1CURLOPT_STREAM_WEIGHT(3) curl_easy_setopt options CURLOPT_STREAM_WEIGHT(3)
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6 CURLOPT_STREAM_WEIGHT - set numerical stream weight
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9 #include <curl/curl.h>
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11 CURLcode curl_easy_setopt(CURL *handle, CURLOPT_STREAM_WEIGHT, long
12 weight);
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15 Set the long weight to a number between 1 and 256.
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17 When using HTTP/2, this option sets the individual weight for this par‐
18 ticular stream used by the easy handle. Setting and using weights only
19 makes sense and is only usable when doing multiple streams over the
20 same connections, which thus implies that you use CURLMOPT_PIPELIN‐
21 ING(3).
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23 This option can be set during transfer and will then cause the updated
24 weight info get sent to the server the next time an HTTP/2 frame is
25 sent to the server.
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27 See section 5.3 of RFC 7540 for protocol details:
28 https://httpwg.github.io/specs/rfc7540.html#StreamPriority
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30 Streams with the same parent should be allocated resources proportion‐
31 ally based on their weight. So if you have two streams going, stream A
32 with weight 16 and stream B with weight 32, stream B will get two
33 thirds (32/48) of the available bandwidth (assuming the server can send
34 off the data equally for both streams).
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37 If nothing is set, the HTTP/2 protocol itself will use its own default
38 which is 16.
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41 HTTP/2
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44 CURL *curl = curl_easy_init();
45 CURL *curl2 = curl_easy_init(); /* a second handle */
46 if(curl) {
47 curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/one");
48 curl_easy_setopt(curl, CURLOPT_STREAM_WEIGHT, 10L);
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50 /* the second has twice the weight */
51 curl_easy_setopt(curl2, CURLOPT_URL, "https://example.com/two");
52 curl_easy_setopt(curl2, CURLOPT_STREAM_WEIGHT, 20L);
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54 /* then add both to a multi handle and transfer them! */
55 }
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58 Added in 7.46.0
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61 Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION
62 if not.
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65 CURLOPT_STREAM_DEPENDS(3), CURLOPT_STREAM_DEPENDS_E(3), CUR‐
66 LOPT_PIPEWAIT(3), CURLMOPT_PIPELINING(3),
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70libcurl 7.76.1 November 04, 2020 CURLOPT_STREAM_WEIGHT(3)