dynamic reevaluation of function

Call `Core._apply_latest` to support `open` mode in `APIResponder` on Julia 0.6.

We can call `Compat.invokelatest` instead after JuliaLang/julia#22646 is merged and assimilated in Compat.jl suitably.

Author: tanmaykm

src/APIResponder.jl

@@ -78,13 +78,23 @@ function get_resp(api::Nullable{APISpec}, status::Symbol, resp=nothing)
     end
 end
 
+# Note: needs to be changed when https://github.com/JuliaLang/julia/pull/22646 is merged
+function dynamic_invoke(conn::APIResponder, f, args...; kwargs...)
+    if conn.open && isdefined(Core, :_apply_latest)
+        inner() = f(args...; kwargs...)
+        Core._apply_latest(inner)
+    else
+        f(args...; kwargs...)
+    end
+end
+
 """call the actual API method, and send the return value back as response"""
 function call_api(api::APISpec, conn::APIResponder, args, data::Dict{Symbol,Any})
     try
         if !applicable(api.fn, args...)
             narrow_args!(args)
         end
-        result = api.fn(args...; data...)
+        result = dynamic_invoke(conn, api.fn, args...; data...)
         respond(conn, Nullable(api), :success, result)
     catch ex
         err("api_exception: $ex")

test/srvr.jl

@@ -13,11 +13,11 @@ const SRVR_ADDR = "tcp://127.0.0.1:9999"
 const JSON_RESP_HDRS = Dict{String,String}("Content-Type" => "application/json; charset=utf-8")
 const BINARY_RESP_HDRS = Dict{String,String}("Content-Type" => "application/octet-stream")
 
-function run_srvr(fmt, tport, async=false)
+function run_srvr(fmt, tport, async=false, open=false)
     Logging.configure(level=INFO, filename="apisrvr_test.log")
     Logging.info("queue is at $SRVR_ADDR")
 
-    api = APIResponder(tport, fmt)
+    api = APIResponder(tport, fmt, nothing, open)
     Logging.info("responding with: $api")
 
     register(api, testfn1; resp_json=true, resp_headers=JSON_RESP_HDRS)
@@ -40,7 +40,7 @@ function test_preproc(req::Request, res::Response)
 end
 
 function run_httprpcsrvr(fmt, tport, async=false)
-    run_srvr(fmt, tport, true)
+    run_srvr(fmt, tport, true, true)
     apiclnt = APIInvoker(ZMQTransport(SRVR_ADDR, REQ, false), fmt)
     if async
         @async run_http(apiclnt, 8888, test_preproc)