Improve JavaScript API and also support arena in lex

Author: marcoroth

ext/herb/extension.c

@@ -25,26 +25,41 @@ static VALUE Herb_lex(int argc, VALUE* argv, VALUE self) {
 
   char* string = (char*) check_string(source);
   bool print_arena_stats = false;
+  VALUE external_arena = Qnil;
 
   if (!NIL_P(options)) {
     VALUE arena_stats = rb_hash_lookup(options, rb_utf8_str_new_cstr("arena_stats"));
     if (NIL_P(arena_stats)) { arena_stats = rb_hash_lookup(options, ID2SYM(rb_intern("arena_stats"))); }
     if (!NIL_P(arena_stats) && RTEST(arena_stats)) { print_arena_stats = true; }
+
+    external_arena = rb_hash_lookup(options, rb_utf8_str_new_cstr("arena"));
+    if (NIL_P(external_arena)) { external_arena = rb_hash_lookup(options, ID2SYM(rb_intern("arena"))); }
   }
 
-  hb_arena_T* arena = malloc(sizeof(hb_arena_T));
-  if (!arena) { return Qnil; }
+  hb_arena_T* arena;
+  bool owns_arena;
 
-  if (!hb_arena_init(arena, KB(512))) {
-    free(arena);
-    return Qnil;
+  if (!NIL_P(external_arena)) {
+    arena = get_arena_from_value(external_arena);
+    owns_arena = false;
+  } else {
+    arena = malloc(sizeof(hb_arena_T));
+    if (!arena) { return Qnil; }
+
+    if (!hb_arena_init(arena, KB(512))) {
+      free(arena);
+      return Qnil;
+    }
+    owns_arena = true;
   }
 
   herb_lex_result_T* lex_result = herb_lex(string, arena);
 
   if (!lex_result) {
-    hb_arena_free(arena);
-    free(arena);
+    if (owns_arena) {
+      hb_arena_free(arena);
+      free(arena);
+    }
     return Qnil;
   }
 
@@ -63,26 +78,41 @@ static VALUE Herb_lex_file(int argc, VALUE* argv, VALUE self) {
 
   char* file_path = (char*) check_string(path);
   bool print_arena_stats = false;
+  VALUE external_arena = Qnil;
 
   if (!NIL_P(options)) {
     VALUE arena_stats = rb_hash_lookup(options, rb_utf8_str_new_cstr("arena_stats"));
     if (NIL_P(arena_stats)) { arena_stats = rb_hash_lookup(options, ID2SYM(rb_intern("arena_stats"))); }
     if (!NIL_P(arena_stats) && RTEST(arena_stats)) { print_arena_stats = true; }
+
+    external_arena = rb_hash_lookup(options, rb_utf8_str_new_cstr("arena"));
+    if (NIL_P(external_arena)) { external_arena = rb_hash_lookup(options, ID2SYM(rb_intern("arena"))); }
   }
 
-  hb_arena_T* arena = malloc(sizeof(hb_arena_T));
-  if (!arena) { return Qnil; }
+  hb_arena_T* arena;
+  bool owns_arena;
 
-  if (!hb_arena_init(arena, KB(512))) {
-    free(arena);
-    return Qnil;
+  if (!NIL_P(external_arena)) {
+    arena = get_arena_from_value(external_arena);
+    owns_arena = false;
+  } else {
+    arena = malloc(sizeof(hb_arena_T));
+    if (!arena) { return Qnil; }
+
+    if (!hb_arena_init(arena, KB(512))) {
+      free(arena);
+      return Qnil;
+    }
+    owns_arena = true;
   }
 
   herb_lex_result_T* lex_result = herb_lex_file(file_path, arena);
 
   if (!lex_result) {
-    hb_arena_free(arena);
-    free(arena);
+    if (owns_arena) {
+      hb_arena_free(arena);
+      free(arena);
+    }
     return Qnil;
   }
 
