1 files changed, 352 insertions, 0 deletions
diff --git a/modules/indexer/code/bleve/bleve.go b/modules/indexer/code/bleve/bleve.go
new file mode 100644
index 00000000..66724a34
--- /dev/null
+++ b/modules/indexer/code/bleve/bleve.go
@@ -0,0 +1,352 @@
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package bleve
+
+import (
+	"bufio"
+	"context"
+	"fmt"
+	"io"
+	"strconv"
+	"strings"
+	"time"
+
+	repo_model "code.gitea.io/gitea/models/repo"
+	"code.gitea.io/gitea/modules/analyze"
+	"code.gitea.io/gitea/modules/charset"
+	"code.gitea.io/gitea/modules/git"
+	"code.gitea.io/gitea/modules/indexer/code/internal"
+	indexer_internal "code.gitea.io/gitea/modules/indexer/internal"
+	inner_bleve "code.gitea.io/gitea/modules/indexer/internal/bleve"
+	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/timeutil"
+	"code.gitea.io/gitea/modules/typesniffer"
+
+	"github.com/blevesearch/bleve/v2"
+	analyzer_custom "github.com/blevesearch/bleve/v2/analysis/analyzer/custom"
+	analyzer_keyword "github.com/blevesearch/bleve/v2/analysis/analyzer/keyword"
+	"github.com/blevesearch/bleve/v2/analysis/token/camelcase"
+	"github.com/blevesearch/bleve/v2/analysis/token/lowercase"
+	"github.com/blevesearch/bleve/v2/analysis/token/unicodenorm"
+	"github.com/blevesearch/bleve/v2/analysis/tokenizer/unicode"
+	"github.com/blevesearch/bleve/v2/mapping"
+	"github.com/blevesearch/bleve/v2/search/query"
+	"github.com/go-enry/go-enry/v2"
+)
+
+const (
+	unicodeNormalizeName = "unicodeNormalize"
+	maxBatchSize         = 16
+	// fuzzyDenominator determines the levenshtein distance per each character of a keyword
+	fuzzyDenominator = 4
+	// see https://github.com/blevesearch/bleve/issues/1563#issuecomment-786822311
+	maxFuzziness = 2
+)
+
+func addUnicodeNormalizeTokenFilter(m *mapping.IndexMappingImpl) error {
+	return m.AddCustomTokenFilter(unicodeNormalizeName, map[string]any{
+		"type": unicodenorm.Name,
+		"form": unicodenorm.NFC,
+	})
+}
+
+// RepoIndexerData data stored in the repo indexer
+type RepoIndexerData struct {
+	RepoID    int64
+	CommitID  string
+	Content   string
+	Language  string
+	UpdatedAt time.Time
+}
+
+// Type returns the document type, for bleve's mapping.Classifier interface.
+func (d *RepoIndexerData) Type() string {
+	return repoIndexerDocType
+}
+
+const (
+	repoIndexerAnalyzer      = "repoIndexerAnalyzer"
+	repoIndexerDocType       = "repoIndexerDocType"
+	repoIndexerLatestVersion = 6
+)
+
+// generateBleveIndexMapping generates a bleve index mapping for the repo indexer
+func generateBleveIndexMapping() (mapping.IndexMapping, error) {
+	docMapping := bleve.NewDocumentMapping()
+	numericFieldMapping := bleve.NewNumericFieldMapping()
+	numericFieldMapping.IncludeInAll = false
+	docMapping.AddFieldMappingsAt("RepoID", numericFieldMapping)
+
+	textFieldMapping := bleve.NewTextFieldMapping()
+	textFieldMapping.IncludeInAll = false
+	docMapping.AddFieldMappingsAt("Content", textFieldMapping)
+
+	termFieldMapping := bleve.NewTextFieldMapping()
+	termFieldMapping.IncludeInAll = false
+	termFieldMapping.Analyzer = analyzer_keyword.Name
+	docMapping.AddFieldMappingsAt("Language", termFieldMapping)
+	docMapping.AddFieldMappingsAt("CommitID", termFieldMapping)
+
+	timeFieldMapping := bleve.NewDateTimeFieldMapping()
+	timeFieldMapping.IncludeInAll = false
+	docMapping.AddFieldMappingsAt("UpdatedAt", timeFieldMapping)
+
+	mapping := bleve.NewIndexMapping()
+	if err := addUnicodeNormalizeTokenFilter(mapping); err != nil {
+		return nil, err
+	} else if err := mapping.AddCustomAnalyzer(repoIndexerAnalyzer, map[string]any{
+		"type":          analyzer_custom.Name,
+		"char_filters":  []string{},
+		"tokenizer":     unicode.Name,
+		"token_filters": []string{unicodeNormalizeName, camelcase.Name, lowercase.Name},
+	}); err != nil {
+		return nil, err
+	}
+	mapping.DefaultAnalyzer = repoIndexerAnalyzer
+	mapping.AddDocumentMapping(repoIndexerDocType, docMapping)
+	mapping.AddDocumentMapping("_all", bleve.NewDocumentDisabledMapping())
+
+	return mapping, nil
+}
+
+var _ internal.Indexer = &Indexer{}
+
