snowflake/proxy/websocket.coffee

57 lines
1.7 KiB
CoffeeScript

###
Only websocket-specific stuff.
###
DEFAULT_PORTS =
http: 80
https: 443
# Build an escaped URL string from unescaped components. Only scheme and host
# are required. See RFC 3986, section 3.
buildUrl = (scheme, host, port, path, params) ->
parts = []
parts.push(encodeURIComponent scheme)
parts.push '://'
# If it contains a colon but no square brackets, treat it as IPv6.
if host.match(/:/) && !host.match(/[[\]]/)
parts.push '['
parts.push host
parts.push ']'
else
parts.push(encodeURIComponent host)
if undefined != port && DEFAULT_PORTS[scheme] != port
parts.push ':'
parts.push(encodeURIComponent port.toString())
if undefined != path && '' != path
if !path.match(/^\//)
path = '/' + path
###
Slash is significant so we must protect it from encodeURIComponent, while
still encoding question mark and number sign. RFC 3986, section 3.3: 'The
path is terminated by the first question mark ('?') or number sign ('#')
character, or by the end of the URI. ... A path consists of a sequence of
path segments separated by a slash ('/') character.'
###
path = path.replace /[^\/]+/, (m) ->
encodeURIComponent m
parts.push path
if undefined != params
parts.push '?'
parts.push Query.buildString params
parts.join ''
makeWebsocket = (addr) ->
url = buildUrl 'wss', addr.host, addr.port, '/'
ws = new WebSocket url
###
'User agents can use this as a hint for how to handle incoming binary data: if
the attribute is set to 'blob', it is safe to spool it to disk, and if it is
set to 'arraybuffer', it is likely more efficient to keep the data in memory.'
###
ws.binaryType = 'arraybuffer'
ws