Standard Library

class ChunkedDecoder

Decodes an HTTP body sent with chunked transfer coding.

since 0.1.0-alpha.1linuxwindowswasm

Overview

Create one decoder per body and give it the received text in pieces, in any sizes; a piece may even end in the middle of a chunk's size line. Each call to feed returns the body text that became complete with that piece. When the final zero-size chunk and the lines after it have been read, isDone becomes true. Chunk extensions after a ; and trailer headers are skipped.

HttpResponse.parse and the HTTP client use this internally, so you only need it to decode a body yourself.

Examples

Feeding a body in two pieces

ChunkedDecoder dec = ChunkedDecoder();
string first = dec.feed("5\r\nhel");
string second = dec.feed("lo\r\n0\r\n\r\n");
console.writeln("[${first}][${second}]");
console.writeln(dec.isDone);

[hel][lo]
true

Fields

bad

bool bad

Becomes true when a chunk size line was not a valid hexadecimal number. Decoding stops and isDone is also true.

isDone

bool isDone

Becomes true once the whole body has been read, or when a malformed chunk made decoding stop.

Methods

feed

feed(string chunk) -> string

Gives the decoder the next piece of the received body and returns the body text decoded so far.

The piece may be of any size and may end anywhere. Text that does not yet form a complete size line is kept until the next call. After isDone is true, further text is ignored.

Parameters

chunk

The next piece of the chunked body, exactly as received.

Returns

The decoded body text that this piece completed; empty when nothing new is ready.

Examples

A malformed size stops decoding

ChunkedDecoder dec = ChunkedDecoder();
string out = dec.feed("zz\r\nabc");
console.writeln("[${out}]");
console.writeln(dec.bad);
console.writeln(dec.isDone);

[]
true
true

See also

• chunkEncode — Wraps text as one chunk of a chunked HTTP body.
• parse — Fills in the response from a complete response text.