Organize dispatch a bit (#2796)

Just some clean up reorganization around flatbuffer/minimal dispatch
code. This is prep for adding a JSON dispatcher.

1 files changed, 216 insertions, 0 deletions

diff --git a/cli/ops/dispatch_flatbuffers.rs b/cli/ops/dispatch_flatbuffers.rs
new file mode 100644
index 000000000..2b2e5050d
--- /dev/null
+++ b/cli/ops/dispatch_flatbuffers.rs
@@ -0,0 +1,216 @@
+use super::utils::CliOpResult;
+use crate::deno_error::GetErrorKind;
+use crate::msg;
+use crate::state::ThreadSafeState;
+use deno::*;
+use flatbuffers::FlatBufferBuilder;
+use hyper::rt::Future;
+
+use super::compiler::{op_cache, op_fetch_source_file};
+use super::errors::{op_apply_source_map, op_format_error};
+use super::fetch::op_fetch;
+use super::files::{op_close, op_open, op_read, op_seek, op_write};
+use super::fs::{
+  op_chdir, op_chmod, op_chown, op_copy_file, op_cwd, op_link,
+  op_make_temp_dir, op_mkdir, op_read_dir, op_read_link, op_remove, op_rename,
+  op_stat, op_symlink, op_truncate, op_utime,
+};
+use super::metrics::op_metrics;
+use super::net::{op_accept, op_dial, op_listen, op_shutdown};
+use super::os::{
+  op_env, op_exec_path, op_exit, op_home_dir, op_is_tty, op_set_env, op_start,
+};
+use super::performance::op_now;
+use super::permissions::{op_permissions, op_revoke_permission};
+use super::process::{op_kill, op_run, op_run_status};
+use super::random::op_get_random_values;
+use super::repl::{op_repl_readline, op_repl_start};
+use super::resources::op_resources;
+use super::timers::{op_global_timer, op_global_timer_stop};
+use super::workers::{
+  op_create_worker, op_host_get_message, op_host_get_worker_closed,
+  op_host_post_message, op_worker_get_message, op_worker_post_message,
+};
+
+type CliDispatchFn = fn(
+  state: &ThreadSafeState,
+  base: &msg::Base<'_>,
+  data: Option<PinnedBuf>,
+) -> CliOpResult;
+
+/// Processes raw messages from JavaScript.
+/// This functions invoked every time Deno.core.dispatch() is called.
+/// control corresponds to the first argument of Deno.core.dispatch().
+/// data corresponds to the second argument of Deno.core.dispatch().
+pub fn dispatch(
+  state: &ThreadSafeState,
+  control: &[u8],
+  zero_copy: Option<PinnedBuf>,
+) -> CoreOp {
+  let base = msg::get_root_as_base(&control);
+  let inner_type = base.inner_type();
+  let is_sync = base.sync();
+  let cmd_id = base.cmd_id();
+
+  debug!(
+    "msg_from_js {} sync {}",
+    msg::enum_name_any(inner_type),
+    is_sync
+  );
+
+  let op_func: CliDispatchFn = match op_selector_std(inner_type) {
+    Some(v) => v,
+    None => panic!("Unhandled message {}", msg::enum_name_any(inner_type)),
+  };
+
+  let op_result = op_func(state, &base, zero_copy);
+
+  let state = state.clone();
+
+  match op_result {
+    Ok(Op::Sync(buf)) => {
+      state.metrics_op_completed(buf.len());
+      Op::Sync(buf)
+    }
+    Ok(Op::Async(fut)) => {
+      let result_fut = Box::new(
+        fut
+          .or_else(move |err: ErrBox| -> Result<Buf, ()> {
+            debug!("op err {}", err);
+            // No matter whether we got an Err or Ok, we want a serialized message to
+            // send back. So transform the DenoError into a Buf.
+            let builder = &mut FlatBufferBuilder::new();
+            let errmsg_offset = builder.create_string(&format!("{}", err));
+            Ok(serialize_response(
+              cmd_id,
+              builder,
+              msg::BaseArgs {
+                error: Some(errmsg_offset),
+                error_kind: err.kind(),
+                ..Default::default()
+              },
+            ))
+          })
+          .and_then(move |buf: Buf| -> Result<Buf, ()> {
+            // Handle empty responses. For sync responses we just want
+            // to send null. For async we want to send a small message
+            // with the cmd_id.
+            let buf = if buf.len() > 0 {
+              buf
+            } else {
+              let builder = &mut FlatBufferBuilder::new();
+              serialize_response(
+                cmd_id,
+                builder,
+                msg::BaseArgs {
+                  ..Default::default()
