1 files changed, 494 insertions, 0 deletions
diff --git a/cli/resources.rs b/cli/resources.rs
new file mode 100644
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--- /dev/null
+++ b/cli/resources.rs
@@ -0,0 +1,494 @@
+// Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
+
+// Think of Resources as File Descriptors. They are integers that are allocated
+// by the privileged side of Deno to refer to various resources.  The simplest
+// example are standard file system files and stdio - but there will be other
+// resources added in the future that might not correspond to operating system
+// level File Descriptors. To avoid confusion we call them "resources" not "file
+// descriptors". This module implements a global resource table. Ops (AKA
+// handlers) look up resources by their integer id here.
+
+use crate::cli::Buf;
+use crate::errors;
+use crate::errors::bad_resource;
+use crate::errors::DenoError;
+use crate::errors::DenoResult;
+use crate::http_body::HttpBody;
+use crate::isolate_state::WorkerChannels;
+use crate::repl::Repl;
+
+use futures;
+use futures::Future;
+use futures::Poll;
+use futures::Sink;
+use futures::Stream;
+use hyper;
+use std;
+use std::collections::HashMap;
+use std::io::{Error, Read, Seek, SeekFrom, Write};
+use std::net::{Shutdown, SocketAddr};
+use std::process::ExitStatus;
+use std::sync::atomic::AtomicUsize;
+use std::sync::atomic::Ordering;
+use std::sync::{Arc, Mutex};
+use tokio;
+use tokio::io::{AsyncRead, AsyncWrite};
+use tokio::net::TcpStream;
+use tokio_process;
+
+pub type ResourceId = u32; // Sometimes referred to RID.
+
+// These store Deno's file descriptors. These are not necessarily the operating
+// system ones.
+type ResourceTable = HashMap<ResourceId, Repr>;
+
+#[cfg(not(windows))]
+use std::os::unix::io::FromRawFd;
+
+#[cfg(windows)]
+use std::os::windows::io::FromRawHandle;
+
+#[cfg(windows)]
+extern crate winapi;
+
+lazy_static! {
+  // Starts at 3 because stdio is [0-2].
+  static ref NEXT_RID: AtomicUsize = AtomicUsize::new(3);
+  static ref RESOURCE_TABLE: Mutex<ResourceTable> = Mutex::new({
+    let mut m = HashMap::new();
+    // TODO Load these lazily during lookup?
+    m.insert(0, Repr::Stdin(tokio::io::stdin()));
+
+    m.insert(1, Repr::Stdout({
+      #[cfg(not(windows))]
+      let stdout = unsafe { std::fs::File::from_raw_fd(1) };
+      #[cfg(windows)]
+      let stdout = unsafe {
+        std::fs::File::from_raw_handle(winapi::um::processenv::GetStdHandle(
+            winapi::um::winbase::STD_OUTPUT_HANDLE))
+      };
+      tokio::fs::File::from_std(stdout)
+    }));
+
+    m.insert(2, Repr::Stderr(tokio::io::stderr()));
+    m
+  });
+}
+
+// Internal representation of Resource.
+enum Repr {
+  Stdin(tokio::io::Stdin),
+  Stdout(tokio::fs::File),
+  Stderr(tokio::io::Stderr),
+  FsFile(tokio::fs::File),
+  // Since TcpListener might be closed while there is a pending accept task,
+  // we need to track the task so that when the listener is closed,
+  // this pending task could be notified and die.
+  // Currently TcpListener itself does not take care of this issue.
+  // See: https://github.com/tokio-rs/tokio/issues/846
+  TcpListener(tokio::net::TcpListener, Option<futures::task::Task>),
+  TcpStream(tokio::net::TcpStream),
+  HttpBody(HttpBody),
+  Repl(Arc<Mutex<Repl>>),
+  // Enum size is bounded by the largest variant.
+  // Use `Box` around large `Child` struct.
