prometheus/promql/test.go

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// Copyright 2015 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package promql
import (
"fmt"
"io/ioutil"
"math"
"regexp"
"strconv"
"strings"
"time"
"github.com/prometheus/common/model"
"github.com/prometheus/prometheus/storage"
"github.com/prometheus/prometheus/storage/local"
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"github.com/prometheus/prometheus/util/testutil"
)
var (
minNormal = math.Float64frombits(0x0010000000000000) // The smallest positive normal value of type float64.
patSpace = regexp.MustCompile("[\t ]+")
patLoad = regexp.MustCompile(`^load\s+(.+?)$`)
patEvalInstant = regexp.MustCompile(`^eval(?:_(fail|ordered))?\s+instant\s+(?:at\s+(.+?))?\s+(.+)$`)
)
const (
testStartTime = model.Time(0)
epsilon = 0.000001 // Relative error allowed for sample values.
)
// Test is a sequence of read and write commands that are run
// against a test storage.
type Test struct {
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testutil.T
cmds []testCommand
storage local.Storage
closeStorage func()
queryEngine *Engine
}
// NewTest returns an initialized empty Test.
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func NewTest(t testutil.T, input string) (*Test, error) {
test := &Test{
T: t,
cmds: []testCommand{},
}
err := test.parse(input)
test.clear()
return test, err
}
func newTestFromFile(t testutil.T, filename string) (*Test, error) {
content, err := ioutil.ReadFile(filename)
if err != nil {
return nil, err
}
return NewTest(t, string(content))
}
// QueryEngine returns the test's query engine.
func (t *Test) QueryEngine() *Engine {
return t.queryEngine
}
// Storage returns the test's storage.
func (t *Test) Storage() local.Storage {
return t.storage
}
func raise(line int, format string, v ...interface{}) error {
return &ParseErr{
Line: line + 1,
Err: fmt.Errorf(format, v...),
}
}
func (t *Test) parseLoad(lines []string, i int) (int, *loadCmd, error) {
if !patLoad.MatchString(lines[i]) {
return i, nil, raise(i, "invalid load command. (load <step:duration>)")
}
parts := patLoad.FindStringSubmatch(lines[i])
gap, err := model.ParseDuration(parts[1])
if err != nil {
return i, nil, raise(i, "invalid step definition %q: %s", parts[1], err)
}
cmd := newLoadCmd(time.Duration(gap))
for i+1 < len(lines) {
i++
defLine := lines[i]
if len(defLine) == 0 {
i--
break
}
metric, vals, err := parseSeriesDesc(defLine)
if err != nil {
if perr, ok := err.(*ParseErr); ok {
perr.Line = i + 1
}
return i, nil, err
}
cmd.set(metric, vals...)
}
return i, cmd, nil
}
func (t *Test) parseEval(lines []string, i int) (int, *evalCmd, error) {
if !patEvalInstant.MatchString(lines[i]) {
return i, nil, raise(i, "invalid evaluation command. (eval[_fail|_ordered] instant [at <offset:duration>] <query>")
}
parts := patEvalInstant.FindStringSubmatch(lines[i])
var (
mod = parts[1]
at = parts[2]
qry = parts[3]
)
expr, err := ParseExpr(qry)
if err != nil {
if perr, ok := err.(*ParseErr); ok {
perr.Line = i + 1
perr.Pos += strings.Index(lines[i], qry)
}
return i, nil, err
}
offset, err := model.ParseDuration(at)
if err != nil {
return i, nil, raise(i, "invalid step definition %q: %s", parts[1], err)
}
ts := testStartTime.Add(time.Duration(offset))
cmd := newEvalCmd(expr, ts, ts, 0)
switch mod {
case "ordered":
cmd.ordered = true
case "fail":
cmd.fail = true
}
for j := 1; i+1 < len(lines); j++ {
i++
defLine := lines[i]
if len(defLine) == 0 {
i--
break
}
if f, err := parseNumber(defLine); err == nil {
cmd.expect(0, nil, sequenceValue{value: model.SampleValue(f)})
break
}
metric, vals, err := parseSeriesDesc(defLine)
if err != nil {
if perr, ok := err.(*ParseErr); ok {
perr.Line = i + 1
}
return i, nil, err
}
// Currently, we are not expecting any matrices.
if len(vals) > 1 {
return i, nil, raise(i, "expecting multiple values in instant evaluation not allowed")
}
cmd.expect(j, metric, vals...)
