Add done mode (#177)

Author: nhz2

docs/src/assets/modes.dot

@@ -12,17 +12,19 @@ digraph modes {
     "read" -> "panic";
 
     "write" -> "write";
-    "write" -> "stop";
+    "write" -> "done";
     "write" -> "close";
     "write" -> "panic";
 
     "stop" -> "close";
+    "done" -> "close";
 
     "start" [ shape = point ];
     "idle"  [ shape = circle ];
     "read"  [ shape = circle ];
     "write" [ shape = circle ];
     "stop"  [ shape = circle; style=bold; ];
+    "done"  [ shape = circle; style=bold; ];
     "close" [ shape = circle; style=bold; ];
     "panic" [ shape = circle; style=bold; ];
 }

docs/src/assets/modes.svg

@@ -46,7 +46,8 @@ The `mode` field may be one of the following value:
 - `:idle` : initial and intermediate mode, no buffered data
 - `:read` : being ready to read data, data may be buffered
 - `:write`: being ready to write data, data may be buffered
-- `:stop` : transcoding is stopped, data may be buffered
+- `:stop` : transcoding is stopped after read, data may be buffered
+- `:done` : transcoding is stopped after write, data may be buffered
 - `:close`: closed, no buffered data
 - `:panic`: an exception has been thrown in codec, data may be buffered but we
             cannot do anything

docs/src/devnotes.md

@@ -9,12 +9,12 @@ See Developer's notes for details.
 """
 mutable struct State
     # current stream mode
-    mode::Symbol  # {:idle, :read, :write, :stop, :close, :panic}
+    mode::Symbol  # {:idle, :read, :write, :stop, :done, :close, :panic}
 
     # return code of the last method call
     code::Symbol  # {:ok, :end, :error}
 
-    # flag to go :stop on :end
+    # flag to go :stop or :done on :end
     stop_on_end::Bool
 
     # exception thrown while data processing

src/state.jl

@@ -183,8 +183,9 @@ function Base.isopen(stream::TranscodingStream)
 end
 
 function Base.close(stream::TranscodingStream)
-    stopped = stream.state.mode == :stop
-    if stream.state.mode != :panic
+    mode = stream.state.mode
+    stopped = mode === :stop || mode === :done
+    if mode != :panic
         changemode!(stream, :close)
     end
     if !stopped
@@ -213,6 +214,8 @@ end
             continue
         elseif mode == :write
             return eof(stream.stream)
+        elseif mode == :done
+            return eof(stream.stream)
         elseif mode == :close
             return true
         elseif mode == :stop
@@ -252,7 +255,7 @@ function Base.skip(stream::TranscodingStream, offset::Integer)
     mode = stream.state.mode
     buffer1 = stream.buffer1
     skipped = 0
-    if mode == :read
+    if mode === :read || mode === :stop
         while !eof(stream) && buffersize(buffer1) < offset - skipped
             n = buffersize(buffer1)
             emptybuffer!(buffer1)
@@ -619,7 +622,7 @@ function flushbuffer(stream::TranscodingStream, all::Bool=false)
     buffer1 = stream.buffer1
     buffer2 = stream.buffer2
     nflushed::Int = 0
-    while (all ? buffersize(buffer1) != 0 : makemargin!(buffer1, 0) == 0) && state.mode != :stop
+    while (all ? buffersize(buffer1) != 0 : makemargin!(buffer1, 0) == 0) && state.mode != :done
         if state.code == :end
             callstartproc(stream, :write)
         end
@@ -684,7 +687,11 @@ function callprocess(stream::TranscodingStream, inbuf::Buffer, outbuf::Buffer)
         # When no progress, expand the output buffer.
         makemargin!(outbuf, max(16, marginsize(outbuf) * 2))
     elseif state.code == :end && state.stop_on_end
-        changemode!(stream, :stop)
+        if stream.state.mode == :read
+            changemode!(stream, :stop)
+        else
+            changemode!(stream, :done)
+        end
     end
     return Δin, Δout
 end
@@ -738,8 +745,6 @@ end
 function changemode!(stream::TranscodingStream, newmode::Symbol)
     state = stream.state
     mode = state.mode
-    buffer1 = stream.buffer1
-    buffer2 = stream.buffer2
     if mode == newmode
         # mode does not change
         return
@@ -770,7 +775,7 @@ function changemode!(stream::TranscodingStream, newmode::Symbol)
             return
         end
     elseif mode == :write
-        if newmode == :close || newmode == :stop
+        if newmode == :close || newmode == :done
             if newmode == :close
                 flushbufferall(stream)
                 flushuntilend(stream)
@@ -784,6 +789,11 @@ function changemode!(stream::TranscodingStream, newmode::Symbol)
             state.mode = newmode
             return
         end
+    elseif mode == :done
+        if newmode == :close
+            state.mode = newmode
+            return
+        end
     elseif mode == :panic
         throw_panic_error()
     end

src/stream.jl

@@ -215,9 +215,8 @@ DoubleFrameDecoderStream(stream::IO; kwargs...) = TranscodingStream(DoubleFrameD
         stream = TranscodingStream(DoubleFrameDecoder(), sink, stop_on_end=true)
         write(stream, "[ yy ]sdfsadfasdfdf")
         flush(stream)
-        @test_broken eof(stream)
-        # TODO This is broken.
-        # @test_throws ArgumentError read(stream, UInt8)
+        @test eof(stream)
+        @test_throws ArgumentError read(stream, UInt8)
         @test take!(sink) == b"y"
         close(stream)
     end