Modify QuerySharedUsers to handle counts/include/exclude (#1219)

* Modify QuerySharedUsers to handle counts/include/exclude

We will need this functionality when working out whether to
send device list changes to users who have joined/left a room.

* Linting

currentstateserver/api/api.go

@@ -37,10 +37,12 @@ type CurrentStateInternalAPI interface {
 
 type QuerySharedUsersRequest struct {
 	UserID         string
+	ExcludeRoomIDs []string
+	IncludeRoomIDs []string
 }
 
 type QuerySharedUsersResponse struct {
-	UserIDs []string
+	UserIDsToCount map[string]int
 }
 
 type QueryRoomsForUserRequest struct {

currentstateserver/currentstateserver_test.go

@@ -20,7 +20,6 @@ import (
 	"encoding/json"
 	"net/http"
 	"reflect"
-	"sort"
 	"testing"
 	"time"
 
@@ -227,13 +226,31 @@ func TestQuerySharedUsers(t *testing.T) {
 		req     api.QuerySharedUsersRequest
 		wantRes api.QuerySharedUsersResponse
 	}{
-		// Simple case: sharing (A,B) (A,C) (A,B) (A) produces (A,B,C)
+		// Simple case: sharing (A,B) (A,C) (A,B) (A) produces (A:4,B:2,C:1)
 		{
 			req: api.QuerySharedUsersRequest{
 				UserID: "@alice:localhost",
 			},
 			wantRes: api.QuerySharedUsersResponse{
-				UserIDs: []string{"@alice:localhost", "@bob:localhost", "@charlie:localhost"},
+				UserIDsToCount: map[string]int{
+					"@alice:localhost":   4,
+					"@bob:localhost":     2,
+					"@charlie:localhost": 1,
+				},
+			},
+		},
+
+		// Exclude (A,C): sharing (A,B) (A,B) (A) produces (A:3,B:2)
+		{
+			req: api.QuerySharedUsersRequest{
+				UserID:         "@alice:localhost",
+				ExcludeRoomIDs: []string{"!foo2:bar"},
+			},
+			wantRes: api.QuerySharedUsersResponse{
+				UserIDsToCount: map[string]int{
+					"@alice:localhost": 3,
+					"@bob:localhost":   2,
+				},
 			},
 		},
 
@@ -243,7 +260,7 @@ func TestQuerySharedUsers(t *testing.T) {
 				UserID: "@unknownuser:localhost",
 			},
 			wantRes: api.QuerySharedUsersResponse{
-				UserIDs: nil,
+				UserIDsToCount: map[string]int{},
 			},
 		},
 
@@ -253,7 +270,35 @@ func TestQuerySharedUsers(t *testing.T) {
 				UserID: "@dave:localhost",
 			},
 			wantRes: api.QuerySharedUsersResponse{
-				UserIDs: nil,
+				UserIDsToCount: map[string]int{},
+			},
+		},
+
+		// left real user but with included room returns the included room member
+		{
+			req: api.QuerySharedUsersRequest{
+				UserID:         "@dave:localhost",
+				IncludeRoomIDs: []string{"!foo:bar"},
+			},
+			wantRes: api.QuerySharedUsersResponse{
+				UserIDsToCount: map[string]int{
+					"@alice:localhost": 1,
+					"@bob:localhost":   1,
+				},
+			},
+		},
+
+		// including a room more than once doesn't double counts
+		{
+			req: api.QuerySharedUsersRequest{
+				UserID:         "@dave:localhost",
+				IncludeRoomIDs: []string{"!foo:bar", "!foo:bar", "!foo:bar"},
+			},
+			wantRes: api.QuerySharedUsersResponse{
+				UserIDsToCount: map[string]int{
+					"@alice:localhost": 1,
+					"@bob:localhost":   1,
+				},
 			},
 		},
 	}
@@ -266,10 +311,8 @@ func TestQuerySharedUsers(t *testing.T) {
 				t.Errorf("QuerySharedUsers returned error: %s", err)
 				continue
 			}
-			sort.Strings(res.UserIDs)
+			if !reflect.DeepEqual(res.UserIDsToCount, tc.wantRes.UserIDsToCount) {
-			sort.Strings(tc.wantRes.UserIDs)
+				t.Errorf("QuerySharedUsers got users %+v want %+v", res.UserIDsToCount, tc.wantRes.UserIDsToCount)
-			if !reflect.DeepEqual(res.UserIDs, tc.wantRes.UserIDs) {
-				t.Errorf("QuerySharedUsers got users %+v want %+v", res.UserIDs, tc.wantRes.UserIDs)
 			}
 		}
 	}

