Merge pull request #133 from wingo/filesystem-advise

wasi:[email protected]: Add tests for fadvise

Author: wingo

tests/rust/wasm32-wasip3/src/bin/filesystem-advise.json

@@ -0,0 +1,3 @@
+{
+    "dirs": ["fs-tests.dir"]
+}

tests/rust/wasm32-wasip3/src/bin/filesystem-advise.rs

@@ -0,0 +1,82 @@
+use std::process;
+extern crate wit_bindgen;
+
+wit_bindgen::generate!({
+    inline: r"
+  package test:test;
+
+  world test {
+      include wasi:filesystem/[email protected];
+      include wasi:cli/[email protected];
+  }
+",
+    additional_derives: [PartialEq, Eq, Hash, Clone],
+    // Work around https://github.com/bytecodealliance/wasm-tools/issues/2285.
+    features:["clocks-timezone"],
+    generate_all
+});
+
+use wasi::filesystem::types::Descriptor;
+use wasi::filesystem::types::Advice;
+use wasi::filesystem::types::{DescriptorFlags, ErrorCode, OpenFlags, PathFlags};
+
+async fn test_advise(dir: &Descriptor) {
+    // Advise should fail on directories.
+    assert_eq!(
+        dir.advise(0, 0, Advice::Normal).await,
+        Err(ErrorCode::BadDescriptor)
+    );
+
+    let fd = dir
+        .open_at(
+            PathFlags::empty(),
+            "a.txt".to_string(),
+            OpenFlags::empty(),
+            DescriptorFlags::READ,
+        )
+        .await
+        .unwrap();
+
+    let size = fd.stat().await.unwrap().size;
+    for advice in [
+        Advice::Normal,
+        Advice::Sequential,
+        Advice::Random,
+        Advice::WillNeed,
+        Advice::DontNeed,
+        Advice::NoReuse,
+    ] {
+        for offset in [0, size.saturating_sub(4096), size, size + 4096] {
+            for length in [0, 10, 4096, size, size + 4096] {
+                match fd.advise(offset, length, advice).await {
+                    Ok(()) => {}
+                    Err(err) => {
+                        eprintln!("fadvise({}, {}, {:?}) => {}", offset, length, advice, err);
+                        process::exit(1);
+                    }
+                }
+            }
+        }
+    }
+}
+
+struct Component;
+export!(Component);
+impl exports::wasi::cli::run::Guest for Component {
+    async fn run() -> Result<(), ()> {
+        match &wasi::filesystem::preopens::get_directories()[..] {
+            [(dir, dirname)] if dirname == "fs-tests.dir" => {
+                test_advise(dir).await;
+            }
+            [..] => {
+                eprintln!("usage: run with one open dir named 'fs-tests.dir'");
+                process::exit(1)
+            }
+        }
+        Ok(())
+    }
+}
+
+fn main() {
+    unreachable!("main is a stub");
+}