Add search engine support for files (#16190)

* Add search engine support for files

* Fixing i18n

* Fix golangci-lint

* Fix consistency problem in the Search receiver functio of the SqlFileStore

* Fixing some tests

* Fixing test

* Apply suggestions from code review

Co-authored-by: Mario de Frutos Dieguez <mario@defrutos.org>

* Addressing PR review comments

* Removing some empty lines

* Address PR review comments

* Fixing problem after merge master

* Fixing spelling problem

* Add missed translations

* Fixing certain global variable usages after merge master

* Fixing some constants usage

* Fixing goimports order

Co-authored-by: Mario de Frutos Dieguez <mario@defrutos.org>

store/opentracinglayer/opentracinglayer.go

@@ -2982,6 +2982,24 @@ func (s *OpenTracingLayerFileInfoStore) Get(id string) (*model.FileInfo, error)
 	return result, err
 }
 
+func (s *OpenTracingLayerFileInfoStore) GetByIds(ids []string) ([]*model.FileInfo, error) {
+	origCtx := s.Root.Store.Context()
+	span, newCtx := tracing.StartSpanWithParentByContext(s.Root.Store.Context(), "FileInfoStore.GetByIds")
+	s.Root.Store.SetContext(newCtx)
+	defer func() {
+		s.Root.Store.SetContext(origCtx)
+	}()
+
+	defer span.Finish()
+	result, err := s.FileInfoStore.GetByIds(ids)
+	if err != nil {
+		span.LogFields(spanlog.Error(err))
+		ext.Error.Set(span, true)
+	}
+
+	return result, err
+}
+
 func (s *OpenTracingLayerFileInfoStore) GetByPath(path string) (*model.FileInfo, error) {
 	origCtx := s.Root.Store.Context()
 	span, newCtx := tracing.StartSpanWithParentByContext(s.Root.Store.Context(), "FileInfoStore.GetByPath")
@@ -3139,6 +3157,24 @@ func (s *OpenTracingLayerFileInfoStore) Save(info *model.FileInfo) (*model.FileI
 	return result, err
 }
 
+func (s *OpenTracingLayerFileInfoStore) Search(paramsList []*model.SearchParams, userId string, teamId string, page int, perPage int) (*model.FileInfoList, error) {
+	origCtx := s.Root.Store.Context()
+	span, newCtx := tracing.StartSpanWithParentByContext(s.Root.Store.Context(), "FileInfoStore.Search")
+	s.Root.Store.SetContext(newCtx)
+	defer func() {
+		s.Root.Store.SetContext(origCtx)
+	}()
+
+	defer span.Finish()
+	result, err := s.FileInfoStore.Search(paramsList, userId, teamId, page, perPage)
+	if err != nil {
+		span.LogFields(spanlog.Error(err))
+		ext.Error.Set(span, true)
+	}
+
+	return result, err
+}
+
 func (s *OpenTracingLayerFileInfoStore) SetContent(fileId string, content string) error {
 	origCtx := s.Root.Store.Context()
 	span, newCtx := tracing.StartSpanWithParentByContext(s.Root.Store.Context(), "FileInfoStore.SetContent")

store/retrylayer/retrylayer.go

@@ -3190,6 +3190,26 @@ func (s *RetryLayerFileInfoStore) Get(id string) (*model.FileInfo, error) {
 
 }
 
+func (s *RetryLayerFileInfoStore) GetByIds(ids []string) ([]*model.FileInfo, error) {
+
+	tries := 0
+	for {
+		result, err := s.FileInfoStore.GetByIds(ids)
+		if err == nil {
+			return result, nil
+		}
+		if !isRepeatableError(err) {
+			return result, err
+		}
+		tries++
+		if tries >= 3 {
+			err = errors.Wrap(err, "giving up after 3 consecutive repeatable transaction failures")
+			return result, err
+		}
+	}
+
+}
+
 func (s *RetryLayerFileInfoStore) GetByPath(path string) (*model.FileInfo, error) {
 
 	tries := 0
@@ -3356,6 +3376,26 @@ func (s *RetryLayerFileInfoStore) Save(info *model.FileInfo) (*model.FileInfo, e
 