+  // https://rust-lang.github.io/rust-clippy/master/index.html#large_enum_variant
+  Child(Box<tokio_process::Child>),
+  ChildStdin(tokio_process::ChildStdin),
+  ChildStdout(tokio_process::ChildStdout),
+  ChildStderr(tokio_process::ChildStderr),
+  Worker(WorkerChannels),
+}
+
+/// If the given rid is open, this returns the type of resource, E.G. "worker".
+/// If the rid is closed or was never open, it returns None.
+pub fn get_type(rid: ResourceId) -> Option<String> {
+  let table = RESOURCE_TABLE.lock().unwrap();
+  table.get(&rid).map(inspect_repr)
+}
+
+pub fn table_entries() -> Vec<(u32, String)> {
+  let table = RESOURCE_TABLE.lock().unwrap();
+
+  table
+    .iter()
+    .map(|(key, value)| (*key, inspect_repr(&value)))
+    .collect()
+}
+
+#[test]
+fn test_table_entries() {
+  let mut entries = table_entries();
+  entries.sort();
+  assert_eq!(entries[0], (0, String::from("stdin")));
+  assert_eq!(entries[1], (1, String::from("stdout")));
+  assert_eq!(entries[2], (2, String::from("stderr")));
+}
+
+fn inspect_repr(repr: &Repr) -> String {
+  let h_repr = match repr {
+    Repr::Stdin(_) => "stdin",
+    Repr::Stdout(_) => "stdout",
+    Repr::Stderr(_) => "stderr",
+    Repr::FsFile(_) => "fsFile",
+    Repr::TcpListener(_, _) => "tcpListener",
+    Repr::TcpStream(_) => "tcpStream",
+    Repr::HttpBody(_) => "httpBody",
+    Repr::Repl(_) => "repl",
+    Repr::Child(_) => "child",
+    Repr::ChildStdin(_) => "childStdin",
+    Repr::ChildStdout(_) => "childStdout",
+    Repr::ChildStderr(_) => "childStderr",
+    Repr::Worker(_) => "worker",
+  };
+
+  String::from(h_repr)
+}
+
+// Abstract async file interface.
+// Ideally in unix, if Resource represents an OS rid, it will be the same.
+#[derive(Clone, Debug)]
+pub struct Resource {
+  pub rid: ResourceId,
+}
+
+impl Resource {
+  // TODO Should it return a Resource instead of net::TcpStream?
+  pub fn poll_accept(&mut self) -> Poll<(TcpStream, SocketAddr), Error> {
+    let mut table = RESOURCE_TABLE.lock().unwrap();
+    let maybe_repr = table.get_mut(&self.rid);
+    match maybe_repr {
+      None => Err(std::io::Error::new(
+        std::io::ErrorKind::Other,
+        "Listener has been closed",
+      )),
+      Some(repr) => match repr {
+        Repr::TcpListener(ref mut s, _) => s.poll_accept(),
+        _ => panic!("Cannot accept"),
+      },
+    }
+  }
+
+  // close(2) is done by dropping the value. Therefore we just need to remove
+  // the resource from the RESOURCE_TABLE.
