Daniel Stenberg b935fd4a07

docs: make each libcurl man specify protocol(s)

The mandatory header now has a mandatory list of protocols for which the
manpage is relevant.

Most man pages already has a "PROTOCOLS" section, but this introduces a
stricter way to specify the relevant protocols.

cd2nroff verifies that at least one protocol is mentioned (which can be
`*`).

This information is not used just yet, but A) the PROTOCOLS section can
now instead get generated and get a unified wording across all manpages
and B) this allows us to more reliably filter/search for protocol
specific manpages/options.

Closes #13166

2024-03-21 15:27:06 +01:00

2.1 KiB

Raw Blame History

c: Copyright (C) Daniel Stenberg, daniel@haxx.se, et al. SPDX-License-Identifier: curl Title: CURLOPT_BUFFERSIZE Section: 3 Source: libcurl See-also: - CURLOPT_MAXFILESIZE (3) - CURLOPT_MAX_RECV_SPEED_LARGE (3) - CURLOPT_UPLOAD_BUFFERSIZE (3) - CURLOPT_WRITEFUNCTION (3) Protocol: - *

NAME

CURLOPT_BUFFERSIZE - receive buffer size

SYNOPSIS

#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_BUFFERSIZE, long size);

DESCRIPTION

Pass a long specifying your preferred size (in bytes) for the receive buffer in libcurl. The main point of this would be that the write callback gets called more often and with smaller chunks. Secondly, for some protocols, there is a benefit of having a larger buffer for performance.

This is just treated as a request, not an order. You cannot be guaranteed to actually get the given size.

This buffer size is by default CURL_MAX_WRITE_SIZE (16kB). The maximum buffer size allowed to be set is CURL_MAX_READ_SIZE (10MB). The minimum buffer size allowed to be set is 1024.

DO NOT set this option on a handle that is currently used for an active transfer as that may lead to unintended consequences.

The maximum size was 512kB until 7.88.0.

Starting in libcurl 8.7.0, there is just a single transfer buffer allocated per multi handle. This buffer is used by all easy handles added to a multi handle no matter how many parallel transfers there are. The buffer remains allocated as long as there are active transfers.

DEFAULT

CURL_MAX_WRITE_SIZE (16kB)

PROTOCOLS

All

EXAMPLE

int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    CURLcode res;
    curl_easy_setopt(curl, CURLOPT_URL, "sftp://example.com/foo.bin");

    /* ask libcurl to allocate a larger receive buffer */
    curl_easy_setopt(curl, CURLOPT_BUFFERSIZE, 120000L);

    res = curl_easy_perform(curl);

    curl_easy_cleanup(curl);
  }
}

AVAILABILITY

Added in 7.10. Growing the buffer was added in 7.53.0.

RETURN VALUE

Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.

2.1 KiB Raw Blame History