first version

src/lib.rs

@@ -5,7 +5,9 @@ extern crate napi_derive;
 
 use std::convert::TryInto;
 
-use napi::{CallContext, Env, JsNumber, JsObject, Module, Result, Task};
+use napi::{CallContext, Env, JsNumber, JsObject, JsString, Module, Result, Task};
+
+mod mdiff;
 
 #[cfg(all(unix, not(target_env = "musl")))]
 #[global_allocator]
@@ -13,41 +15,34 @@ static ALLOC: jemallocator::Jemalloc = jemallocator::Jemalloc;
 
 register_module!(example, init);
 
-struct AsyncTask(u32);
-
-impl Task for AsyncTask {
-  type Output = u32;
-  type JsValue = JsNumber;
-
-  fn compute(&mut self) -> Result<Self::Output> {
-    use std::thread::sleep;
-    use std::time::Duration;
-    sleep(Duration::from_millis(self.0 as u64));
-    Ok(self.0 * 2)
-  }
-
-  fn resolve(&self, env: &mut Env, output: Self::Output) -> Result<Self::JsValue> {
-    env.create_uint32(output)
-  }
-}
-
 fn init(module: &mut Module) -> Result<()> {
-  module.create_named_method("sync", sync_fn)?;
-
-  module.create_named_method("sleep", sleep)?;
+  module.create_named_method("diff", diff_char)?;
   Ok(())
 }
 
-#[js_function(1)]
-fn sync_fn(ctx: CallContext) -> Result<JsNumber> {
-  let argument: u32 = ctx.get::<JsNumber>(0)?.try_into()?;
+#[js_function(2)]
+fn diff_char(ctx: CallContext) -> Result<JsObject> {
+  let str1: String = ctx.get::<JsString>(0)?.try_into()?;
+  let str2: String = ctx.get::<JsString>(1)?.try_into()?;
 
-  ctx.env.create_uint32(argument + 100)
-}
+  let res = mdiff::diff_chars(str1.as_str(), str2.as_str());
 
-#[js_function(1)]
-fn sleep(ctx: CallContext) -> Result<JsObject> {
-  let argument: u32 = ctx.get::<JsNumber>(0)?.try_into()?;
-  let task = AsyncTask(argument);
-  ctx.env.spawn(task)
+  let mut obj = ctx.env.create_array_with_length(res.len()).unwrap();
+
+  let mut idx = 0;
+  for it in res.iter() {
+    let mut item = ctx.env.create_object().unwrap();
+    item.set_named_property(
+      "count",
+      ctx.env.create_int64(it.count.try_into().unwrap()).unwrap(),
+    );
+    item.set_named_property("value", ctx.env.create_string(&it.value).unwrap());
+    item.set_named_property("added", ctx.env.get_boolean(it.added).unwrap());
+    item.set_named_property("removed", ctx.env.get_boolean(it.removed).unwrap());
+
+    obj.set_index(idx, item);
+    idx += 1;
+  }
+
+  Ok(obj)
 }

src/mdiff.rs

@@ -0,0 +1,66 @@
+pub struct Res {
+  pub count: usize,
+  pub added: bool,
+  pub removed: bool,
+  pub value: String,
+}
+
+#[derive(PartialEq, Debug)]
+pub enum Mode {
+  INIT,
+  BOTH,
+  LEFT,
+  RIGHT,
+}
+
+fn get_res(s: &String, mode: Mode) -> Res {
+  Res {
+    count: s.chars().count(),
+    added: if mode == Mode::RIGHT { true } else { false },
+    removed: if mode == Mode::LEFT { true } else { false },
+    value: s.clone(),
+  }
+}
+
+pub fn diff_chars(s1: &str, s2: &str) -> Vec<Res> {
+  let mut mode = Mode::INIT;
+  let mut s: String = String::new();
+
+  let mut result: Vec<Res> = Vec::new();
+
+  for d in diff::chars(s1, s2) {
+    match d {
+      diff::Result::Left(l) => {
+        if mode != Mode::LEFT && mode != Mode::INIT {
+          result.push(get_res(&s, mode));
+          s.clear();
+        }
+        mode = Mode::LEFT;
+        s.push(l);
+      }
+      diff::Result::Right(r) => {
+        if mode != Mode::RIGHT && mode != Mode::INIT {
+          result.push(get_res(&s, mode));
+          s.clear();
+        }
+        mode = Mode::RIGHT;
+        s.push(r);
+      }
+      diff::Result::Both(l, _) => {
+        if mode != Mode::BOTH && mode != Mode::INIT {
+          result.push(get_res(&s, mode));
+          s.clear();
+        }
+        mode = Mode::BOTH;
+        s.push(l);
+      }
+    }
+  }
+
+  if s.len() > 0 {
+    result.push(get_res(&s, mode));
+    s.clear();
+  }
+
+  result
+}