latest system-interface provides ReadReady::num_ready_bytes

Cargo.lock

@@ -993,7 +993,7 @@ dependencies = [
  "cc",
  "libc",
  "log",
- "rustc_version",
+ "rustc_version 0.2.3",
  "winapi",
 ]
 
@@ -1558,6 +1558,15 @@ dependencies = [
 name = "peepmatic-traits"
 version = "0.69.0"
 
+[[package]]
+name = "pest"
+version = "2.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "10f4872ae94d7b90ae48754df22fd42ad52ce740b8f370b03da4835417403e53"
+dependencies = [
+ "ucd-trie",
+]
+
 [[package]]
 name = "pin-project-lite"
 version = "0.2.0"
@@ -1790,7 +1799,7 @@ checksum = "1fdf7d9dbd43f3d81d94a49c1c3df73cc2b3827995147e6cf7f89d4ec5483e73"
 dependencies = [
  "bitflags",
  "cc",
- "rustc_version",
+ "rustc_version 0.2.3",
 ]
 
 [[package]]
@@ -1934,7 +1943,16 @@ version = "0.2.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "138e3e0acb6c9fb258b19b67cb8abd63c00679d2851805ea151465464fe9030a"
 dependencies = [
- "semver",
+ "semver 0.9.0",
+]
+
+[[package]]
+name = "rustc_version"
+version = "0.3.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f0dfe2087c51c460008730de8b57e6a320782fbfb312e1f4d520e6c6fae155ee"
+dependencies = [
+ "semver 0.11.0",
 ]
 
 [[package]]
@@ -2002,7 +2020,16 @@ version = "0.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1d7eb9ef2c18661902cc47e535f9bc51b78acd254da71d375c2f6720d9a40403"
 dependencies = [
- "semver-parser",
+ "semver-parser 0.7.0",
+]
+
+[[package]]
+name = "semver"
+version = "0.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f301af10236f6df4160f7c3f04eec6dbc70ace82d23326abad5edee88801c6b6"
+dependencies = [
+ "semver-parser 0.10.2",
 ]
 
 [[package]]
@@ -2011,6 +2038,15 @@ version = "0.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "388a1df253eca08550bef6c72392cfe7c30914bf41df5269b68cbd6ff8f570a3"
 
+[[package]]
+name = "semver-parser"
+version = "0.10.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "00b0bef5b7f9e0df16536d3961cfb6e84331c065b4066afb39768d0e319411f7"
+dependencies = [
+ "pest",
+]
+
 [[package]]
 name = "serde"
 version = "1.0.118"
@@ -2153,14 +2189,17 @@ dependencies = [
 
 [[package]]
 name = "system-interface"
-version = "0.2.0"
+version = "0.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "95457b1e5a9657ffd02a43048aeb083f20848d82176c0e1313facc1a23ba74da"
+checksum = "2f4491d080ba27a6e906f264ad9b3d3db925b53160e71df56e65973441a186ab"
 dependencies = [
  "atty",
+ "cap-std",
  "posish",
+ "rustc_version 0.3.3",
+ "unsafe-io",
  "winapi",
- "winx 0.21.0",
+ "winx 0.22.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -2384,6 +2423,12 @@ version = "1.12.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "373c8a200f9e67a0c95e62a4f52fbf80c23b4381c05a17845531982fa99e6b33"
 
+[[package]]
+name = "ucd-trie"
+version = "0.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "56dee185309b50d1f11bfedef0fe6d036842e3fb77413abef29f8f8d1c5d4c1c"
+
 [[package]]
 name = "unicode-segmentation"
 version = "1.7.1"
@@ -2411,6 +2456,15 @@ dependencies = [
  "traitobject",
 ]
 
