122 lines
3.3 KiB
Go
122 lines
3.3 KiB
Go
package main
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import (
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"encoding/json"
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"errors"
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"fmt"
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"io"
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"net/http"
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"net/url"
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"strconv"
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"strings"
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"github.com/julienschmidt/httprouter"
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"greenlight.alexedwards.net/internal/validator"
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)
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type envelope map[string]any
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func (app *application) readIDParam(r *http.Request) (int64, error) {
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params := httprouter.ParamsFromContext(r.Context())
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id, err := strconv.ParseInt(params.ByName("id"), 10, 64)
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if err != nil || id < 1 {
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return 0, errors.New("invalid id paramerer")
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}
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return id, nil
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}
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func (app *application) writeJSON(w http.ResponseWriter, status int, data envelope, headers http.Header) error {
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js, err := json.MarshalIndent(data, "", "\t")
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if err != nil {
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return err
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}
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js = append(js, '\n')
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for key, value := range headers {
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w.Header()[key] = value
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}
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w.Header().Set("Content-Type", "application/json")
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w.WriteHeader(status)
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w.Write(js)
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return nil
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}
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func (app *application) readJSON(w http.ResponseWriter, r *http.Request, dst any) error {
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maxBytes := 1_048_576
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r.Body = http.MaxBytesReader(w, r.Body, int64(maxBytes))
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dec := json.NewDecoder(r.Body)
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dec.DisallowUnknownFields()
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err := dec.Decode(dst)
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if err != nil {
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var syntaxError *json.SyntaxError
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var unmarshalTypeError *json.UnmarshalTypeError
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var invalidUnmarshalError *json.InvalidUnmarshalError
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var maxBytesError *http.MaxBytesError
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switch {
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case errors.As(err, &syntaxError):
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return fmt.Errorf("body contains badly-formed JSON (at character %d)", syntaxError.Offset)
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case errors.Is(err, io.ErrUnexpectedEOF):
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return errors.New("body contains badly-formed JSON")
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case errors.As(err, &unmarshalTypeError):
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if unmarshalTypeError.Field != "" {
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return fmt.Errorf("body contains an invalid value for the %q field (at character %d)", unmarshalTypeError.Field, unmarshalTypeError.Offset)
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}
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return fmt.Errorf("body contains an invalid value (at character %d)", unmarshalTypeError.Offset)
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case errors.Is(err, io.EOF):
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return errors.New("body must not be empty")
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case strings.HasPrefix(err.Error(), "json: unknown field "):
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fieldName := strings.TrimPrefix(err.Error(), "json: unknown field ")
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return fmt.Errorf("body contains unknown key %s", fieldName)
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case errors.As(err, &maxBytesError):
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return fmt.Errorf("body must not be larger than %d bytes", maxBytesError.Limit)
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case errors.As(err, &invalidUnmarshalError):
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panic(err)
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default:
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return err
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}
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}
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err = dec.Decode(&struct{}{})
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if err != io.EOF {
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return errors.New("body must only contain a single JSON value")
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}
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return nil
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}
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func (app *application) readString(qs url.Values, key string, defaultValue string) string {
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s := qs.Get(key)
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if s == "" {
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return defaultValue
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}
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return s
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}
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func (app *application) readCSV(qs url.Values, key string, defaultValue []string) []string {
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csv := qs.Get(key)
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if csv == "" {
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return defaultValue
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}
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return strings.Split(csv, ",")
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}
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func (app *application) readInt(qs url.Values, key string, defaultValue int, v *validator.Validator) int {
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s := qs.Get(key)
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if s == "" {
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return defaultValue
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}
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i, err := strconv.Atoi(s)
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if err != nil {
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v.AddError(key, "must be a integer value")
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return defaultValue
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}
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return i
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}
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func (app *application) background(fn func()) {
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app.wg.Add(1)
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go func() {
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defer app.wg.Done()
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defer func() {
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if err := recover(); err != nil {
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app.logger.PrintError(fmt.Errorf("%s", err), nil)
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}
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}()
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fn()
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}()
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}
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