Adding upstream version 1.34.4.

Signed-off-by: Daniel Baumann <daniel@debian.org>

internal/templating/engine.go

@@ -0,0 +1,88 @@
+package templating
+
+import (
+	"sort"
+	"strings"
+)
+
+const (
+	// DefaultSeparator is the default separation character to use when separating template parts.
+	DefaultSeparator = "."
+)
+
+// Engine uses a Matcher to retrieve the appropriate template and applies the template
+// to the input string
+type Engine struct {
+	joiner  string
+	matcher *matcher
+}
+
+// Apply extracts the template fields from the given line and returns the measurement
+// name, tags and field name
+//
+//nolint:revive //function-result-limit conditionally 4 return results allowed
+func (e *Engine) Apply(line string) (measurementName string, tags map[string]string, field string, err error) {
+	return e.matcher.match(line).Apply(line, e.joiner)
+}
+
+// NewEngine creates a new templating engine
+func NewEngine(joiner string, defaultTemplate *Template, templates []string) (*Engine, error) {
+	engine := Engine{
+		joiner:  joiner,
+		matcher: newMatcher(defaultTemplate),
+	}
+	templateSpecs := parseTemplateSpecs(templates)
+
+	for _, templateSpec := range templateSpecs {
+		if err := engine.matcher.addSpec(templateSpec); err != nil {
+			return nil, err
+		}
+	}
+
+	return &engine, nil
+}
+
+func parseTemplateSpecs(templates []string) templateSpecs {
+	tmplts := templateSpecs{}
+	for _, pattern := range templates {
+		tmplt := templateSpec{
+			separator: DefaultSeparator,
+		}
+
+		// Format is [separator] [filter] <template> [tag1=value1,tag2=value2]
+		parts := strings.Fields(pattern)
+		partsLength := len(parts)
+		if partsLength < 1 {
+			// ignore
+			continue
+		}
+		if partsLength == 1 {
+			tmplt.template = pattern
+		} else if partsLength == 4 {
+			tmplt.separator = parts[0]
+			tmplt.filter = parts[1]
+			tmplt.template = parts[2]
+			tmplt.tagstring = parts[3]
+		} else {
+			hasTagstring := strings.Contains(parts[partsLength-1], "=")
+			if hasTagstring {
+				tmplt.tagstring = parts[partsLength-1]
+				tmplt.template = parts[partsLength-2]
+				if partsLength == 3 {
+					tmplt.filter = parts[0]
+				}
+			} else {
+				tmplt.template = parts[partsLength-1]
+				if partsLength == 2 {
+					tmplt.filter = parts[0]
+				} else { // length == 3
+					tmplt.separator = parts[0]
+					tmplt.filter = parts[1]
+				}
+			}
+		}
+		tmplts = append(tmplts, tmplt)
+	}
+	sort.Sort(tmplts)
+	return tmplts
+}

