7 files changed, 203 insertions, 92 deletions

diff --git a/core/examples/http_bench.js b/core/examples/http_bench.js
index 4c68f2be6..a7142b09d 100644
--- a/core/examples/http_bench.js
+++ b/core/examples/http_bench.js
@@ -1,11 +1,6 @@
 // This is not a real HTTP server. We read blindly one time into 'requestBuf',
 // then write this fixed 'responseBuf'. The point of this benchmark is to
 // exercise the event loop in a simple yet semi-realistic way.
-const OP_LISTEN = 1;
-const OP_ACCEPT = 2;
-const OP_READ = 3;
-const OP_WRITE = 4;
-const OP_CLOSE = 5;
 const requestBuf = new Uint8Array(64 * 1024);
 const responseBuf = new Uint8Array(
   "HTTP/1.1 200 OK\r\nContent-Length: 12\r\n\r\nHello World\n"
@@ -80,12 +75,12 @@ function handleAsyncMsgFromRust(opId, buf) {
 
 /** Listens on 0.0.0.0:4500, returns rid. */
 function listen() {
-  return sendSync(OP_LISTEN, -1);
+  return sendSync(ops["listen"], -1);
 }
 
 /** Accepts a connection, returns rid. */
 async function accept(rid) {
-  return await sendAsync(OP_ACCEPT, rid);
+  return await sendAsync(ops["accept"], rid);
 }
 
 /**
@@ -93,16 +88,16 @@ async function accept(rid) {
  * Returns bytes read.
  */
 async function read(rid, data) {
-  return await sendAsync(OP_READ, rid, data);
+  return await sendAsync(ops["read"], rid, data);
 }
 
 /** Writes a fixed HTTP response to the socket rid. Returns bytes written. */
 async function write(rid, data) {
-  return await sendAsync(OP_WRITE, rid, data);
+  return await sendAsync(ops["write"], rid, data);
 }
 
 function close(rid) {
-  return sendSync(OP_CLOSE, rid);
+  return sendSync(ops["close"], rid);
 }
 
 async function serve(rid) {
@@ -120,8 +115,11 @@ async function serve(rid) {
   close(rid);
 }
 
+let ops;
+
 async function main() {
   Deno.core.setAsyncHandler(handleAsyncMsgFromRust);
+  ops = Deno.core.ops();
 
   Deno.core.print("http_bench.js start\n");
 
diff --git a/core/examples/http_bench.rs b/core/examples/http_bench.rs
index 3c077562d..c019d8a11 100644
--- a/core/examples/http_bench.rs
+++ b/core/examples/http_bench.rs
@@ -36,12 +36,6 @@ impl log::Log for Logger {
   fn flush(&self) {}
 }
 
-const OP_LISTEN: OpId = 1;
-const OP_ACCEPT: OpId = 2;
-const OP_READ: OpId = 3;
-const OP_WRITE: OpId = 4;
-const OP_CLOSE: OpId = 5;
-
 #[derive(Clone, Debug, PartialEq)]
 pub struct Record {
   pub promise_id: i32,
@@ -104,48 +98,24 @@ fn test_record_from() {
   // TODO test From<&[u8]> for Record
 }
 
-pub type HttpBenchOp = dyn Future<Item = i32, Error = std::io::Error> + Send;
-
-fn dispatch(
-  op_id: OpId,
-  control: &[u8],
-  zero_copy_buf: Option<PinnedBuf>,
-) -> CoreOp {
-  let record = Record::from(control);
-  let is_sync = record.promise_id == 0;
-  let http_bench_op = match op_id {
-    OP_LISTEN => {
-      assert!(is_sync);
-      op_listen()
-    }
-    OP_CLOSE => {
-      assert!(is_sync);
-      let rid = record.arg;
-      op_close(rid)
-    }
-    OP_ACCEPT => {
-      assert!(!is_sync);
-      let listener_rid = record.arg;
-      op_accept(listener_rid)
-    }
-    OP_READ => {
-      assert!(!is_sync);
-      let rid = record.arg;
-      op_read(rid, zero_copy_buf)
-    }
-    OP_WRITE => {
-      assert!(!is_sync);
-      let rid = record.arg;
-      op_write(rid, zero_copy_buf)
-    }
-    _ => panic!("bad op {}", op_id),
-  };
-  let mut record_a = record.clone();
-  let mut record_b = record.clone();
+pub type HttpOp = dyn Future<Item = i32, Error = std::io::Error> + Send;
 