+  pub fn close(&self) {
+    let mut table = RESOURCE_TABLE.lock().unwrap();
+    let r = table.remove(&self.rid);
+    assert!(r.is_some());
+  }
+
+  pub fn shutdown(&mut self, how: Shutdown) -> Result<(), DenoError> {
+    let mut table = RESOURCE_TABLE.lock().unwrap();
+    let maybe_repr = table.get_mut(&self.rid);
+    match maybe_repr {
+      None => panic!("bad rid"),
+      Some(repr) => match repr {
+        Repr::TcpStream(ref mut f) => {
+          TcpStream::shutdown(f, how).map_err(DenoError::from)
+        }
+        _ => panic!("Cannot shutdown"),
+      },
+    }
+  }
+}
+
+impl Read for Resource {
+  fn read(&mut self, _buf: &mut [u8]) -> std::io::Result<usize> {
+    unimplemented!();
+  }
+}
+
+impl AsyncRead for Resource {
+  fn poll_read(&mut self, buf: &mut [u8]) -> Poll<usize, Error> {
+    let mut table = RESOURCE_TABLE.lock().unwrap();
+    let maybe_repr = table.get_mut(&self.rid);
+    match maybe_repr {
+      None => panic!("bad rid"),
+      Some(repr) => match repr {
+        Repr::FsFile(ref mut f) => f.poll_read(buf),
+        Repr::Stdin(ref mut f) => f.poll_read(buf),
+        Repr::TcpStream(ref mut f) => f.poll_read(buf),
+        Repr::HttpBody(ref mut f) => f.poll_read(buf),
+        Repr::ChildStdout(ref mut f) => f.poll_read(buf),
+        Repr::ChildStderr(ref mut f) => f.poll_read(buf),
+        _ => panic!("Cannot read"),
+      },
+    }
+  }
+}
+
+impl Write for Resource {
+  fn write(&mut self, _buf: &[u8]) -> std::io::Result<usize> {
+    unimplemented!()
+  }
+
+  fn flush(&mut self) -> std::io::Result<()> {
+    unimplemented!()
+  }
+}
+
+impl AsyncWrite for Resource {
+  fn poll_write(&mut self, buf: &[u8]) -> Poll<usize, Error> {
+    let mut table = RESOURCE_TABLE.lock().unwrap();
+    let maybe_repr = table.get_mut(&self.rid);
+    match maybe_repr {
+      None => panic!("bad rid"),
+      Some(repr) => match repr {
+        Repr::FsFile(ref mut f) => f.poll_write(buf),
+        Repr::Stdout(ref mut f) => f.poll_write(buf),
+        Repr::Stderr(ref mut f) => f.poll_write(buf),
+        Repr::TcpStream(ref mut f) => f.poll_write(buf),
+        Repr::ChildStdin(ref mut f) => f.poll_write(buf),
+        _ => panic!("Cannot write"),
+      },
+    }
+  }
+
+  fn shutdown(&mut self) -> futures::Poll<(), std::io::Error> {
+    unimplemented!()
+  }
+}
+
+fn new_rid() -> ResourceId {
+  let next_rid = NEXT_RID.fetch_add(1, Ordering::SeqCst);
+  next_rid as ResourceId
+}
+
+pub fn add_fs_file(fs_file: tokio::fs::File) -> Resource {
+  let rid = new_rid();
+  let mut tg = RESOURCE_TABLE.lock().unwrap();
+  match tg.insert(rid, Repr::FsFile(fs_file)) {
+    Some(_) => panic!("There is already a file with that rid"),
+    None => Resource { rid },
+  }
+}
+
+pub fn add_tcp_listener(listener: tokio::net::TcpListener) -> Resource {
+  let rid = new_rid();
+  let mut tg = RESOURCE_TABLE.lock().unwrap();
+  let r = tg.insert(rid, Repr::TcpListener(listener, None));
+  assert!(r.is_none());
+  Resource { rid }
+}
+
+pub fn add_tcp_stream(stream: tokio::net::TcpStream) -> Resource {
+  let rid = new_rid();
+  let mut tg = RESOURCE_TABLE.lock().unwrap();
+  let r = tg.insert(rid, Repr::TcpStream(stream));
+  assert!(r.is_none());
+  Resource { rid }
+}
+
+pub fn add_hyper_body(body: hyper::Body) -> Resource {
