quickjs-tart

quickjs-based runtime for wallet-core logic
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CURLOPT_UPKEEP_INTERVAL_MS.md (2035B)

      1 ---
      2 c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
      3 SPDX-License-Identifier: curl
      4 Title: CURLOPT_UPKEEP_INTERVAL_MS
      5 Section: 3
      6 Source: libcurl
      7 See-also:
      8   - CURLOPT_TCP_KEEPALIVE (3)
      9 Protocol:
     10   - All
     11 Added-in: 7.62.0
     12 ---
     13 
     14 # NAME
     15 
     16 CURLOPT_UPKEEP_INTERVAL_MS - connection upkeep interval
     17 
     18 # SYNOPSIS
     19 
     20 ~~~c
     21 #include <curl/curl.h>
     22 
     23 CURLcode curl_easy_setopt(CURL *handle, CURLOPT_UPKEEP_INTERVAL_MS,
     24                           long upkeep_interval_ms);
     25 ~~~
     26 
     27 # DESCRIPTION
     28 
     29 Some protocols have "connection upkeep" mechanisms. These mechanisms usually
     30 send some traffic on existing connections in order to keep them alive; this
     31 can prevent connections from being closed due to overzealous firewalls, for
     32 example.
     33 
     34 The user needs to explicitly call curl_easy_upkeep(3) in order to
     35 perform the upkeep work.
     36 
     37 Currently the only protocol with a connection upkeep mechanism is HTTP/2: when
     38 the connection upkeep interval is exceeded and curl_easy_upkeep(3)
     39 is called, an HTTP/2 PING frame is sent on the connection.
     40 
     41 # DEFAULT
     42 
     43 CURL_UPKEEP_INTERVAL_DEFAULT (currently defined as 60000L, which is 60 seconds)
     44 
     45 # %PROTOCOLS%
     46 
     47 # EXAMPLE
     48 
     49 ~~~c
     50 int main(void)
     51 {
     52   CURL *curl = curl_easy_init();
     53   if(curl) {
     54     /* Make a connection to an HTTP/2 server. */
     55     curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
     56 
     57     /* Set the interval to 30000ms / 30s */
     58     curl_easy_setopt(curl, CURLOPT_UPKEEP_INTERVAL_MS, 30000L);
     59 
     60     curl_easy_perform(curl);
     61 
     62     /* Perform more work here. */
     63 
     64     /* While the connection is being held open, curl_easy_upkeep() can be
     65        called. If curl_easy_upkeep() is called and the time since the last
     66        upkeep exceeds the interval, then an HTTP/2 PING is sent. */
     67     curl_easy_upkeep(curl);
     68 
     69     /* Perform more work here. */
     70 
     71     /* always cleanup */
     72     curl_easy_cleanup(curl);
     73   }
     74 }
     75 ~~~
     76 
     77 # %AVAILABILITY%
     78 
     79 # RETURN VALUE
     80 
     81 curl_easy_setopt(3) returns a CURLcode indicating success or error.
     82 
     83 CURLE_OK (0) means everything was OK, non-zero means an error occurred, see
     84 libcurl-errors(3).