+// Indexer represents a bleve indexer implementation
+type Indexer struct {
+	inner                    *inner_bleve.Indexer
+	indexer_internal.Indexer // do not composite inner_bleve.Indexer directly to avoid exposing too much
+}
+
+// NewIndexer creates a new bleve local indexer
+func NewIndexer(indexDir string) *Indexer {
+	inner := inner_bleve.NewIndexer(indexDir, repoIndexerLatestVersion, generateBleveIndexMapping)
+	return &Indexer{
+		Indexer: inner,
+		inner:   inner,
+	}
+}
+
+func (b *Indexer) addUpdate(ctx context.Context, batchWriter git.WriteCloserError, batchReader *bufio.Reader, commitSha string,
+	update internal.FileUpdate, repo *repo_model.Repository, batch *inner_bleve.FlushingBatch,
+) error {
+	// Ignore vendored files in code search
+	if setting.Indexer.ExcludeVendored && analyze.IsVendor(update.Filename) {
+		return nil
+	}
+
+	size := update.Size
+
+	var err error
+	if !update.Sized {
+		var stdout string
+		stdout, _, err = git.NewCommand(ctx, "cat-file", "-s").AddDynamicArguments(update.BlobSha).RunStdString(&git.RunOpts{Dir: repo.RepoPath()})
+		if err != nil {
+			return err
+		}
+		if size, err = strconv.ParseInt(strings.TrimSpace(stdout), 10, 64); err != nil {
+			return fmt.Errorf("misformatted git cat-file output: %w", err)
+		}
+	}
+
+	if size > setting.Indexer.MaxIndexerFileSize {
+		return b.addDelete(update.Filename, repo, batch)
+	}
+
+	if _, err := batchWriter.Write([]byte(update.BlobSha + "\n")); err != nil {
+		return err
+	}
+
+	_, _, size, err = git.ReadBatchLine(batchReader)
+	if err != nil {
+		return err
+	}
+
+	fileContents, err := io.ReadAll(io.LimitReader(batchReader, size))
+	if err != nil {
+		return err
+	} else if !typesniffer.DetectContentType(fileContents).IsText() {
+		// FIXME: UTF-16 files will probably fail here
+		return nil
+	}
+
+	if _, err = batchReader.Discard(1); err != nil {
+		return err
+	}
+	id := internal.FilenameIndexerID(repo.ID, update.Filename)
+	return batch.Index(id, &RepoIndexerData{
+		RepoID:    repo.ID,
+		CommitID:  commitSha,
+		Content:   string(charset.ToUTF8DropErrors(fileContents, charset.ConvertOpts{})),
+		Language:  analyze.GetCodeLanguage(update.Filename, fileContents),
+		UpdatedAt: time.Now().UTC(),
+	})
+}
+
+func (b *Indexer) addDelete(filename string, repo *repo_model.Repository, batch *inner_bleve.FlushingBatch) error {
+	id := internal.FilenameIndexerID(repo.ID, filename)
+	return batch.Delete(id)
+}
+
+// Index indexes the data
+func (b *Indexer) Index(ctx context.Context, repo *repo_model.Repository, sha string, changes *internal.RepoChanges) error {
+	batch := inner_bleve.NewFlushingBatch(b.inner.Indexer, maxBatchSize)
+	if len(changes.Updates) > 0 {
+		// Now because of some insanity with git cat-file not immediately failing if not run in a valid git directory we need to run git rev-parse first!
+		if err := git.EnsureValidGitRepository(ctx, repo.RepoPath()); err != nil {
+			log.Error("Unable to open git repo: %s for %-v: %v", repo.RepoPath(), repo, err)
+			return err
+		}
+
+		batchWriter, batchReader, cancel := git.CatFileBatch(ctx, repo.RepoPath())
+		defer cancel()
+
+		for _, update := range changes.Updates {
+			if err := b.addUpdate(ctx, batchWriter, batchReader, sha, update, repo, batch); err != nil {
+				return err
+			}
+		}
+		cancel()
+	}
+	for _, filename := range changes.RemovedFilenames {
+		if err := b.addDelete(filename, repo, batch); err != nil {
+			return err
+		}
+	}
+	return batch.Flush()
+}
+
+// Delete deletes indexes by ids
+func (b *Indexer) Delete(_ context.Context, repoID int64) error {
+	query := inner_bleve.NumericEqualityQuery(repoID, "RepoID")
+	searchRequest := bleve.NewSearchRequestOptions(query, 2147483647, 0, false)
+	result, err := b.inner.Indexer.Search(searchRequest)
+	if err != nil {
+		return err
+	}
+	batch := inner_bleve.NewFlushingBatch(b.inner.Indexer, maxBatchSize)
+	for _, hit := range result.Hits {
+		if err = batch.Delete(hit.ID); err != nil {
+			return err
+		}
+	}
+	return batch.Flush()
+}
+
+// Search searches for files in the specified repo.
