package db // this file implements the database functions to load/store/read from a sql database. import ( "context" "database/sql" "encoding/json" "fmt" "strconv" "strings" "time" "github.com/jmoiron/sqlx" "github.com/kschamplin/gotelem/skylab" sqlite3 "github.com/mattn/go-sqlite3" ) func init() { sql.Register("custom_sqlite3", &sqlite3.SQLiteDriver{ // TODO: add functions that convert between unix milliseconds and ISO 8601 }) } type TelemDb struct { db *sqlx.DB } type TelemDbOption func(*TelemDb) error func OpenTelemDb(path string, options ...TelemDbOption) (tdb *TelemDb, err error) { tdb = &TelemDb{} tdb.db, err = sqlx.Connect("sqlite3", path) if err != nil { return } // TODO: add options support. for _, fn := range options { err = fn(tdb) if err != nil { return } } // execute database up statement (better hope it is idempotent!) // FIXME: only do this when it's a new database (instead warn the user about potential version mismatches) // TODO: store gotelem version (commit hash?) in DB (PRAGMA user_version) var version int err = tdb.db.Get(&version, "PRAGMA user_version") if err != nil { return } // get latest version of migrations - then run the SQL in order. fmt.Printf("starting version %d\n", version) version, err = RunMigrations(version, tdb) fmt.Printf("ending version %d\n", version) return tdb, err } // the sql commands to create the database. const sqlDbUp = ` CREATE TABLE IF NOT EXISTS "bus_events" ( "ts" INTEGER NOT NULL, -- timestamp, unix milliseconds "id" INTEGER NOT NULL, -- can ID "name" TEXT NOT NULL, -- name of base packet "data" TEXT NOT NULL CHECK(json_valid(data)) -- JSON object describing the data, including index if any ); CREATE INDEX IF NOT EXISTS "ids_timestamped" ON "bus_events" ( "id", "ts" DESC ); CREATE INDEX IF NOT EXISTS "times" ON "bus_events" ( "ts" DESC ); -- this table shows when we started/stopped logging. CREATE TABLE "drive_records" ( "id" INTEGER NOT NULL UNIQUE, -- unique ID of the drive. "start_time" INTEGER NOT NULL, -- when the drive started "end_time" INTEGER, -- when it ended, or NULL if it's ongoing. "note" TEXT, -- optional description of the segment/experiment/drive PRIMARY KEY("id" AUTOINCREMENT), CONSTRAINT "duration_valid" CHECK(end_time is null or start_time < end_time) ); -- gps logs TODO: use GEOJSON/Spatialite tracks instead? CREATE TABLE "position_logs" ( "ts" INTEGER NOT NULL, "source" TEXT NOT NULL, "lat" REAL NOT NULL, "lon" REAL NOT NULL, "elevation" REAL, CONSTRAINT "no_empty_source" CHECK(source is not "") ); -- TODO: ensure only one "active" (end_time == null) drive record at a time using triggers/constraints/index ` // sql sequence to tear down the database. // not used often, but good to keep track of what's going on. // Up() then Down() should result in an empty database. const sqlDbDown = ` DROP TABLE "bus_events"; DROP INDEX "ids_timestamped"; DROP INDEX "times"; DROP TABLE "drive_records"; DROP TABLE "position_logs"; ` // sql expression to insert a bus event into the packets database.1 const sqlInsertEvent = ` INSERT INTO "bus_events" (ts, id, name, data) VALUES ($1, $2, $3, json($4)); ` // AddEvent adds the bus event to the database. func (tdb *TelemDb) AddEventsCtx(ctx context.Context, events ...skylab.BusEvent) (err error) { // tx, err := tdb.db.BeginTx(ctx, nil) if err != nil { tx.Rollback() return } for _, b := range events { var j []byte j, err = json.Marshal(b.Data) if err != nil { tx.Rollback() return } _, err = tx.ExecContext(ctx, sqlInsertEvent, b.Timestamp.UnixMilli(), b.Id, b.Data.String(), j) if