currentstateserver/internal/api.go

@@ -74,10 +74,27 @@ func (a *CurrentStateInternalAPI) QuerySharedUsers(ctx context.Context, req *api
 	if err != nil {
 		return err
 	}
+	roomIDs = append(roomIDs, req.IncludeRoomIDs...)
+	excludeMap := make(map[string]bool)
+	for _, roomID := range req.ExcludeRoomIDs {
+		excludeMap[roomID] = true
+	}
+	// filter out excluded rooms
+	j := 0
+	for i := range roomIDs {
+		// move elements to include to the beginning of the slice
+		// then trim elements on the right
+		if !excludeMap[roomIDs[i]] {
+			roomIDs[j] = roomIDs[i]
+			j++
+		}
+	}
+	roomIDs = roomIDs[:j]
+
 	users, err := a.DB.JoinedUsersSetInRooms(ctx, roomIDs)
 	if err != nil {
 		return err
 	}
-	res.UserIDs = users
+	res.UserIDsToCount = users
 	return nil
 }

currentstateserver/storage/interface.go

@@ -37,6 +37,6 @@ type Database interface {
 	GetBulkStateContent(ctx context.Context, roomIDs []string, tuples []gomatrixserverlib.StateKeyTuple, allowWildcards bool) ([]tables.StrippedEvent, error)
 	// Redact a state event
 	RedactEvent(ctx context.Context, redactedEventID string, redactedBecause gomatrixserverlib.HeaderedEvent) error
-	// JoinedUsersSetInRooms returns all joined users in the rooms given.
+	// JoinedUsersSetInRooms returns all joined users in the rooms given, along with the count of how many times they appear.
-	JoinedUsersSetInRooms(ctx context.Context, roomIDs []string) ([]string, error)
+	JoinedUsersSetInRooms(ctx context.Context, roomIDs []string) (map[string]int, error)
 }

currentstateserver/storage/postgres/current_room_state_table.go

@@ -78,7 +78,8 @@ const selectBulkStateContentWildSQL = "" +
 	"SELECT room_id, type, state_key, content_value FROM currentstate_current_room_state WHERE room_id = ANY($1) AND type = ANY($2)"
 
 const selectJoinedUsersSetForRoomsSQL = "" +
-	"SELECT DISTINCT state_key FROM currentstate_current_room_state WHERE room_id = ANY($1) AND type = 'm.room.member' and content_value = 'join'"
+	"SELECT state_key, COUNT(room_id) FROM currentstate_current_room_state WHERE room_id = ANY($1) AND" +
+	" type = 'm.room.member' and content_value = 'join' GROUP BY state_key"
 
 type currentRoomStateStatements struct {
 	upsertRoomStateStmt              *sql.Stmt
@@ -124,21 +125,22 @@ func NewPostgresCurrentRoomStateTable(db *sql.DB) (tables.CurrentRoomState, erro
 	return s, nil
 }
 
-func (s *currentRoomStateStatements) SelectJoinedUsersSetForRooms(ctx context.Context, roomIDs []string) ([]string, error) {
+func (s *currentRoomStateStatements) SelectJoinedUsersSetForRooms(ctx context.Context, roomIDs []string) (map[string]int, error) {
 	rows, err := s.selectJoinedUsersSetForRoomsStmt.QueryContext(ctx, pq.StringArray(roomIDs))
 	if err != nil {
 		return nil, err
 	}
 	defer internal.CloseAndLogIfError(ctx, rows, "selectJoinedUsersSetForRooms: rows.close() failed")
-	var userIDs []string
+	result := make(map[string]int)
 	for rows.Next() {
 		var userID string
-		if err := rows.Scan(&userID); err != nil {
+		var count int
+		if err := rows.Scan(&userID, &count); err != nil {
 			return nil, err
 		}
-		userIDs = append(userIDs, userID)
+		result[userID] = count
 	}
-	return userIDs, rows.Err()
+	return result, rows.Err()
 }
 
