From bb87949d5c40d70308fc46940e8b7885681c6097 Mon Sep 17 00:00:00 2001
From: Aliaksandr Valialkin <valyala@victoriametrics.com>
Date: Thu, 28 Oct 2021 12:46:27 +0300
Subject: [PATCH] lib/protoparser/influx: automatically detect timestamp
 precision depending on the number of decimal digits in the timestamp

---
 docs/CHANGELOG.md                           |  1 +
 lib/protoparser/influx/streamparser.go      | 32 +++++++++++++++++++--
 lib/protoparser/influx/streamparser_test.go | 30 +++++++++++++++++++
 3 files changed, 60 insertions(+), 3 deletions(-)
 create mode 100644 lib/protoparser/influx/streamparser_test.go

diff --git a/docs/CHANGELOG.md b/docs/CHANGELOG.md
index 330d475c0..5022c901e 100644
--- a/docs/CHANGELOG.md
+++ b/docs/CHANGELOG.md
@@ -8,6 +8,7 @@ sort: 15
 
 * FEATURE: vmalert: allow groups with empty rules list like Prometheus does. See [this pull request](https://github.com/VictoriaMetrics/VictoriaMetrics/pull/1742).
 * FEATURE: vmagent: add `collapse` and `expand` buttons per each group of targets with the same `job_name` at `http://vmagent:8429/targets` page.
+* FEATURE: automatically detect timestamp precision (ns, us, ms or s) for the data ingested into VictoriaMetrics via [InfluxDB line protocol](https://docs.victoriametrics.com/#how-to-send-data-from-influxdb-compatible-agents-such-as-telegraf).
 
 * BUGFIX: vmagent: properly display `proxy_url` config option at `http://vmagent:8429/config` page. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1755).
 * BUGFIX: fix tests for Apple M1. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1653).
diff --git a/lib/protoparser/influx/streamparser.go b/lib/protoparser/influx/streamparser.go
index 7bc98a0fd..96f865b6a 100644
--- a/lib/protoparser/influx/streamparser.go
+++ b/lib/protoparser/influx/streamparser.go
@@ -36,8 +36,7 @@ func ParseStream(r io.Reader, isGzipped bool, precision, db string, callback fun
 		r = zr
 	}
 
-	// Default precision is 'ns'. See https://docs.influxdata.com/influxdb/v1.7/write_protocols/line_protocol_tutorial/#timestamp
-	tsMultiplier := int64(1e6)
+	tsMultiplier := int64(0)
 	switch precision {
 	case "ns":
 		tsMultiplier = 1e6
@@ -189,7 +188,14 @@ func (uw *unmarshalWork) Unmarshal() {
 	// Adjust timestamps according to uw.tsMultiplier
 	currentTs := time.Now().UnixNano() / 1e6
 	tsMultiplier := uw.tsMultiplier
-	if tsMultiplier >= 1 {
+	if tsMultiplier == 0 {
+		// Default precision is 'ns'. See https://docs.influxdata.com/influxdb/v1.7/write_protocols/line_protocol_tutorial/#timestamp
+		// But it can be in ns, us, ms or s depending on the number of digits in practice.
+		for i := range rows {
+			tsPtr := &rows[i].Timestamp
+			*tsPtr = detectTimestamp(*tsPtr, currentTs)
+		}
+	} else if tsMultiplier >= 1 {
 		for i := range rows {
 			row := &rows[i]
 			if row.Timestamp == 0 {
@@ -237,3 +243,23 @@ func putUnmarshalWork(uw *unmarshalWork) {
 }
 
 var unmarshalWorkPool sync.Pool
+
+func detectTimestamp(ts, currentTs int64) int64 {
+	if ts == 0 {
+		return currentTs
+	}
+	if ts >= 1e17 {
+		// convert nanoseconds to milliseconds
+		return ts / 1e6
+	}
+	if ts >= 1e14 {
+		// convert microseconds to milliseconds
+		return ts / 1e3
+	}
+	if ts >= 1e11 {
+		// the ts is in milliseconds
+		return ts
+	}
+	// convert seconds to milliseconds
+	return ts * 1e3
+}
diff --git a/lib/protoparser/influx/streamparser_test.go b/lib/protoparser/influx/streamparser_test.go
new file mode 100644
index 000000000..ca7bd1b30
--- /dev/null
+++ b/lib/protoparser/influx/streamparser_test.go
@@ -0,0 +1,30 @@
+package influx
+
+import (
+	"testing"
+)
+
+func TestDetectTimestamp(t *testing.T) {
+	tsDefault := int64(123)
+	f := func(ts, tsExpected int64) {
+		t.Helper()
+		tsResult := detectTimestamp(ts, tsDefault)
+		if tsResult != tsExpected {
+			t.Fatalf("unexpected timestamp for detectTimestamp(%d, %d); got %d; want %d", ts, tsDefault, tsResult, tsExpected)
+		}
+	}
+	f(0, tsDefault)
+	f(1, 1e3)
+	f(1e7, 1e10)
+	f(1e8, 1e11)
+	f(1e9, 1e12)
+	f(1e10, 1e13)
+	f(1e11, 1e11)
+	f(1e12, 1e12)
+	f(1e13, 1e13)
+	f(1e14, 1e11)
+	f(1e15, 1e12)
+	f(1e16, 1e13)
+	f(1e17, 1e11)
+	f(1e18, 1e12)
+}