+[[package]]
+name = "unsafe-io"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "80ba583908d065c07f1eaf5eb389b9454f8bc735d182c8b93538e274568509b0"
+dependencies = [
+ "rustc_version 0.3.3",
+]
+
 [[package]]
 name = "vec_map"
 version = "0.8.2"
@@ -3088,6 +3142,17 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "winx"
+version = "0.22.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f7d35176e4c7e0daf9d8da18b7e9df81a8f2358fb3d6feea775ce810f974a512"
+dependencies = [
+ "bitflags",
+ "cvt",
+ "winapi",
+]
+
 [[package]]
 name = "witx"
 version = "0.8.8"

crates/wasi-c2/Cargo.toml

@@ -24,7 +24,7 @@ thiserror = "1.0"
 libc = "0.2"
 wiggle = { path = "../wiggle", default-features = false, version = "0.22.0" }
 tracing = "0.1.19"
-system-interface = "0.2"
+system-interface = { version = "0.5", features = ["cap_std_impls"] }
 cap-std = "0.9"
 cap-fs-ext = "0.9"
 cap-time-ext = "0.9"

crates/wasi-c2/src/file.rs

@@ -5,8 +5,9 @@ use std::any::Any;
 use std::cell::Ref;
 use std::ops::Deref;
 use system_interface::fs::FileIoExt;
+use system_interface::io::ReadReady;
 
-pub trait WasiFile: FileIoExt + SetTimes {
+pub trait WasiFile: FileIoExt + SetTimes + ReadReady {
     fn as_any(&self) -> &dyn Any;
     fn datasync(&self) -> Result<(), Error>;
     fn sync(&self) -> Result<(), Error>;

crates/wasi-c2/src/sched/sync.rs

@@ -72,10 +72,8 @@ mod unix {
                     if let Some(revents) = pollfd.revents() {
                         let (nbytes, rwsub) = match rwsub {
                             Subscription::Read(sub) => {
-                                (1, sub)
+                                let ready = sub.file.num_ready_bytes()?;
-                                // XXX FIXME: query_nbytes in wasi-common/src/sys/poll.rs
+                                (std::cmp::max(ready, 1), sub)
-                                // uses metadata.len - tell to calculate for regular files,
-                                // ioctl(fd, FIONREAD) for large files
                             }
                             Subscription::Write(sub) => (0, sub),
                             _ => unreachable!(),

crates/wasi-c2/src/stdio.rs

@@ -3,6 +3,7 @@ use crate::Error;
 use std::any::Any;
 #[cfg(unix)]
 use std::os::unix::io::{AsRawFd, RawFd};
+use system_interface::io::ReadReady;
 
 pub struct Stdin(std::io::Stdin);
 
@@ -17,6 +18,12 @@ impl AsRawFd for Stdin {
     }
 }
 
+impl ReadReady for Stdin {
+    fn num_ready_bytes(&self) -> Result<u64, std::io::Error> {
+        self.0.num_ready_bytes()
+    }
+}
+
 impl WasiFile for Stdin {
     fn as_any(&self) -> &dyn Any {
         self
@@ -57,6 +64,12 @@ impl AsRawFd for Stdout {
     }
 }
 
+impl ReadReady for Stdout {
+    fn num_ready_bytes(&self) -> Result<u64, std::io::Error> {
+        Ok(0)
+    }
+}
+
 impl WasiFile for Stdout {
     fn as_any(&self) -> &dyn Any {
         self
@@ -97,6 +110,12 @@ impl AsRawFd for Stderr {
     }
 }
 
+impl ReadReady for Stderr {
+    fn num_ready_bytes(&self) -> Result<u64, std::io::Error> {
+        Ok(0)
+    }
+}
+
 impl WasiFile for Stderr {
     fn as_any(&self) -> &dyn Any {
         self

crates/wasi-c2/src/virt/pipe.rs

@@ -15,6 +15,7 @@ use std::any::Any;
 use std::io::{self, Read, Write};
 use std::sync::{Arc, RwLock};
 use system_interface::fs::{Advice, FileIoExt};
+use system_interface::io::ReadReady;
 
