Tribblix: manual page: CURLOPT_STREAM_DEPENDS

CURLOPT_STREAM_DEPENDS_E(3) Introduction to Library Functions

NAME

CURLOPT_STREAM_DEPENDS_E - stream this transfer depends on
exclusively

SYNOPSIS

#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_STREAM_DEPENDS_E,
CURL *dephandle);

DESCRIPTION

Pass a CURL pointer in dephandle to identify the stream within the
same connection that this stream is depending upon exclusively. That
means it depends on it and sets the Exclusive bit.

The spec says "Including a dependency expresses a preference to
allocate resources to the identified stream rather than to the
dependent stream."

Setting a dependency with the exclusive flag for a reprioritized
stream causes all the dependencies of the new parent stream to become
dependent on the reprioritized stream.

This option can be set during transfer.

dephandle must not be the same as handle, that makes this function
return an error. It must be another easy handle, and it also needs to
be a handle of a transfer that is about to be sent over the same
HTTP/2 connection for this option to have an actual effect.

DEFAULT

NULL

PROTOCOLS

This functionality affects http only

EXAMPLE

int main(void)
{
CURL *curl = curl_easy_init();
CURL *curl2 = curl_easy_init(); /* a second handle */
if(curl) {
curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/one");

/* the second depends on the first */
curl_easy_setopt(curl2, CURLOPT_URL, "https://example.com/two");
curl_easy_setopt(curl2, CURLOPT_STREAM_DEPENDS_E, curl);

/* then add both to a multi handle and transfer them */
}
}

AVAILABILITY

Added in curl 7.46.0

RETURN VALUE

curl_easy_setopt(3) returns a CURLcode indicating success or error.

CURLE_OK (0) means everything was OK, non-zero means an error
occurred, see libcurl-errors(3).