Mercurial > prosody-modules
view mod_storage_multi/mod_storage_multi.lua @ 4282:281a864e7472
mod_pubsub_feeds: Don't skip publishing items after an existing one
I encountered a feed which was backwards, such that older entries were
considered first and then it would skip newer entries.
This may however run into trouble if the feed contains more items than
what's persisted in pubsub.
author | Kim Alvefur <zash@zash.se> |
---|---|
date | Mon, 30 Nov 2020 15:17:29 +0100 |
parents | 8c4a2d85e8bf |
children |
line wrap: on
line source
-- mod_storage_multi local storagemanager = require"core.storagemanager"; local backends = module:get_option_array(module.name); -- TODO better name? -- TODO migrate data "upwards" -- one → one successful write is success -- all → all backends must report success -- majority → majority of backends must report success local policy = module:get_option_string(module.name.."_policy", "all"); local keyval_store = {}; keyval_store.__index = keyval_store; function keyval_store:get(username) local backends = self.backends; local data, err; for i = 1, #backends do module:log("debug", "%s:%s:get(%q)", tostring(backends[i].get), backends[i]._store, username); data, err = backends[i]:get(username); if err then module:log("error", tostring(err)); elseif not data then module:log("debug", "No data returned"); else module:log("debug", "Data returned"); return data, err; end end end -- This is where it gets complicated function keyval_store:set(username, data) local backends = self.backends; local ok, err, backend; local all, one, oks = true, false, 0; for i = 1, #backends do backend = backends[i]; module:log("debug", "%s:%s:set(%q)", tostring(backends[i].get), backends[i].store, username); ok, err = backend:set(username, data); if not ok then module:log("error", "Error in storage driver %s: %s", backend.name, tostring(err)); else oks = oks + 1; end one = one or ok; -- At least one successful write all = all and ok; -- All successful end if policy == "all" then return all, err elseif policy == "majority" then return oks > (#backends/2), err; end -- elseif policy == "one" then return one, err; end local stores = { keyval = keyval_store; } local driver = {}; function driver:open(store, typ) local store_mt = stores[typ or "keyval"]; if store_mt then local my_backends = {}; local driver, opened for i = 1, #backends do driver = storagemanager.load_driver(module.host, backends[i]); opened = driver:open(store, typ); my_backends[i] = assert(driver:open(store, typ)); my_backends[i]._store = store; end return setmetatable({ backends = my_backends }, store_mt); end return nil, "unsupported-store"; end module:provides("storage", driver);