Function QoS returns HTTP API wrapped within simple request priority manager.
HttpAPI QoS(http_api, default_priority = 3)
Simply wrap minetest.request_http_api with QoS and you're good to go.
local http = minetest.request_http_api()
http = QoS and QoS(http, 2) or httpor alternative if you like:
local http = QoS and QoS(minetest.request_http_api(), 2) or minetest.request_http_api()QoS comes with 3 priority levels without interesting names, priority levels are 1, 2 and 3.
Lowest number is highest priority and priority 1 requests can cause queue to get clogged.
Priorities 2 and 3 will always leave empty space for priority 1 requests and cannot completely fill queues ever.
Queued requests will be processed in first in, first out order but in a way that queued highest priority requests will be handled first and lower priorities only if there's still free slots for parallel processing.
Configuration key value pairs goes to main minetest.cfg. Default values listed below.
Code for solving dynamic default values is shown between < and >.
Changing these values makes them static.
Important Minetest engine configuration keys:
curl_parallel_limit = 8How many http requests can be parallelized by engine. It is recommended to increase this a bit when using qos mod.
QoS configuration keys:
qos.info_priv = basic_privsqos.admin_priv = basic_privsqos.register_chatcommands = trueqos.enforce_timeouts = falseqos.queue_size.1 = <curl_parallel_limit * 16>qos.queue_size.2 = <curl_parallel_limit * 12>qos.queue_size.3 = <curl_parallel_limit * 8>qos.max_timeout.1 = 5qos.max_timeout.2 = 4qos.max_timeout.3 = 3qos.limits.1 = curl_parallel_limit * 4Limit queue utilization to 400%, this forces to overcommit requests to engine queue. Engine queues are not very efficient as of Minetest 5.4, for very large queues it is recommended to keep this smaller.qos.limits.2 = <math.floor(curl_parallel_limit * 0.8)>Limit queue utilization to 80% by default. Attempts to always leave at least 20% reserved for priority 1 requests.qos.limits.3 = <math.floor(curl_parallel_limit * 0.5)>Limit queue utilization to 50% by default. Attempts to always leaves at least 50% reserved for priority 2 and 1.
QoS provides priority_override as last argument for HTTP API functions, this can be used to override default priority.
http.fetch(req, callback, priority_override)If nopriority_overrideprovided then one given toQoS(http_api, priority)initialization function is used.http.fetch_async(req, priority_override)If nopriority_overrideprovided then one given toQoS(http_api, priority)initialization function is used.
QoS.queue_length(priority)Return total number of queued requests by priority. If priority not given then return sum of all priorities.QoS.active_requests()Return total number of active executed but not yet finished requests.QoS.active_utilization()Return % utilization of engine request queue.QoS.queue_size(priority)Return size of QoS request queue.QoS.utilization(priority)Return % utilization of queue by priority. If priority not given then aggregate utilization of all queues is returned.
QoS.data.queues[<priority>]Direct access to queues, seeQueue.QoS.data.dropped[<priority>]Dropped request counter. Behavior is about to change, currently ever increasing counters for dropped requests.
Queue:push(value)Push variable to queue, normally should not be used externally.Queue:pop()Remove and return variable from queue, normally should not be used externally.Queue:clear()Clear all values from queue, does not return values.
/qos:queue_length [priority]Return current QoS queue length./qos:active_requestsReturn number of active requests executed with QoS controller./qos:active_utilizationReturn current QoS active requests utilization percentage value./qos:utilization [priority]Return current QoS queue utilization percentage value./qos:clear <priority>|allClears selected or all queues. All queued requests are gone for good.