Files
wasmtime/crates/wasi-common/src/ctx.rs
2021-01-29 15:48:55 -08:00

134 lines
3.5 KiB
Rust

use crate::clocks::WasiClocks;
use crate::dir::{DirCaps, DirEntry, WasiDir};
use crate::file::{FileCaps, FileEntry, WasiFile};
use crate::sched::WasiSched;
use crate::string_array::{StringArray, StringArrayError};
use crate::table::Table;
use crate::Error;
use cap_rand::RngCore;
use std::cell::{RefCell, RefMut};
use std::path::{Path, PathBuf};
use std::rc::Rc;
pub struct WasiCtx {
pub args: StringArray,
pub env: StringArray,
pub random: RefCell<Box<dyn RngCore>>,
pub clocks: WasiClocks,
pub sched: Box<dyn WasiSched>,
pub table: Rc<RefCell<Table>>,
}
impl WasiCtx {
pub fn builder(
random: RefCell<Box<dyn RngCore>>,
clocks: WasiClocks,
sched: Box<dyn WasiSched>,
table: Rc<RefCell<Table>>,
) -> WasiCtxBuilder {
WasiCtxBuilder(WasiCtx {
args: StringArray::new(),
env: StringArray::new(),
random,
clocks,
sched,
table,
})
}
pub fn insert_file(&self, fd: u32, file: Box<dyn WasiFile>, caps: FileCaps) {
self.table()
.insert_at(fd, Box::new(FileEntry::new(caps, file)));
}
pub fn insert_dir(
&self,
fd: u32,
dir: Box<dyn WasiDir>,
caps: DirCaps,
file_caps: FileCaps,
path: PathBuf,
) {
self.table().insert_at(
fd,
Box::new(DirEntry::new(caps, file_caps, Some(path), dir)),
);
}
pub fn table(&self) -> RefMut<Table> {
self.table.borrow_mut()
}
}
pub struct WasiCtxBuilder(WasiCtx);
impl WasiCtxBuilder {
pub fn build(self) -> Result<WasiCtx, Error> {
use crate::file::TableFileExt;
let t = self.0.table();
for (fd, name) in ["stdin", "stdout", "stderr"].iter().enumerate() {
if t.get_file(fd as u32).is_err() {
return Err(anyhow::anyhow!(
"Cannot build WasiCtx: Missing required file `{}`",
name
));
}
}
drop(t);
Ok(self.0)
}
pub fn arg(mut self, arg: &str) -> Result<Self, StringArrayError> {
self.0.args.push(arg.to_owned())?;
Ok(self)
}
pub fn env(mut self, var: &str, value: &str) -> Result<Self, StringArrayError> {
self.0.env.push(format!("{}={}", var, value))?;
Ok(self)
}
pub fn stdin(self, f: Box<dyn WasiFile>) -> Self {
self.0.insert_file(
0,
f,
FileCaps::READ | FileCaps::POLL_READWRITE, // XXX fixme: more rights are ok, but this is read-only
);
self
}
pub fn stdout(self, f: Box<dyn WasiFile>) -> Self {
self.0.insert_file(
1,
f,
FileCaps::WRITE | FileCaps::POLL_READWRITE, // XXX fixme: more rights are ok, but this is append only
);
self
}
pub fn stderr(self, f: Box<dyn WasiFile>) -> Self {
self.0.insert_file(
2,
f,
FileCaps::WRITE | FileCaps::POLL_READWRITE, // XXX fixme: more rights are ok, but this is append only
);
self
}
pub fn preopened_dir(
self,
dir: Box<dyn WasiDir>,
path: impl AsRef<Path>,
) -> Result<Self, Error> {
let caps = DirCaps::all();
let file_caps = FileCaps::all();
self.0.table().push(Box::new(DirEntry::new(
caps,
file_caps,
Some(path.as_ref().to_owned()),
dir,
)))?;
Ok(self)
}
}