curl/lib/easyif.h
Stefan Eissing 3755153571
lib: Curl_read/Curl_write clarifications
- replace `Curl_read()`, `Curl_write()` and `Curl_nwrite()` to
  clarify when and at what level they operate
- send/recv of transfer related data is now done via
  `Curl_xfer_send()/Curl_xfer_recv()` which no longer has
  socket/socketindex as parameter. It decides on the transfer
  setup of `conn->sockfd` and `conn->writesockfd` on which
  connection filter chain to operate.
- send/recv on a specific connection filter chain is done via
  `Curl_conn_send()/Curl_conn_recv()` which get the socket index
  as parameter.
- rename `Curl_setup_transfer()` to `Curl_xfer_setup()` for
  naming consistency
- clarify that the special CURLE_AGAIN hangling to return
  `CURLE_OK` with length 0 only applies to `Curl_xfer_send()`
  and CURLE_AGAIN is returned by all other send() variants.
- fix a bug in websocket `curl_ws_recv()` that mixed up data
  when it arrived in more than a single chunk

The method for sending not just raw bytes, but bytes that are either
"headers" or "body". The send abstraction stack, to to bottom, now is:

* `Curl_req_send()`: has parameter to indicate amount of header bytes,
  buffers all data.
* `Curl_xfer_send()`: knows on which socket index to send, returns
  amount of bytes sent.
* `Curl_conn_send()`: called with socket index, returns amount of bytes
  sent.

In addition there is `Curl_req_flush()` for writing out all buffered
bytes.

`Curl_req_send()` is active for requests without body,
`Curl_buffer_send()` still being used for others. This is because the
special quirks need to be addressed in future parts:

* `expect-100` handling
* `Curl_fillreadbuffer()` needs to add directly to the new
  `data->req.sendbuf`
* special body handlings, like `chunked` encodings and line end
  conversions will be moved into something like a Client Reader.

In functions of the pattern `CURLcode xxx_send(..., ssize_t *written)`,
replace the `ssize_t` with a `size_t`. It makes no sense to allow for negative
values as the returned `CURLcode` already specifies error conditions. This
allows easier handling of lengths without casting.

Closes #12964
2024-02-27 14:13:56 +01:00

42 lines
1.5 KiB
C

#ifndef HEADER_CURL_EASYIF_H
#define HEADER_CURL_EASYIF_H
/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
* are also available at https://curl.se/docs/copyright.html.
*
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
* copies of the Software, and permit persons to whom the Software is
* furnished to do so, under the terms of the COPYING file.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
* SPDX-License-Identifier: curl
*
***************************************************************************/
/*
* Prototypes for library-wide functions provided by easy.c
*/
CURLcode Curl_senddata(struct Curl_easy *data, const void *buffer,
size_t buflen, size_t *n);
#ifdef USE_WEBSOCKETS
CURLcode Curl_connect_only_attach(struct Curl_easy *data);
#endif
#ifdef CURLDEBUG
CURL_EXTERN CURLcode curl_easy_perform_ev(struct Curl_easy *easy);
#endif
#endif /* HEADER_CURL_EASYIF_H */