Restore lost code (#199)

* Restore lost code

* Remove old line

datastore/datastore/storagebackend/postgresql/getextents.go

@@ -5,79 +5,80 @@ import (
 	"datastore/common"
 	"datastore/datastore"
 	"fmt"
+	"time"
 
 	_ "github.com/lib/pq"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/protobuf/types/known/timestamppb"
 )
 
-// createExtQueryVals creates from request values used for querying extensions.
-//
-// Values to be used for query placeholders are appended to phVals.
-//
-// Returns:
-// - time filter used in a 'WHERE ... AND ...' clause
-// - filter for reflectable metadata fields of type int64 ... ditto
-// - filter for reflectable metadata fields of type string ... ditto
-func createExtQueryVals(request *datastore.GetExtentsRequest, phVals *[]interface{}) (
-	string, string, string) {
+// getTemporalExtent gets the current temporal extent of all observations in the storage.
+func getTemporalExtent(db *sql.DB) (*datastore.TimeInterval, error) {
+	query := "SELECT min(obstime_instant), max(obstime_instant) FROM observation"
+	row := db.QueryRow(query)
 
-	loTime, hiTime := common.GetValidTimeRange()
-	timeFilter := fmt.Sprintf(`
-		((obstime_instant >= to_timestamp(%d)) AND (obstime_instant <= to_timestamp(%d)))
-	`, loTime.Unix(), hiTime.Unix())
+	var start, end time.Time
+
+	err := row.Scan(&start, &end)
+	if err != nil {
+		return nil, fmt.Errorf("row.Scan() failed: %v", err)
+	}
 
-	int64MdataFilter := getInt64MdataFilter(request.GetFilter(), phVals)
-	stringMdataFilter := getStringMdataFilter(request.GetFilter(), phVals)
+	loTime, hiTime := common.GetValidTimeRange()
+	if start.Before(loTime) {
+		start = loTime
+	}
+	if end.After(hiTime) {
+		end = hiTime
+	}
 
-	return timeFilter, int64MdataFilter, stringMdataFilter
+	return &datastore.TimeInterval{
+		Start: timestamppb.New(start),
+		End:   timestamppb.New(end),
+	}, nil
 }
 
-// GetExtents ... (see documentation in StorageBackend interface)
-func (sbe *PostgreSQL) GetExtents(request *datastore.GetExtentsRequest) (
-	*datastore.GetExtentsResponse, codes.Code, string) {
+// getSpatialExtent gets the current horizontally spatial extent of all observations in the storage.
+func getSpatialExtent(db *sql.DB) (*datastore.BoundingBox, error) {
+	query := `
+		SELECT ST_XMin(ext), ST_YMin(ext), ST_XMax(ext), ST_YMax(ext)
+		FROM (SELECT ST_Extent(point::geometry) AS ext FROM geo_point) t
+	`
+	row := db.QueryRow(query)
+
+	var xmin, ymin, xmax, ymax float64
 
-	// get values needed for query
-	phVals := []interface{}{} // placeholder values
-	timeFilter, int64MdataFilter, stringMdataFilter := createExtQueryVals(request, &phVals)
+	err := row.Scan(&xmin, &ymin, &xmax, &ymax)
+	if err != nil {
+		return nil, fmt.Errorf("row.Scan() failed: %v", err)
+	}
 
-	query := fmt.Sprintf(`
-		SELECT temp_min, temp_max,
-			ST_XMin(spat_ext), ST_YMin(spat_ext), ST_XMax(spat_ext), ST_YMax(spat_ext)
-		FROM (
-			SELECT min(obstime_instant) AS temp_min, max(obstime_instant) AS temp_max,
-				ST_Extent(point::geometry) AS spat_ext
-			FROM observation
-			JOIN time_series ON observation.ts_id = time_series.id
-			JOIN geo_point ON observation.geo_point_id = geo_point.id
-			WHERE %s AND %s AND %s
-		) t
-	`, timeFilter, int64MdataFilter, stringMdataFilter)
+	return &datastore.BoundingBox{
+		Left:   xmin,
+		Bottom: ymin,
+		Right:  xmax,
+		Top:    ymax,
+	}, nil
+}
 
-	row := sbe.Db.QueryRow(query, phVals...)
+// GetExtents ... (see documentation in StorageBackend interface)
+func (sbe *PostgreSQL) GetExtents(_ *datastore.GetExtentsRequest) (
+	*datastore.GetExtentsResponse, codes.Code, string,
+) {
+	var err error
 
-	var (
-		start, end             sql.NullTime
-		xmin, ymin, xmax, ymax float64
-	)
+	temporalExtent, err := getTemporalExtent(sbe.Db)
+	if err != nil {
+		return nil, codes.Internal, fmt.Sprintf("getTemporalExtent() failed: %v", err)
+	}
 
-	err := row.Scan(&start, &end, &xmin, &ymin, &xmax, &ymax)
-	if !start.Valid { // indicates no matching rows found!
-		return nil, codes.NotFound, "no matching data to compute extensions for"
-	} else if err != nil {
-		return nil, codes.Internal, fmt.Sprintf("row.Scan() failed: %v", err)
+	spatialExtent, err := getSpatialExtent(sbe.Db)
+	if err != nil {
+		return nil, codes.Internal, fmt.Sprintf("getSpatialExtent() failed: %v", err)
 	}
 
 	return &datastore.GetExtentsResponse{
-		TemporalExtent: &datastore.TimeInterval{
-			Start: timestamppb.New(start.Time),
-			End:   timestamppb.New(end.Time),
-		},
-		SpatialExtent: &datastore.BoundingBox{
-			Left:   xmin,
-			Bottom: ymin,
-			Right:  xmax,
-			Top:    ymax,
-		},
+		TemporalExtent: temporalExtent,
+		SpatialExtent:  spatialExtent,
 	}, codes.OK, ""
 }

protobuf/datastore.proto

@@ -305,15 +305,7 @@ message GetTSAGResponse {
 //---------------------------------------------------------------------------
 
 message GetExtentsRequest {
-  // --- BEGIN filter for reflectable metadata of type int64 or string -------------------------
-
-  // general filter
-  // - map keys must correspond exactly with string field names in TSMetadata or ObsMetadata
-  // - if map key F is specified (where F is for example 'platform'), only observations that match
-  //   at least one of these values for F may be returned
-  map<string, Strings> filter = 1;
-
-  // --- END filter for reflectable metadata of type int64 or string -------------------------
+  // No parameters
 }
 
 message GetExtentsResponse {