-  let fut = Box::new(
-    http_bench_op
-      .and_then(move |result| {
+pub type HttpOpHandler =
+  fn(record: Record, zero_copy_buf: Option<PinnedBuf>) -> Box<HttpOp>;
+
+fn http_op(
+  handler: HttpOpHandler,
+) -> impl Fn(&[u8], Option<PinnedBuf>) -> CoreOp {
+  move |control: &[u8], zero_copy_buf: Option<PinnedBuf>| -> CoreOp {
+    let record = Record::from(control);
+    let is_sync = record.promise_id == 0;
+    let op = handler(record.clone(), zero_copy_buf);
+
+    let mut record_a = record.clone();
+    let mut record_b = record.clone();
+
+    let fut = Box::new(
+      op.and_then(move |result| {
         record_a.result = result;
         Ok(record_a)
       })
@@ -158,12 +128,13 @@ fn dispatch(
         let record = result.unwrap();
         Ok(record.into())
       }),
-  );
+    );
 
-  if is_sync {
-    Op::Sync(fut.wait().unwrap())
-  } else {
-    Op::Async(fut)
+    if is_sync {
+      Op::Sync(fut.wait().unwrap())
+    } else {
+      Op::Async(fut)
+    }
   }
 }
 
@@ -181,7 +152,11 @@ fn main() {
     });
 
     let mut isolate = deno::Isolate::new(startup_data, false);
-    isolate.set_dispatch(dispatch);
+    isolate.register_op("listen", http_op(op_listen));
+    isolate.register_op("accept", http_op(op_accept));
+    isolate.register_op("read", http_op(op_read));
+    isolate.register_op("write", http_op(op_write));
+    isolate.register_op("close", http_op(op_close));
 
     isolate.then(|r| {
       js_check(r);
@@ -225,7 +200,8 @@ fn new_rid() -> i32 {
   rid as i32
 }
 
-fn op_accept(listener_rid: i32) -> Box<HttpBenchOp> {
+fn op_accept(record: Record, _zero_copy_buf: Option<PinnedBuf>) -> Box<HttpOp> {
+  let listener_rid = record.arg;
   debug!("accept {}", listener_rid);
   Box::new(
     futures::future::poll_fn(move || {
@@ -248,9 +224,11 @@ fn op_accept(listener_rid: i32) -> Box<HttpBenchOp> {
   )
 }
 
-fn op_listen() -> Box<HttpBenchOp> {
+fn op_listen(
+  _record: Record,
+  _zero_copy_buf: Option<PinnedBuf>,
+) -> Box<HttpOp> {
   debug!("listen");
-
   Box::new(lazy(move || {
     let addr = "127.0.0.1:4544".parse::<SocketAddr>().unwrap();
     let listener = tokio::net::TcpListener::bind(&addr).unwrap();
@@ -262,8 +240,9 @@ fn op_listen() -> Box<HttpBenchOp> {
   }))
 }
 
-fn op_close(rid: i32) -> Box<HttpBenchOp> {
+fn op_close(record: Record, _zero_copy_buf: Option<PinnedBuf>) -> Box<HttpOp> {
   debug!("close");
+  let rid = record.arg;
   Box::new(lazy(move || {
     let mut table = RESOURCE_TABLE.lock().unwrap();
     let r = table.remove(&rid);
@@ -272,7 +251,8 @@ fn op_close(rid: i32) -> Box<HttpBenchOp> {
   }))
 }
 
