add alsa_plugins (#70)

* add alsa_plugins

* avoid get!

Project.toml

@@ -4,12 +4,14 @@ repo = "https://github.com/JuliaAudio/PortAudio.jl.git"
 version = "1.1.1"
 
 [deps]
+alsa_plugins_jll = "5ac2f6bb-493e-5871-9171-112d4c21a6e7"
 libportaudio_jll = "2d7b7beb-0762-5160-978e-1ab83a1e8a31"
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
 SampledSignals = "bd7594eb-a658-542f-9e75-4c4d8908c167"
 
 [compat]
 julia = "1.3"
+alsa_plugins_jll = "1.2.2"
 libportaudio_jll = "19.6.0"
 SampledSignals = "2.1.1"
 

src/PortAudio.jl

@@ -1,5 +1,6 @@
 module PortAudio
 
+using alsa_plugins_jll: alsa_plugins_jll
 using libportaudio_jll, SampledSignals
 
 import Base: eltype, show
@@ -402,6 +403,11 @@ function __init__()
             confdir = searchdirs[confdir_idx]
             ENV[envkey] = confdir
         end
+
+        plugin_key = "ALSA_PLUGIN_DIR"
+        if plugin_key ∉ keys(ENV) && alsa_plugins_jll.is_available()
+            ENV[plugin_key] = joinpath(alsa_plugins_jll.artifact_dir, "lib", "alsa-lib")
+        end
     end
     # initialize PortAudio on module load. libportaudio prints a bunch of
     # junk to STDOUT on initialization, so we swallow it.