Send debug to debug (#74)

* send to debug

* use Suppressor

* actually, this might be nicer as a macro

* return

* fix, add test

* small fix

* Logging target

* send xrun messages to debug

* Add note to README

* Revert "send xrun messages to debug"

This reverts commit d47abb9072.

Project.toml

@@ -8,15 +8,18 @@ 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"
+Suppressor = "fd094767-a336-5f1f-9728-57cf17d0bbfb"
 
 [compat]
 julia = "1.3"
 alsa_plugins_jll = "1.2.2"
 libportaudio_jll = "19.6.0"
 SampledSignals = "2.1.1"
+Suppressor = "0.2.0"
 
 [extras]
+Logging = "56ddb016-857b-54e1-b83d-db4d58db5568"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 
 [targets]
-test = ["Test"]
+test = ["Logging", "Test"]

README.md

@@ -45,6 +45,16 @@ The `PortAudioStream` type has `source` and `sink` fields which are of type `Por
 
 PortAudio.jl also provides convenience wrappers around the `PortAudioStream` type so you can read and write to it directly, e.g. `write(stream, stream)` will set up a loopback that will read from the input and play it back on the output.
 
+## Debugging
+
+If you are experiencing issues and wish to view detailed logging and debug information, set
+
+```
+ENV["JULIA_DEBUG"] = :PortAudio
+```
+
+before using the package.
+
 ## Examples
 
 ### Set up an audio pass-through from microphone to speaker

src/PortAudio.jl

@@ -1,7 +1,9 @@
 module PortAudio
 
 using alsa_plugins_jll: alsa_plugins_jll
-using libportaudio_jll, SampledSignals
+using libportaudio_jll: libportaudio
+using SampledSignals
+using Suppressor: @capture_err
 
 import Base: eltype, show
 import Base: close, isopen
@@ -14,6 +16,15 @@ export PortAudioStream
 
 include("libportaudio.jl")
 
+macro stderr_as_debug(expression)
+    quote
+        local result
+        debug_message = @capture_err result = $(esc(expression))
+        @debug debug_message
+        result
+    end
+end
+
 # This size is in frames
 
 # data is passed to and from portaudio in chunks with this many frames, because
@@ -94,10 +105,8 @@ mutable struct PortAudioStream{T}
         # finalizer(close, this)
         this.sink = PortAudioSink{T}(outdev.name, this, outchans)
         this.source = PortAudioSource{T}(indev.name, this, inchans)
-        this.stream = suppress_err() do
-            Pa_OpenStream(inparams, outparams, sr, 0, paNoFlag,
+        this.stream = @stderr_as_debug Pa_OpenStream(inparams, outparams, sr, 0, paNoFlag,
                           nothing, nothing)
-        end
 
         Pa_StartStream(this.stream)
         # pre-fill the output stream so we're less likely to underrun
@@ -370,13 +379,6 @@ function discard_input(source::PortAudioSource)
     end
 end
 
-function suppress_err(dofunc::Function)
-    nullfile = @static Sys.iswindows() ? "nul" : "/dev/null"
-    open(nullfile, "w") do io
-        redirect_stderr(dofunc, io)
-    end
-end
-
 function __init__()
     if Sys.islinux()
         envkey = "ALSA_CONFIG_DIR"
@@ -415,9 +417,7 @@ function __init__()
     # junk to STDOUT on initialization, so we swallow it.
     # TODO: actually check the junk to make sure there's nothing in there we
     # don't expect
-    suppress_err() do
-        Pa_Initialize()
-    end
+    @stderr_as_debug Pa_Initialize()
 
     atexit() do
         Pa_Terminate()

test/runtests.jl

@@ -1,10 +1,18 @@
 #!/usr/bin/env julia
 
+using Logging: Debug
 using PortAudio
-using PortAudio: Pa_GetDefaultInputDevice, Pa_GetDefaultOutputDevice, Pa_GetDeviceInfo, Pa_GetHostApiInfo, PortAudioDevice
+using PortAudio: Pa_GetDefaultInputDevice, Pa_GetDefaultOutputDevice, Pa_GetDeviceInfo, Pa_GetHostApiInfo, PortAudioDevice, @stderr_as_debug
 using Test
 using SampledSignals
 
+@testset "Debug messages" begin
+    @test_logs (:debug, "hi") min_level = Debug @test_nowarn @stderr_as_debug begin
+        print(stderr, "hi")
+        true
+    end
+end
+
 @testset "PortAudio Tests" begin
     @testset "Reports version" begin
         io = IOBuffer()