+  let rid = new_rid();
+  let mut tg = RESOURCE_TABLE.lock().unwrap();
+  let body = HttpBody::from(body);
+  let r = tg.insert(rid, Repr::HttpBody(body));
+  assert!(r.is_none());
+  Resource { rid }
+}
+
+pub fn add_repl(repl: Repl) -> Resource {
+  let rid = new_rid();
+  let mut tg = RESOURCE_TABLE.lock().unwrap();
+  let r = tg.insert(rid, Repr::Repl(Arc::new(Mutex::new(repl))));
+  assert!(r.is_none());
+  Resource { rid }
+}
+
+pub fn add_worker(wc: WorkerChannels) -> Resource {
+  let rid = new_rid();
+  let mut tg = RESOURCE_TABLE.lock().unwrap();
+  let r = tg.insert(rid, Repr::Worker(wc));
+  assert!(r.is_none());
+  Resource { rid }
+}
+
+pub fn worker_post_message(
+  rid: ResourceId,
+  buf: Buf,
+) -> futures::sink::Send<futures::sync::mpsc::Sender<Buf>> {
+  let mut table = RESOURCE_TABLE.lock().unwrap();
+  let maybe_repr = table.get_mut(&rid);
+  match maybe_repr {
+    Some(Repr::Worker(ref mut wc)) => {
+      // unwrap here is incorrect, but doing it anyway
+      wc.0.clone().send(buf)
+    }
+    _ => panic!("bad resource"), // futures::future::err(bad_resource()).into(),
+  }
+}
+
+pub struct WorkerReceiver {
+  rid: ResourceId,
+}
+
+// Invert the dumbness that tokio_process causes by making Child itself a future.
+impl Future for WorkerReceiver {
+  type Item = Option<Buf>;
+  type Error = DenoError;
+
+  fn poll(&mut self) -> Poll<Option<Buf>, DenoError> {
+    let mut table = RESOURCE_TABLE.lock().unwrap();
+    let maybe_repr = table.get_mut(&self.rid);
+    match maybe_repr {
+      Some(Repr::Worker(ref mut wc)) => wc.1.poll().map_err(|()| {
+        errors::new(errors::ErrorKind::Other, "recv msg error".to_string())
+      }),
+      _ => Err(bad_resource()),
+    }
+  }
+}
+
+pub fn worker_recv_message(rid: ResourceId) -> WorkerReceiver {
+  WorkerReceiver { rid }
+}
+
+#[cfg_attr(feature = "cargo-clippy", allow(stutter))]
+pub struct ChildResources {
+  pub child_rid: ResourceId,
+  pub stdin_rid: Option<ResourceId>,
+  pub stdout_rid: Option<ResourceId>,
+  pub stderr_rid: Option<ResourceId>,
+}
+
+pub fn add_child(mut c: tokio_process::Child) -> ChildResources {
+  let child_rid = new_rid();
+  let mut tg = RESOURCE_TABLE.lock().unwrap();
+
+  let mut resources = ChildResources {
+    child_rid,
+    stdin_rid: None,
+    stdout_rid: None,
+    stderr_rid: None,
+  };
+
+  if c.stdin().is_some() {
+    let stdin = c.stdin().take().unwrap();
+    let rid = new_rid();
+    let r = tg.insert(rid, Repr::ChildStdin(stdin));
+    assert!(r.is_none());
+    resources.stdin_rid = Some(rid);
+  }
+  if c.stdout().is_some() {
+    let stdout = c.stdout().take().unwrap();
+    let rid = new_rid();
+    let r = tg.insert(rid, Repr::ChildStdout(stdout));
+    assert!(r.is_none());
+    resources.stdout_rid = Some(rid);
+  }
+  if c.stderr().is_some() {
+    let stderr = c.stderr().take().unwrap();
+    let rid = new_rid();
+    let r = tg.insert(rid, Repr::ChildStderr(stderr));
+    assert!(r.is_none());
+    resources.stderr_rid = Some(rid);
+  }
+
+  let r = tg.insert(child_rid, Repr::Child(Box::new(c)));
+  assert!(r.is_none());
+
+  resources
+}
+
+pub struct ChildStatus {
+  rid: ResourceId,
+}
+
+// Invert the dumbness that tokio_process causes by making Child itself a future.