}
return i, cmd, nil
}
// parse the given command sequence and appends it to the test.
func (t *Test) parse(input string) error {
// Trim lines and remove comments.
lines := strings.Split(input, "\n")
for i, l := range lines {
l = strings.TrimSpace(l)
if strings.HasPrefix(l, "#") {
l = ""
}
lines[i] = l
}
var err error
// Scan for steps line by line.
for i := 0; i < len(lines); i++ {
l := lines[i]
if len(l) == 0 {
continue
}
var cmd testCommand
switch c := strings.ToLower(patSpace.Split(l, 2)[0]); {
case c == "clear":
cmd = &clearCmd{}
case c == "load":
i, cmd, err = t.parseLoad(lines, i)
case strings.HasPrefix(c, "eval"):
i, cmd, err = t.parseEval(lines, i)
default:
return raise(i, "invalid command %q", l)
}
if err != nil {
return err
}
t.cmds = append(t.cmds, cmd)
}
return nil
}
// testCommand is an interface that ensures that only the package internal
// types can be a valid command for a test.
type testCommand interface {
testCmd()
}
func (*clearCmd) testCmd() {}
func (*loadCmd) testCmd() {}
func (*evalCmd) testCmd() {}
// loadCmd is a command that loads sequences of sample values for specific
// metrics into the storage.
type loadCmd struct {
gap time.Duration
metrics map[model.Fingerprint]model.Metric
defs map[model.Fingerprint][]model.SamplePair
}
func newLoadCmd(gap time.Duration) *loadCmd {
return &loadCmd{
gap: gap,
metrics: map[model.Fingerprint]model.Metric{},
defs: map[model.Fingerprint][]model.SamplePair{},
}
}
func (cmd loadCmd) String() string {
return "load"
}
// set a sequence of sample values for the given metric.
func (cmd *loadCmd) set(m model.Metric, vals ...sequenceValue) {
fp := m.Fingerprint()
samples := make([]model.SamplePair, 0, len(vals))
ts := testStartTime
for _, v := range vals {
if !v.omitted {
samples = append(samples, model.SamplePair{
Timestamp: ts,
Value: v.value,
})
}
ts = ts.Add(cmd.gap)
}
cmd.defs[fp] = samples
cmd.metrics[fp] = m
}
// append the defined time series to the storage.
func (cmd *loadCmd) append(a storage.SampleAppender) {
for fp, samples := range cmd.defs {
met := cmd.metrics[fp]
for _, smpl := range samples {
s := &model.Sample{
Metric: met,
Value: smpl.Value,
Timestamp: smpl.Timestamp,
}
a.Append(s)
}
}
}
// evalCmd is a command that evaluates an expression for the given time (range)
// and expects a specific result.
type evalCmd struct {
expr Expr
start, end model.Time
interval time.Duration
instant bool
fail, ordered bool
metrics map[model.Fingerprint]model.Metric
expected map[model.Fingerprint]entry
}
type entry struct {
pos int
vals []sequenceValue
}
func (e entry) String() string {
return fmt.Sprintf("%d: %s", e.pos, e.vals)
}
func newEvalCmd(expr Expr, start, end model.Time, interval time.Duration) *evalCmd {
return &evalCmd{
expr: expr,
start: start,
end: end,
interval: interval,
instant: start == end && interval == 0,
metrics: map[model.Fingerprint]model.Metric{},
expected: map[model.Fingerprint]entry{},
}
}
func (ev *evalCmd) String() string {
return "eval"
}
// expect adds a new metric with a sequence of values to the set of expected
// results for the query.
func (ev *evalCmd) expect(pos int, m model.Metric, vals ...sequenceValue) {
if m == nil {
ev.expected[0] = entry{pos: pos, vals: vals}
return
}
fp := m.Fingerprint()
ev.metrics[fp] = m
ev.expected[fp] = entry{pos: pos, vals: vals}
}
// compareResult compares the result value with the defined expectation.
