Use batched inserts instead of prepared statements.

main/datalog.go

@@ -12,6 +12,7 @@ package main
 
 import (
 	"database/sql"
+	"errors"
 	"fmt"
 	_ "github.com/mattn/go-sqlite3"
 	"log"
@@ -203,6 +204,45 @@ func makeTable(i interface{}, tbl string, db *sql.DB) {
 	}
 }
 
+/*
+	bulkInsert().
+		Reads insertBatch and insertBatchIfs. This is called after a group of insertData() calls.
+*/
+
+func bulkInsert(tbl string, db *sql.DB) (res sql.Result, err error) {
+	if _, ok := insertString[tbl]; !ok {
+		return nil, errors.New("no insert statement")
+	}
+
+	batchVals := insertBatchIfs[tbl]
+	for len(batchVals) > 0 {
+		i := int(0) // Maximum of 10 rows per INSERT statement.
+		stmt := ""
+		vals := make([]interface{}, 0)
+		for len(batchVals) > 0 && i < 10 {
+			if len(stmt) == 0 { // The first set will be covered by insertString.
+				stmt = insertString[tbl]
+			} else {
+				stmt += ", (" + strings.Join(strings.Split(strings.Repeat("?", len(batchVals[0])), ""), ",") + ")"
+			}
+			vals = append(vals, batchVals[0]...)
+			batchVals = batchVals[1:]
+			i++
+		}
+		log.Printf("bulkInsert %d vals: %s\n", len(vals), stmt)
+		res, err = db.Exec(stmt, vals...)
+		if err != nil {
+			return
+		}
+	}
+
+	// Clear the buffers.
+	delete(insertString, tbl)
+	delete(insertBatchIfs, tbl)
+
+	return
+}
+
 /*
 	insertData().
 		Inserts an arbitrary struct into an SQLite table.
@@ -210,8 +250,9 @@ func makeTable(i interface{}, tbl string, db *sql.DB) {
 
 */
 
-// Cached prepared statements. Indexed by table name.
-var preparedStmts map[string]*sql.Stmt
+// Cached 'VALUES' statements. Indexed by table name.
+var insertString map[string]string // INSERT INTO tbl (col1, col2, ...) VALUES(?, ?, ...). Only for one value.
+var insertBatchIfs map[string][][]interface{}
 
 func insertData(i interface{}, tbl string, db *sql.DB, ts_num int64) int64 {
 	val := reflect.ValueOf(i)
@@ -245,34 +286,33 @@ func insertData(i interface{}, tbl string, db *sql.DB, ts_num int64) int64 {
 		values = append(values, strconv.FormatInt(dataLogTimestamps[ts_num].id, 10))
 	}
 
-	if _, ok := preparedStmts[tbl]; !ok {
+	if _, ok := insertString[tbl]; !ok {
 		// Prepare the statement.
 		tblInsert := fmt.Sprintf("INSERT INTO %s (%s) VALUES(%s)", tbl, strings.Join(keys, ","),
 			strings.Join(strings.Split(strings.Repeat("?", len(keys)), ""), ","))
-		s, err := db.Prepare(tblInsert)
-		if err != nil {
-			log.Printf("insertData: db.Prepare() error (%s): %s\n", tblInsert, err.Error)
-			panic(err.Error())
-		}
-		preparedStmts[tbl] = s
+		insertString[tbl] = tblInsert
 	}
 
+	// Make the values slice into a slice of interface{}.
 	ifs := make([]interface{}, len(values))
 	for i := 0; i < len(values); i++ {
 		ifs[i] = values[i]
 	}
-	res, err := preparedStmts[tbl].Exec(ifs...)
-	if err != nil {
-		log.Printf("ERROR: %s\n", err.Error())
-	}
-	id, err := res.LastInsertId()
-	if err == nil {
-		if tbl == "timestamp" {
-			ts := dataLogTimestamps[ts_num]
-			ts.id = id
-			dataLogTimestamps[ts_num] = ts
+
+	insertBatchIfs[tbl] = append(insertBatchIfs[tbl], ifs)
+
+	if tbl == "timestamp" { // Immediate insert always for "timestamp" table.
+		res, err := bulkInsert("timestamp", db) // Bulk insert of 1, always.
+		if err == nil {
+			id, err := res.LastInsertId()
+			if err == nil {
+				ts := dataLogTimestamps[ts_num]
+				ts.id = id
+				dataLogTimestamps[ts_num] = ts
+				log.Printf("new ts=%d\n", id)
+			}
+			return id
 		}
-		return id
 	}
 
 	return 0
@@ -301,7 +341,12 @@ func dataLogWriter(db *sql.DB) {
 			// Accept timestamped row.
 			rowsQueuedForWrite = append(rowsQueuedForWrite, r)
 		case <-writeTicker.C:
+			for i := 0; i < 1000; i++ {
+				logSituation()
+			}
 			// Write the buffered rows. This will block while it is writing.
+			// Save the names of the tables affected so that we can run bulkInsert() on after the insertData() calls.
+			tblsAffected := make(map[string]bool)
 			// Start transaction.
 			log.Printf("go %d\n", len(rowsQueuedForWrite))
 			tx, err := db.Begin()
@@ -310,8 +355,13 @@ func dataLogWriter(db *sql.DB) {
 				break // from select {}
 			}
 			for _, r := range rowsQueuedForWrite {
+				tblsAffected[r.tbl] = true
 				insertData(r.data, r.tbl, db, r.ts_num)
 			}
+			// Do the bulk inserts.
+			for tbl, _ := range tblsAffected {
+				bulkInsert(tbl, db)
+			}
 			// Close the transaction.
 			tx.Commit()
 			log.Printf("done\n")
@@ -419,6 +469,7 @@ func logDump1090TermMessage(m Dump1090TermMessage) {
 }
 
 func initDataLog() {
-	preparedStmts = make(map[string]*sql.Stmt)
+	insertString = make(map[string]string)
+	insertBatchIfs = make(map[string][][]interface{})
 	go dataLog()
 }

main/ry835ai.go

@@ -430,10 +430,13 @@ return is true if parse occurs correctly and position is valid.
 
 */
 
-func processNMEALine(l string) bool {
+func processNMEALine(l string) (sentenceUsed bool) {
 	mySituation.mu_GPS.Lock()
+
 	defer func() {
-		logSituation()
+		if sentenceUsed || globalSettings.DEBUG {
+			logSituation()
+		}
 		mySituation.mu_GPS.Unlock()
 	}()
 
@@ -622,7 +625,6 @@ func processNMEALine(l string) bool {
 			                                x[8+6*i] // lock time, sec, 0-64
 			*/
 			return true
-
 		} else if x[1] == "04" { // clock message
 			// field 5 is UTC week (epoch = 1980-JAN-06). If this is invalid, do not parse date / time
 			utcWeek, err0 := strconv.Atoi(x[5])