-fn op_read(rid: i32, zero_copy_buf: Option<PinnedBuf>) -> Box<HttpBenchOp> {
+fn op_read(record: Record, zero_copy_buf: Option<PinnedBuf>) -> Box<HttpOp> {
+  let rid = record.arg;
   debug!("read rid={}", rid);
   let mut zero_copy_buf = zero_copy_buf.unwrap();
   Box::new(
@@ -293,7 +273,8 @@ fn op_read(rid: i32, zero_copy_buf: Option<PinnedBuf>) -> Box<HttpBenchOp> {
   )
 }
 
-fn op_write(rid: i32, zero_copy_buf: Option<PinnedBuf>) -> Box<HttpBenchOp> {
+fn op_write(record: Record, zero_copy_buf: Option<PinnedBuf>) -> Box<HttpOp> {
+  let rid = record.arg;
   debug!("write rid={}", rid);
   let zero_copy_buf = zero_copy_buf.unwrap();
   Box::new(
diff --git a/core/isolate.rs b/core/isolate.rs
index bad79b579..6795f25f0 100644
--- a/core/isolate.rs
+++ b/core/isolate.rs
@@ -13,10 +13,10 @@ use crate::libdeno::deno_buf;
 use crate::libdeno::deno_dyn_import_id;
 use crate::libdeno::deno_mod;
 use crate::libdeno::deno_pinned_buf;
-use crate::libdeno::OpId;
 use crate::libdeno::PinnedBuf;
 use crate::libdeno::Snapshot1;
 use crate::libdeno::Snapshot2;
+use crate::ops::*;
 use crate::shared_queue::SharedQueue;
 use crate::shared_queue::RECOMMENDED_SIZE;
 use futures::stream::FuturesUnordered;
@@ -34,24 +34,6 @@ use std::fmt;
 use std::ptr::null;
 use std::sync::{Arc, Mutex, Once};
 
-pub type Buf = Box<[u8]>;
-
-pub type OpAsyncFuture<E> = Box<dyn Future<Item = Buf, Error = E> + Send>;
-
-type PendingOpFuture =
-  Box<dyn Future<Item = (OpId, Buf), Error = CoreError> + Send>;
-
-pub enum Op<E> {
-  Sync(Buf),
-  Async(OpAsyncFuture<E>),
-}
-
-pub type CoreError = ();
-
-pub type CoreOp = Op<CoreError>;
-
-pub type OpResult<E> = Result<Op<E>, E>;
-
 /// Args: op_id, control_buf, zero_copy_buf
 type CoreDispatchFn = dyn Fn(OpId, &[u8], Option<PinnedBuf>) -> CoreOp;
 
@@ -179,6 +161,7 @@ pub struct Isolate {
   pending_dyn_imports: FuturesUnordered<StreamFuture<DynImport>>,
   have_unpolled_ops: bool,
   startup_script: Option<OwnedScript>,
+  op_registry: OpRegistry,
 }
 
 unsafe impl Send for Isolate {}
@@ -244,12 +227,17 @@ impl Isolate {
       have_unpolled_ops: false,
       pending_dyn_imports: FuturesUnordered::new(),
       startup_script,
+      op_registry: OpRegistry::new(),
     }
   }
 
   /// Defines the how Deno.core.dispatch() acts.
   /// Called whenever Deno.core.dispatch() is called in JavaScript. zero_copy_buf
   /// corresponds to the second argument of Deno.core.dispatch().
+  ///
+  /// If this method is used then ops registered using `op_register` function are
+  /// ignored and all dispatching must be handled manually in provided callback.
+  // TODO: we want to deprecate and remove this API and move to `register_op` API
   pub fn set_dispatch<F>(&mut self, f: F)
   where
     F: Fn(OpId, &[u8], Option<PinnedBuf>) -> CoreOp + Send + Sync + 'static,
@@ -257,6 +245,22 @@ impl Isolate {
     self.dispatch = Some(Arc::new(f));
   }
 