internal/templating/engine_test.go

@@ -0,0 +1,77 @@
+package templating
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestEngineAlternateSeparator(t *testing.T) {
+	defaultTemplate, err := NewDefaultTemplateWithPattern("measurement*")
+	require.NoError(t, err)
+	engine, err := NewEngine("_", defaultTemplate, []string{
+		"/ /*/*/* /measurement/origin/measurement*",
+	})
+	require.NoError(t, err)
+	name, tags, field, err := engine.Apply("/telegraf/host01/cpu")
+	require.NoError(t, err)
+	require.Equal(t, "telegraf_cpu", name)
+	require.Equal(t, map[string]string{
+		"origin": "host01",
+	}, tags)
+	require.Empty(t, field)
+}
+
+func TestEngineWithWildcardTemplate(t *testing.T) {
+	var (
+		defaultTmpl, err = NewDefaultTemplateWithPattern("measurement*")
+		templates        = []string{
+			"taskmanagerTask.alarm-detector.Assign.alarmDefinitionId metricsType.process.nodeId.x.alarmDefinitionId.measurement.field rule=1",
+			"taskmanagerTask.*.*.*.*                                 metricsType.process.nodeId.measurement rule=2",
+		}
+	)
+	require.NoError(t, err)
+
+	engine, err := NewEngine(".", defaultTmpl, templates)
+	require.NoError(t, err)
+
+	for _, testCase := range []struct {
+		line        string
+		measurement string
+		field       string
+		tags        map[string]string
+	}{
+		{
+			line:        "taskmanagerTask.alarm-detector.Assign.alarmDefinitionId.timeout_errors.duration.p75",
+			measurement: "duration",
+			field:       "p75",
+			tags: map[string]string{
+				"metricsType":       "taskmanagerTask",
+				"process":           "alarm-detector",
+				"nodeId":            "Assign",
+				"x":                 "alarmDefinitionId",
+				"alarmDefinitionId": "timeout_errors",
+				"rule":              "1",
+			},
+		},
+		{
+			line:        "taskmanagerTask.alarm-detector.Assign.numRecordsInPerSecond.m5_rate",
+			measurement: "numRecordsInPerSecond",
+			tags: map[string]string{
+				"metricsType": "taskmanagerTask",
+				"process":     "alarm-detector",
+				"nodeId":      "Assign",
+				"rule":        "2",
+			},
+		},
+	} {
+		t.Run(testCase.line, func(t *testing.T) {
+			measurement, tags, field, err := engine.Apply(testCase.line)
+			require.NoError(t, err)
+
+			require.Equal(t, testCase.measurement, measurement)
+			require.Equal(t, testCase.field, field)
+			require.Equal(t, testCase.tags, tags)
+		})
+	}
+}

internal/templating/matcher.go

@@ -0,0 +1,58 @@
+package templating
+
+import (
+	"strings"
+)
+
+// matcher determines which template should be applied to a given metric
+// based on a filter tree.
+type matcher struct {
+	root            *node
+	defaultTemplate *Template
+}
+
+// newMatcher creates a new matcher.
+func newMatcher(defaultTemplate *Template) *matcher {
+	return &matcher{
+		root:            &node{},
+		defaultTemplate: defaultTemplate,
+	}
+}
+
+func (m *matcher) addSpec(tmplt templateSpec) error {
+	// Parse out the default tags specific to this template
+	tags := make(map[string]string)
+	if tmplt.tagstring != "" {
+		for _, kv := range strings.Split(tmplt.tagstring, ",") {
+			parts := strings.Split(kv, "=")
+			tags[parts[0]] = parts[1]
+		}
+	}
+
+	tmpl, err := NewTemplate(tmplt.separator, tmplt.template, tags)
+	if err != nil {
+		return err
+	}
+	m.add(tmplt.filter, tmpl)
+	return nil
+}
+
+// add inserts the template in the filter tree based the given filter
+func (m *matcher) add(filter string, template *Template) {
+	if filter == "" {
+		m.defaultTemplate = template
+		m.root.separator = template.separator
+		return
+	}
+	m.root.insert(filter, template)
+}
+
+// match returns the template that matches the given measurement line.
+// If no template matches, the default template is returned.
+func (m *matcher) match(line string) *Template {
+	tmpl := m.root.search(line)
+	if tmpl != nil {
+		return tmpl
+	}
+	return m.defaultTemplate
+}

