do parsing inline for small html documents

hansihe · hansihe · commit 1723af91ae89 · 2017-01-16T13:31:42.000+01:00
diff --git a/lib/ex_html5ever.ex b/lib/ex_html5ever.ex
@@ -3,7 +3,14 @@ defmodule ExHtml5ever do
   Documentation for ExHtml5ever.
   """
 
+  def parse(html) when byte_size(html) > 500 do
+    parse_async(html)
+  end
   def parse(html) do
+    parse_sync(html)
+  end
+
+  defp parse_async(html) do
     ExHtml5ever.Native.parse_async(html)
     receive do
       {:html5ever_nif_result, :ok, result} ->
@@ -13,4 +20,13 @@ defmodule ExHtml5ever do
     end
   end
 
+  defp parse_sync(html) do
+    case ExHtml5ever.Native.parse_sync(html) do
+      {:html5ever_nif_result, :ok, result} ->
+        {:ok, result}
+      {:html5ever_nif_result, :error, err} ->
+        {:error, err}
+    end
+  end
+
 end
diff --git a/lib/ex_html5ever/native.ex b/lib/ex_html5ever/native.ex
@@ -6,6 +6,7 @@ defmodule ExHtml5ever.Native do
   use Rustler, otp_app: :ex_html5ever, crate: "html5ever_nif"
 
   def parse_async(binary), do: err()
+  def parse_sync(binary), do: err()
 
   defp err() do
     throw NifNotLoadedError
diff --git a/native/html5ever_nif/src/lib.rs b/native/html5ever_nif/src/lib.rs
@@ -156,9 +156,28 @@ fn parse_async<'a>(env: NifEnv<'a>, args: &Vec<NifTerm<'a>>) -> NifResult<NifTer
     Ok(atoms::ok().encode(env))
 }
 
+fn parse_sync<'a>(env: NifEnv<'a>, args: &Vec<NifTerm<'a>>) -> NifResult<NifTerm<'a>> {
+    let binary: NifBinary = args[0].decode()?;
+    let sink = RcDom::default();
+
+    // TODO: Use Parser.from_bytes instead?
+    let parser = html5ever::parse_document(sink, Default::default());
+    let result = parser.one(
+        std::str::from_utf8(binary.as_slice()).unwrap());
+
+    //std::thread::sleep(std::time::Duration::from_millis(10));
+
+    let result_term = handle_to_term(env, &result.document);
+
+    Ok((atoms::html5ever_nif_result(), atoms::ok(), result_term)
+        .encode(env))
+
+}
+
 rustler_export_nifs!(
     "Elixir.ExHtml5ever.Native",
-    [("parse_async", 1, parse_async)],
+    [("parse_async", 1, parse_async),
+     ("parse_sync", 1, parse_sync)],
     Some(on_load)
 );
 
diff --git a/test/ex_html5ever_test.exs b/test/ex_html5ever_test.exs
@@ -2,6 +2,19 @@ defmodule ExHtml5everTest do
   use ExUnit.Case
   doctest ExHtml5ever
 
+  #def p() do
+  #  receive do
+  #    thing -> IO.inspect thing
+  #  end
+  #  p()
+  #end
+
+  #setup_all do
+  #  pid = Process.spawn(ExHtml5everTest, :p, [], [])
+  #  :erlang.system_monitor(pid, [{:long_schedule, 1}])
+  #  :ok
+  #end
+
   def read_html(name) do
     dir = to_string(:code.priv_dir(:ex_html5ever)) <> "/test_data/"
     File.read!(dir <> name)
@@ -14,7 +27,7 @@ defmodule ExHtml5everTest do
   end
 
   test "parse example.com html" do
-    html = read_html("drudgereport.html")
+    html = read_html("example.html")
     assert match?({:ok, _}, ExHtml5ever.parse(html))
   end
 
@@ -23,4 +36,9 @@ defmodule ExHtml5everTest do
     assert match?({:ok, _}, ExHtml5ever.parse(html))
   end
 
+  test "unbalanced worst case" do
+    html = String.duplicate("<div>", 100)
+    assert match?({:ok, _}, ExHtml5ever.parse(html))
+  end
+
 end
