On Monday, 25 March 2019 14:31:18 CET Richard W.M. Jones wrote:
On Fri, Mar 22, 2019 at 04:33:41PM +0100, Pino Toscano wrote:
Enhance the helper printf function for machine readable output to always flush after each string: this way, readers of the machine readable stream can get the output as soon as it is outputted. --- common/mltools/tools_utils.ml | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/common/mltools/tools_utils.ml b/common/mltools/tools_utils.ml index 5a35708cd..ade4cb37f 100644 --- a/common/mltools/tools_utils.ml +++ b/common/mltools/tools_utils.ml @@ -59,7 +59,11 @@ let machine_readable () = | None -> None | Some chan -> let pr fs = - ksprintf (output_string chan) fs + let out s = + output_string chan s; + flush chan + in + ksprintf out fs in Some { pr }
I was looking to see if any of the existing calls to machine_readable are using %! (a format directive which causes the channel to be flushed). I had expected there would be some, but my simple "git grep"s aren't turning up anything right now.
Yes, I know about %!, and that was my first attempt in patch 4, which had: pr "%s\n%!" (JSON.string_of_doc ~fmt:JSON.Compact json) However, it did not seem to work: the output seemed batched every 1/2 minutes or so, and even extra `pr "%!"` did not change anything. Even when using Obj.magic, the fd still is not flushed immediately with %!... -- Pino Toscano