Use copy instead of insert when storing metrics

This patch changes processCSI to use COPY to store
metrics instead of multi-value INSERTs.

cmd/tsbs_load_timescaledb/process.go

@@ -9,6 +9,7 @@ import (
 
 	"bitbucket.org/440-labs/tsbs/load"
 	"github.com/jmoiron/sqlx"
+	"github.com/lib/pq"
 )
 
 const insertCSI = `INSERT INTO %s(time,tags_id,%s%s,additional_tags) VALUES %s`
@@ -96,17 +97,16 @@ func insertTags(db *sqlx.DB, tagRows [][]string, returnResults bool) map[string]
 }
 
 func (p *processor) processCSI(hypertable string, rows []*insertData) uint64 {
-	partitionKey := ""
-	if inTableTag {
-		partitionKey = tableCols["tags"][0] + ","
-	}
-
-	hypertableCols := strings.Join(tableCols[hypertable], ",")
-
 	tagRows := make([][]string, 0, len(rows))
-	dataRows := make([]string, 0, len(rows))
+	dataRows := make([][]interface{}, 0, len(rows))
 	ret := uint64(0)
 	commonTagsLen := len(tableCols["tags"])
+
+	colLen := len(tableCols[hypertable]) + 2
+	if inTableTag {
+		colLen++
+	}
+
 	for _, data := range rows {
 		// Split the tags into individual common tags and an extra bit leftover
 		// for non-common tags that need to be added separately. For each of
@@ -116,7 +116,7 @@ func (p *processor) processCSI(hypertable string, rows []*insertData) uint64 {
 		for i := 0; i < commonTagsLen; i++ {
 			tags[i] = strings.Split(tags[i], "=")[1]
 		}
-		json := "NULL"
+		var json interface{} = nil
 		if len(tags) > commonTagsLen {
 			json = subsystemTagsToJSON(strings.Split(tags[commonTagsLen], ","))
 		}
@@ -130,16 +130,14 @@ func (p *processor) processCSI(hypertable string, rows []*insertData) uint64 {
 		}
 		ts := time.Unix(0, timeInt).Format("2006-01-02 15:04:05.999999 -0700")
 
-		// The last arguments in these sprintf's may seem a bit confusing at first, but
-		// it does work. We want each value to be surrounded by single quotes (' '), and
-		// to be separated by a comma. That means we strings.Join them with "', '", which
-		// leaves the first value without a preceding ' and the last with out a trailing ',
-		// therefore we put the %s returned by the Join inside of '' to solve the problem
-		var r string
+		// use nil at 2nd position as placeholder for tagKey
+		r := make([]interface{}, 0, colLen)
+		r = append(r, ts, nil, json)
 		if inTableTag {
-			r = fmt.Sprintf("('%s','[REPLACE_CSI]', '%s', '%s', %s)", ts, tags[0], strings.Join(metrics[1:], "', '"), json)
-		} else {
-			r = fmt.Sprintf("('%s', '[REPLACE_CSI]', '%s', %s)", ts, strings.Join(metrics[1:], "', '"), json)
+			r = append(r, tags[0])
+		}
+		for _, v := range metrics[1:] {
+			r = append(r, v)
 		}
 
 		dataRows = append(dataRows, r)
@@ -165,16 +163,35 @@ func (p *processor) processCSI(hypertable string, rows []*insertData) uint64 {
 	}
 
 	p.csi.mutex.RLock()
-	for i, r := range dataRows {
-		// TODO -- support more than 10 common tags
+	for i := range dataRows {
 		tagKey := tagRows[i][0]
-		dataRows[i] = strings.Replace(r, "[REPLACE_CSI]", strconv.FormatInt(p.csi.m[tagKey], 10), 1)
+		dataRows[i][1] = p.csi.m[tagKey]
 	}
 	p.csi.mutex.RUnlock()
 	tx := p.db.MustBegin()
-	_ = tx.MustExec(fmt.Sprintf(insertCSI, hypertable, partitionKey, hypertableCols, strings.Join(dataRows, ",")))
 
-	err := tx.Commit()
+	cols := make([]string, 0, colLen)
+	cols = append(cols, "time", "tags_id", "additional_tags")
+	if inTableTag {
+		cols = append(cols, tableCols["tags"][0])
+	}
+	cols = append(cols, tableCols[hypertable]...)
+	stmt, err := tx.Prepare(pq.CopyIn(hypertable, cols...))
+	for _, r := range dataRows {
+		stmt.Exec(r...)
+	}
+
+	_, err = stmt.Exec()
+	if err != nil {
+		panic(err)
+	}
+
+	err = stmt.Close()
+	if err != nil {
+		panic(err)
+	}
+
+	err = tx.Commit()
 	if err != nil {
 		panic(err)
 	}