micro/meter/handler/handler.go
Vasiliy Tolstov 0e42033e7f meter/handler: more idiomatic option handling
Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>
2021-03-29 17:51:44 +03:00

70 lines
1.2 KiB
Go

package handler
import (
"bytes"
"context"
"github.com/unistack-org/micro/v3/codec"
"github.com/unistack-org/micro/v3/errors"
"github.com/unistack-org/micro/v3/meter"
)
var (
// guard to fail early
_ MeterServer = &handler{}
)
type handler struct {
opts Options
}
type Option func(*Options)
type Options struct {
Meter meter.Meter
MeterOptions []meter.Option
Name string
}
func Meter(m meter.Meter) Option {
return func(o *Options) {
o.Meter = m
}
}
func Name(name string) Option {
return func(o *Options) {
o.Name = name
}
}
func MeterOptions(opts ...meter.Option) Option {
return func(o *Options) {
o.MeterOptions = append(o.MeterOptions, opts...)
}
}
func NewOptions(opts ...Option) Options {
options := Options{Meter: meter.DefaultMeter}
for _, o := range opts {
o(&options)
}
return options
}
func NewHandler(opts ...Option) *handler {
options := NewOptions(opts...)
return &handler{opts: options}
}
func (h *handler) Metrics(ctx context.Context, req *codec.Frame, rsp *codec.Frame) error {
buf := bytes.NewBuffer(nil)
if err := h.opts.Meter.Write(buf, h.opts.MeterOptions...); err != nil {
return errors.InternalServerError(h.opts.Name, "%v", err)
}
rsp.Data = buf.Bytes()
return nil
}