AdGuardHome/internal/aghhttp/json.go
2023-09-07 17:13:48 +03:00

142 lines
3.9 KiB
Go

package aghhttp
import (
"encoding/json"
"fmt"
"net/http"
"strconv"
"time"
"github.com/AdguardTeam/golibs/httphdr"
"github.com/AdguardTeam/golibs/log"
)
// JSON Utilities
// nsecPerMsec is the number of nanoseconds in a millisecond.
const nsecPerMsec = float64(time.Millisecond / time.Nanosecond)
// JSONDuration is a time.Duration that can be decoded from JSON and encoded
// into JSON according to our API conventions.
type JSONDuration time.Duration
// type check
var _ json.Marshaler = JSONDuration(0)
// MarshalJSON implements the json.Marshaler interface for JSONDuration. err is
// always nil.
func (d JSONDuration) MarshalJSON() (b []byte, err error) {
msec := float64(time.Duration(d)) / nsecPerMsec
b = strconv.AppendFloat(nil, msec, 'f', -1, 64)
return b, nil
}
// type check
var _ json.Unmarshaler = (*JSONDuration)(nil)
// UnmarshalJSON implements the json.Marshaler interface for *JSONDuration.
func (d *JSONDuration) UnmarshalJSON(b []byte) (err error) {
if d == nil {
return fmt.Errorf("json duration is nil")
}
msec, err := strconv.ParseFloat(string(b), 64)
if err != nil {
return fmt.Errorf("parsing json time: %w", err)
}
*d = JSONDuration(int64(msec * nsecPerMsec))
return nil
}
// JSONTime is a time.Time that can be decoded from JSON and encoded into JSON
// according to our API conventions.
type JSONTime time.Time
// type check
var _ json.Marshaler = JSONTime{}
// MarshalJSON implements the json.Marshaler interface for JSONTime. err is
// always nil.
func (t JSONTime) MarshalJSON() (b []byte, err error) {
msec := float64(time.Time(t).UnixNano()) / nsecPerMsec
b = strconv.AppendFloat(nil, msec, 'f', -1, 64)
return b, nil
}
// type check
var _ json.Unmarshaler = (*JSONTime)(nil)
// UnmarshalJSON implements the json.Marshaler interface for *JSONTime.
func (t *JSONTime) UnmarshalJSON(b []byte) (err error) {
if t == nil {
return fmt.Errorf("json time is nil")
}
msec, err := strconv.ParseFloat(string(b), 64)
if err != nil {
return fmt.Errorf("parsing json time: %w", err)
}
*t = JSONTime(time.Unix(0, int64(msec*nsecPerMsec)).UTC())
return nil
}
// WriteJSONResponse writes headers with the code, encodes resp into w, and logs
// any errors it encounters. r is used to get additional information from the
// request.
func WriteJSONResponse(w http.ResponseWriter, r *http.Request, code int, resp any) {
h := w.Header()
h.Set(httphdr.ContentType, HdrValApplicationJSON)
h.Set(httphdr.Server, UserAgent())
w.WriteHeader(code)
err := json.NewEncoder(w).Encode(resp)
if err != nil {
log.Error("aghhttp: writing json resp to %s %s: %s", r.Method, r.URL.Path, err)
}
}
// WriteJSONResponseOK writes headers with the code 200 OK, encodes v into w,
// and logs any errors it encounters. r is used to get additional information
// from the request.
func WriteJSONResponseOK(w http.ResponseWriter, r *http.Request, v any) {
WriteJSONResponse(w, r, http.StatusOK, v)
}
// ErrorCode is the error code as used by the HTTP API. See the ErrorCode
// definition in the OpenAPI specification.
type ErrorCode string
// ErrorCode constants.
//
// TODO(a.garipov): Expand and document codes.
const (
// ErrorCodeTMP000 is the temporary error code used for all errors.
ErrorCodeTMP000 = ""
)
// HTTPAPIErrorResp is the error response as used by the HTTP API. See the
// BadRequestResp, InternalServerErrorResp, and similar objects in the OpenAPI
// specification.
type HTTPAPIErrorResp struct {
Code ErrorCode `json:"code"`
Msg string `json:"msg"`
}
// WriteJSONResponseError encodes err as a JSON error into w, and logs any
// errors it encounters. r is used to get additional information from the
// request.
func WriteJSONResponseError(w http.ResponseWriter, r *http.Request, err error) {
log.Error("aghhttp: writing json error to %s %s: %s", r.Method, r.URL.Path, err)
WriteJSONResponse(w, r, http.StatusUnprocessableEntity, &HTTPAPIErrorResp{
Code: ErrorCodeTMP000,
Msg: err.Error(),
})
}