+  /// New dispatch mechanism. Requires runtime to explicitly ask for op ids
+  /// before using any of the ops.
+  ///
+  /// Ops added using this method are only usable if `dispatch` is not set
+  /// (using `set_dispatch` method).
+  pub fn register_op<F>(&mut self, name: &str, op: F) -> OpId
+  where
+    F: Fn(&[u8], Option<PinnedBuf>) -> CoreOp + Send + Sync + 'static,
+  {
+    assert!(
+      self.dispatch.is_none(),
+      "set_dispatch should not be used in conjunction with register_op"
+    );
+    self.op_registry.register(name, op)
+  }
+
   pub fn set_dyn_import<F>(&mut self, f: F)
   where
     F: Fn(deno_dyn_import_id, &str, &str) -> DynImportStream
@@ -329,9 +333,17 @@ impl Isolate {
     let isolate = unsafe { Isolate::from_raw_ptr(user_data) };
 
     let op = if let Some(ref f) = isolate.dispatch {
+      assert!(
+        op_id != 0,
+        "op_id 0 is a special value that shouldn't be used with dispatch"
+      );
       f(op_id, control_buf.as_ref(), PinnedBuf::new(zero_copy_buf))
     } else {
-      panic!("isolate.dispatch not set")
+      isolate.op_registry.call(
+        op_id,
+        control_buf.as_ref(),
+        PinnedBuf::new(zero_copy_buf),
+      )
     };
 
     debug_assert_eq!(isolate.shared.size(), 0);
diff --git a/core/lib.rs b/core/lib.rs
index 9be1c3891..42a692f1a 100644
--- a/core/lib.rs
+++ b/core/lib.rs
@@ -11,6 +11,7 @@ mod js_errors;
 mod libdeno;
 mod module_specifier;
 mod modules;
+mod ops;
 mod shared_queue;
 
 pub use crate::any_error::*;
@@ -22,6 +23,7 @@ pub use crate::libdeno::OpId;
 pub use crate::libdeno::PinnedBuf;
 pub use crate::module_specifier::*;
 pub use crate::modules::*;
+pub use crate::ops::*;
 
