Add FixedPointDecimals package extension for FixedDecimal → Dec128 BSON representation

Project.toml

@@ -1,7 +1,7 @@
 name = "LightBSON"
 uuid = "a4a7f996-b3a6-4de6-b9db-2fa5f350df41"
 authors = ["Christian Rorvik <christian.rorvik@gmail.com>"]
-version = "1.4.0"
+version = "1.5.0"
 
 [deps]
 DataStructures = "864edb3b-99cc-5e75-8d2d-829cb0a9cfe8"
@@ -20,6 +20,7 @@ WeakRefStrings = "ea10d353-3f73-51f8-a26c-33c1cb351aa5"
 DataStructures = "0.18, 0.19"
 Dates = "1"
 DecFP = "1"
+FixedPointDecimals = "0.5, 0.6"
 FNVHash = "0.1"
 JSON3 = "1"
 Sockets = "1"
@@ -28,10 +29,17 @@ Transducers = "0.4"
 UUIDs = "1"
 UnsafeArrays = "1"
 WeakRefStrings = "1"
-julia = "1.8"
+julia = "1.9"
+
+[weakdeps]
+FixedPointDecimals = "fb4d412d-6eee-574d-9565-ede6634db7b0"
+
+[extensions]
+LightBSONFixedPointDecimalsExt = "FixedPointDecimals"
 
 [extras]
+FixedPointDecimals = "fb4d412d-6eee-574d-9565-ede6634db7b0"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 
 [targets]
-test = ["Test"]
+test = ["Test", "FixedPointDecimals"]

ext/LightBSONFixedPointDecimalsExt.jl

@@ -0,0 +1,15 @@
+module LightBSONFixedPointDecimalsExt
+
+using LightBSON
+using FixedPointDecimals
+using DecFP
+
+@inline LightBSON.bson_representation_type(::Type{FixedDecimal{T, f}}) where {T, f} = Dec128
+
+@inline LightBSON.bson_representation_convert(::Type{Dec128}, x::FixedDecimal{T, f}) where {T, f} =
+    Dec128(x.i, -f)
+
+@inline LightBSON.bson_representation_convert(::Type{FixedDecimal{T, f}}, x::Dec128) where {T, f} =
+    reinterpret(FixedDecimal{T, f}, T(x * Dec128(1, f)))
+
+end

test/fixed_decimal_tests.jl

@@ -0,0 +1,26 @@
+using FixedPointDecimals
+
+@testset "FixedDecimal" begin
+
+@testset "FixedDecimal{Int64, $f} roundtrip" for (f, v) in [(0, 125), (2, 1.25), (4, 1.25)]
+    buf = empty!(fill(0xff, 1000))
+    writer = BSONWriter(buf)
+    x = FixedDecimal{Int64, f}(v)
+    writer["x"] = x
+    close(writer)
+    @test BSONReader(buf, StrictBSONValidator())["x"][Dec128] == Dec128(x.i, -f)
+    @test BSONReader(buf, StrictBSONValidator())["x"][FixedDecimal{Int64, f}] == x
+end
+
+@testset "FixedDecimal precise conversion" begin
+    x = FixedDecimal{Int64, 2}(1.23)
+    @test Dec128(x.i, -2) == d128"1.23"
+    buf = empty!(fill(0xff, 1000))
+    writer = BSONWriter(buf)
+    writer["x"] = x
+    close(writer)
+    @test BSONReader(buf, StrictBSONValidator())["x"][Dec128] == d128"1.23"
+    @test BSONReader(buf, StrictBSONValidator())["x"][FixedDecimal{Int64, 2}] == x
+end
+
+end

test/runtests.jl

@@ -23,4 +23,5 @@ struct EmptyStruct end
     include("object_id_tests.jl")
     include("convenience_tests.jl")
     include("representation_tests.jl")
+    include("fixed_decimal_tests.jl")
 end