provide community search backend

pkg/api/errors.go

@@ -0,0 +1,7 @@
+package api
+
+import "errors"
+
+// ErrTooManyRoutes is returned when the result set
+// of a route query exceeds the maximum allowed number of routes.
+var ErrTooManyRoutes = errors.New("too many routes")

pkg/config/config.go

@@ -87,6 +87,7 @@ type ServerConfig struct {
 	NeighborsStoreRefreshParallelism  int    `ini:"neighbors_store_refresh_parallelism"`
 	RoutesStoreRefreshInterval        int    `ini:"routes_store_refresh_interval"`
 	RoutesStoreRefreshParallelism     int    `ini:"routes_store_refresh_parallelism"`
+	RoutesStoreQueryLimit             uint   `ini:"routes_store_query_limit"`
 	StoreBackend                      string `ini:"store_backend"`
 	DefaultAsn                        int    `ini:"asn"`
 	EnableNeighborsStatusRefresh      bool   `ini:"enable_neighbors_status_refresh"`

pkg/http/api_endpoints_search.go

@@ -50,10 +50,18 @@ func (s *Server) apiLookupPrefixGlobal(
 	// Merge query filters into applied filters
 	filtersApplied = filtersApplied.Combine(queryFilters)
 
-	// Check what we want to query
+	// Select the query strategy:
 	//  Prefix -> fetch prefix
 	//       _ -> fetch neighbors and routes
+	//
 	lookupPrefix := decoders.MaybePrefix(q)
+	lookupEmptyQuery := false
+	if q == "" && (filtersApplied.HasGroup(api.SearchKeyCommunities) ||
+		filtersApplied.HasGroup(api.SearchKeyExtCommunities) ||
+		filtersApplied.HasGroup(api.SearchKeyLargeCommunities)) {
+		lookupPrefix = true
+		lookupEmptyQuery = true
+	}
 
 	// Measure response time
 	t0 := time.Now()
@@ -61,10 +69,12 @@ func (s *Server) apiLookupPrefixGlobal(
 	// Perform query
 	var routes api.LookupRoutes
 	if lookupPrefix {
+		if !lookupEmptyQuery {
 			q, err = validatePrefixQuery(q)
 			if err != nil {
 				return nil, err
 			}
+		}
 		routes, err = s.routesStore.LookupPrefix(ctx, q, filtersApplied)
 		if err != nil {
 			return nil, err

pkg/http/api_errors.go

@@ -71,6 +71,13 @@ func apiErrorResponse(
 	tag := TagGenericError
 	status := StatusError
 
+	// TODO: This needs refactoring.
+	if err == api.ErrTooManyRoutes {
+		tag = TagValidationError
+		code = CodeValidationError
+		status = StatusValidationError
+	} else {
+
 		switch e := err.(type) {
 		case ErrTimeout:
 			tag = TagConnectionTimeout
@@ -96,6 +103,7 @@ func apiErrorResponse(
 			status = StatusValidationError
 			message = e.Reason
 		}
+	}
 
 	return api.ErrorResponse{
 		Code:          code,

pkg/store/backends/memory/routes_backend.go

@@ -95,12 +95,22 @@ func (r *RoutesBackend) FindByPrefix(
 	ctx context.Context,
 	prefix string,
 	filters *api.SearchFilters,
+	limit uint,
 ) (api.LookupRoutes, error) {
 	// We make our compare case insensitive
+	var (
+		count         uint
+		limitExceeded bool
+	)
+
 	prefix = strings.ToLower(prefix)
 	result := api.LookupRoutes{}
 	hasPrefix := prefix != ""
 	r.routes.Range(func(k, rs interface{}) bool {
+		if limit > 0 && count >= limit {
+			limitExceeded = true
+			return false
+		}
 		for _, route := range rs.(api.LookupRoutes) {
 			// Naiive string filtering:
 			if hasPrefix && !strings.HasPrefix(strings.ToLower(route.Network), prefix) {
@@ -110,8 +120,16 @@ func (r *RoutesBackend) FindByPrefix(
 				continue
 			}
 			result = append(result, route)
+			count++
+			if limit > 0 && count >= limit {
+				limitExceeded = true
+				return false
+			}
 		}
 		return true
 	})
+	if limitExceeded {
+		return nil, api.ErrTooManyRoutes
+	}
 	return result, nil
 }

