rectify control of write callback

Author: StefanKarpinski

src/Curl/Easy.jl

@@ -3,7 +3,7 @@ mutable struct Easy
     input    :: Union{Vector{UInt8},Nothing}
     ready    :: Threads.Event
     seeker   :: Union{Function,Nothing}
-    output   :: Channel{Vector{UInt8}}
+    output   :: IO
     progress :: Function
     req_hdrs :: Ptr{curl_slist_t}
     res_hdrs :: Vector{String}
@@ -13,13 +13,16 @@ end
 
 const EMPTY_BYTE_VECTOR = UInt8[]
 
-function Easy(progress::Union{Function,Nothing})
+function Easy(
+    output::IO,
+    progress::Union{Function,Nothing},
+)
     easy = Easy(
         curl_easy_init(),
         EMPTY_BYTE_VECTOR,
         Threads.Event(),
         nothing,
-        Channel{Vector{UInt8}}(Inf),
+        output,
         something(progress, (_, _, _, _) -> nothing),
         C_NULL,
         String[],
@@ -356,12 +359,11 @@ function write_callback(
     count  :: Csize_t,
     easy_p :: Ptr{Cvoid},
 )::Csize_t
+    @assert size == sizeof(Cchar)
     easy = unsafe_pointer_to_objref(easy_p)::Easy
-    n = size * count
-    buf = Array{UInt8}(undef, n)
-    ccall(:memcpy, Ptr{Cvoid}, (Ptr{Cvoid}, Ptr{Cvoid}, Csize_t), buf, data, n)
-    put!(easy.output, buf)
-    return n
+    buf = unsafe_wrap(Vector{Cchar}, data, size*count)
+    write(easy.output, buf)
+    return size*count
 end
 
 function progress_callback(

src/Curl/Multi.jl

@@ -85,7 +85,6 @@ function check_multi_info(multi::Multi)
             easy = unsafe_pointer_to_objref(easy_p_ref[])::Easy
             @assert easy_handle == easy.handle
             easy.code = message.code
-            close(easy.output)
             easy.input = nothing
             notify(easy.ready)
         else

src/Downloads.jl

@@ -308,7 +308,7 @@ function request(
     progress = p_func(progress, input, output)
     arg_read(input) do input
         arg_write(output) do output
-            with_handle(Easy(progress)) do easy
+            with_handle(Easy(output, progress)) do easy
                 # setup the request
                 set_url(easy, url)
                 set_timeout(easy, timeout)
@@ -345,12 +345,10 @@ function request(
                 add_handle(downloader.multi, easy)
                 try # ensure handle is removed
                     @sync begin
-                        @async for buf in easy.output
-                            write(output, buf)
-                        end
                         if have_input
                             @async upload_data(easy, input)
                         end
+                        @async wait(easy.ready)
                     end
                 finally
                     remove_handle(downloader.multi, easy)