Software /
code /
verse
File
plugins/compression.lua @ 383:72be3c2cf602
libs.adhoc: Don't set unintentional globals
author | Kim Alvefur <zash@zash.se> |
---|---|
date | Tue, 05 May 2015 01:10:33 +0200 |
parent | 380:0891b4e27766 |
line wrap: on
line source
-- Copyright (C) 2009-2010 Matthew Wild -- Copyright (C) 2009-2010 Tobias Markmann -- -- This project is MIT/X11 licensed. Please see the -- COPYING file in the source package for more information. -- local verse = require "verse"; local zlib = require "zlib"; local xmlns_compression_feature = "http://jabber.org/features/compress" local xmlns_compression_protocol = "http://jabber.org/protocol/compress" local xmlns_stream = "http://etherx.jabber.org/streams"; local compression_level = 9; -- returns either nil or a fully functional ready to use inflate stream local function get_deflate_stream(session) local status, deflate_stream = pcall(zlib.deflate, compression_level); if status == false then local error_st = verse.stanza("failure", {xmlns=xmlns_compression_protocol}):tag("setup-failed"); session:send(error_st); session:error("Failed to create zlib.deflate filter: %s", tostring(deflate_stream)); return end return deflate_stream end -- returns either nil or a fully functional ready to use inflate stream local function get_inflate_stream(session) local status, inflate_stream = pcall(zlib.inflate); if status == false then local error_st = verse.stanza("failure", {xmlns=xmlns_compression_protocol}):tag("setup-failed"); session:send(error_st); session:error("Failed to create zlib.inflate filter: %s", tostring(inflate_stream)); return end return inflate_stream end -- setup compression for a stream local function setup_compression(session, deflate_stream) function session:send(t) --TODO: Better code injection in the sending process local status, compressed, eof = pcall(deflate_stream, tostring(t), 'sync'); if status == false then session:close({ condition = "undefined-condition"; text = compressed; extra = verse.stanza("failure", {xmlns=xmlns_compression_protocol}):tag("processing-failed"); }); session:warn("Compressed send failed: %s", tostring(compressed)); return; end session.conn:write(compressed); end; end -- setup decompression for a stream local function setup_decompression(session, inflate_stream) local old_data = session.data session.data = function(conn, data) session:debug("Decompressing data..."); local status, decompressed, eof = pcall(inflate_stream, data); if status == false then session:close({ condition = "undefined-condition"; text = decompressed; extra = verse.stanza("failure", {xmlns=xmlns_compression_protocol}):tag("processing-failed"); }); stream:warn("%s", tostring(decompressed)); return; end return old_data(conn, decompressed); end; end function verse.plugins.compression(stream) local function handle_features(features) if not stream.compressed then -- does remote server support compression? local comp_st = features:child_with_name("compression"); if comp_st then -- do we support the mechanism for a in comp_st:children() do local algorithm = a[1] if algorithm == "zlib" then stream:send(verse.stanza("compress", {xmlns=xmlns_compression_protocol}):tag("method"):text("zlib")) stream:debug("Enabled compression using zlib.") return true; end end session:debug("Remote server supports no compression algorithm we support.") end end end local function handle_compressed(stanza) if stanza.name == "compressed" then stream:debug("Activating compression...") -- create deflate and inflate streams local deflate_stream = get_deflate_stream(stream); if not deflate_stream then return end local inflate_stream = get_inflate_stream(stream); if not inflate_stream then return end -- setup compression for stream.w setup_compression(stream, deflate_stream); -- setup decompression for stream.data setup_decompression(stream, inflate_stream); stream.compressed = true; stream:reopen(); elseif stanza.name == "failure" then stream:warn("Failed to establish compression"); end end stream:hook("stream-features", handle_features, 250); stream:hook("stream/"..xmlns_compression_protocol, handle_compressed); end