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func (ev *evalCmd) compareResult(result model.Value) error {
switch val := result.(type) {
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case model.Matrix:
if ev.instant {
return fmt.Errorf("received range result on instant evaluation")
}
seen := map[model.Fingerprint]bool{}
for pos, v := range val {
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fp := v.Metric.Fingerprint()
if _, ok := ev.metrics[fp]; !ok {
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return fmt.Errorf("unexpected metric %s in result", v.Metric)
}
exp := ev.expected[fp]
if ev.ordered && exp.pos != pos+1 {
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return fmt.Errorf("expected metric %s with %v at position %d but was at %d", v.Metric, exp.vals, exp.pos, pos+1)
}
for i, expVal := range exp.vals {
if !almostEqual(float64(expVal.value), float64(v.Values[i].Value)) {
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return fmt.Errorf("expected %v for %s but got %v", expVal, v.Metric, v.Values)
}
}
seen[fp] = true
}
for fp, expVals := range ev.expected {
if !seen[fp] {
return fmt.Errorf("expected metric %s with %v not found", ev.metrics[fp], expVals)
}
}
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case model.Vector:
if !ev.instant {
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return fmt.Errorf("received instant result on range evaluation")
}
seen := map[model.Fingerprint]bool{}
for pos, v := range val {
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fp := v.Metric.Fingerprint()
if _, ok := ev.metrics[fp]; !ok {
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return fmt.Errorf("unexpected metric %s in result", v.Metric)
}
exp := ev.expected[fp]
if ev.ordered && exp.pos != pos+1 {
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return fmt.Errorf("expected metric %s with %v at position %d but was at %d", v.Metric, exp.vals, exp.pos, pos+1)
}
if !almostEqual(float64(exp.vals[0].value), float64(v.Value)) {
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return fmt.Errorf("expected %v for %s but got %v", exp.vals[0].value, v.Metric, v.Value)
}
seen[fp] = true
}
for fp, expVals := range ev.expected {
if !seen[fp] {
return fmt.Errorf("expected metric %s with %v not found", ev.metrics[fp], expVals)
}
}
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case *model.Scalar:
if !almostEqual(float64(ev.expected[0].vals[0].value), float64(val.Value)) {
return fmt.Errorf("expected scalar %v but got %v", val.Value, ev.expected[0].vals[0].value)
}
default:
panic(fmt.Errorf("promql.Test.compareResult: unexpected result type %T", result))
}
return nil
}
// clearCmd is a command that wipes the test's storage state.
type clearCmd struct{}
func (cmd clearCmd) String() string {
return "clear"
}
// Run executes the command sequence of the test. Until the maximum error number
// is reached, evaluation errors do not terminate execution.
func (t *Test) Run() error {
for _, cmd := range t.cmds {
err := t.exec(cmd)
// TODO(fabxc): aggregate command errors, yield diffs for result
// comparison errors.
if err != nil {
return err
}
}
return nil
}
// exec processes a single step of the test
func (t *Test) exec(tc testCommand) error {
switch cmd := tc.(type) {
case *clearCmd:
t.clear()
case *loadCmd:
cmd.append(t.storage)
t.storage.WaitForIndexing()
case *evalCmd:
q := t.queryEngine.newQuery(cmd.expr, cmd.start, cmd.end, cmd.interval)
res := q.Exec()
if res.Err != nil {
if cmd.fail {
return nil
}
return fmt.Errorf("error evaluating query: %s", res.Err)
}
if res.Err == nil && cmd.fail {
return fmt.Errorf("expected error evaluating query but got none")
}
err := cmd.compareResult(res.Value)
if err != nil {
return fmt.Errorf("error in %s %s: %s", cmd, cmd.expr, err)
}
default:
panic("promql.Test.exec: unknown test command type")
}
return nil
}
// clear the current test storage of all inserted samples.
func (t *Test) clear() {
if t.closeStorage != nil {
t.closeStorage()
}
if t.queryEngine != nil {
t.queryEngine.Stop()
}
var closer testutil.Closer
t.storage, closer = local.NewTestStorage(t, 1)
t.closeStorage = closer.Close
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t.queryEngine = NewEngine(t.storage, nil)
}
// Close closes resources associated with the Test.
func (t *Test) Close() {
t.queryEngine.Stop()
t.closeStorage()
}
// samplesAlmostEqual returns true if the two sample lines only differ by a
// small relative error in their sample value.
func almostEqual(a, b float64) bool {
// NaN has no equality but for testing we still want to know whether both values
// are NaN.
if math.IsNaN(a) && math.IsNaN(b) {
return true
}
// Cf. http://floating-point-gui.de/errors/comparison/
if a == b {
return true
}
diff := math.Abs(a - b)
if a == 0 || b == 0 || diff < minNormal {
return diff < epsilon*minNormal
}
return diff/(math.Abs(a)+math.Abs(b)) < epsilon
}
func parseNumber(s string) (float64, error) {
n, err := strconv.ParseInt(s, 0, 64)
f := float64(n)
if err != nil {
f, err = strconv.ParseFloat(s, 64)
}
if err != nil {
return 0, fmt.Errorf("error parsing number: %s", err)
}
return f, nil
}