func()

in plugins/processors/regex/regex.go [168:270]

• 84 lines of code
• 27 McCabe index (conditional complexity)

func (r *Regex) Apply(in ...telegraf.Metric) []telegraf.Metric {
	for _, metric := range in {
		for _, converter := range r.Tags {
			if value, ok := metric.GetTag(converter.Key); ok {
				if key, newValue := r.convert(converter, value); newValue != "" {
					if converter.Append {
						if v, ok := metric.GetTag(key); ok {
							newValue = v + newValue
						}
					}
					metric.AddTag(key, newValue)
				}
			}
		}

		for _, converter := range r.Fields {
			if value, ok := metric.GetField(converter.Key); ok {
				if v, ok := value.(string); ok {
					if key, newValue := r.convert(converter, v); newValue != "" {
						metric.AddField(key, newValue)
					}
				}
			}
		}

		for _, converter := range r.TagRename {
			regex := r.regexCache[converter.Pattern]
			replacements := make(map[string]string)
			for _, tag := range metric.TagList() {
				name := tag.Key
				if regex.MatchString(name) {
					newName := regex.ReplaceAllString(name, converter.Replacement)

					if !metric.HasTag(newName) {
						// There is no colliding tag, we can just change the name.
						tag.Key = newName
						continue
					}

					if converter.ResultKey == "overwrite" {
						// We got a colliding tag, remember the replacement and do it later
						replacements[name] = newName
					}
				}
			}
			// We needed to postpone the replacement as we cannot modify the tag-list
			// while iterating it as this will result in invalid memory dereference panic.
			for oldName, newName := range replacements {
				value, ok := metric.GetTag(oldName)
				if !ok {
					// Just in case the tag got removed in the meantime
					continue
				}
				metric.AddTag(newName, value)
				metric.RemoveTag(oldName)
			}
		}

		for _, converter := range r.FieldRename {
			regex := r.regexCache[converter.Pattern]
			replacements := make(map[string]string)
			for _, field := range metric.FieldList() {
				name := field.Key
				if regex.MatchString(name) {
					newName := regex.ReplaceAllString(name, converter.Replacement)

					if !metric.HasField(newName) {
						// There is no colliding field, we can just change the name.
						field.Key = newName
						continue
					}

					if converter.ResultKey == "overwrite" {
						// We got a colliding field, remember the replacement and do it later
						replacements[name] = newName
					}
				}
			}
			// We needed to postpone the replacement as we cannot modify the field-list
			// while iterating it as this will result in invalid memory dereference panic.
			for oldName, newName := range replacements {
				value, ok := metric.GetField(oldName)
				if !ok {
					// Just in case the field got removed in the meantime
					continue
				}
				metric.AddField(newName, value)
				metric.RemoveField(oldName)
			}
		}

		for _, converter := range r.MetricRename {
			regex := r.regexCache[converter.Pattern]
			value := metric.Name()
			if regex.MatchString(value) {
				newValue := regex.ReplaceAllString(value, converter.Replacement)
				metric.SetName(newValue)
			}
		}
	}

	return in
}