internal/templating/node.go

@@ -0,0 +1,136 @@
+package templating
+
+import (
+	"sort"
+	"strings"
+)
+
+// node is an item in a sorted k-ary tree of filter parts. Each child is sorted by its part value.
+// The special value of "*", is always sorted last.
+type node struct {
+	separator string
+	value     string
+	children  nodes
+	template  *Template
+}
+
+// insert inserts the given string template into the tree.  The filter string is separated
+// on the template separator and each part is used as the path in the tree.
+func (n *node) insert(filter string, template *Template) {
+	n.separator = template.separator
+	n.recursiveInsert(strings.Split(filter, n.separator), template)
+}
+
+// recursiveInsert does the actual recursive insertion
+func (n *node) recursiveInsert(values []string, template *Template) {
+	// Add the end, set the template
+	if len(values) == 0 {
+		n.template = template
+		return
+	}
+
+	// See if the current element already exists in the tree. If so, insert the
+	// into that sub-tree
+	for _, v := range n.children {
+		if v.value == values[0] {
+			v.recursiveInsert(values[1:], template)
+			return
+		}
+	}
+
+	// New element, add it to the tree and sort the children
+	newNode := &node{value: values[0]}
+	n.children = append(n.children, newNode)
+	sort.Sort(&n.children)
+
+	// Now insert the rest of the tree into the new element
+	newNode.recursiveInsert(values[1:], template)
+}
+
+// search searches for a template matching the input string
+func (n *node) search(line string) *Template {
+	separator := n.separator
+	return n.recursiveSearch(strings.Split(line, separator))
+}
+
+// recursiveSearch performs the actual recursive search
+func (n *node) recursiveSearch(lineParts []string) *Template {
+	// nothing to search
+	if len(lineParts) == 0 || len(n.children) == 0 {
+		return n.template
+	}
+
+	var (
+		hasWildcard bool
+		length      = len(n.children)
+	)
+
+	// exclude last child from search if it is a wildcard. sort.Search expects
+	// a lexicographically sorted set of children and we have artificially sorted
+	// wildcards to the end of the child set
+	// wildcards will be searched separately if no exact match is found
+	if hasWildcard = n.children[length-1].value == "*"; hasWildcard {
+		length--
+	}
+
+	i := sort.Search(length, func(i int) bool {
+		return n.children[i].value >= lineParts[0]
+	})
+
+	// given an exact match is found within children set
+	if i < length && n.children[i].value == lineParts[0] {
+		// descend into the matching node
+		if tmpl := n.children[i].recursiveSearch(lineParts[1:]); tmpl != nil {
+			// given a template is found return it
+			return tmpl
+		}
+	}
+
+	// given no template is found and the last child is a wildcard
+	if hasWildcard {
+		// also search the wildcard child node
+		return n.children[length].recursiveSearch(lineParts[1:])
+	}
+
+	// fallback to returning template at this node
+	return n.template
+}
+
+// nodes is simply an array of nodes implementing the sorting interface.
+type nodes []*node
+
+// Less returns a boolean indicating whether the filter at position j
+// is less than the filter at position k. Filters are order by string
+// comparison of each component parts.  A wildcard value "*" is never
+// less than a non-wildcard value.
+//
+// For example, the filters:
+//
+//	"*.*"
+//	"servers.*"
+//	"servers.localhost"
+//	"*.localhost"
+//
+// Would be sorted as:
+//
+//	"servers.localhost"
+//	"servers.*"
+//	"*.localhost"
+//	"*.*"
+func (n *nodes) Less(j, k int) bool {
+	if (*n)[j].value == "*" && (*n)[k].value != "*" {
+		return false
+	}
+
+	if (*n)[j].value != "*" && (*n)[k].value == "*" {
+		return true
+	}
+
+	return (*n)[j].value < (*n)[k].value
+}
+
+// Swap swaps two elements of the array
+func (n *nodes) Swap(i, j int) { (*n)[i], (*n)[j] = (*n)[j], (*n)[i] }
+
+// Len returns the length of the array
+func (n *nodes) Len() int { return len(*n) }