 }
 
+func (s *RetryLayerFileInfoStore) Search(paramsList []*model.SearchParams, userId string, teamId string, page int, perPage int) (*model.FileInfoList, error) {
+
+	tries := 0
+	for {
+		result, err := s.FileInfoStore.Search(paramsList, userId, teamId, page, perPage)
+		if err == nil {
+			return result, nil
+		}
+		if !isRepeatableError(err) {
+			return result, err
+		}
+		tries++
+		if tries >= 3 {
+			err = errors.Wrap(err, "giving up after 3 consecutive repeatable transaction failures")
+			return result, err
+		}
+	}
+
+}
+
 func (s *RetryLayerFileInfoStore) SetContent(fileId string, content string) error {
 
 	tries := 0

store/searchlayer/channel_layer.go

@@ -24,6 +24,7 @@ func (c *SearchChannelStore) deleteChannelIndex(channel *model.Channel) {
 				runIndexFn(engine, func(engineCopy searchengine.SearchEngineInterface) {
 					if err := engineCopy.DeleteChannel(channel); err != nil {
 						mlog.Warn("Encountered error deleting channel", mlog.String("channel_id", channel.Id), mlog.String("search_engine", engineCopy.GetName()), mlog.Err(err))
+						return
 					}
 					mlog.Debug("Removed channel from index in search engine", mlog.String("search_engine", engineCopy.GetName()), mlog.String("channel_id", channel.Id))
 				})
@@ -39,6 +40,7 @@ func (c *SearchChannelStore) indexChannel(channel *model.Channel) {
 				runIndexFn(engine, func(engineCopy searchengine.SearchEngineInterface) {
 					if err := engineCopy.IndexChannel(channel); err != nil {
 						mlog.Warn("Encountered error indexing channel", mlog.String("channel_id", channel.Id), mlog.String("search_engine", engineCopy.GetName()), mlog.Err(err))
+						return
 					}
 					mlog.Debug("Indexed channel in search engine", mlog.String("search_engine", engineCopy.GetName()), mlog.String("channel_id", channel.Id))
 				})