 /// A virtual pipe read end.
 ///
@@ -123,12 +124,6 @@ impl<R: Read> FileIoExt for ReadPipe<R> {
     fn read_to_string(&self, buf: &mut String) -> io::Result<usize> {
         self.borrow().read_to_string(buf)
     }
-    fn bytes(self) -> io::Bytes<std::fs::File> {
-        panic!("impossible to implement, removing from trait")
-    }
-    fn take(self, limit: u64) -> io::Take<std::fs::File> {
-        panic!("impossible to implement, removing from trait")
-    }
     fn write(&self, buf: &[u8]) -> io::Result<usize> {
         Err(std::io::Error::from_raw_os_error(libc::EBADF))
     }
@@ -144,7 +139,7 @@ impl<R: Read> FileIoExt for ReadPipe<R> {
     fn write_vectored(&self, bufs: &[io::IoSlice]) -> io::Result<usize> {
         Err(std::io::Error::from_raw_os_error(libc::EBADF))
     }
-    fn write_fmt(&mut self, fmt: std::fmt::Arguments) -> io::Result<()> {
+    fn write_fmt(&self, fmt: std::fmt::Arguments) -> io::Result<()> {
         Err(std::io::Error::from_raw_os_error(libc::EBADF))
     }
     fn flush(&self) -> io::Result<()> {
@@ -156,6 +151,9 @@ impl<R: Read> FileIoExt for ReadPipe<R> {
     fn stream_position(&self) -> io::Result<u64> {
         Err(std::io::Error::from_raw_os_error(libc::ESPIPE))
     }
+    fn peek(&self, _buf: &mut [u8]) -> io::Result<usize> {
+        Err(std::io::Error::from_raw_os_error(libc::EBADF)) // XXX is this right? or do we have to implement this faithfully, and add a buffer of peeked values to handle during reads?
+    }
 }
 
 impl<R: Read> fs_set_times::SetTimes for ReadPipe<R> {
@@ -167,6 +165,13 @@ impl<R: Read> fs_set_times::SetTimes for ReadPipe<R> {
         todo!()
     }
 }
+
+impl<R: Read + Any> ReadReady for ReadPipe<R> {
+    fn num_ready_bytes(&self) -> Result<u64, std::io::Error> {
+        todo!()
+    }
+}
+
 impl<R: Read + Any> WasiFile for ReadPipe<R> {
     fn as_any(&self) -> &dyn Any {
         self
@@ -296,12 +301,6 @@ impl<W: Write> FileIoExt for WritePipe<W> {
     fn read_to_string(&self, buf: &mut String) -> io::Result<usize> {
         Err(std::io::Error::from_raw_os_error(libc::EBADF))
     }
-    fn bytes(self) -> io::Bytes<std::fs::File> {
-        todo!() // removing from trait
-    }
-    fn take(self, limit: u64) -> io::Take<std::fs::File> {
-        todo!() // removing from trait
-    }
     fn write(&self, buf: &[u8]) -> io::Result<usize> {
         self.borrow().write(buf)
     }
@@ -317,7 +316,7 @@ impl<W: Write> FileIoExt for WritePipe<W> {
     fn write_vectored(&self, bufs: &[io::IoSlice]) -> io::Result<usize> {
         self.borrow().write_vectored(bufs)
     }
-    fn write_fmt(&mut self, fmt: std::fmt::Arguments) -> io::Result<()> {
+    fn write_fmt(&self, fmt: std::fmt::Arguments) -> io::Result<()> {
         self.borrow().write_fmt(fmt)
     }
     fn flush(&self) -> io::Result<()> {
@@ -329,6 +328,9 @@ impl<W: Write> FileIoExt for WritePipe<W> {
     fn stream_position(&self) -> io::Result<u64> {
         Err(std::io::Error::from_raw_os_error(libc::ESPIPE))
     }
+    fn peek(&self, _buf: &mut [u8]) -> io::Result<usize> {
+        Err(std::io::Error::from_raw_os_error(libc::EBADF))
+    }
 }
 
 impl<W: Write> fs_set_times::SetTimes for WritePipe<W> {
@@ -341,6 +343,12 @@ impl<W: Write> fs_set_times::SetTimes for WritePipe<W> {
     }
 }
 
+impl<W: Write + Any> ReadReady for WritePipe<W> {
+    fn num_ready_bytes(&self) -> Result<u64, std::io::Error> {
+        Ok(0)
+    }
+}
+
 impl<W: Write + Any> WasiFile for WritePipe<W> {
     fn as_any(&self) -> &dyn Any {
         self