view mod_storage_gdbm/mod_storage_gdbm.lua @ 5119:048e339706ba

mod_rest: Remove manual reference expansion in schema This hack was originally added to reduce the number of definitions of common attributes (type, to, from etc) and payloads (e.g. delay). This predated pointers and references, and until now was needed because parsing picked out the correct stanza kind from the schema, which broke internal references. Removing this hack paves the way for allowing the schema to be configured or customized more easily.
author Kim Alvefur <zash@zash.se>
date Tue, 20 Dec 2022 21:48:28 +0100
parents 95ad6e68e203
children
line wrap: on
line source

-- mod_storage_gdbm
-- Copyright (C) 2014-2015 Kim Alvefur
--
-- This file is MIT/X11 licensed.
-- 
-- Depends on lgdbm:
-- http://webserver2.tecgraf.puc-rio.br/~lhf/ftp/lua/#lgdbm
--
-- luacheck: globals open purge

local gdbm = require"gdbm";
local path = require"util.paths";
local lfs = require"lfs";
local st = require"util.stanza";
local uuid = require"util.uuid".generate;

local serialization = require"util.serialization";
local serialize = serialization.serialize;
local deserialize = serialization.deserialize;

local g_set, g_get, g_del = gdbm.replace, gdbm.fetch, gdbm.delete;
local g_first, g_next = gdbm.firstkey, gdbm.nextkey;

local empty = {};

local function id(v) return v; end

local function is_stanza(s)
	return getmetatable(s) == st.stanza_mt;
end

local base_path = path.resolve_relative_path(prosody.paths.data, module.host);
lfs.mkdir(base_path);

local cache = {};

local keyval = {};
local keyval_mt = { __index = keyval, suffix = ".db" };

function keyval:set(user, value)
	if type(value) == "table" and next(value) == nil then
		value = nil;
	end
	if value ~= nil then
		value = serialize(value);
	end
	local ok, err = (value and g_set or g_del)(self._db, user or "@", value);
	if not ok then return nil, err; end
	return true;
end

function keyval:get(user)
	local data, err = g_get(self._db, user or "@");
	if not data then return nil, err; end
	return deserialize(data);
end

local function g_keys(db, key)
	return (key == nil and g_first or g_next)(db, key);
end

function keyval:users()
	return g_keys, self._db, nil;
end

local archive = {};
local archive_mt = { __index = archive, suffix = ".adb" };

archive.get = keyval.get;
archive.set = keyval.set;

function archive:append(username, key, value, when, with)
	if type(when) ~= "number" then
		when, with, value = value, when, with;
	end

	key = key or uuid();
	local meta = self:get(username);
	if not meta then
		meta = {};
	end
	local i = meta[key] or #meta+1;
	local type;
	if is_stanza(value) then
		type, value = "stanza", st.preserialize(value);
	end
	meta[i] = { key = key, when = when, with = with, type = type };
	meta[key] = i;
	local prefix = (username or "@") .. "#";
	local ok, err = self:set(prefix..key, value);
	if not ok then return nil, err; end
	ok, err = self:set(username, meta);
	if not ok then return nil, err; end
	return key;
end

local deserialize_map = {
	stanza = st.deserialize;
};

function archive:find(username, query)
	query = query or empty;
	local meta = self:get(username) or empty;
	local prefix = (username or "@") .. "#";
	local reverse = query.reverse;
	local step = reverse and -1 or 1;
	local first = meta[query.after];
	local last = meta[query.before];
	-- we don't want to include the actual 'after' or 'before' item
	if first then first = first + 1; end
	if last then last = last - 1; end
	first, last = first or 1, last or #meta;
	if reverse then first, last = last, first; end
	local limit = query.limit;
	local count = 0;
	return function ()
		if limit and count >= limit then return end
		local item, value;
		for i = first, last, step do
			item = meta[i];
			if (not query.with or item.with == query.with)
			and (not query.start or item.when >= query.start)
			and (not query["end"] or item.when <= query["end"]) then
				first = i + step; count = count + 1;
				value = self:get(prefix..item.key);
				return item.key, (deserialize_map[item.type] or id)(value), item.when, item.with;
			end
		end
	end
end

local drivers = {
	keyval = keyval_mt;
	archive = archive_mt;
}

function open(_, store, typ)
	typ = typ or "keyval";
	local driver_mt = drivers[typ];
	if not driver_mt then
		return nil, "unsupported-store";
	end

	local db_path = path.join(base_path, store) .. driver_mt.suffix;

	local db = cache[db_path];
	if not db then
		db = assert(gdbm.open(db_path, "c"));
		cache[db_path] = db;
	end
	return setmetatable({ _db = db; _path = db_path; store = store, type = typ }, driver_mt);
end

function purge(_, user)
	for dir in lfs.dir(base_path) do
		local name, ext = dir:match("^(.-)%.a?db$");
		if ext == ".db" then
			open(_, name, "keyval"):set(user, nil);
		elseif ext == ".adb" then
			open(_, name, "archive"):delete(user);
		end
	end
	return true;
end

function module.unload()
	for db_path, db in pairs(cache) do
		module:log("debug", "Closing db at %q", db_path);
		gdbm.reorganize(db);
		gdbm.sync(db);
		gdbm.close(db);
	end
end

module:provides"storage";