Lesson 21 · Body to the end of the stream

Body to the end of the stream

Not every response declares a length. When there is no Content-Length, the body runs until the connection closes - so today you read the body as everything left on the stream.

The goal

Read the body as all remaining bytes when no Content-Length header is present.

Start here - the target

TO DO

Scenario: Reading a body with no declared length

Givena response with no Content-Length header, the reader positioned at the body "the rest of the stream"

Whenthe body is read to the end of the stream

Thenthe body is exactly "the rest of the stream" (every remaining byte until the stream ends)

Andan empty remaining stream yields an empty body ""

Background

Some responses give no Content-Length - the server just streams the body and then closes the connection to signal the end. HTTP/1.0 worked this way by default, and HTTP/1.1 still allows it. With no declared length, the only framing is the end of the stream itself, so the body is all remaining bytes until EOF. For the rest of the stream sitting on the reader, that is the whole thing.

This is the third and simplest body-framing rule, and it completes the set for now: read Content-Length bytes when the header is present, read to EOF when it is not. The one framing still missing is chunked transfer-encoding, where the body arrives in sized pieces with no length known up front - that is the headline of chapter four. Notice that read-to-close consumes the whole stream, so it cannot share a connection; that tension is exactly what keep-alive resolves.

Make it work

// when there is no Content-Length (and no chunked encoding yet),
// the body is delimited by the connection closing: read the
// reader until EOF and take all of it as the body.
func (r *reader) readAll() ([]byte, error) {
  // read until the stream is exhausted
}

CheckpointDONE

You can read an unframed body as everything up to the end of the stream. Commit and stop here.