+// Returns the matching file-paths
+func (b *Indexer) Search(ctx context.Context, opts *internal.SearchOptions) (int64, []*internal.SearchResult, []*internal.SearchResultLanguages, error) {
+	var (
+		indexerQuery query.Query
+		keywordQuery query.Query
+	)
+
+	phraseQuery := bleve.NewMatchPhraseQuery(opts.Keyword)
+	phraseQuery.FieldVal = "Content"
+	phraseQuery.Analyzer = repoIndexerAnalyzer
+	keywordQuery = phraseQuery
+	if opts.IsKeywordFuzzy {
+		phraseQuery.Fuzziness = min(maxFuzziness, len(opts.Keyword)/fuzzyDenominator)
+	}
+
+	if len(opts.RepoIDs) > 0 {
+		repoQueries := make([]query.Query, 0, len(opts.RepoIDs))
+		for _, repoID := range opts.RepoIDs {
+			repoQueries = append(repoQueries, inner_bleve.NumericEqualityQuery(repoID, "RepoID"))
+		}
+
+		indexerQuery = bleve.NewConjunctionQuery(
+			bleve.NewDisjunctionQuery(repoQueries...),
+			keywordQuery,
+		)
+	} else {
+		indexerQuery = keywordQuery
+	}
+
+	// Save for reuse without language filter
+	facetQuery := indexerQuery
+	if len(opts.Language) > 0 {
+		languageQuery := bleve.NewMatchQuery(opts.Language)
+		languageQuery.FieldVal = "Language"
+		languageQuery.Analyzer = analyzer_keyword.Name
+
+		indexerQuery = bleve.NewConjunctionQuery(
+			indexerQuery,
+			languageQuery,
+		)
+	}
+
+	from, pageSize := opts.GetSkipTake()
+	searchRequest := bleve.NewSearchRequestOptions(indexerQuery, pageSize, from, false)
+	searchRequest.Fields = []string{"Content", "RepoID", "Language", "CommitID", "UpdatedAt"}
+	searchRequest.IncludeLocations = true
+
+	if len(opts.Language) == 0 {
+		searchRequest.AddFacet("languages", bleve.NewFacetRequest("Language", 10))
+	}
+
+	result, err := b.inner.Indexer.SearchInContext(ctx, searchRequest)
+	if err != nil {
+		return 0, nil, nil, err
+	}
+
+	total := int64(result.Total)
+
+	searchResults := make([]*internal.SearchResult, len(result.Hits))
+	for i, hit := range result.Hits {
+		startIndex, endIndex := -1, -1
+		for _, locations := range hit.Locations["Content"] {
+			location := locations[0]
+			locationStart := int(location.Start)
+			locationEnd := int(location.End)
+			if startIndex < 0 || locationStart < startIndex {
+				startIndex = locationStart
+			}
+			if endIndex < 0 || locationEnd > endIndex {
+				endIndex = locationEnd
+			}
+		}
+		language := hit.Fields["Language"].(string)
+		var updatedUnix timeutil.TimeStamp
+		if t, err := time.Parse(time.RFC3339, hit.Fields["UpdatedAt"].(string)); err == nil {
+			updatedUnix = timeutil.TimeStamp(t.Unix())
+		}
+		searchResults[i] = &internal.SearchResult{
+			RepoID:      int64(hit.Fields["RepoID"].(float64)),
+			StartIndex:  startIndex,
+			EndIndex:    endIndex,
+			Filename:    internal.FilenameOfIndexerID(hit.ID),
+			Content:     hit.Fields["Content"].(string),
+			CommitID:    hit.Fields["CommitID"].(string),
+			UpdatedUnix: updatedUnix,
+			Language:    language,
+			Color:       enry.GetColor(language),
+		}
+	}
+
+	searchResultLanguages := make([]*internal.SearchResultLanguages, 0, 10)
+	if len(opts.Language) > 0 {
+		// Use separate query to go get all language counts
+		facetRequest := bleve.NewSearchRequestOptions(facetQuery, 1, 0, false)
+		facetRequest.Fields = []string{"Content", "RepoID", "Language", "CommitID", "UpdatedAt"}
+		facetRequest.IncludeLocations = true
+		facetRequest.AddFacet("languages", bleve.NewFacetRequest("Language", 10))
+
+		if result, err = b.inner.Indexer.Search(facetRequest); err != nil {
+			return 0, nil, nil, err
+		}
+	}
+	languagesFacet := result.Facets["languages"]
+	for _, term := range languagesFacet.Terms.Terms() {
+		if len(term.Term) == 0 {
+			continue
+		}
+		searchResultLanguages = append(searchResultLanguages, &internal.SearchResultLanguages{
+			Language: term.Term,
+			Color:    enry.GetColor(term.Term),
+			Count:    term.Count,
+		})
+	}
+	return total, searchResults, searchResultLanguages, nil
+}