1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
|
// Copyright 2018 the Deno authors. All rights reserved. MIT license.
// Think of Resources as File Descriptors. They are integers that are allocated
// by the privlaged 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 futures;
use futures::Poll;
use std;
use std::collections::HashMap;
use std::io::Error;
use std::io::{Read, Write};
use std::net::SocketAddr;
use std::sync::atomic::AtomicIsize;
use std::sync::atomic::Ordering;
use std::sync::Mutex;
use tokio;
use tokio::io::{AsyncRead, AsyncWrite};
use tokio::net::TcpStream;
pub type ResourceId = i32; // Sometimes referred to RID.
// These store Deno's file descriptors. These are not necessarily the operating
// system ones.
type ResourceTable = HashMap<ResourceId, Repr>;
lazy_static! {
// Starts at 3 because stdio is [0-2].
static ref NEXT_RID: AtomicIsize = AtomicIsize::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(tokio::io::stdout()));
m.insert(2, Repr::Stderr(tokio::io::stderr()));
m
});
}
// Internal representation of Resource.
enum Repr {
Stdin(tokio::io::Stdin),
Stdout(tokio::io::Stdout),
Stderr(tokio::io::Stderr),
FsFile(tokio::fs::File),
TcpListener(tokio::net::TcpListener),
TcpStream(tokio::net::TcpStream),
}
// Abstract async file interface.
// Ideally in unix, if Resource represents an OS rid, it will be the same.
#[derive(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 => panic!("bad rid"),
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(&mut self) {
let mut table = RESOURCE_TABLE.lock().unwrap();
let r = table.remove(&self.rid);
assert!(r.is_some());
}
}
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::Stdout(_) | Repr::Stderr(_) => {
panic!("Cannot read from stdout/stderr")
}
Repr::TcpListener(_) => 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::Stdin(_) => panic!("Cannot write to stdin"),
Repr::TcpListener(_) => 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));
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 lookup(rid: ResourceId) -> Option<Resource> {
let table = RESOURCE_TABLE.lock().unwrap();
table.get(&rid).map(|_| Resource { rid })
}
|