store/searchlayer/file_info_layer.go

@@ -0,0 +1,197 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package searchlayer
+
+import (
+	"github.com/mattermost/mattermost-server/v5/mlog"
+	"github.com/mattermost/mattermost-server/v5/model"
+	"github.com/mattermost/mattermost-server/v5/services/searchengine"
+	"github.com/mattermost/mattermost-server/v5/store"
+)
+
+type SearchFileInfoStore struct {
+	store.FileInfoStore
+	rootStore *SearchStore
+}
+
+func (s SearchFileInfoStore) indexFile(file *model.FileInfo) {
+	for _, engine := range s.rootStore.searchEngine.GetActiveEngines() {
+		if engine.IsIndexingEnabled() {
+			runIndexFn(engine, func(engineCopy searchengine.SearchEngineInterface) {
+				if file.PostId == "" {
+					return
+				}
+				post, postErr := s.rootStore.Post().GetSingle(file.PostId)
+				if postErr != nil {
+					mlog.Error("Couldn't get post for file for SearchEngine indexing.", mlog.String("post_id", file.PostId), mlog.String("search_engine", engineCopy.GetName()), mlog.String("file_info_id", file.Id), mlog.Err(postErr))
+					return
+				}
+
+				if err := engineCopy.IndexFile(file, post.ChannelId); err != nil {
+					mlog.Error("Encountered error indexing file", mlog.String("file_info_id", file.Id), mlog.String("search_engine", engineCopy.GetName()), mlog.Err(err))
+					return
+				}
+				mlog.Debug("Indexed file in search engine", mlog.String("search_engine", engineCopy.GetName()), mlog.String("file_info_id", file.Id))
+			})
+		}
+	}
+}
+
+func (s SearchFileInfoStore) deleteFileIndex(fileID string) {
+	for _, engine := range s.rootStore.searchEngine.GetActiveEngines() {
+		if engine.IsIndexingEnabled() {
+			runIndexFn(engine, func(engineCopy searchengine.SearchEngineInterface) {
+				if err := engineCopy.DeleteFile(fileID); err != nil {
+					mlog.Error("Encountered error deleting file", mlog.String("file_info_id", fileID), mlog.String("search_engine", engineCopy.GetName()), mlog.Err(err))
+					return
+				}
+				mlog.Debug("Removed file from the index in search engine", mlog.String("search_engine", engineCopy.GetName()), mlog.String("file_info_id", fileID))
+			})
+		}
+	}
+}
+
+func (s SearchFileInfoStore) deleteFileIndexForUser(userID string) {
+	for _, engine := range s.rootStore.searchEngine.GetActiveEngines() {
+		if engine.IsIndexingEnabled() {
+			runIndexFn(engine, func(engineCopy searchengine.SearchEngineInterface) {
+				if err := engineCopy.DeleteUserFiles(userID); err != nil {
+					mlog.Error("Encountered error deleting files for user", mlog.String("user_id", userID), mlog.String("search_engine", engineCopy.GetName()), mlog.Err(err))
+					return
+				}
+				mlog.Debug("Removed user's files from the index in search engine", mlog.String("search_engine", engineCopy.GetName()), mlog.String("user_id", userID))
+			})
+		}
+	}
+}
+
+func (s SearchFileInfoStore) deleteFileIndexForPost(postID string) {
+	for _, engine := range s.rootStore.searchEngine.GetActiveEngines() {
+		if engine.IsIndexingEnabled() {
+			runIndexFn(engine, func(engineCopy searchengine.SearchEngineInterface) {
+				if err := engineCopy.DeletePostFiles(postID); err != nil {
+					mlog.Error("Encountered error deleting files for post", mlog.String("post_id", postID), mlog.String("search_engine", engineCopy.GetName()), mlog.Err(err))
+					return
+				}
+				mlog.Debug("Removed post's files from the index in search engine", mlog.String("search_engine", engineCopy.GetName()), mlog.String("post_id", postID))
+			})
+		}
+	}
+}
+
+func (s SearchFileInfoStore) deleteFileIndexBatch(endTime, limit int64) {
+	for _, engine := range s.rootStore.searchEngine.GetActiveEngines() {
+		if engine.IsIndexingEnabled() {
+			runIndexFn(engine, func(engineCopy searchengine.SearchEngineInterface) {
+				if err := engineCopy.DeleteFilesBatch(endTime, limit); err != nil {
+					mlog.Error("Encountered error deleting a batch of files", mlog.Int64("limit", limit), mlog.Int64("end_time", endTime), mlog.String("search_engine", engineCopy.GetName()), mlog.Err(err))
+					return
+				}
+				mlog.Debug("Removed batch of files from the index in search engine", mlog.String("search_engine", engineCopy.GetName()), mlog.Int64("end_time", endTime), mlog.Int64("limit", limit))
+			})
+		}
+	}
+}
+
+func (s SearchFileInfoStore) Save(info *model.FileInfo) (*model.FileInfo, error) {
+	nfile, err := s.FileInfoStore.Save(info)
+	if err == nil {
+		s.indexFile(nfile)
+	}
+	return nfile, err
+}
+
+func (s SearchFileInfoStore) SetContent(fileID, content string) error {
+	err := s.FileInfoStore.SetContent(fileID, content)
+	if err == nil {
+		nfile, err2 := s.FileInfoStore.Get(fileID)
+		if err2 == nil {
+			nfile.Content = content
+			s.indexFile(nfile)
+		}
+	}
+	return err
+}
+
+func (s SearchFileInfoStore) AttachToPost(fileId, postId, creatorId string) error {
+	err := s.FileInfoStore.AttachToPost(fileId, postId, creatorId)
+	if err == nil {
+		nFileInfo, err2 := s.FileInfoStore.Get(fileId)
+		if err2 == nil {
+			s.indexFile(nFileInfo)
+		}
+	}
+	return err
+}
+
+func (s SearchFileInfoStore) DeleteForPost(postId string) (string, error) {
+	result, err := s.FileInfoStore.DeleteForPost(postId)
+	if err == nil {
+		s.deleteFileIndexForPost(postId)
+	}
+	return result, err
+}
+
+func (s SearchFileInfoStore) PermanentDelete(fileId string) error {
+	err := s.FileInfoStore.PermanentDelete(fileId)
+	if err == nil {
+		s.deleteFileIndex(fileId)
+	}
+	return err
+}
+
+func (s SearchFileInfoStore) PermanentDeleteBatch(endTime int64, limit int64) (int64, error) {
+	result, err := s.FileInfoStore.PermanentDeleteBatch(endTime, limit)
+	if err == nil {
+		s.deleteFileIndexBatch(endTime, limit)
+	}
+	return result, err
+}
+
+func (s SearchFileInfoStore) PermanentDeleteByUser(userId string) (int64, error) {
+	result, err := s.FileInfoStore.PermanentDeleteByUser(userId)
+	if err == nil {
+		s.deleteFileIndexForUser(userId)
+	}
+	return result, err
+}
+
+func (s SearchFileInfoStore) Search(paramsList []*model.SearchParams, userId, teamId string, page, perPage int) (*model.FileInfoList, error) {
+	for _, engine := range s.rootStore.searchEngine.GetActiveEngines() {
+		if engine.IsSearchEnabled() {
+			userChannels, nErr := s.rootStore.Channel().GetChannels(teamId, userId, paramsList[0].IncludeDeletedChannels, 0)
+			if nErr != nil {
+				return nil, nErr
+			}
+			fileIds, appErr := engine.SearchFiles(userChannels, paramsList, page, perPage)
+			if appErr != nil {
+				mlog.Error("Encountered error on Search.", mlog.String("search_engine", engine.GetName()), mlog.Err(appErr))
+				continue
+			}
+			mlog.Debug("Using the first available search engine", mlog.String("search_engine", engine.GetName()))
+
+			// Get the files
+			filesList := model.NewFileInfoList()
+			if len(fileIds) > 0 {
+				files, nErr := s.FileInfoStore.GetByIds(fileIds)
+				if nErr != nil {
+					return nil, nErr
+				}
+				for _, f := range files {
+					filesList.AddFileInfo(f)
+					filesList.AddOrder(f.Id)
+				}
+			}
+			return filesList, nil
+		}
+	}
+
+	if *s.rootStore.getConfig().SqlSettings.DisableDatabaseSearch {
+		mlog.Debug("Returning empty results for file Search as the database search is disabled")
+		return model.NewFileInfoList(), nil
+	}
+
+	mlog.Debug("Using database search because no other search engine is available")
+	return s.FileInfoStore.Search(paramsList, userId, teamId, page, perPage)
+}