pkg/store/backends/postgres/routes_backend.go

@@ -249,7 +249,7 @@ func (b *RoutesBackend) FindByNeighbors(
 		return nil, err
 	}
 
-	return fetchRoutes(rows, filters)
+	return fetchRoutes(rows, filters, 0)
 }
 
 // FindByPrefix will return the prefixes matching a pattern
@@ -257,6 +257,7 @@ func (b *RoutesBackend) FindByPrefix(
 	ctx context.Context,
 	prefix string,
 	filters *api.SearchFilters,
+	limit uint,
 ) (api.LookupRoutes, error) {
 	tx, err := b.pool.BeginTx(ctx, pgx.TxOptions{
 		IsoLevel: pgx.ReadCommitted,
@@ -280,11 +281,16 @@ func (b *RoutesBackend) FindByPrefix(
 	if err != nil {
 		return nil, err
 	}
-	return fetchRoutes(rows, filters)
+	return fetchRoutes(rows, filters, limit)
 }
 
 // Private fetchRoutes will load the queried result set
-func fetchRoutes(rows pgx.Rows, filters *api.SearchFilters) (api.LookupRoutes, error) {
+func fetchRoutes(
+	rows pgx.Rows,
+	filters *api.SearchFilters,
+	limit uint,
+) (api.LookupRoutes, error) {
+	var count uint
 	cmd := rows.CommandTag()
 	results := make(api.LookupRoutes, 0, cmd.RowsAffected())
 	for rows.Next() {
@@ -296,6 +302,10 @@ func fetchRoutes(rows pgx.Rows, filters *api.SearchFilters) (api.LookupRoutes, e
 			continue
 		}
 		results = append(results, route)
+		count++
+		if limit > 0 && count >= limit {
+			return nil, api.ErrTooManyRoutes
+		}
 	}
 	return results, nil
 }

pkg/store/routes_store.go

@@ -60,6 +60,7 @@ type RoutesStoreBackend interface {
 		ctx context.Context,
 		prefix string,
 		filters *api.SearchFilters,
+		limit uint,
 	) (api.LookupRoutes, error)
 }
 
@@ -70,6 +71,7 @@ type RoutesStore struct {
 	backend   RoutesStoreBackend
 	sources   *SourcesStore
 	neighbors *NeighborsStore
+	limit     uint
 }
 
 // NewRoutesStore makes a new store instance
@@ -93,6 +95,7 @@ func NewRoutesStore(
 
 	log.Println("Routes refresh interval set to:", refreshInterval)
 	log.Println("Routes refresh parallelism:", refreshParallelism)
+	log.Println("Routes store query limit:", cfg.Server.RoutesStoreQueryLimit)
 
 	// Store refresh information per store
 	sources := NewSourcesStore(cfg, refreshInterval, refreshParallelism)
@@ -100,6 +103,7 @@ func NewRoutesStore(
 		backend:   backend,
 		sources:   sources,
 		neighbors: neighbors,
+		limit:     cfg.Server.RoutesStoreQueryLimit,
 	}
 	return store
 }
@@ -332,7 +336,7 @@ func (s *RoutesStore) LookupPrefix(
 	prefix string,
 	filters *api.SearchFilters,
 ) (api.LookupRoutes, error) {
-	return s.backend.FindByPrefix(ctx, prefix, filters)
+	return s.backend.FindByPrefix(ctx, prefix, filters, s.limit)
 }
 
 // LookupPrefixForNeighbors returns all routes for