internal/templating/template.go

@@ -0,0 +1,142 @@
+package templating
+
+import (
+	"fmt"
+	"strings"
+)
+
+// Template represents a pattern and tags to map a metric string to an influxdb Point
+type Template struct {
+	separator         string
+	parts             []string
+	defaultTags       map[string]string
+	greedyField       bool
+	greedyMeasurement bool
+}
+
+// Apply extracts the template fields from the given line and returns the measurement
+// name, tags and field name
+//
+//nolint:revive //function-result-limit conditionally 4 return results allowed
+func (t *Template) Apply(line string, joiner string) (measurementName string, tags map[string]string, field string, err error) {
+	allFields := strings.Split(line, t.separator)
+	var (
+		measurements []string
+		tagsMap      = make(map[string][]string)
+		fields       []string
+	)
+
+	// Set any default tags
+	for k, v := range t.defaultTags {
+		tagsMap[k] = append(tagsMap[k], v)
+	}
+
+	// See if an invalid combination has been specified in the template:
+	for _, tag := range t.parts {
+		if tag == "measurement*" {
+			t.greedyMeasurement = true
+		} else if tag == "field*" {
+			t.greedyField = true
+		}
+	}
+	if t.greedyField && t.greedyMeasurement {
+		return "", nil, "",
+			fmt.Errorf("either 'field*' or 'measurement*' can be used in each "+
+				"template (but not both together): %q",
+				strings.Join(t.parts, joiner))
+	}
+
+	for i, tag := range t.parts {
+		if i >= len(allFields) {
+			continue
+		}
+		if tag == "" {
+			continue
+		}
+
+		switch tag {
+		case "measurement":
+			measurements = append(measurements, allFields[i])
+		case "field":
+			fields = append(fields, allFields[i])
+		case "field*":
+			fields = append(fields, allFields[i:]...)
+		case "measurement*":
+			measurements = append(measurements, allFields[i:]...)
+		default:
+			tagsMap[tag] = append(tagsMap[tag], allFields[i])
+		}
+	}
+
+	// Convert to map of strings.
+	tags = make(map[string]string)
+	for k, values := range tagsMap {
+		tags[k] = strings.Join(values, joiner)
+	}
+
+	return strings.Join(measurements, joiner), tags, strings.Join(fields, joiner), nil
+}
+
+func NewDefaultTemplateWithPattern(pattern string) (*Template, error) {
+	return NewTemplate(DefaultSeparator, pattern, nil)
+}
+
+// NewTemplate returns a new template ensuring it has a measurement specified.
+func NewTemplate(separator, pattern string, defaultTags map[string]string) (*Template, error) {
+	parts := strings.Split(pattern, separator)
+	hasMeasurement := false
+	template := &Template{
+		separator:   separator,
+		parts:       parts,
+		defaultTags: defaultTags,
+	}
+
+	for _, part := range parts {
+		if strings.HasPrefix(part, "measurement") {
+			hasMeasurement = true
+		}
+		if part == "measurement*" {
+			template.greedyMeasurement = true
+		} else if part == "field*" {
+			template.greedyField = true
+		}
+	}
+
+	if !hasMeasurement {
+		return nil, fmt.Errorf("no measurement specified for template. %q", pattern)
+	}
+
+	return template, nil
+}
+
+// templateSpec is a template string split in its constituent parts
+type templateSpec struct {
+	separator string
+	filter    string
+	template  string
+	tagstring string
+}
+
+// templateSpecs is simply an array of template specs implementing the sorting interface
+type templateSpecs []templateSpec
+
+// Less reports whether the element with
+// index j should sort before the element with index k.
+func (e templateSpecs) Less(j, k int) bool {
+	jlen := len(e[j].filter)
+	klen := len(e[k].filter)
+	if jlen == 0 && klen != 0 {
+		return true
+	}
+	if klen == 0 && jlen != 0 {
+		return false
+	}
+	return strings.Count(e[j].template, e[j].separator) <
+		strings.Count(e[k].template, e[k].separator)
+}
+
+// Swap swaps the elements with indexes i and j.
+func (e templateSpecs) Swap(i, j int) { e[i], e[j] = e[j], e[i] }
+
+// Len is the number of elements in the collection.
+func (e templateSpecs) Len() int { return len(e) }

internal/templating/template_test.go

@@ -0,0 +1,14 @@
+package templating
+
+import "testing"
+
+func BenchmarkTemplateLess(b *testing.B) {
+	a := templateSpec{
+		template:  "aa|bb|cc|dd|ee|ff",
+		separator: "|",
+	}
+	specs := templateSpecs{a, a}
+	for i := 0; i < b.N; i++ {
+		specs.Less(0, 1)
+	}
+}