store/searchlayer/layer.go

@@ -19,6 +19,7 @@ type SearchStore struct {
 	team         *SearchTeamStore
 	channel      *SearchChannelStore
 	post         *SearchPostStore
+	fileInfo     *SearchFileInfoStore
 	configValue  atomic.Value
 }
 
@@ -32,6 +33,7 @@ func NewSearchLayer(baseStore store.Store, searchEngine *searchengine.Broker, cf
 	searchStore.post = &SearchPostStore{PostStore: baseStore.Post(), rootStore: searchStore}
 	searchStore.team = &SearchTeamStore{TeamStore: baseStore.Team(), rootStore: searchStore}
 	searchStore.user = &SearchUserStore{UserStore: baseStore.User(), rootStore: searchStore}
+	searchStore.fileInfo = &SearchFileInfoStore{FileInfoStore: baseStore.FileInfo(), rootStore: searchStore}
 
 	return searchStore
 }
@@ -52,6 +54,10 @@ func (s *SearchStore) Post() store.PostStore {
 	return s.post
 }
 
+func (s *SearchStore) FileInfo() store.FileInfoStore {
+	return s.fileInfo
+}
+
 func (s *SearchStore) Team() store.TeamStore {
 	return s.team
 }

store/searchlayer/post_layer.go

@@ -28,6 +28,7 @@ func (s SearchPostStore) indexPost(post *model.Post) {
 				}
 				if err := engineCopy.IndexPost(post, channel.TeamId); err != nil {
 					mlog.Warn("Encountered error indexing post", mlog.String("post_id", post.Id), mlog.String("search_engine", engineCopy.GetName()), mlog.Err(err))
+					return
 				}
 				mlog.Debug("Indexed post in search engine", mlog.String("search_engine", engineCopy.GetName()), mlog.String("post_id", post.Id))
 			})
@@ -41,6 +42,7 @@ func (s SearchPostStore) deletePostIndex(post *model.Post) {
 			runIndexFn(engine, func(engineCopy searchengine.SearchEngineInterface) {
 				if err := engineCopy.DeletePost(post); err != nil {
 					mlog.Warn("Encountered error deleting post", mlog.String("post_id", post.Id), mlog.String("search_engine", engineCopy.GetName()), mlog.Err(err))
+					return
 				}
 				mlog.Debug("Removed post from the index in search engine", mlog.String("search_engine", engineCopy.GetName()), mlog.String("post_id", post.Id))
 			})
@@ -54,6 +56,7 @@ func (s SearchPostStore) deleteChannelPostsIndex(channelID string) {
 			runIndexFn(engine, func(engineCopy searchengine.SearchEngineInterface) {
 				if err := engineCopy.DeleteChannelPosts(channelID); err != nil {
 					mlog.Warn("Encountered error deleting channel posts", mlog.String("channel_id", channelID), mlog.String("search_engine", engineCopy.GetName()), mlog.Err(err))
+					return
 				}
 				mlog.Debug("Removed all channel posts from the index in search engine", mlog.String("channel_id", channelID), mlog.String("search_engine", engineCopy.GetName()))
 			})
@@ -67,6 +70,7 @@ func (s SearchPostStore) deleteUserPostsIndex(userID string) {
 			runIndexFn(engine, func(engineCopy searchengine.SearchEngineInterface) {
 				if err := engineCopy.DeleteUserPosts(userID); err != nil {
 					mlog.Warn("Encountered error deleting user posts", mlog.String("user_id", userID), mlog.String("search_engine", engineCopy.GetName()), mlog.Err(err))
+					return
 				}
 				mlog.Debug("Removed all user posts from the index in search engine", mlog.String("user_id", userID), mlog.String("search_engine", engineCopy.GetName()))
 			})

store/searchtest/helper.go

@@ -392,6 +392,36 @@ func (th *SearchTestHelper) createPost(userID, channelID, message, hashtags, pos
 	return post, nil
 }
 
