Save on memory more

JuliaString · Nov 24, 2017 · a5d65d4 · a5d65d4
1 parent dae2726
commit a5d65d4
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Showing 2 changed files with 73 additions and 38 deletions.
diff --git a/src/corefunctionality.jl b/src/corefunctionality.jl
@@ -1,32 +1,29 @@
 
-const pool = WeakKeyDict{String, WeakRef}()
+const pool = WeakKeyDict{String, Void}()
 
-# work around   https://github.com/JuliaLang/julia/issues/24721
-function patched_get!(wkd::WeakKeyDict{K}, key, default) where{K}
+function intern!(wkd::WeakKeyDict{K}, key)::K where K
     kk = convert(K, key)
     kwr = WeakRef(kk)
     lock(wkd) do
-        if haskey(wkd.ht, kwr)
-            return wkd.ht[kwr]
+        found_key = getkey(wkd.ht, kwr, Base.secret_table_token)
+        found = !(found_key === Base.secret_table_token)
+
+        if found
+            return found_key.value
         else
             # Not found, so add it,
             # and mark it as a reference we track to delete!
             finalizer(kk, wkd.finalizer)
-            return wkd.ht[kwr]=default
+            wkd.ht[kwr]=nothing
+            return kk
         end
     end
 end
 
 struct InternedString <: AbstractString
     value::String
 
-    function InternedString(s)
-        #can't use get! as  https://github.com/JuliaLang/julia/issues/24721
-        value = convert(String, s)
-        ret = new(patched_get!(pool, value, WeakRef(value)).value)
-        @assert ret.value == value
-        ret
-    end
+    InternedString(s) = new(intern!(pool, s))
 end
 
 macro i_str(s)

diff --git a/test/corefunctionality.jl b/test/corefunctionality.jl
@@ -47,30 +47,68 @@ end end
 end end
 
 
-@testset "Garbage Collections" begin let
-    @testset "Garbage Collection 1" begin let
-        empty!(StringInterning.pool)
-        @test length(StringInterning.pool)==0
-        ai =  InternedString("Hello My Friends3")
-        ai = [44] #remove the reference
-        gc();
-        @test 0<=length(StringInterning.pool)<=1 #May or may not have been collected yet
-    end end
-
-    @testset "Garbage Collection 2" begin let
-        empty!(StringInterning.pool)
-        @test length(StringInterning.pool)==0
-        ai = InternedString("Hello My Friends4")
-        bi = InternedString(join(["Hello", "My", "Friends4"], " "))
-        @test ai.value === bi.value
-        @test length(StringInterning.pool)==1
-        use(ai,bi)
-        ai = [44]
-        gc()
-        @test length(StringInterning.pool)==1 #don't collect when only one reference is gone
-        use(bi)
-        bi=[32]
+
+@testset "Garbage Collection 1" begin let
+    empty!(StringInterning.pool)
+    @test length(StringInterning.pool)==0
+    ai =  InternedString("Hello My Friends3")
+    ai = [44] #remove the reference
+    gc();
+    @test 0<=length(StringInterning.pool)<=1 #May or may not have been collected yet
+end end
+
+@testset "Garbage Collection 2" begin let
+    empty!(StringInterning.pool)
+    @test length(StringInterning.pool)==0
+    ai = InternedString("Hello My Friends4")
+    bi = InternedString(join(["Hello", "My", "Friends4"], " "))
+    @test ai.value === bi.value
+    @test length(StringInterning.pool)==1
+    use(ai,bi)
+    ai = [44]
+    gc()
+    @test length(StringInterning.pool)==1 #don't collect when only one reference is gone
+    use(bi)
+    bi=[32]
+    gc()
+    @test 0<=length(StringInterning.pool)<=1
+end end
+
+
+
+srand(1)
+@testset "Garbage Collection stress test" begin let
+    empty!(StringInterning.pool)
+    oldpoolsize = length(StringInterning.pool)
+    function checkpool(op)
         gc()
-        @test 0<=length(StringInterning.pool)<=1
-    end end
+        @test op(length(StringInterning.pool), oldpoolsize)
+        oldpoolsize = length(StringInterning.pool)
+    end
+
+    originals = [randstring(rand(1:1024)) for _ in 1:10^5]
+    n_orginals = length(originals)
+
+    interns = InternedString.(originals);
+    checkpool(>)
+
+    for ii in 1:10^5
+        push!(interns, InternedString(rand(originals)))
+    end
+    checkpool(==)
+    originals = nothing
+    checkpool(==)
+
+
+
+    for ii in 1:30
+        shuffle!(interns)
+        for jj in 1:1000
+            pop!(interns)
+        end
+        checkpool(<=)
+    end
+
+    # This one matters:
+    @test length(StringInterning.pool) < n_orginals
 end end