err != nil { tx.Rollback() return } } tx.Commit() return } func (tdb *TelemDb) AddEvents(events ...skylab.BusEvent) (err error) { return tdb.AddEventsCtx(context.Background(), events...) } /// Query fragment guide: /// We need to be able to easily construct safe(!) and meaningful queries programatically /// so we make some new types that can be turned into SQL fragments that go inside the where clause. /// These all implement the QueryFrag interface, meaning the actual query function (that acts on the DB) /// can deal with them agnostically. The Query function joins all the fragments it is given with AND. /// to get OR, // QueryFrag is anything that can be turned into a Query WHERE clause type QueryFrag interface { Query() string } // QueryIdRange represents a range of IDs to select for, inclusive. type QueryIdRange struct { Start uint32 End uint32 } func (q *QueryIdRange) Query() string { return fmt.Sprintf("id BETWEEN %d AND %d", q.Start, q.End) } // QueryIds selects for individual CAN ids type QueryIds []uint32 func (q QueryIds) Query() string { var idStrings []string for _, id := range q { idStrings = append(idStrings, strconv.FormatUint(uint64(id), 10)) } return fmt.Sprintf("id IN (%s)", strings.Join(idStrings, ",")) } // QueryTimeRange represents a query of a specific time range. For "before" or "after" queries, // use time.Unix(0,0) or time.Now() in start and end respectively. type QueryTimeRange struct { Start time.Time End time.Time } func (q *QueryTimeRange) Query() string { startUnix := q.Start.UnixMilli() endUnix := q.End.UnixMilli() return fmt.Sprintf("ts BETWEEN %d AND %d", startUnix, endUnix) } type QueryNames []string func (q QueryNames) Query() string { return fmt.Sprintf("name IN (%s)", strings.Join(q, ", ")) } type QueryOr []QueryFrag func (q QueryOr) Query() string { var qStrings []string for _, frag := range q { qStrings = append(qStrings, frag.Query()) } return fmt.Sprintf("(%s)", strings.Join(qStrings, " OR ")) } // GetEvents is the mechanism to request underlying event data. // it takes functions (which are defined in db.go) that modify the query, // and then return the results. func (tdb *TelemDb) GetEvents(limit int, where ...QueryFrag) (events []skylab.BusEvent, err error) { // Simple mechanism for combining query frags: // join with " AND ". To join expressions with or, use QueryOr var fragStr []string for _, f := range where { fragStr = append(fragStr, f.Query()) } qString := fmt.Sprintf(`SELECT * FROM "bus_events" WHERE %s LIMIT %d`, strings.Join(fragStr, " AND "), limit) rows, err := tdb.db.Queryx(qString) if err != nil { return } defer rows.Close() if limit < 0 { // special case: limit negative means unrestricted. events = make([]skylab.BusEvent, 0, 20) } else { events = make([]skylab.BusEvent, 0, limit) } // scan rows into busevent list... for rows.Next() { var ev skylab.RawJsonEvent err = rows.StructScan(&ev) if err != nil { return } BusEv := skylab.BusEvent{ Timestamp: time.UnixMilli(int64(ev.Timestamp)), Id: ev.Id, } BusEv.Data, err = skylab.FromJson(ev.Id, ev.Data) // FIXME: this is slow! events = append(events, BusEv) } err = rows.Err() return } // GetActiveDrive finds the non-null drive and returns it, if any. func (tdb *TelemDb) GetActiveDrive() (res int, err error) { err = tdb.db.Get(&res, "SELECT id FROM drive_records WHERE end_time IS NULL LIMIT 1") return } func (tdb *TelemDb) NewDrive(start time.Time, note string) { } func (tdb *TelemDb) EndDrive() { } func (tdb *TelemDb) UpdateDrive(id int, note string) { }