 pub fn v8_version() -> &'static str {
   use std::ffi::CStr;
diff --git a/core/ops.rs b/core/ops.rs
new file mode 100644
index 000000000..84c15e096
--- /dev/null
+++ b/core/ops.rs
@@ -0,0 +1,111 @@
+// Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
+pub use crate::libdeno::OpId;
+use crate::PinnedBuf;
+use futures::Future;
+use std::collections::HashMap;
+
+pub type Buf = Box<[u8]>;
+
+pub type OpAsyncFuture<E> = Box<dyn Future<Item = Buf, Error = E> + Send>;
+
+pub(crate) type PendingOpFuture =
+  Box<dyn Future<Item = (OpId, Buf), Error = CoreError> + Send>;
+
+pub type OpResult<E> = Result<Op<E>, E>;
+
+pub enum Op<E> {
+  Sync(Buf),
+  Async(OpAsyncFuture<E>),
+}
+
+pub type CoreError = ();
+
+pub type CoreOp = Op<CoreError>;
+
+/// Main type describing op
+type OpDispatcher = dyn Fn(&[u8], Option<PinnedBuf>) -> CoreOp;
+
+#[derive(Default)]
+pub struct OpRegistry {
+  dispatchers: Vec<Box<OpDispatcher>>,
+  name_to_id: HashMap<String, OpId>,
+}
+
+impl OpRegistry {
+  pub fn new() -> Self {
+    let mut registry = Self::default();
+    let op_id = registry.register("ops", |_, _| {
+      // ops is a special op which is handled in call.
+      unreachable!()
+    });
+    assert_eq!(op_id, 0);
+    registry
+  }
+
+  pub fn register<F>(&mut self, name: &str, op: F) -> OpId
+  where
+    F: Fn(&[u8], Option<PinnedBuf>) -> CoreOp + Send + Sync + 'static,
+  {
+    let op_id = self.dispatchers.len() as u32;
+
+    let existing = self.name_to_id.insert(name.to_string(), op_id);
+    assert!(
+      existing.is_none(),
+      format!("Op already registered: {}", name)
+    );
+
+    self.dispatchers.push(Box::new(op));
+    op_id
+  }
+
+  fn json_map(&self) -> Buf {
+    let op_map_json = serde_json::to_string(&self.name_to_id).unwrap();
+    op_map_json.as_bytes().to_owned().into_boxed_slice()
+  }
+
+  pub fn call(
+    &self,
+    op_id: OpId,
+    control: &[u8],
+    zero_copy_buf: Option<PinnedBuf>,
+  ) -> CoreOp {
+    // Op with id 0 has special meaning - it's a special op that is always
+    // provided to retrieve op id map. The map consists of name to `OpId`
+    // mappings.
+    if op_id == 0 {
+      return Op::Sync(self.json_map());
+    }
+
+    let d = &*self.dispatchers.get(op_id as usize).expect("Op not found!");
+    d(control, zero_copy_buf)
+  }
+}
+
+#[test]
+fn test_op_registry() {
+  use std::sync::atomic;
+  use std::sync::Arc;
+  let mut op_registry = OpRegistry::new();
+
+  let c = Arc::new(atomic::AtomicUsize::new(0));
+  let c_ = c.clone();
+
+  let test_id = op_registry.register("test", move |_, _| {
+    c_.fetch_add(1, atomic::Ordering::SeqCst);
+    CoreOp::Sync(Box::new([]))
+  });
+  assert!(test_id != 0);
+
+  let mut expected = HashMap::new();
+  expected.insert("ops".to_string(), 0);
+  expected.insert("test".to_string(), 1);
+  assert_eq!(op_registry.name_to_id, expected);
+
+  let res = op_registry.call(test_id, &[], None);
+  if let Op::Sync(buf) = res {
+    assert_eq!(buf.len(), 0);
+  } else {
+    unreachable!();
+  }
+  assert_eq!(c.load(atomic::Ordering::SeqCst), 1);
+}
diff --git a/core/shared_queue.js b/core/shared_queue.js
index 22a64a312..7eeb61255 100644
--- a/core/shared_queue.js
+++ b/core/shared_queue.js
@@ -58,6 +58,13 @@ SharedQueue Binary Layout
     Deno.core.recv(handleAsyncMsgFromRust);
   }
 
+  function ops() {
+    // op id 0 is a special value to retreive the map of registered ops.
+    const opsMapBytes = Deno.core.send(0, new Uint8Array([]), null);
+    const opsMapJson = String.fromCharCode.apply(null, opsMapBytes);
+    return JSON.parse(opsMapJson);
+  }
+
   function assert(cond) {
     if (!cond) {
       throw Error("assert");
@@ -84,7 +91,6 @@ SharedQueue Binary Layout
     return shared32[INDEX_NUM_RECORDS] - shared32[INDEX_NUM_SHIFTED_OFF];
   }
 
-  // TODO(ry) rename to setMeta
   function setMeta(index, end, opId) {
     shared32[INDEX_OFFSETS + 2 * index] = end;
     shared32[INDEX_OFFSETS + 2 * index + 1] = opId;
@@ -189,7 +195,8 @@ SharedQueue Binary Layout
       push,
       reset,
       shift
-    }
+    },
+    ops
   };
 
   assert(window[GLOBAL_NAMESPACE] != null);
diff --git a/core/shared_queue.rs b/core/shared_queue.rs
index 5f9554ad2..dbb738f15 100644
--- a/core/shared_queue.rs
+++ b/core/shared_queue.rs
@@ -196,7 +196,7 @@ impl SharedQueue {
 #[cfg(test)]
 mod tests {
   use super::*;
-  use crate::isolate::Buf;
+  use crate::ops::Buf;
 
   #[test]
   fn basic() {