+func (th *SearchTestHelper) createFileInfoModel(creatorID, postID, name, content, extension, mimeType string, createAt, size int64) *model.FileInfo {
+	return &model.FileInfo{
+		CreatorId: creatorID,
+		PostId:    postID,
+		CreateAt:  createAt,
+		UpdateAt:  createAt,
+		DeleteAt:  0,
+		Name:      name,
+		Content:   content,
+		Path:      name,
+		Extension: extension,
+		Size:      size,
+		MimeType:  mimeType,
+	}
+}
+
+func (th *SearchTestHelper) createFileInfo(creatorID, postID, name, content, extension, mimeType string, createAt, size int64) (*model.FileInfo, error) {
+	var creationTime int64 = 1000000
+	if createAt > 0 {
+		creationTime = createAt
+	}
+	fileInfoModel := th.createFileInfoModel(creatorID, postID, name, content, extension, mimeType, creationTime, size)
+	fileInfo, appError := th.Store.FileInfo().Save(fileInfoModel)
+	if appError != nil {
+		return nil, errors.New(appError.Error())
+	}
+
+	return fileInfo, nil
+}
+
 func (th *SearchTestHelper) createReply(userID, message, hashtags string, parent *model.Post, createAt int64, pinned bool) (*model.Post, error) {
 	replyModel := th.createPostModel(userID, parent.ChannelId, message, hashtags, parent.Type, createAt, pinned)
 	replyModel.ParentId = parent.Id
@@ -411,6 +441,13 @@ func (th *SearchTestHelper) deleteUserPosts(userID string) error {
 	return nil
 }
 
+func (th *SearchTestHelper) deleteUserFileInfos(userID string) error {
+	if _, err := th.Store.FileInfo().PermanentDeleteByUser(userID); err != nil {
+		return errors.New(err.Error())
+	}
+	return nil
+}
+
 func (th *SearchTestHelper) addUserToTeams(user *model.User, teamIDS []string) error {
 	for _, teamID := range teamIDS {
 		_, err := th.Store.Team().SaveMember(&model.TeamMember{TeamId: teamID, UserId: user.Id}, -1)
@@ -467,6 +504,15 @@ func (th *SearchTestHelper) checkPostInSearchResults(t *testing.T, postID string
 	assert.Contains(t, postIDS, postID, "Did not find expected post in search results.")
 }
 
+func (th *SearchTestHelper) checkFileInfoInSearchResults(t *testing.T, fileID string, searchResults map[string]*model.FileInfo) {
+	t.Helper()
+	fileIDS := make([]string, len(searchResults))
+	for ID := range searchResults {
+		fileIDS = append(fileIDS, ID)
+	}
+	assert.Contains(t, fileIDS, fileID, "Did not find expected file in search results.")
+}
+
 func (th *SearchTestHelper) checkChannelIdsMatch(t *testing.T, expected []string, results *model.ChannelList) {
 	t.Helper()
 	channelIds := make([]string, len(*results))

store/sqlstore/file_info_store.go

@@ -6,11 +6,15 @@ package sqlstore
 import (
 	"database/sql"
 	"fmt"
+	"regexp"
+	"strconv"
+	"strings"
 
 	sq "github.com/Masterminds/squirrel"
 	"github.com/pkg/errors"
 
 	"github.com/mattermost/mattermost-server/v5/einterfaces"
+	"github.com/mattermost/mattermost-server/v5/mlog"
 	"github.com/mattermost/mattermost-server/v5/model"
 	"github.com/mattermost/mattermost-server/v5/store"
 )
@@ -73,6 +77,9 @@ func (fs SqlFileInfoStore) createIndexesIfNotExists() {
 	fs.CreateIndexIfNotExists("idx_fileinfo_create_at", "FileInfo", "CreateAt")
 	fs.CreateIndexIfNotExists("idx_fileinfo_delete_at", "FileInfo", "DeleteAt")
 	fs.CreateIndexIfNotExists("idx_fileinfo_postid_at", "FileInfo", "PostId")
+	fs.CreateIndexIfNotExists("idx_fileinfo_extension_at", "FileInfo", "Extension")
+	fs.CreateFullTextIndexIfNotExists("idx_fileinfo_name_txt", "FileInfo", "Name")
+	fs.CreateFullTextIndexIfNotExists("idx_fileinfo_content_txt", "FileInfo", "Content")
 }
 
 func (fs SqlFileInfoStore) Save(info *model.FileInfo) (*model.FileInfo, error) {
@@ -87,6 +94,26 @@ func (fs SqlFileInfoStore) Save(info *model.FileInfo) (*model.FileInfo, error) {
 	return info, nil
 }
 