@@ -176,6 +206,7 @@ static VALUE Herb_parse_file(int argc, VALUE* argv, VALUE self) {
 
   parser_options_T parser_options = HERB_DEFAULT_PARSER_OPTIONS;
   bool print_arena_stats = false;
+  VALUE external_arena = Qnil;
 
   if (!NIL_P(options)) {
     VALUE track_whitespace = rb_hash_lookup(options, rb_utf8_str_new_cstr("track_whitespace"));
@@ -193,24 +224,40 @@ static VALUE Herb_parse_file(int argc, VALUE* argv, VALUE self) {
     VALUE arena_stats = rb_hash_lookup(options, rb_utf8_str_new_cstr("arena_stats"));
     if (NIL_P(arena_stats)) { arena_stats = rb_hash_lookup(options, ID2SYM(rb_intern("arena_stats"))); }
     if (!NIL_P(arena_stats) && RTEST(arena_stats)) { print_arena_stats = true; }
+
+    external_arena = rb_hash_lookup(options, rb_utf8_str_new_cstr("arena"));
+    if (NIL_P(external_arena)) { external_arena = rb_hash_lookup(options, ID2SYM(rb_intern("arena"))); }
   }
 
-  hb_arena_T* arena = malloc(sizeof(hb_arena_T));
-  if (!arena) { return Qnil; }
+  hb_arena_T* arena;
+  bool owns_arena;
 
-  if (!hb_arena_init(arena, KB(512))) {
-    free(arena);
-    return Qnil;
+  if (!NIL_P(external_arena)) {
+    arena = get_arena_from_value(external_arena);
+    owns_arena = false;
+  } else {
+    arena = malloc(sizeof(hb_arena_T));
+    if (!arena) { return Qnil; }
+
+    if (!hb_arena_init(arena, KB(512))) {
+      free(arena);
+      return Qnil;
+    }
+    owns_arena = true;
   }
 
   AST_DOCUMENT_NODE_T* root = herb_parse(string, &parser_options, arena);
 
   if (!root) {
-    hb_arena_free(arena);
-    free(arena);
+    if (owns_arena) {
+      hb_arena_free(arena);
+      free(arena);
+    }
     return Qnil;
   }
 
+  root->owns_arena = owns_arena;
+
   VALUE result = create_parse_result(root, source_value);
 
   if (print_arena_stats) { hb_arena_print_stats(arena); }

javascript/packages/browser/src/wasm-backend.ts

@@ -1,6 +1,37 @@
 import { name, version } from "../package.json"
 
-import { HerbBackend } from "@herb-tools/core"
+import { HerbBackend, Arena } from "@herb-tools/core"
+import type { ArenaBackend, CreateArenaOptions } from "@herb-tools/core"
+
+class WASMArenaBackend implements ArenaBackend {
+  private backend: any
+  private arenaId: number
+
+  constructor(backend: any, arenaId: number) {
+    this.backend = backend
+    this.arenaId = arenaId
+  }
+
+  get position(): number {
+    return this.backend.arenaPosition(this.arenaId)
+  }
+
+  get capacity(): number {
+    return this.backend.arenaCapacity(this.arenaId)
+  }
+
+  reset(): void {
+    this.backend.resetArena(this.arenaId)
+  }
+
+  free(): void {
+    this.backend.freeArena(this.arenaId)
+  }
+
+  toBackendOption(): { arenaId: number } {
+    return { arenaId: this.arenaId }
+  }
+}
 
 export class HerbBackendWASM extends HerbBackend {
   lexFile(): never {
@@ -14,4 +45,10 @@ export class HerbBackendWASM extends HerbBackend {
   backendVersion(): string {
     return `${name}@${version}`
   }
+
+  createArena(options?: CreateArenaOptions): Arena {
+    this.ensureBackend()
+    const arenaId = (this.backend as any).createArena(options?.size ?? 0)
+    return new Arena(new WASMArenaBackend(this.backend, arenaId))
+  }
 }