streamPos)
+}
+
+func TestDelete(t *testing.T) {
+	fts := mustOpenIndex(t, "")
+	defer fts.Close()
+	eventIDs, roomIDs := mustAddTestData(t, fts, 0)
+	res1, err := fts.Search("lorem", roomIDs[:1], nil, 50, 0, false)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if err = fts.Delete(eventIDs[0]); err != nil {
+		t.Fatal(err)
+	}
+
+	res2, err := fts.Search("lorem", roomIDs[:1], nil, 50, 0, false)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if res1.Total <= res2.Total {
+		t.Fatalf("got unexpected result: %d <= %d", res1.Total, res2.Total)
+	}
+}
+
+func TestSearch(t *testing.T) {
+	type args struct {
+		term             string
+		keys             []string
+		limit            int
+		from             int
+		orderByStreamPos bool
+		roomIndex        []int
+	}
+	tests := []struct {
+		name      string
+		args      args
+		wantCount int
+		wantErr   bool
+	}{
+		{
+			name:      "Can search for many results in one room",
+			wantCount: 16,
+			args: args{
+				term:      "lorem",
+				roomIndex: []int{0},
+				limit:     20,
+			},
+		},
+		{
+			name:      "Can search for one result in one room",
+			wantCount: 1,
+			args: args{
+				term:      "lorem",
+				roomIndex: []int{16},
+				limit:     20,
+			},
+		},
+		{
+			name:      "Can search for many results in multiple rooms",
+			wantCount: 17,
+			args: args{
+				term:      "lorem",
+				roomIndex: []int{0, 16},
+				limit:     20,
+			},
+		},
+		{
+			name:      "Can search for many results in all rooms, reversed",
+			wantCount: 30,
+			args: args{
+				term:             "lorem",
+				limit:            30,
+				orderByStreamPos: true,
+			},
+		},
+		{
+			name:      "Can search for specific search room name",
+			wantCount: 1,
+			args: args{
+				term:      "testing",
+				roomIndex: []int{},
+				limit:     20,
+				keys:      []string{"content.name"},
+			},
+		},
+		{
+			name:      "Can search for specific search room topic",
+			wantCount: 1,
+			args: args{
+				term:      "fulltext",
+				roomIndex: []int{},
+				limit:     20,
+				keys:      []string{"content.topic"},
+			},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			f := mustOpenIndex(t, "")
+			eventIDs, roomIDs := mustAddTestData(t, f, 0)
+			var searchRooms []string
+			for _, x := range tt.args.roomIndex {
+				searchRooms = append(searchRooms, roomIDs[x])
+			}
+			t.Logf("searching in rooms: %v - %v\n", searchRooms, tt.args.keys)
+
+			got, err := f.Search(tt.args.term, searchRooms, tt.args.keys, tt.args.limit, tt.args.from, tt.args.orderByStreamPos)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("Search() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+			if !reflect.DeepEqual(len(got.Hits), tt.wantCount) {
+				t.Errorf("Search() got = %v, want %v", len(got.Hits), tt.wantCount)
+			}
+			if tt.args.orderByStreamPos {
+				if got.Hits[0].ID != eventIDs[29] {
+					t.Fatalf("expected ID %s, got %s", eventIDs[29], got.Hits[0].ID)
+				}
+			}
+		})
+	}
+}
diff --git a/internal/fulltext/bleve_wasm.go b/internal/fulltext/bleve_wasm.go
new file mode 100644
index 00000000..a69a8926
--- /dev/null
+++ b/internal/fulltext/bleve_wasm.go
@@ -0,0 +1,65 @@
+// Copyright 2022 The Matrix.org Foundation C.I.C.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package fulltext
+
+import (
+	"github.com/matrix-org/dendrite/setup/config"
+	"time"
+)
+
+type Search struct{}
+type IndexElement struct {
+	EventID        string
+	RoomID         string
+	Content        string
+	ContentType    string
+	StreamPosition int64
+}
+
+type SearchResult struct {
+	Status   interface{}   `json:"status"`
+	Request  *interface{}  `json:"request"`
+	Hits     []interface{} `json:"hits"`
+	Total    uint64        `json:"total_hits"`
+	MaxScore float64       `json:"max_score"`
+	Took     time.Duration `json:"took"`
+	Facets   interface{}   `json:"facets"`
+}
+
+func (i *IndexElement) SetContentType(v string) {}
+
+func New(cfg config.Fulltext) (fts *Search, err error) {
+	return &Search{}, nil
+}
+
+func (f *Search) Close() error {
+	return nil
+}
+
+func (f *Search) Index(e IndexElement) error {
+	return nil
+}
+
+func (f *Search) BatchIndex(elements []IndexElement) error {
+	return nil
+}
+
+func (f *Search) Delete(eventID string) error {
+	return nil
+}
+
+func (f *Search) Search(term string, roomIDs, keys []string, limit, from int, orderByStreamPos bool) (SearchResult, error) {
+	return SearchResult{}, nil
+}