+impl Future for ChildStatus {
+  type Item = ExitStatus;
+  type Error = DenoError;
+
+  fn poll(&mut self) -> Poll<ExitStatus, DenoError> {
+    let mut table = RESOURCE_TABLE.lock().unwrap();
+    let maybe_repr = table.get_mut(&self.rid);
+    match maybe_repr {
+      Some(Repr::Child(ref mut child)) => child.poll().map_err(DenoError::from),
+      _ => Err(bad_resource()),
+    }
+  }
+}
+
+pub fn child_status(rid: ResourceId) -> DenoResult<ChildStatus> {
+  let mut table = RESOURCE_TABLE.lock().unwrap();
+  let maybe_repr = table.get_mut(&rid);
+  match maybe_repr {
+    Some(Repr::Child(ref mut _child)) => Ok(ChildStatus { rid }),
+    _ => Err(bad_resource()),
+  }
+}
+
+pub fn get_repl(rid: ResourceId) -> DenoResult<Arc<Mutex<Repl>>> {
+  let mut table = RESOURCE_TABLE.lock().unwrap();
+  let maybe_repr = table.get_mut(&rid);
+  match maybe_repr {
+    Some(Repr::Repl(ref mut r)) => Ok(r.clone()),
+    _ => Err(bad_resource()),
+  }
+}
+
+pub fn lookup(rid: ResourceId) -> Option<Resource> {
+  debug!("resource lookup {}", rid);
+  let table = RESOURCE_TABLE.lock().unwrap();
+  table.get(&rid).map(|_| Resource { rid })
+}
+
+// TODO(kevinkassimo): revamp this after the following lands:
+// https://github.com/tokio-rs/tokio/pull/785
+pub fn seek(
+  resource: Resource,
+  offset: i32,
+  whence: u32,
+) -> Box<dyn Future<Item = (), Error = DenoError> + Send> {
+  let mut table = RESOURCE_TABLE.lock().unwrap();
+  // We take ownership of File here.
+  // It is put back below while still holding the lock.
+  let maybe_repr = table.remove(&resource.rid);
+  match maybe_repr {
+    None => panic!("bad rid"),
+    Some(Repr::FsFile(f)) => {
+      let seek_from = match whence {
+        0 => SeekFrom::Start(offset as u64),
+        1 => SeekFrom::Current(offset as i64),
+        2 => SeekFrom::End(offset as i64),
+        _ => {
+          return Box::new(futures::future::err(errors::new(
+            errors::ErrorKind::InvalidSeekMode,
+            format!("Invalid seek mode: {}", whence),
+          )));
+        }
+      };
+      // Trait Clone not implemented on tokio::fs::File,
+      // so convert to std File first.
+      let std_file = f.into_std();
+      // Create a copy and immediately put back.
+      // We don't want to block other resource ops.
+      // try_clone() would yield a copy containing the same
+      // underlying fd, so operations on the copy would also
+      // affect the one in resource table, and we don't need
+      // to write back.
+      let maybe_std_file_copy = std_file.try_clone();
+      // Insert the entry back with the same rid.
+      table.insert(
+        resource.rid,
+        Repr::FsFile(tokio_fs::File::from_std(std_file)),
+      );
+      if maybe_std_file_copy.is_err() {
+        return Box::new(futures::future::err(DenoError::from(
+          maybe_std_file_copy.unwrap_err(),
+        )));
+      }
+      let mut std_file_copy = maybe_std_file_copy.unwrap();
+      return Box::new(futures::future::lazy(move || {
+        let result = std_file_copy
+          .seek(seek_from)
+          .map(|_| {
+            return ();
+          }).map_err(DenoError::from);
+        futures::future::result(result)
+      }));
+    }
+    _ => panic!("cannot seek"),
+  }
+}