Add Base.close for TBLogger (#109)

* Add Base.close for TBLogger

* Add finalizer for TBLogger

* Add tests for closing and finalizer

Author: darsnack

src/TBLogger.jl

@@ -5,6 +5,16 @@ mutable struct TBLogger{P,S} <: AbstractLogger
     global_step::Int
     step_increment::Int
     min_level::LogLevel
+
+    function TBLogger{P,S}(logdir::P,
+                           file::S,
+                           all_files::Dict{String, S},
+                           global_step::Int,
+                           step_increment::Int,
+                           min_level::LogLevel) where {P,S}
+        lg = new{P, S}(logdir, file, all_files, global_step, step_increment, min_level)
+        return Base.finalizer(Base.close, lg)
+    end
 end
 
 
@@ -195,6 +205,18 @@ Returns the internal step counter of the logger.
 """
 step(lg::TBLogger) = lg.global_step
 
+"""
+    close(lg)
+
+Close the TBLogger `lg`, releasing all file handles.
+"""
+function Base.close(lg::TBLogger)
+    # close open streams
+    for k=keys(lg.all_files)
+        close(lg.all_files[k])
+    end
+end
+
 """
     reset!(lg)
 

test/test_TBLogger.jl

@@ -89,6 +89,31 @@ end
     close.(values(tbl.all_files))
 end
 
+@testset "closing" begin
+    tbl = TBLogger(test_log_dir*"run", tb_overwrite)
+    TensorBoardLogger.add_eventfile(tbl, "pp")
+    files = keys(tbl.all_files)
+
+    close(tbl)
+    @test begin
+        foreach(f -> rm(joinpath(test_log_dir*"run", f)), files)
+        # rm will error if the file is still open
+        true
+    end
+
+    tbl = TBLogger(test_log_dir*"run", tb_overwrite)
+    TensorBoardLogger.add_eventfile(tbl, "pp")
+    files = keys(tbl.all_files)
+
+    tbl = nothing
+    Base.finalize(tbl)
+    @test begin
+        foreach(f -> rm(joinpath(test_log_dir*"run", f)), files)
+        # rm will error if the file is still open
+        true
+    end
+end
+
 @testset "resetting" begin
     tbl = TBLogger(test_log_dir*"run", tb_overwrite)
     TensorBoardLogger.add_eventfile(tbl, "pp")