feat: use native interrupt support in Downloads.jl (#82)

Detect if we are using a newer version of Download.jl that supports interrupting of requests natively and use that instead of throwing `InterruptException`.

ref: JuliaLang/Downloads.jl#256 and JuliaLang/Downloads.jl#259

fixes: #81

Author: tanmaykm

Project.toml

@@ -4,7 +4,7 @@ keywords = ["Swagger", "OpenAPI", "REST"]
 license = "MIT"
 desc = "OpenAPI server and client helper for Julia"
 authors = ["JuliaHub Inc."]
-version = "0.1.25"
+version = "0.1.26"
 
 [deps]
 Base64 = "2a0f44e3-6c83-55bd-87e4-b1978d98bd5f"

src/client.jl

@@ -151,6 +151,7 @@ struct Client
     escape_path_params::Union{Nothing,Bool}
     chunk_reader_type::Union{Nothing,Type{<:AbstractChunkReader}}
     long_polling_timeout::Int
+    request_interrupt_supported::Bool
 
     function Client(root::String;
             headers::Dict{String,String}=Dict{String,String}(),
@@ -174,7 +175,8 @@ struct Client
             # disable ALPN to support servers that enable both HTTP/2 and HTTP/1.1 on same port
             Downloads.Curl.setopt(easy, LibCURL.CURLOPT_SSL_ENABLE_ALPN, 0)
         end
-        new(root, headers, get_return_type, clntoptions, downloader, Ref{Int}(timeout), pre_request_hook, escape_path_params, chunk_reader_type, long_polling_timeout)
+        interruptable = request_supports_interrupt()
+        new(root, headers, get_return_type, clntoptions, downloader, Ref{Int}(timeout), pre_request_hook, escape_path_params, chunk_reader_type, long_polling_timeout, interruptable)
     end
 end
 
@@ -556,6 +558,10 @@ function do_request(ctx::Ctx, stream::Bool=false; stream_to::Union{Channel,Nothi
 
     try
         if stream
+            interrupt = nothing
+            if ctx.client.request_interrupt_supported
+                kwargs[:interrupt] = interrupt = Base.Event()
+            end
             @sync begin
                 download_task = @async begin
                     try
@@ -565,7 +571,10 @@ function do_request(ctx::Ctx, stream::Bool=false; stream_to::Union{Channel,Nothi
                             kwargs...
                         )
                     catch ex
-                        if !isa(ex, InterruptException)
+                        # If request method does not support interrupt natively, InterrptException is used to
+                        # signal the download task to stop. Otherwise, InterrptException is not handled and is rethrown.
+                        # Any exception other than InterruptException is rethrown always.
+                        if ctx.client.request_interrupt_supported || !isa(ex, InterruptException)
                             @error("exception invoking request", exception=(ex,catch_backtrace()))
                             rethrow()
                         end
@@ -604,10 +613,25 @@ function do_request(ctx::Ctx, stream::Bool=false; stream_to::Union{Channel,Nothi
                         catch ex
                             isa(ex, InvalidStateException) || rethrow(ex)
                             interrupted = true
-                            istaskdone(download_task) || schedule(download_task, InterruptException(), error=true)
+                            if !istaskdone(download_task)
+                                # If the download task is still running, interrupt it.
+                                # If it supports interrupt natively, then use event to signal it.
+                                # Otherwise, throw an InterruptException to stop the download task.
+                                if ctx.client.request_interrupt_supported
+                                    notify(interrupt)
+                                else
+                                    schedule(download_task, InterruptException(), error=true)
+                                end
+                            end
+                        end
+                    end
+                    if !interrupted && !istaskdone(download_task)
+                        if ctx.client.request_interrupt_supported
+                            notify(interrupt)
+                        else
+                            schedule(download_task, InterruptException(), error=true)
                         end
                     end
-                    interrupted || istaskdone(download_task) || schedule(download_task, InterruptException(), error=true)
                 end
             end
         else
@@ -863,4 +887,13 @@ function deep_object_serialize(dict::Dict, parent_key::String = "")
     return Dict(parts)
 end
 
+function request_supports_interrupt()
+    for m in methods(request)
+        if :interrupt in Base.kwarg_decl(m)
+            return true
+        end
+    end
+    return false
+end
+
 end # module Clients