Merge pull request #76 from Leonidas-from-XIV/revive-benchmark

Revive benchmark

Makefile

@@ -16,7 +16,7 @@ uninstall:
 
 .PHONY: bench
 bench:
-	@dune build bench/bench.exe
+	@dune build @bench --force
 
 .PHONY: clean
 clean:
@@ -25,3 +25,4 @@ clean:
 .PHONY: test
 test:
 	@dune runtest --force
+

bench/README.md

@@ -0,0 +1,20 @@
+Benchmark for Yojson
+====================
+
+These benchmarks require `Core_bench` which is not a dependency of Yojson,
+because it is not part of the regular installation/testing flow. This is solely
+meant for developers that are worried about performance changes in Yojson.
+
+This is also why it is deemed appropriate to depend on a benchmarking library
+with this many dependencies: we rather spend time writing benchmarks than to
+build a benchmarking library if a perfectly good one already exists in OCaml.
+
+Install
+-------
+
+`opam install core_benchmark`
+
+Running the benchmark
+---------------------
+
+`make bench` in the top level directory.

bench/bench.ml

@@ -1,53 +1,18 @@
-open Printf
+open Core
+open Core_bench
 
 let data =
-  let l = ref [] in
-  try
-    while true do
-      l := input_line stdin :: !l
-    done;
-    assert false
-  with End_of_file -> String.concat "\n" (List.rev !l)
+  In_channel.read_all "bench.json"
 
 let yojson_data = Yojson.Safe.from_string data
-let jsonwheel_data = Json_io.json_of_string data
 
-let n = 10_000
-
-let yojson_rd_loop () =
-  for i = 1 to n do
-    ignore (Yojson.Safe.from_string data)
-  done
-
-let yojson_wr_loop () =
-  for i = 1 to n do
-    ignore (Yojson.Safe.to_string yojson_data)
-  done
-
-let jsonwheel_rd_loop () =
-  for i = 1 to n do
-    ignore (Json_io.json_of_string data)
-  done
-
-let jsonwheel_wr_loop () =
-  for i = 1 to n do
-    ignore (Json_io.string_of_json ~compact:true jsonwheel_data)
-  done
-
-let time msg f =
-  let t1 = Unix.gettimeofday () in
-  f ();
-  let t2 = Unix.gettimeofday () in
-  printf "%s: %.3f\n%!" msg (t2 -. t1)
+let main () =
+  Command.run (Bench.make_command [
+    Bench.Test.create ~name:"JSON reading" (fun () ->
+      ignore (Yojson.Safe.from_string data));
+    Bench.Test.create ~name:"JSON writing" (fun () ->
+      ignore (Yojson.Safe.to_string yojson_data));
+  ])
 
 let () =
-  time "rd yojson" yojson_rd_loop;
-  time "rd json-wheel" jsonwheel_rd_loop;
-  time "rd yojson" yojson_rd_loop;
-  time "rd json-wheel" jsonwheel_rd_loop;
-
-  time "wr yojson" yojson_wr_loop;
-  time "wr json-wheel" jsonwheel_wr_loop;
-  time "wr yojson" yojson_wr_loop;
-  time "wr json-wheel" jsonwheel_wr_loop
-
+  main ()

bench/dune

@@ -1,5 +1,9 @@
-;; doesn't actually build b/c json_io doesn't exist
 (executable
  (name bench)
  (flags (-safe-string))
- (libraries yojson))
+ (libraries yojson core_bench core))
+
+(alias
+  (name bench)
+  (deps bench.json)
+  (action (run ./bench.exe)))