+                },
+              )
+            };
+            state.metrics_op_completed(buf.len());
+            Ok(buf)
+          })
+          .map_err(|err| panic!("unexpected error {:?}", err)),
+      );
+      Op::Async(result_fut)
+    }
+    Err(err) => {
+      debug!("op err {}", err);
+      // No matter whether we got an Err or Ok, we want a serialized message to
+      // send back. So transform the DenoError into a Buf.
+      let builder = &mut FlatBufferBuilder::new();
+      let errmsg_offset = builder.create_string(&format!("{}", err));
+      let response_buf = serialize_response(
+        cmd_id,
+        builder,
+        msg::BaseArgs {
+          error: Some(errmsg_offset),
+          error_kind: err.kind(),
+          ..Default::default()
+        },
+      );
+      state.metrics_op_completed(response_buf.len());
+      Op::Sync(response_buf)
+    }
+  }
+}
+
+pub fn serialize_response(
+  cmd_id: u32,
+  builder: &mut FlatBufferBuilder<'_>,
+  mut args: msg::BaseArgs<'_>,
+) -> Buf {
+  args.cmd_id = cmd_id;
+  let base = msg::Base::create(builder, &args);
+  msg::finish_base_buffer(builder, base);
+  let data = builder.finished_data();
+  // println!("serialize_response {:x?}", data);
+  data.into()
+}
+
+/// Standard ops set for most isolates
+pub fn op_selector_std(inner_type: msg::Any) -> Option<CliDispatchFn> {
+  match inner_type {
+    msg::Any::Accept => Some(op_accept),
+    msg::Any::ApplySourceMap => Some(op_apply_source_map),
+    msg::Any::Cache => Some(op_cache),
+    msg::Any::Chdir => Some(op_chdir),
+    msg::Any::Chmod => Some(op_chmod),
+    msg::Any::Chown => Some(op_chown),
+    msg::Any::Close => Some(op_close),
+    msg::Any::CopyFile => Some(op_copy_file),
+    msg::Any::CreateWorker => Some(op_create_worker),
+    msg::Any::Cwd => Some(op_cwd),
+    msg::Any::Dial => Some(op_dial),
+    msg::Any::Environ => Some(op_env),
+    msg::Any::ExecPath => Some(op_exec_path),
+    msg::Any::Exit => Some(op_exit),
+    msg::Any::Fetch => Some(op_fetch),
+    msg::Any::FetchSourceFile => Some(op_fetch_source_file),
+    msg::Any::FormatError => Some(op_format_error),
+    msg::Any::GetRandomValues => Some(op_get_random_values),
+    msg::Any::GlobalTimer => Some(op_global_timer),
+    msg::Any::GlobalTimerStop => Some(op_global_timer_stop),
+    msg::Any::HostGetMessage => Some(op_host_get_message),
+    msg::Any::HostGetWorkerClosed => Some(op_host_get_worker_closed),
+    msg::Any::HostPostMessage => Some(op_host_post_message),
+    msg::Any::IsTTY => Some(op_is_tty),
+    msg::Any::Kill => Some(op_kill),
+    msg::Any::Link => Some(op_link),
+    msg::Any::Listen => Some(op_listen),
+    msg::Any::MakeTempDir => Some(op_make_temp_dir),
+    msg::Any::Metrics => Some(op_metrics),
+    msg::Any::Mkdir => Some(op_mkdir),
+    msg::Any::Now => Some(op_now),
+    msg::Any::Open => Some(op_open),
+    msg::Any::PermissionRevoke => Some(op_revoke_permission),
+    msg::Any::Permissions => Some(op_permissions),
+    msg::Any::Read => Some(op_read),
+    msg::Any::ReadDir => Some(op_read_dir),
+    msg::Any::Readlink => Some(op_read_link),
+    msg::Any::Remove => Some(op_remove),
+    msg::Any::Rename => Some(op_rename),
+    msg::Any::ReplReadline => Some(op_repl_readline),
+    msg::Any::ReplStart => Some(op_repl_start),
+    msg::Any::Resources => Some(op_resources),
+    msg::Any::Run => Some(op_run),
+    msg::Any::RunStatus => Some(op_run_status),
+    msg::Any::Seek => Some(op_seek),
+    msg::Any::SetEnv => Some(op_set_env),
+    msg::Any::Shutdown => Some(op_shutdown),
+    msg::Any::Start => Some(op_start),
+    msg::Any::Stat => Some(op_stat),
+    msg::Any::Symlink => Some(op_symlink),
+    msg::Any::Truncate => Some(op_truncate),
+    msg::Any::HomeDir => Some(op_home_dir),
+    msg::Any::Utime => Some(op_utime),
+    msg::Any::Write => Some(op_write),
+
+    // TODO(ry) split these out so that only the appropriate Workers can access
+    // them.
+    msg::Any::WorkerGetMessage => Some(op_worker_get_message),
+    msg::Any::WorkerPostMessage => Some(op_worker_post_message),
+
+    _ => None,
+  }
+}