chore: add --var-max flag to cli

bin/main.ml

@@ -29,12 +29,17 @@ let print_timing ~time name f =
     out
 
 let main file func_name input loop timeout_ms allowed_paths allowed_hosts config
-    memory_max http_max log_level log_file wasi stdin time =
+    memory_max http_max var_max log_level log_file wasi stdin time _manifest =
   let input = if stdin then read_stdin () else input in
   let allowed_paths = split_allowed_paths allowed_paths in
   let config = split_config config in
   let memory =
-    Manifest.{ max_pages = memory_max; max_http_response_bytes = http_max }
+    Manifest.
+      {
+        max_pages = memory_max;
+        max_http_response_bytes = http_max;
+        max_var_bytes = var_max;
+      }
   in
   let manifest =
     print_timing ~time "loaded manifest" @@ fun () ->
@@ -101,6 +106,10 @@ let http_max =
     & opt (some int) None
     & info [ "http-response-max" ] ~docv:"BYTES" ~doc)
 
+let var_max =
+  let doc = "Max number of bytes allowed in the Extism var store" in
+  Arg.(value & opt (some int) None & info [ "var-max" ] ~docv:"BYTES" ~doc)
+
 let timeout =
   let doc = "Plugin timeout in milliseconds." in
   Arg.(value & opt int 30000 & info [ "timeout"; "t" ] ~docv:"MILLIS" ~doc)
@@ -145,6 +154,10 @@ let wasi =
   let doc = "Enable WASI." in
   Arg.(value & flag & info [ "wasi" ] ~doc)
 
+let manifest =
+  let doc = "Unused, exists for compatibility with Go CLI" in
+  Arg.(value & flag & info [ "manifest" ] ~doc)
+
 let stdin =
   let doc = "Read function input from stdin." in
   Arg.(value & flag & info [ "stdin" ] ~doc)
@@ -156,8 +169,8 @@ let time =
 let main_t =
   Term.(
     const main $ file $ func_name $ input $ loop $ timeout $ allowed_paths
-    $ allowed_hosts $ config $ memory_max $ http_max $ log_level $ log_file
-    $ wasi $ stdin $ time)
+    $ allowed_hosts $ config $ memory_max $ http_max $ var_max $ log_level
+    $ log_file $ wasi $ stdin $ time $ manifest)
 
 let cmd = Cmd.v (Cmd.info "extism-call") main_t
 let () = exit (Cmd.eval cmd)

manifest/extism_manifest.ml

@@ -8,6 +8,7 @@ let base64_of_yojson j = Yojson.Safe.Util.to_string j
 type memory_options = {
   max_pages : int option; [@yojson.option]
   max_http_response_bytes : int option; [@yojson.option]
+  max_var_bytes : int option; [@yojson.option]
 }
 [@@deriving yojson]
 
@@ -107,7 +108,13 @@ let with_memory_max max t =
   | None ->
       {
         t with
-        memory = Some { max_http_response_bytes = None; max_pages = Some max };
+        memory =
+          Some
+            {
+              max_http_response_bytes = None;
+              max_pages = Some max;
+              max_var_bytes = None;
+            };
       }
   | Some m -> { t with memory = Some { m with max_pages = Some max } }
 
@@ -116,14 +123,42 @@ let with_http_response_max_bytes max t =
   | None ->
       {
         t with
-        memory = Some { max_http_response_bytes = Some max; max_pages = None };
+        memory =
+          Some
+            {
+              max_http_response_bytes = Some max;
+              max_pages = None;
+              max_var_bytes = None;
+            };
+      }
+  | Some m ->
+      { t with memory = Some { m with max_http_response_bytes = Some max } }
+
+let with_var_max_bytes max t =
+  match t.memory with
+  | None ->
+      {
+        t with
+        memory =
+          Some
+            {
+              max_var_bytes = Some max;
+              max_pages = None;
+              max_http_response_bytes = None;
+            };
       }
   | Some m ->
       { t with memory = Some { m with max_http_response_bytes = Some max } }
 
 let%test "rountrip" =
   let config = [ ("a", Some "b"); ("b", Some "c") ] in
-  let memory = { max_pages = Some 5; max_http_response_bytes = Some 9999 } in
+  let memory =
+    {
+      max_pages = Some 5;
+      max_http_response_bytes = Some 9999;
+      max_var_bytes = Some 12300;
+    }
+  in
   let t =
     create ~config ~memory ~allowed_hosts:[ "example.com" ]
       ~allowed_paths:[ ("a", "b") ]

manifest/extism_manifest.mli

@@ -30,6 +30,8 @@ type memory_options = {
   max_http_response_bytes: int option;
   (** [max_http_response_bytes] can be used to limit the size of the response returned by
       [extism_http_request] *)
+  max_var_bytes: int option;
+  (** [max_var_bytes] can be used to limit the size of the Extism var store *)
 }
 [@@deriving yojson]
 (** Memory options *)
@@ -135,3 +137,6 @@ val with_memory_max : int -> t -> t
 
 val with_http_response_max_bytes : int -> t -> t
 (** Returns a new {!t} with [memory.max_http_response_bytes] updated *)
+
+val with_var_max_bytes : int -> t -> t
+(** Returns a new {!t} with [memory.max_var_bytes] updated *)