+func (fs SqlFileInfoStore) GetByIds(ids []string) ([]*model.FileInfo, error) {
+	query := fs.getQueryBuilder().
+		Select("*").
+		From("FileInfo").
+		Where(sq.Eq{"Id": ids}).
+		Where(sq.Eq{"DeleteAt": 0}).
+		OrderBy("CreateAt DESC")
+
+	queryString, args, err := query.ToSql()
+	if err != nil {
+		return nil, errors.Wrap(err, "file_info_tosql")
+	}
+
+	var infos []*model.FileInfo
+	if _, err := fs.GetReplica().Select(&infos, queryString, args...); err != nil {
+		return nil, errors.Wrap(err, "failed to find FileInfos")
+	}
+	return infos, nil
+}
+
 func (fs SqlFileInfoStore) Upsert(info *model.FileInfo) (*model.FileInfo, error) {
 	info.PreSave()
 	if err := info.IsValid(); err != nil {
@@ -393,3 +420,176 @@ func (fs SqlFileInfoStore) PermanentDeleteByUser(userId string) (int64, error) {
 
 	return rowsAffected, nil
 }
+
+func (fs SqlFileInfoStore) Search(paramsList []*model.SearchParams, userId, teamId string, page, perPage int) (*model.FileInfoList, error) {
+	// Since we don't support paging for DB search, we just return nothing for later pages
+	if page > 0 {
+		return model.NewFileInfoList(), nil
+	}
+	if err := model.IsSearchParamsListValid(paramsList); err != nil {
+		return nil, err
+	}
+	query := fs.getQueryBuilder().
+		Select("FI.*").
+		From("FileInfo AS FI").
+		LeftJoin("Posts as P ON FI.PostId=P.Id").
+		LeftJoin("Channels as C ON C.Id=P.ChannelId").
+		LeftJoin("ChannelMembers as CM ON C.Id=CM.ChannelId").
+		Where(sq.Or{sq.Eq{"C.TeamId": teamId}, sq.Eq{"C.TeamId": ""}}).
+		Where(sq.Eq{"FI.DeleteAt": 0}).
+		OrderBy("FI.CreateAt DESC").
+		Limit(100)
+
+	for _, params := range paramsList {
+		params.Terms = removeNonAlphaNumericUnquotedTerms(params.Terms, " ")
+
+		if !params.IncludeDeletedChannels {
+			query = query.Where(sq.Eq{"C.DeleteAt": 0})
+		}
+
+		if !params.SearchWithoutUserId {
+			query = query.Where(sq.Eq{"CM.UserId": userId})
+		}
+
+		if len(params.InChannels) != 0 {
+			query = query.Where(sq.Eq{"C.Id": params.InChannels})
+		}
+
+		if len(params.Extensions) != 0 {
+			query = query.Where(sq.Eq{"FI.Extension": params.Extensions})
+		}
+
+		if len(params.ExcludedExtensions) != 0 {
+			query = query.Where(sq.NotEq{"FI.Extension": params.ExcludedExtensions})
+		}
+
+		if len(params.ExcludedChannels) != 0 {
+			query = query.Where(sq.NotEq{"C.Id": params.ExcludedChannels})
+		}
+
+		if len(params.FromUsers) != 0 {
+			query = query.Where(sq.Eq{"FI.CreatorId": params.FromUsers})
+		}
+
+		if len(params.ExcludedUsers) != 0 {
+			query = query.Where(sq.NotEq{"FI.CreatorId": params.ExcludedUsers})
+		}
+
+		// handle after: before: on: filters
+		if len(params.OnDate) > 0 {
+			onDateStart, onDateEnd := params.GetOnDateMillis()
+			query = query.Where(sq.Expr("FI.CreateAt BETWEEN ? AND ?", strconv.FormatInt(onDateStart, 10), strconv.FormatInt(onDateEnd, 10)))
+		} else {
+			if len(params.ExcludedDate) > 0 {
+				excludedDateStart, excludedDateEnd := params.GetExcludedDateMillis()
+				query = query.Where(sq.Expr("FI.CreateAt NOT BETWEEN ? AND ?", strconv.FormatInt(excludedDateStart, 10), strconv.FormatInt(excludedDateEnd, 10)))
+			}
+
+			if len(params.AfterDate) > 0 {
+				afterDate := params.GetAfterDateMillis()
+				query = query.Where(sq.GtOrEq{"FI.CreateAt": strconv.FormatInt(afterDate, 10)})
+			}
+
+			if len(params.BeforeDate) > 0 {
+				beforeDate := params.GetBeforeDateMillis()
+				query = query.Where(sq.LtOrEq{"FI.CreateAt": strconv.FormatInt(beforeDate, 10)})
+			}
+
+			if len(params.ExcludedAfterDate) > 0 {
+				afterDate := params.GetExcludedAfterDateMillis()
+				query = query.Where(sq.Lt{"FI.CreateAt": strconv.FormatInt(afterDate, 10)})
+			}
+
+			if len(params.ExcludedBeforeDate) > 0 {
+				beforeDate := params.GetExcludedBeforeDateMillis()
+				query = query.Where(sq.Gt{"FI.CreateAt": strconv.FormatInt(beforeDate, 10)})
+			}
+		}
+
+		terms := params.Terms
+		excludedTerms := params.ExcludedTerms
+
+		// these chars have special meaning and can be treated as spaces
+		for _, c := range specialSearchChar {
+			terms = strings.Replace(terms, c, " ", -1)
+			excludedTerms = strings.Replace(excludedTerms, c, " ", -1)
+		}
+
+		if terms == "" && excludedTerms == "" {
+			// we've already confirmed that we have a channel or user to search for
+		} else if fs.DriverName() == model.DATABASE_DRIVER_POSTGRES {
+			// Parse text for wildcards
+			if wildcard, err := regexp.Compile(`\*($| )`); err == nil {
+				terms = wildcard.ReplaceAllLiteralString(terms, ":* ")
+				excludedTerms = wildcard.ReplaceAllLiteralString(excludedTerms, ":* ")
+			}
+
+			excludeClause := ""
+			if excludedTerms != "" {
+				excludeClause = " & !(" + strings.Join(strings.Fields(excludedTerms), " | ") + ")"
+			}
+
+			queryTerms := ""
+			if params.OrTerms {
+				queryTerms = "(" + strings.Join(strings.Fields(terms), " | ") + ")" + excludeClause
+			} else {
+				queryTerms = "(" + strings.Join(strings.Fields(terms), " & ") + ")" + excludeClause
+			}
+
+			query = query.Where(sq.Or{
+				sq.Expr("to_tsvector('english', FI.Name) @@  to_tsquery('english', ?)", queryTerms),
+				sq.Expr("to_tsvector('english', FI.Content) @@  to_tsquery('english', ?)", queryTerms),
+			})
+		} else if fs.DriverName() == model.DATABASE_DRIVER_MYSQL {
+			var err error
+			terms, err = removeMysqlStopWordsFromTerms(terms)
+			if err != nil {
+				return nil, errors.Wrap(err, "failed to remove Mysql stop-words from terms")
+			}
+
+			if terms == "" {
+				return model.NewFileInfoList(), nil
+			}
+
+			excludeClause := ""
+			if excludedTerms != "" {
+				excludeClause = " -(" + excludedTerms + ")"
+			}
+
+			queryTerms := ""
+			if params.OrTerms {
+				queryTerms = terms + excludeClause
+			} else {
+				splitTerms := []string{}
+				for _, t := range strings.Fields(terms) {
+					splitTerms = append(splitTerms, "+"+t)
+				}
+				queryTerms = strings.Join(splitTerms, " ") + excludeClause
+			}
+			query = query.Where(sq.Or{
+				sq.Expr("MATCH (FI.Name) AGAINST (? IN BOOLEAN MODE)", queryTerms),
+				sq.Expr("MATCH (FI.Content) AGAINST (? IN BOOLEAN MODE)", queryTerms),
+			})
+		}
+	}
+
+	queryString, args, err := query.ToSql()
+	if err != nil {
+		return nil, errors.Wrap(err, "file_info_tosql")
+	}
+
+	list := model.NewFileInfoList()
+	fileInfos := []*model.FileInfo{}
+	_, err = fs.GetSearchReplica().Select(&fileInfos, queryString, args...)
+	if err != nil {
+		mlog.Warn("Query error searching files.", mlog.Err(err))
+		// Don't return the error to the caller as it is of no use to the user. Instead return an empty set of search results.
+	} else {
+		for _, f := range fileInfos {
+			list.AddFileInfo(f)
+			list.AddOrder(f.Id)
+		}
+	}
+	list.MakeNonNil()
+	return list, nil
+}