 // SelectRoomIDsWithMembership returns the list of room IDs which have the given user in the given membership state.

currentstateserver/storage/shared/storage.go

@@ -86,6 +86,6 @@ func (d *Database) GetRoomsByMembership(ctx context.Context, userID, membership
 	return d.CurrentRoomState.SelectRoomIDsWithMembership(ctx, nil, userID, membership)
 }
 
-func (d *Database) JoinedUsersSetInRooms(ctx context.Context, roomIDs []string) ([]string, error) {
+func (d *Database) JoinedUsersSetInRooms(ctx context.Context, roomIDs []string) (map[string]int, error) {
 	return d.CurrentRoomState.SelectJoinedUsersSetForRooms(ctx, roomIDs)
 }

currentstateserver/storage/sqlite3/current_room_state_table.go

@@ -67,7 +67,7 @@ const selectBulkStateContentWildSQL = "" +
 	"SELECT room_id, type, state_key, content_value FROM currentstate_current_room_state WHERE room_id IN ($1) AND type IN ($2)"
 
 const selectJoinedUsersSetForRoomsSQL = "" +
-	"SELECT DISTINCT state_key FROM currentstate_current_room_state WHERE room_id IN ($1) AND type = 'm.room.member' and content_value = 'join'"
+	"SELECT state_key, COUNT(room_id) FROM currentstate_current_room_state WHERE room_id IN ($1) AND type = 'm.room.member' and content_value = 'join' GROUP BY state_key"
 
 type currentRoomStateStatements struct {
 	db                               *sql.DB
@@ -106,7 +106,7 @@ func NewSqliteCurrentRoomStateTable(db *sql.DB) (tables.CurrentRoomState, error)
 	return s, nil
 }
 
-func (s *currentRoomStateStatements) SelectJoinedUsersSetForRooms(ctx context.Context, roomIDs []string) ([]string, error) {
+func (s *currentRoomStateStatements) SelectJoinedUsersSetForRooms(ctx context.Context, roomIDs []string) (map[string]int, error) {
 	iRoomIDs := make([]interface{}, len(roomIDs))
 	for i, v := range roomIDs {
 		iRoomIDs[i] = v
@@ -117,15 +117,16 @@ func (s *currentRoomStateStatements) SelectJoinedUsersSetForRooms(ctx context.Co
 		return nil, err
 	}
 	defer internal.CloseAndLogIfError(ctx, rows, "selectJoinedUsersSetForRooms: rows.close() failed")
-	var userIDs []string
+	result := make(map[string]int)
 	for rows.Next() {
 		var userID string
-		if err := rows.Scan(&userID); err != nil {
+		var count int
+		if err := rows.Scan(&userID, &count); err != nil {
 			return nil, err
 		}
-		userIDs = append(userIDs, userID)
+		result[userID] = count
 	}
-	return userIDs, rows.Err()
+	return result, rows.Err()
 }
 
 // SelectRoomIDsWithMembership returns the list of room IDs which have the given user in the given membership state.

currentstateserver/storage/tables/interface.go

@@ -36,8 +36,9 @@ type CurrentRoomState interface {
 	// SelectRoomIDsWithMembership returns the list of room IDs which have the given user in the given membership state.
 	SelectRoomIDsWithMembership(ctx context.Context, txn *sql.Tx, userID string, membership string) ([]string, error)
 	SelectBulkStateContent(ctx context.Context, roomIDs []string, tuples []gomatrixserverlib.StateKeyTuple, allowWildcards bool) ([]StrippedEvent, error)
-	// SelectJoinedUsersSetForRooms returns the set of all users in the rooms who are joined to any of these rooms.
+	// SelectJoinedUsersSetForRooms returns the set of all users in the rooms who are joined to any of these rooms, along with the
-	SelectJoinedUsersSetForRooms(ctx context.Context, roomIDs []string) ([]string, error)
+	// counts of how many rooms they are joined.
+	SelectJoinedUsersSetForRooms(ctx context.Context, roomIDs []string) (map[string]int, error)
 }
 
 // StrippedEvent represents a stripped event for returning extracted content values.