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util/caps.lua @ 11962:9a70a543c727

util.async: Add next-tick configuration Running woken runners in the next iteration of the event loop prevents unexpected recursion, unexpected tracebacks, and is generally more predictable. The pattern is borrowed from util.promise, where we're now doing the same.
author Matthew Wild <mwild1@gmail.com>
date Mon, 29 Nov 2021 14:14:30 +0000
parent 8555:4f0f5b49bb03
child 12975:d10957394a3c
line wrap: on
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-- Prosody IM
-- Copyright (C) 2008-2010 Matthew Wild
-- Copyright (C) 2008-2010 Waqas Hussain
--
-- This project is MIT/X11 licensed. Please see the
-- COPYING file in the source package for more information.
--

local base64 = require "util.encodings".base64.encode;
local sha1 = require "util.hashes".sha1;

local t_insert, t_sort, t_concat = table.insert, table.sort, table.concat;
local ipairs = ipairs;

local _ENV = nil;
-- luacheck: std none

local function calculate_hash(disco_info)
	local identities, features, extensions = {}, {}, {};
	for _, tag in ipairs(disco_info) do
		if tag.name == "identity" then
			t_insert(identities, (tag.attr.category or "").."\0"..(tag.attr.type or "").."\0"..(tag.attr["xml:lang"] or "").."\0"..(tag.attr.name or ""));
		elseif tag.name == "feature" then
			t_insert(features, tag.attr.var or "");
		elseif tag.name == "x" and tag.attr.xmlns == "jabber:x:data" then
			local form = {};
			local FORM_TYPE;
			for _, field in ipairs(tag.tags) do
				if field.name == "field" and field.attr.var then
					local values = {};
					for _, val in ipairs(field.tags) do
						val = #val.tags == 0 and val:get_text();
						if val then t_insert(values, val); end
					end
					t_sort(values);
					if field.attr.var == "FORM_TYPE" then
						FORM_TYPE = values[1];
					elseif #values > 0 then
						t_insert(form, field.attr.var.."\0"..t_concat(values, "<"));
					else
						t_insert(form, field.attr.var);
					end
				end
			end
			t_sort(form);
			form = t_concat(form, "<");
			if FORM_TYPE then form = FORM_TYPE.."\0"..form; end
			t_insert(extensions, form);
		end
	end
	t_sort(identities);
	t_sort(features);
	t_sort(extensions);
	if #identities > 0 then identities = t_concat(identities, "<"):gsub("%z", "/").."<"; else identities = ""; end
	if #features > 0 then features = t_concat(features, "<").."<"; else features = ""; end
	if #extensions > 0 then extensions = t_concat(extensions, "<"):gsub("%z", "<").."<"; else extensions = ""; end
	local S = identities..features..extensions;
	local ver = base64(sha1(S));
	return ver, S;
end

return {
	calculate_hash = calculate_hash;
};