"strconv"
	"strings"
	"time"
)

// Reader provides sequential access to the contents of a tar archive.
// Reader.Next advances to the next file in the archive (including the first),
// and then Reader can be treated as an io.Reader to access the file's data.
type Reader struct {
	r    io.Reader
	pad  int64      // Amount of padding (ignored) after current file entry
	curr fileReader // Reader for current file entry

func (r *Reader) AddChecksumNoTrailer(headers http.Header, ignoreValue bool) error {
	cs, err := GetContentChecksum(headers)
	if err != nil {
		return ErrInvalidChecksum
	}
	if cs == nil {
		return nil
	}
	r.contentHash = *cs
	return r.AddNonTrailingChecksum(cs, ignoreValue)
}

// AddNonTrailingChecksum will add a checksum to the reader.
// The checksum cannot be trailing.

# Header-Parameter { #header-parameters }

Sie können Header-Parameter genauso definieren, wie Sie `Query`-, `Path`- und `Cookie`-Parameter definieren.

## `Header` importieren { #import-header }

Importieren Sie zuerst `Header`:

{* ../../docs_src/header_params/tutorial001_an_py310.py hl[3] *}

## `Header`-Parameter deklarieren { #declare-header-parameters }

	hdr := r.opts.HeaderSize // remaining header bytes
	var tokens int           // number of tokens to request

	if hdr > 0 { // available tokens go towards header first
		if hdr < b { // all of header can be accommodated
			r.opts.HeaderSize = 0
			need = int(math.Min(float64(b-hdr), float64(need))) // use remaining tokens towards payload
			tokens = need + hdr
		} else { // part of header can be accommodated
			r.opts.HeaderSize -= b - 1

	"github.com/minio/minio/internal/s3select/jstream"
	"github.com/minio/minio/internal/s3select/sql"
)

// PReader - JSON record reader for S3Select.
// Operates concurrently on line-delimited JSON.
type PReader struct {
	args        *ReaderArgs
	readCloser  io.ReadCloser             // raw input
	buf         *bufio.Reader             // input to the splitter
	current     []jstream.KVS             // current block of results to be returned

// the [ErrInsecurePath] error and use the returned reader.
func NewReader(r io.ReaderAt, size int64) (*Reader, error) {
	if size < 0 {
		return nil, errors.New("zip: size cannot be negative")
	}
	zr := new(Reader)
	var err error
	if err = zr.init(r, size); err != nil && err != ErrInsecurePath {
		return nil, err
	}
	return zr, err
}

func (r *Reader) init(rdr io.ReaderAt, size int64) error {

Und da die `Response` häufig zum Setzen von Headern und Cookies verwendet wird, stellt **FastAPI** diese auch unter `fastapi.Response` bereit.

///

## Benutzerdefinierte Header { #custom-headers }

Beachten Sie, dass benutzerdefinierte proprietäre Header <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers" class="external-link" target="_blank">mittels des Präfix `X-`</a> hinzugefügt werden können.

	csv "github.com/minio/csvparser"
	"github.com/minio/minio/internal/bpool"
	"github.com/minio/minio/internal/s3select/sql"
)

// Reader - CSV record reader for S3Select.
type Reader struct {
	args         *ReaderArgs
	readCloser   io.ReadCloser          // raw input
	buf          *bufio.Reader          // input to the splitter
	columnNames  []string               // names of columns

Sie können die erforderlichen Header in der Dokumentationsoberfläche unter `/docs` sehen:

<div class="screenshot">
<img src="/img/tutorial/header-param-models/image01.png">
</div>

## Zusätzliche Header verbieten { #forbid-extra-headers }

In einigen speziellen Anwendungsfällen (wahrscheinlich nicht sehr häufig) möchten Sie möglicherweise die **Header einschränken**, die Sie erhalten möchten.

    /**
     * Add a header with the specified name and formatted date. Does validation of header names and
     * value.
     */
    fun add(
      name: String,
      value: Date,
    ) = add(name, value.toHttpDateString())

    /**
     * Add a header with the specified name and formatted instant. Does validation of header names
     * and value.
     */