add initialized flag (#59)

Author: bicycle1885

src/stream.jl

@@ -20,19 +20,22 @@ struct TranscodingStream{C<:Codec,S<:IO} <: IO
     # mutable state of the stream
     state::State
 
-    function TranscodingStream{C,S}(codec::C, stream::S, state::State) where {C<:Codec,S<:IO}
+    function TranscodingStream{C,S}(codec::C, stream::S, state::State, initialized::Bool) where {C<:Codec,S<:IO}
         if !isopen(stream)
             throw(ArgumentError("closed stream"))
         elseif state.mode != :idle
             throw(ArgumentError("invalid initial mode"))
         end
-        initialize(codec)
+        if !initialized
+            initialize(codec)
+        end
         return new(codec, stream, state)
     end
 end
 
-function TranscodingStream(codec::C, stream::S, state::State) where {C<:Codec,S<:IO}
-    return TranscodingStream{C,S}(codec, stream, state)
+function TranscodingStream(codec::C, stream::S, state::State;
+                           initialized::Bool=false) where {C<:Codec,S<:IO}
+    return TranscodingStream{C,S}(codec, stream, state, initialized)
 end
 
 const DEFAULT_BUFFER_SIZE = 16 * 2^10  # 16KiB

src/testtools.jl

@@ -32,7 +32,9 @@ end
 function test_roundtrip_transcode(encode, decode)
     seed!(TEST_RANDOM_SEED)
     encoder = encode()
+    initialize(encoder)
     decoder = decode()
+    initialize(decoder)
     for n in vcat(0:30, sort!(rand(500:100_000, 30))), alpha in (0x00:0xff, 0x00:0x0f)
         data = rand(alpha, n)
         Test.@test hash(transcode(decode, transcode(encode, data))) == hash(data)

src/transcode.jl

@@ -29,6 +29,7 @@ julia> String(decompressed)
 """
 function Base.transcode(::Type{C}, data::Vector{UInt8}) where C<:Codec
     codec = C()
+    initialize(codec)
     try
         return transcode(codec, data)
     finally
@@ -74,7 +75,7 @@ function Base.transcode(codec::Codec, data::Vector{UInt8})
     buffer2 = Buffer(
         expectedsize(codec, Memory(data)) + minoutsize(codec, Memory(C_NULL, 0)))
     mark!(buffer2)
-    stream = TranscodingStream(codec, devnull, State(Buffer(data), buffer2))
+    stream = TranscodingStream(codec, devnull, State(Buffer(data), buffer2); initialized=true)
     write(stream, TOKEN_END)
     return takemarked!(buffer2)
 end