Refactor issue indexer (#5363)

modules/indexer/issues/bleve.go

@@ -0,0 +1,250 @@
+// Copyright 2018 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package issues
+
+import (
+	"fmt"
+	"os"
+	"strconv"
+
+	"github.com/blevesearch/bleve"
+	"github.com/blevesearch/bleve/analysis/analyzer/custom"
+	"github.com/blevesearch/bleve/analysis/token/lowercase"
+	"github.com/blevesearch/bleve/analysis/token/unicodenorm"
+	"github.com/blevesearch/bleve/analysis/tokenizer/unicode"
+	"github.com/blevesearch/bleve/index/upsidedown"
+	"github.com/blevesearch/bleve/mapping"
+	"github.com/blevesearch/bleve/search/query"
+	"github.com/ethantkoenig/rupture"
+)
+
+const (
+	issueIndexerAnalyzer      = "issueIndexer"
+	issueIndexerDocType       = "issueIndexerDocType"
+	issueIndexerLatestVersion = 1
+)
+
+// indexerID a bleve-compatible unique identifier for an integer id
+func indexerID(id int64) string {
+	return strconv.FormatInt(id, 36)
+}
+
+// idOfIndexerID the integer id associated with an indexer id
+func idOfIndexerID(indexerID string) (int64, error) {
+	id, err := strconv.ParseInt(indexerID, 36, 64)
+	if err != nil {
+		return 0, fmt.Errorf("Unexpected indexer ID %s: %v", indexerID, err)
+	}
+	return id, nil
+}
+
+// numericEqualityQuery a numeric equality query for the given value and field
+func numericEqualityQuery(value int64, field string) *query.NumericRangeQuery {
+	f := float64(value)
+	tru := true
+	q := bleve.NewNumericRangeInclusiveQuery(&f, &f, &tru, &tru)
+	q.SetField(field)
+	return q
+}
+
+func newMatchPhraseQuery(matchPhrase, field, analyzer string) *query.MatchPhraseQuery {
+	q := bleve.NewMatchPhraseQuery(matchPhrase)
+	q.FieldVal = field
+	q.Analyzer = analyzer
+	return q
+}
+
+const unicodeNormalizeName = "unicodeNormalize"
+
+func addUnicodeNormalizeTokenFilter(m *mapping.IndexMappingImpl) error {
+	return m.AddCustomTokenFilter(unicodeNormalizeName, map[string]interface{}{
+		"type": unicodenorm.Name,
+		"form": unicodenorm.NFC,
+	})
+}
+
+const maxBatchSize = 16
+
+// openIndexer open the index at the specified path, checking for metadata
+// updates and bleve version updates.  If index needs to be created (or
+// re-created), returns (nil, nil)
+func openIndexer(path string, latestVersion int) (bleve.Index, error) {
+	_, err := os.Stat(path)
+	if err != nil && os.IsNotExist(err) {
+		return nil, nil
+	} else if err != nil {
+		return nil, err
+	}
+
+	metadata, err := rupture.ReadIndexMetadata(path)
+	if err != nil {
+		return nil, err
+	}
+	if metadata.Version < latestVersion {
+		// the indexer is using a previous version, so we should delete it and
+		// re-populate
+		return nil, os.RemoveAll(path)
+	}
+
+	index, err := bleve.Open(path)
+	if err != nil && err == upsidedown.IncompatibleVersion {
+		// the indexer was built with a previous version of bleve, so we should
+		// delete it and re-populate
+		return nil, os.RemoveAll(path)
+	} else if err != nil {
+		return nil, err
+	}
+
+	return index, nil
+}
+
+// BleveIndexerData an update to the issue indexer
+type BleveIndexerData IndexerData
+
+// Type returns the document type, for bleve's mapping.Classifier interface.