store/sqlstore/file_info_store_test.go

@@ -6,9 +6,14 @@ package sqlstore
 import (
 	"testing"
 
+	"github.com/mattermost/mattermost-server/v5/store/searchtest"
 	"github.com/mattermost/mattermost-server/v5/store/storetest"
 )
 
 func TestFileInfoStore(t *testing.T) {
 	StoreTest(t, storetest.TestFileInfoStore)
 }
+
+func TestSearchFileInfoStore(t *testing.T) {
+	StoreTestWithSearchTestEngine(t, searchtest.TestSearchFileInfoStore)
+}

store/store.go

@@ -564,6 +564,7 @@ type FileInfoStore interface {
 	Save(info *model.FileInfo) (*model.FileInfo, error)
 	Upsert(info *model.FileInfo) (*model.FileInfo, error)
 	Get(id string) (*model.FileInfo, error)
+	GetByIds(ids []string) ([]*model.FileInfo, error)
 	GetByPath(path string) (*model.FileInfo, error)
 	GetForPost(postId string, readFromMaster, includeDeleted, allowFromCache bool) ([]*model.FileInfo, error)
 	GetForUser(userId string) ([]*model.FileInfo, error)
@@ -575,6 +576,7 @@ type FileInfoStore interface {
 	PermanentDeleteBatch(endTime int64, limit int64) (int64, error)
 	PermanentDeleteByUser(userId string) (int64, error)
 	SetContent(fileId, content string) error
+	Search(paramsList []*model.SearchParams, userId, teamId string, page, perPage int) (*model.FileInfoList, error)
 	ClearCaches()
 }
 

store/storetest/mocks/FileInfoStore.go

@@ -77,6 +77,29 @@ func (_m *FileInfoStore) Get(id string) (*model.FileInfo, error) {
 	return r0, r1
 }
 
