84 lines
2 KiB
Markdown
84 lines
2 KiB
Markdown
|
---
|
||
|
|
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:
|
||
|
|
- All
|
||
|
|
Added-in: 7.10
|
||
|
|
---
|
||
|
|
|
||
|
|
# NAME
|
||
|
|
|
||
|
|
CURLOPT_BUFFERSIZE - receive buffer size
|
||
|
|
|
||
|
|
# SYNOPSIS
|
||
|
|
|
||
|
|
~~~c
|
||
|
|
#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%
|
||
|
|
|
||
|
|
# EXAMPLE
|
||
|
|
|
||
|
|
~~~c
|
||
|
|
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%
|
||
|
|
|
||
|
|
# RETURN VALUE
|
||
|
|
|
||
|
|
Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.
|