telegraf/plugins/parsers/graphite/parser.go

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package graphite
import (
"bufio"
"bytes"
"fmt"
"io"
"math"
"sort"
"strconv"
"strings"
"time"
"github.com/influxdata/telegraf"
)
// Minimum and maximum supported dates for timestamps.
var (
MinDate = time.Date(1901, 12, 13, 0, 0, 0, 0, time.UTC)
MaxDate = time.Date(2038, 1, 19, 0, 0, 0, 0, time.UTC)
)
// Parser encapsulates a Graphite Parser.
type GraphiteParser struct {
Separator string
Templates []string
DefaultTags map[string]string
matcher *matcher
}
func NewGraphiteParser(
separator string,
templates []string,
defaultTags map[string]string,
) (*GraphiteParser, error) {
var err error
if separator == "" {
separator = DefaultSeparator
}
p := &GraphiteParser{
Separator: separator,
Templates: templates,
}
if defaultTags != nil {
p.DefaultTags = defaultTags
}
matcher := newMatcher()
p.matcher = matcher
defaultTemplate, _ := NewTemplate("measurement*", nil, p.Separator)
matcher.AddDefaultTemplate(defaultTemplate)
for _, pattern := range p.Templates {
template := pattern
filter := ""
// Format is [filter] <template> [tag1=value1,tag2=value2]
parts := strings.Fields(pattern)
if len(parts) < 1 {
continue
} else if len(parts) >= 2 {
if strings.Contains(parts[1], "=") {
template = parts[0]
} else {
filter = parts[0]
template = parts[1]
}
}
// Parse out the default tags specific to this template
tags := map[string]string{}
if strings.Contains(parts[len(parts)-1], "=") {
tagStrs := strings.Split(parts[len(parts)-1], ",")
for _, kv := range tagStrs {
parts := strings.Split(kv, "=")
tags[parts[0]] = parts[1]
}
}
tmpl, err1 := NewTemplate(template, tags, p.Separator)
if err1 != nil {
err = err1
break
}
matcher.Add(filter, tmpl)
}
if err != nil {
return p, fmt.Errorf("exec input parser config is error: %s ", err.Error())
} else {
return p, nil
}
}
func (p *GraphiteParser) Parse(buf []byte) ([]telegraf.Metric, error) {
// parse even if the buffer begins with a newline
buf = bytes.TrimPrefix(buf, []byte("\n"))
// add newline to end if not exists:
if len(buf) > 0 && !bytes.HasSuffix(buf, []byte("\n")) {
buf = append(buf, []byte("\n")...)
}
metrics := make([]telegraf.Metric, 0)
buffer := bytes.NewBuffer(buf)
reader := bufio.NewReader(buffer)
for {
// Read up to the next newline.
buf, err := reader.ReadBytes('\n')
if err == io.EOF {
return metrics, nil
}
if err != nil && err != io.EOF {
return metrics, err
}
// Trim the buffer, even though there should be no padding
line := strings.TrimSpace(string(buf))
if metric, err := p.ParseLine(line); err == nil {
metrics = append(metrics, metric)
}
}
}
// Parse performs Graphite parsing of a single line.
func (p *GraphiteParser) ParseLine(line string) (telegraf.Metric, error) {
// Break into 3 fields (name, value, timestamp).
fields := strings.Fields(line)
if len(fields) != 2 && len(fields) != 3 {
return nil, fmt.Errorf("received %q which doesn't have required fields", line)
}
// decode the name and tags
template := p.matcher.Match(fields[0])
measurement, tags, field, err := template.Apply(fields[0])
if err != nil {
return nil, err
}
// Could not extract measurement, use the raw value
if measurement == "" {
measurement = fields[0]
}
// Parse value.
v, err := strconv.ParseFloat(fields[1], 64)
if err != nil {
return nil, fmt.Errorf(`field "%s" value: %s`, fields[0], err)
}
if math.IsNaN(v) || math.IsInf(v, 0) {
return nil, &UnsupposedValueError{Field: fields[0], Value: v}
}
fieldValues := map[string]interface{}{}
if field != "" {
fieldValues[field] = v
} else {
fieldValues["value"] = v
}
// If no 3rd field, use now as timestamp
timestamp := time.Now().UTC()
if len(fields) == 3 {
// Parse timestamp.
unixTime, err := strconv.ParseFloat(fields[2], 64)
if err != nil {
return nil, fmt.Errorf(`field "%s" time: %s`, fields[0], err)
}
// -1 is a special value that gets converted to current UTC time
// See https://github.com/graphite-project/carbon/issues/54
if unixTime != float64(-1) {
// Check if we have fractional seconds
timestamp = time.Unix(int64(unixTime), int64((unixTime-math.Floor(unixTime))*float64(time.Second)))
if timestamp.Before(MinDate) || timestamp.After(MaxDate) {
return nil, fmt.Errorf("timestamp out of range")
}
}
}
// Set the default tags on the point if they are not already set
for k, v := range p.DefaultTags {
if _, ok := tags[k]; !ok {
tags[k] = v
}
}
return telegraf.NewMetric(measurement, tags, fieldValues, timestamp)
}
// ApplyTemplate extracts the template fields from the given line and
// returns the measurement name and tags.
