telegraf/plugins/inputs/jolokia2/point_builder.go

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package jolokia2
import (
"fmt"
"strings"
)
type point struct {
Tags map[string]string
Fields map[string]interface{}
}
type pointBuilder struct {
metric Metric
objectAttributes []string
objectPath string
substitutions []string
}
func newPointBuilder(metric Metric, attributes []string, path string) *pointBuilder {
return &pointBuilder{
metric: metric,
objectAttributes: attributes,
objectPath: path,
substitutions: makeSubstitutionList(metric.Mbean),
}
}
// Build generates a point for a given mbean name/pattern and value object.
func (pb *pointBuilder) Build(mbean string, value interface{}) []point {
hasPattern := strings.Contains(mbean, "*")
if !hasPattern {
value = map[string]interface{}{mbean: value}
}
valueMap, ok := value.(map[string]interface{})
if !ok { // FIXME: log it and move on.
panic(fmt.Sprintf("There should be a map here for %s!\n", mbean))
}
points := make([]point, 0)
for mbean, value := range valueMap {
points = append(points, point{
Tags: pb.extractTags(mbean),
Fields: pb.extractFields(mbean, value),
})
}
return compactPoints(points)
}
// extractTags generates the map of tags for a given mbean name/pattern.
func (pb *pointBuilder) extractTags(mbean string) map[string]string {
propertyMap := makePropertyMap(mbean)
tagMap := make(map[string]string)
for key, value := range propertyMap {
if pb.includeTag(key) {
tagName := pb.formatTagName(key)
tagMap[tagName] = value
}
}
return tagMap
}
func (pb *pointBuilder) includeTag(tagName string) bool {
for _, t := range pb.metric.TagKeys {
if tagName == t {
return true
}
}
return false
}
func (pb *pointBuilder) formatTagName(tagName string) string {
if tagName == "" {
return ""
}
if tagPrefix := pb.metric.TagPrefix; tagPrefix != "" {
return tagPrefix + tagName
}
return tagName
}
// extractFields generates the map of fields for a given mbean name
// and value object.
func (pb *pointBuilder) extractFields(mbean string, value interface{}) map[string]interface{} {
fieldMap := make(map[string]interface{})
valueMap, ok := value.(map[string]interface{})
if ok {
// complex value
if len(pb.objectAttributes) == 0 {
// if there were no attributes requested,
// then the keys are attributes
pb.fillFields("", valueMap, fieldMap)
} else if len(pb.objectAttributes) == 1 {
// if there was a single attribute requested,
// then the keys are the attribute's properties
fieldName := pb.formatFieldName(pb.objectAttributes[0], pb.objectPath)
pb.fillFields(fieldName, valueMap, fieldMap)
} else {
// if there were multiple attributes requested,
// then the keys are the attribute names
for _, attribute := range pb.objectAttributes {
fieldName := pb.formatFieldName(attribute, pb.objectPath)
pb.fillFields(fieldName, valueMap[attribute], fieldMap)
}
}
} else {
// scalar value
var fieldName string
if len(pb.objectAttributes) == 0 {
fieldName = pb.formatFieldName(defaultFieldName, pb.objectPath)
} else {
fieldName = pb.formatFieldName(pb.objectAttributes[0], pb.objectPath)
}
pb.fillFields(fieldName, value, fieldMap)
}
if len(pb.substitutions) > 1 {
pb.applySubstitutions(mbean, fieldMap)
}
return fieldMap
}
// formatFieldName generates a field name from the supplied attribute and
// path. The return value has the configured FieldPrefix and FieldSuffix
// instructions applied.
func (pb *pointBuilder) formatFieldName(attribute, path string) string {
fieldName := attribute
fieldPrefix := pb.metric.FieldPrefix
fieldSeparator := pb.metric.FieldSeparator
if fieldPrefix != "" {
fieldName = fieldPrefix + fieldName
}
if path != "" {
fieldName = fieldName + fieldSeparator + strings.Replace(path, "/", fieldSeparator, -1)
}
return fieldName
}
// fillFields recurses into the supplied value object, generating a named field
// for every value it discovers.
func (pb *pointBuilder) fillFields(name string, value interface{}, fieldMap map[string]interface{}) {
if valueMap, ok := value.(map[string]interface{}); ok {
// keep going until we get to something that is not a map
for key, innerValue := range valueMap {
var innerName string
if name == "" {
innerName = pb.metric.FieldPrefix + key
} else {
innerName = name + pb.metric.FieldSeparator + key
}
pb.fillFields(innerName, innerValue, fieldMap)
}
return
}
if pb.metric.FieldName != "" {
name = pb.metric.FieldName
if prefix := pb.metric.FieldPrefix; prefix != "" {
name = prefix + name
}
}
if name == "" {
name = defaultFieldName
}
fieldMap[name] = value
}
// applySubstitutions updates all the keys in the supplied map
// of fields to account for $1-style substitution instructions.
func (pb *pointBuilder) applySubstitutions(mbean string, fieldMap map[string]interface{}) {
properties := makePropertyMap(mbean)
for i, subKey := range pb.substitutions[1:] {
symbol := fmt.Sprintf("$%d", i+1)
substitution := properties[subKey]
for fieldName, fieldValue := range fieldMap {
newFieldName := strings.Replace(fieldName, symbol, substitution, -1)
if fieldName != newFieldName {
fieldMap[newFieldName] = fieldValue
delete(fieldMap, fieldName)
}
}
}
}
// makePropertyMap returns a the mbean property-key list as
// a dictionary. foo:x=y becomes map[string]string { "x": "y" }
func makePropertyMap(mbean string) map[string]string {
props := make(map[string]string)
object := strings.SplitN(mbean, ":", 2)
domain := object[0]
if domain != "" && len(object) == 2 {
list := object[1]
for _, keyProperty := range strings.Split(list, ",") {
pair := strings.SplitN(keyProperty, "=", 2)
if len(pair) != 2 {
continue
}
if key := pair[0]; key != "" {
props[key] = pair[1]
}
}
}
return props
}
// makeSubstitutionList returns an array of values to
// use as substitutions when renaming fields
// with the $1..$N syntax. The first item in the list
// is always the mbean domain.
func makeSubstitutionList(mbean string) []string {
subs := make([]string, 0)
object := strings.SplitN(mbean, ":", 2)
domain := object[0]
if domain != "" && len(object) == 2 {
subs = append(subs, domain)
list := object[1]
for _, keyProperty := range strings.Split(list, ",") {
pair := strings.SplitN(keyProperty, "=", 2)
if len(pair) != 2 {
continue
}
key := pair[0]
if key == "" {
continue
}
property := pair[1]
if !strings.Contains(property, "*") {
continue
}
subs = append(subs, key)
}
}
return subs
}