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# Get the value associated to a variable in the process environment.
# Returns "" if the variable is not set.
# @category System
def getenv(~default="", s) =
list.assoc(default=default, s, environment())
end
# Split the arguments of an url of the form `arg=bar&arg2=bar2` into
# `[("arg","bar"),("arg2","bar2")]`. The returned strings are decoded (see
# `url.decode`).
# @category String
# @param args Argument string to split.
def url.split_args(args) =
def f(x) =
ret = r/=/.split(x)
arg = url.decode(list.nth(default="",ret,0))
val = url.decode(list.nth(default="",ret,1))
(arg,val)
end
l = r/&/.split(args)
list.map(f,l)
end
# Split an url of the form `foo?arg=bar&arg2=bar2` into
# `("foo",[("arg","bar"),("arg2","bar2")])`. The returned strings are decoded
# (see `url.decode`).
# @category String
# @param uri Url to split.
def url.split(uri) =
ret = r/([^\?]*)\?(.*)/.exec(uri)
args = ret[2]
if args != "" then
(url.decode(ret[1]),url.split_args(ret[2]))
else
(url.decode(uri),[])
end
end
let frame = ()
# Duration of a frame.
# @category Liquidsoap
def frame.duration =
settings.frame.duration
end
# Keep a record of played files. This is primarily useful to know when a song
# was last played and avoid repetitions.
# @param ~duration Duration (in seconds) after which songs are forgotten. By default, songs are not forgotten which means that the playlog will contain all the songs ever played.
# @param ~hash Function to extract an identifier from the metadata. By default, the filename is used but we could return the artist to know when a song from a given artist was last played for instance.
# @param ~persistency Set a file name where the values are stored and loaded in case the script is restarted.
# @category Source / Track Processing
# @method add Record that file with given metadata has been played.
# @method last How long ago a file was played (in seconds), `infinity` is returned if the song has never been played.
def playlog(~duration=infinity, ~persistency=null(), ~hash=fun(m)->m["filename"])
l = ref([])
# Load from persistency file
if null.defined(persistency) then
if file.exists(null.get(persistency)) then
let json.parse ( parsed : [(string * float)]? ) = file.contents(null.get(persistency))
if null.defined(parsed) then
l := null.get(parsed)
end
end
end
# Save into persistency file
def save()
if null.defined(persistency) then
let json.stringify data = !l
file.write(data=data, null.get(persistency))
end
end
# Remove too old elements
def prune()
if duration != infinity then
t = time()
l := list.assoc.filter(fun(_, tf) -> t - tf <= duration, !l)
end
end
# Add a new entry
def add(m)
prune()
f = hash(m)
l := (f, time()) :: !l
save()
end
# Last time this entry was played
def last(m)
f = hash(m)
time() - list.assoc(default = 0.-infinity, f, !l)
end
{ add=add, last=last }
end
# Top-level init module for convenience
# @flag hidden
init = settings.init
# Memoize the result of a function,
# making sure it is only executed once.
def memoize(fn) =
cached_result = ref([])
fun () -> begin
if !cached_result != [] then
list.hd(!cached_result)
else
result = fn()
cached_result := [result]
result
end
end
end
# Set the current time zone. This is
# equivalent to setting the `TZ` environment
# variable.
# @category Liquidsoap
def time.zone.set(tz) =
setenv("TZ", tz)
end
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