func (p *GraphiteParser) ApplyTemplate(line string) (string, map[string]string, string, error) {
// Break line into fields (name, value, timestamp), only name is used
fields := strings.Fields(line)
if len(fields) == 0 {
return "", make(map[string]string), "", nil
}
// decode the name and tags
template := p.matcher.Match(fields[0])
name, tags, field, err := template.Apply(fields[0])
// Set the default tags on the point if they are not already set
for k, v := range p.DefaultTags {
if _, ok := tags[k]; !ok {
tags[k] = v
}
}
return name, tags, field, err
}
// template represents a pattern and tags to map a graphite metric string to a influxdb Point
type template struct {
tags []string
defaultTags map[string]string
greedyMeasurement bool
separator string
}
// NewTemplate returns a new template ensuring it has a measurement
// specified.
func NewTemplate(pattern string, defaultTags map[string]string, separator string) (*template, error) {
tags := strings.Split(pattern, ".")
hasMeasurement := false
template := &template{tags: tags, defaultTags: defaultTags, separator: separator}
for _, tag := range tags {
if strings.HasPrefix(tag, "measurement") {
hasMeasurement = true
}
if tag == "measurement*" {
template.greedyMeasurement = true
}
}
if !hasMeasurement {
return nil, fmt.Errorf("no measurement specified for template. %q", pattern)
}
return template, nil
}
// Apply extracts the template fields from the given line and returns the measurement
// name and tags
func (t *template) Apply(line string) (string, map[string]string, string, error) {
fields := strings.Split(line, ".")
var (
measurement []string
tags = make(map[string]string)
field string
)
// Set any default tags
for k, v := range t.defaultTags {
tags[k] = v
}
for i, tag := range t.tags {
if i >= len(fields) {
continue
}
if tag == "measurement" {
measurement = append(measurement, fields[i])
} else if tag == "field" {
if len(field) != 0 {
return "", nil, "", fmt.Errorf("'field' can only be used once in each template: %q", line)
}
field = fields[i]
} else if tag == "measurement*" {
measurement = append(measurement, fields[i:]...)
break
} else if tag != "" {
tags[tag] = fields[i]
}
}
return strings.Join(measurement, t.separator), tags, field, nil
}
// matcher determines which template should be applied to a given metric
// based on a filter tree.
type matcher struct {
root *node
defaultTemplate *template
}
func newMatcher() *matcher {
return &matcher{
root: &node{},
}
}
// Add inserts the template in the filter tree based the given filter
func (m *matcher) Add(filter string, template *template) {
if filter == "" {
m.AddDefaultTemplate(template)
return
}
m.root.Insert(filter, template)
}
func (m *matcher) AddDefaultTemplate(template *template) {
m.defaultTemplate = template
}
// Match returns the template that matches the given graphite line
func (m *matcher) Match(line string) *template {
tmpl := m.root.Search(line)
if tmpl != nil {
return tmpl
}
return m.defaultTemplate
}
// node is an item in a sorted k-ary tree. Each child is sorted by its value.
// The special value of "*", is always last.
type node struct {
value string
children nodes
template *template
}
func (n *node) insert(values []string, template *template) {
// Add the end, set the template
if len(values) == 0 {
n.template = template
return
}
// See if the 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.insert(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.insert(values[1:], template)
}
// Insert inserts the given string template into the tree. The filter string is separated
// on "." and each part is used as the path in the tree.
func (n *node) Insert(filter string, template *template) {
n.insert(strings.Split(filter, "."), template)
}
func (n *node) search(lineParts []string) *template {
// Nothing to search
if len(lineParts) == 0 || len(n.children) == 0 {
return n.template
}
// If last element is a wildcard, don't include in this search since it's sorted
// to the end but lexicographically it would not always be and sort.Search assumes
// the slice is sorted.
length := len(n.children)
if n.children[length-1].value == "*" {
length--
}
// Find the index of child with an exact match
i := sort.Search(length, func(i int) bool {
return n.children[i].value >= lineParts[0]
})
// Found an exact match, so search that child sub-tree
if i < len(n.children) && n.children[i].value == lineParts[0] {
return n.children[i].search(lineParts[1:])
}
// Not an exact match, see if we have a wildcard child to search
if n.children[len(n.children)-1].value == "*" {
return n.children[len(n.children)-1].search(lineParts[1:])
}
return n.template
}
func (n *node) Search(line string) *template {
return n.search(strings.Split(line, "."))
}
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
}
func (n *nodes) Swap(i, j int) { (*n)[i], (*n)[j] = (*n)[j], (*n)[i] }
func (n *nodes) Len() int { return len(*n) }