+// GetByIds provides a mock function with given fields: ids
+func (_m *FileInfoStore) GetByIds(ids []string) ([]*model.FileInfo, error) {
+	ret := _m.Called(ids)
+
+	var r0 []*model.FileInfo
+	if rf, ok := ret.Get(0).(func([]string) []*model.FileInfo); ok {
+		r0 = rf(ids)
+	} else {
+		if ret.Get(0) != nil {
+			r0 = ret.Get(0).([]*model.FileInfo)
+		}
+	}
+
+	var r1 error
+	if rf, ok := ret.Get(1).(func([]string) error); ok {
+		r1 = rf(ids)
+	} else {
+		r1 = ret.Error(1)
+	}
+
+	return r0, r1
+}
+
 // GetByPath provides a mock function with given fields: path
 func (_m *FileInfoStore) GetByPath(path string) (*model.FileInfo, error) {
 	ret := _m.Called(path)
@@ -253,6 +276,29 @@ func (_m *FileInfoStore) Save(info *model.FileInfo) (*model.FileInfo, error) {
 	return r0, r1
 }
 
+// Search provides a mock function with given fields: paramsList, userId, teamId, page, perPage
+func (_m *FileInfoStore) Search(paramsList []*model.SearchParams, userId string, teamId string, page int, perPage int) (*model.FileInfoList, error) {
+	ret := _m.Called(paramsList, userId, teamId, page, perPage)
+
+	var r0 *model.FileInfoList
+	if rf, ok := ret.Get(0).(func([]*model.SearchParams, string, string, int, int) *model.FileInfoList); ok {
+		r0 = rf(paramsList, userId, teamId, page, perPage)
+	} else {
+		if ret.Get(0) != nil {
+			r0 = ret.Get(0).(*model.FileInfoList)
+		}
+	}
+
+	var r1 error
+	if rf, ok := ret.Get(1).(func([]*model.SearchParams, string, string, int, int) error); ok {
+		r1 = rf(paramsList, userId, teamId, page, perPage)
+	} else {
+		r1 = ret.Error(1)
+	}
+
+	return r0, r1
+}
+
 // SetContent provides a mock function with given fields: fileId, content
 func (_m *FileInfoStore) SetContent(fileId string, content string) error {
 	ret := _m.Called(fileId, content)

store/timerlayer/timerlayer.go

@@ -2734,6 +2734,22 @@ func (s *TimerLayerFileInfoStore) Get(id string) (*model.FileInfo, error) {
 	return result, err
 }
 
+func (s *TimerLayerFileInfoStore) GetByIds(ids []string) ([]*model.FileInfo, error) {
+	start := timemodule.Now()
+
+	result, err := s.FileInfoStore.GetByIds(ids)
+
+	elapsed := float64(timemodule.Since(start)) / float64(timemodule.Second)
+	if s.Root.Metrics != nil {
+		success := "false"
+		if err == nil {
+			success = "true"
+		}
+		s.Root.Metrics.ObserveStoreMethodDuration("FileInfoStore.GetByIds", success, elapsed)
+	}
+	return result, err
+}
+
 func (s *TimerLayerFileInfoStore) GetByPath(path string) (*model.FileInfo, error) {
 	start := timemodule.Now()
 
@@ -2877,6 +2893,22 @@ func (s *TimerLayerFileInfoStore) Save(info *model.FileInfo) (*model.FileInfo, e
 	return result, err
 }
 
+func (s *TimerLayerFileInfoStore) Search(paramsList []*model.SearchParams, userId string, teamId string, page int, perPage int) (*model.FileInfoList, error) {
+	start := timemodule.Now()
+
+	result, err := s.FileInfoStore.Search(paramsList, userId, teamId, page, perPage)
+
+	elapsed := float64(timemodule.Since(start)) / float64(timemodule.Second)
+	if s.Root.Metrics != nil {
+		success := "false"
+		if err == nil {
+			success = "true"
+		}
+		s.Root.Metrics.ObserveStoreMethodDuration("FileInfoStore.Search", success, elapsed)
+	}
+	return result, err
+}
+
 func (s *TimerLayerFileInfoStore) SetContent(fileId string, content string) error {
 	start := timemodule.Now()