xstringext: Add benchmark for escaped

Signed-off-by: Christian Pardillo Laursen <christian.pardillolaursen@citrix.com>

Author: cplaursen

ocaml/libs/xapi-stdext/lib/xapi-stdext-std/bench/bench_xstringext.ml

@@ -0,0 +1,130 @@
+open Bechamel
+open Toolkit
+module XString = Xapi_stdext_std.Xstringext.String
+
+(* Test data generators *)
+let make_string len = String.init len (fun i -> Char.chr (33 + (i mod 94)))
+
+let escape_rules =
+  [('a', "[A]"); ('e', "[E]"); ('i', "[I]"); ('o', "[O]"); ('u', "[U]")]
+
+(* Reference implementation from xstringext_test.ml *)
+let escaped_spec ?rules string =
+  match rules with
+  | None ->
+      String.escaped string
+  | Some rules ->
+      let apply_rules char =
+        match List.assoc_opt char rules with
+        | None ->
+            Seq.return char
+        | Some replacement ->
+            String.to_seq replacement
+      in
+      string |> String.to_seq |> Seq.concat_map apply_rules |> String.of_seq
+
+let escaped_benchmark n =
+  let s = make_string n in
+  Staged.stage @@ fun () -> ignore (XString.escaped ~rules:escape_rules s)
+
+let escaped_spec_benchmark n =
+  let s = make_string n in
+  Staged.stage @@ fun () -> ignore (escaped_spec ~rules:escape_rules s)
+
+let test_escaped =
+  Test.make_indexed ~name:"escaped" ~fmt:"%s %d" ~args:[100; 500; 1000]
+    escaped_benchmark
+
+let test_escaped_spec =
+  Test.make_indexed ~name:"escaped-spec" ~fmt:"%s %d" ~args:[100; 500; 1000]
+    escaped_spec_benchmark
+
+let benchmark () =
+  let ols =
+    Analyze.ols ~bootstrap:0 ~r_square:true ~predictors:Measure.[|run|]
+  in
+  let instances =
+    Instance.[minor_allocated; major_allocated; monotonic_clock]
+  in
+  let cfg =
+    Benchmark.cfg ~limit:2000 ~quota:(Time.second 0.5) ~kde:(Some 1000) ()
+  in
+  let test =
+    Test.make_grouped ~name:"escaped-comparison"
+      [test_escaped; test_escaped_spec]
+  in
+  let raw_results = Benchmark.all cfg instances test in
+  let results =
+    List.map (fun instance -> Analyze.all ols instance raw_results) instances
+  in
+  let results = Analyze.merge ols instances results in
+  (results, raw_results)
+
+let () =
+  let all_results = benchmark () in
+  let results, _ = all_results in
+
+  (* Extract timing data from the actual benchmark results *)
+  let result_groups =
+    Hashtbl.fold
+      (fun _ v a -> Hashtbl.fold (fun k v a -> (k, v) :: a) v [] :: a)
+      results []
+  in
+
+  (* Find the monotonic-clock result group (timing data) *)
+  let timing_group =
+    match result_groups with _ :: _ :: timing :: _ -> Some timing | _ -> None
+  in
+
+  let get_timing test_name =
+    match timing_group with
+    | None ->
+        None
+    | Some group -> (
+      match List.assoc_opt test_name group with
+      | Some estimator -> (
+          let estimates = Analyze.OLS.estimates estimator in
+          match estimates with Some (x :: _) -> Some x | _ -> None
+        )
+      | None ->
+          None
+    )
+  in
+
+  Printf.printf "\n=== Performance Comparison: Optimized vs Reference ===\n\n" ;
+
+  let sizes = ["100"; "500"; "1000"] in
+  List.iter
+    (fun size ->
+      Printf.printf "String size %s:\n" size ;
+      let opt_test = Printf.sprintf "escaped-comparison/escaped %s" size in
+      let ref_test = Printf.sprintf "escaped-comparison/escaped-spec %s" size in
+      match (get_timing opt_test, get_timing ref_test) with
+      | Some opt_time, Some ref_time ->
+          let improvement = (ref_time -. opt_time) /. ref_time *. 100.0 in
+          Printf.printf "  Optimized: %.3f μs\n" opt_time ;
+          Printf.printf "  Reference: %.3f μs\n" ref_time ;
+          Printf.printf "  Improvement: %.1f%% %s\n\n" improvement
+            (if improvement > 0.0 then "faster" else "slower")
+      | None, _ ->
+          Printf.printf "  Optimized implementation data missing\n\n"
+      | _, None ->
+          Printf.printf "  Reference implementation data missing\n\n"
+    )
+    sizes ;
+
+  Printf.printf "\n=== Detailed Results ===\n" ;
+  match result_groups with
+  | [results] ->
+      let print (k, ols) = Fmt.pr "%s: %a\n%!" k Analyze.OLS.pp ols in
+      List.iter print results
+  | results_list ->
+      Printf.printf "Results structure: %d result groups\n"
+        (List.length results_list) ;
+      List.iteri
+        (fun i results ->
+          Printf.printf "Result group %d:\n" i ;
+          let print (k, ols) = Fmt.pr "  %s: %a\n%!" k Analyze.OLS.pp ols in
+          List.iter print results
+        )
+        results_list

ocaml/libs/xapi-stdext/lib/xapi-stdext-std/bench/dune

@@ -0,0 +1,6 @@
+(executable
+ (name bench_xstringext)
+ (modes exe)
+ (optional)
+ (libraries bechamel xapi-stdext-std bechamel-notty notty.unix fmt)
+)