+func (i *BleveIndexerData) Type() string {
+	return issueIndexerDocType
+}
+
+// createIssueIndexer create an issue indexer if one does not already exist
+func createIssueIndexer(path string, latestVersion int) (bleve.Index, error) {
+	mapping := bleve.NewIndexMapping()
+	docMapping := bleve.NewDocumentMapping()
+
+	numericFieldMapping := bleve.NewNumericFieldMapping()
+	numericFieldMapping.IncludeInAll = false
+	docMapping.AddFieldMappingsAt("RepoID", numericFieldMapping)
+
+	textFieldMapping := bleve.NewTextFieldMapping()
+	textFieldMapping.Store = false
+	textFieldMapping.IncludeInAll = false
+	docMapping.AddFieldMappingsAt("Title", textFieldMapping)
+	docMapping.AddFieldMappingsAt("Content", textFieldMapping)
+	docMapping.AddFieldMappingsAt("Comments", textFieldMapping)
+
+	if err := addUnicodeNormalizeTokenFilter(mapping); err != nil {
+		return nil, err
+	} else if err = mapping.AddCustomAnalyzer(issueIndexerAnalyzer, map[string]interface{}{
+		"type":          custom.Name,
+		"char_filters":  []string{},
+		"tokenizer":     unicode.Name,
+		"token_filters": []string{unicodeNormalizeName, lowercase.Name},
+	}); err != nil {
+		return nil, err
+	}
+
+	mapping.DefaultAnalyzer = issueIndexerAnalyzer
+	mapping.AddDocumentMapping(issueIndexerDocType, docMapping)
+	mapping.AddDocumentMapping("_all", bleve.NewDocumentDisabledMapping())
+
+	index, err := bleve.New(path, mapping)
+	if err != nil {
+		return nil, err
+	}
+
+	if err = rupture.WriteIndexMetadata(path, &rupture.IndexMetadata{
+		Version: latestVersion,
+	}); err != nil {
+		return nil, err
+	}
+	return index, nil
+}
+
+var (
+	_ Indexer = &BleveIndexer{}
+)
+
+// BleveIndexer implements Indexer interface
+type BleveIndexer struct {
+	indexDir string
+	indexer  bleve.Index
+}
+
+// NewBleveIndexer creates a new bleve local indexer
+func NewBleveIndexer(indexDir string) *BleveIndexer {
+	return &BleveIndexer{
+		indexDir: indexDir,
+	}
+}
+
+// Init will initial the indexer
+func (b *BleveIndexer) Init() (bool, error) {
+	var err error
+	b.indexer, err = openIndexer(b.indexDir, issueIndexerLatestVersion)
+	if err != nil {
+		return false, err
+	}
+	if b.indexer != nil {
+		return true, nil
+	}
+
+	b.indexer, err = createIssueIndexer(b.indexDir, issueIndexerLatestVersion)
+	return false, err
+}
+
+// Index will save the index data
+func (b *BleveIndexer) Index(issues []*IndexerData) error {
+	batch := rupture.NewFlushingBatch(b.indexer, maxBatchSize)
+	for _, issue := range issues {
+		if err := batch.Index(indexerID(issue.ID), struct {
+			RepoID   int64
+			Title    string
+			Content  string
+			Comments []string
+		}{
+			RepoID:   issue.RepoID,
+			Title:    issue.Title,
+			Content:  issue.Content,
+			Comments: issue.Comments,
+		}); err != nil {
+			return err
+		}
+	}
+	return batch.Flush()
+}
+
+// Delete deletes indexes by ids
+func (b *BleveIndexer) Delete(ids ...int64) error {
+	batch := rupture.NewFlushingBatch(b.indexer, maxBatchSize)
+	for _, id := range ids {
+		if err := batch.Delete(indexerID(id)); err != nil {
+			return err
+		}
+	}
+	return batch.Flush()
+}
+
+// Search searches for issues by given conditions.
+// Returns the matching issue IDs
+func (b *BleveIndexer) Search(keyword string, repoID int64, limit, start int) (*SearchResult, error) {
+	indexerQuery := bleve.NewConjunctionQuery(
+		numericEqualityQuery(repoID, "RepoID"),
+		bleve.NewDisjunctionQuery(
+			newMatchPhraseQuery(keyword, "Title", issueIndexerAnalyzer),
+			newMatchPhraseQuery(keyword, "Content", issueIndexerAnalyzer),
+			newMatchPhraseQuery(keyword, "Comments", issueIndexerAnalyzer),
+		))
+	search := bleve.NewSearchRequestOptions(indexerQuery, limit, start, false)
+
+	result, err := b.indexer.Search(search)
+	if err != nil {
+		return nil, err
+	}
+
+	var ret = SearchResult{
+		Hits: make([]Match, 0, len(result.Hits)),
+	}
+	for _, hit := range result.Hits {
+		id, err := idOfIndexerID(hit.ID)
+		if err != nil {
+			return nil, err
+		}
+		ret.Hits = append(ret.Hits, Match{
+			ID:     id,
+			RepoID: repoID,
+		})
+	}
+	return &ret, nil
+}