wasm: example code for my gophercon EU talk

Signed-off-by: Xe Iaso <me@xeiaso.net>

5 files changed, 214 insertions, 0 deletions

diff --git a/wasm/cmd/aiyou/main.go b/wasm/cmd/aiyou/main.go
new file mode 100644
index 0000000..45e9a46
--- /dev/null
+++ b/wasm/cmd/aiyou/main.go
@@ -0,0 +1,84 @@
+package main
+
+import (
+	"context"
+	"flag"
+	"io/fs"
+	"math/rand"
+	"net"
+	"os"
+	"strconv"
+	"time"
+
+	"github.com/tetratelabs/wazero"
+	"github.com/tetratelabs/wazero/imports/wasi_snapshot_preview1"
+	"within.website/ln"
+	"within.website/ln/opname"
+	"within.website/x/internal"
+)
+
+var (
+	r    wazero.Runtime
+	code wazero.CompiledModule
+
+	binary = flag.String("wasm-binary", "./bin.wasm", "binary to run against every line of input from connections")
+)
+
+func main() {
+	internal.HandleStartup()
+	ctx := opname.With(context.Background(), "tensei")
+
+	data, err := os.ReadFile(*binary)
+	if err != nil {
+		ln.FatalErr(ctx, err)
+	}
+
+	r = wazero.NewRuntime(ctx)
+
+	wasi_snapshot_preview1.MustInstantiate(ctx, r)
+
+	code, err = r.CompileModule(ctx, data)
+	if err != nil {
+		ln.FatalErr(ctx, err)
+	}
+
+	name := strconv.Itoa(rand.Int())
+	config := wazero.NewModuleConfig().WithStdout(os.Stdout).WithStdin(os.Stdin).WithStderr(os.Stderr).WithArgs("aiyou").WithName(name).WithFS(ConnFS{})
+
+	mod, err := r.InstantiateModule(ctx, code, config)
+	if err != nil {
+		ln.Error(ctx, err)
+		return
+	}
+	defer mod.Close(ctx)
+}
+
+type ConnFS struct{}
+
+func (ConnFS) Open(name string) (fs.File, error) {
+	conn, err := net.Dial("tcp", name)
+	if err != nil {
+		return nil, err
+	}
+
+	return ConnFile{Conn: conn}, nil
+}
+
+type ConnFile struct {
+	net.Conn
+}
+
+func (c ConnFile) Stat() (fs.FileInfo, error) {
+	return ConnFileInfo{c.Conn}, nil
+}
+
+type ConnFileInfo struct {
+	conn net.Conn
+}
+
+func (c ConnFileInfo) Name() string       { return c.conn.RemoteAddr().String() } // base name of the file
+func (c ConnFileInfo) Size() int64        { return 0 }                            // length in bytes for regular files; system-dependent for others
+func (c ConnFileInfo) Mode() fs.FileMode  { return 0 }                            // file mode bits
+func (c ConnFileInfo) ModTime() time.Time { return time.Now() }                   // modification time
+func (c ConnFileInfo) IsDir() bool        { return false }                        // abbreviation for Mode().IsDir()
+func (c ConnFileInfo) Sys() any           { return c.conn }                       // underlying data source (can return nil)
diff --git a/wasm/cmd/tensei/main.go b/wasm/cmd/tensei/main.go
new file mode 100644
index 0000000..987ff48
--- /dev/null
+++ b/wasm/cmd/tensei/main.go
@@ -0,0 +1,94 @@
+package main
+
+import (
+	"bufio"
+	"bytes"
+	"context"
+	"flag"
+	"fmt"
+	"log"
+	"math/rand"
+	"net"
+	"os"
+	"strconv"
+
+	"github.com/tetratelabs/wazero"
+	"github.com/tetratelabs/wazero/imports/wasi_snapshot_preview1"
+	"within.website/ln"
+	"within.website/ln/opname"
+	"within.website/x/internal"
+)
+
+var (
+	r    wazero.Runtime
+	code wazero.CompiledModule
+
+	binary = flag.String("wasm-binary", "./bin.wasm", "binary to run against every line of input from connections")
+	bind   = flag.String("bind", ":1997", "TCP host:port to bind on")
+)
+
+func main() {
+	internal.HandleStartup()
+	ctx := opname.With(context.Background(), "tensei")
+
+	data, err := os.ReadFile(*binary)
+	if err != nil {
+		ln.FatalErr(ctx, err)
+	}
+
+	r = wazero.NewRuntime(ctx)
+
+	wasi_snapshot_preview1.MustInstantiate(ctx, r)
+
+	code, err = r.CompileModule(ctx, data)
+	if err != nil {
+		ln.FatalErr(ctx, err)
+	}
+
+	server, err := net.Listen("tcp", *bind)
+	if err != nil {
+		ln.FatalErr(ctx, err)
+	}
+
+	for {
+		conn, err := server.Accept()
+		if err != nil {
+			log.Println("Failed to accept conn.", err)
+			continue
+		}
+
+		fmt.Println(conn.RemoteAddr().String())
+
+		go func(conn net.Conn) {
+			defer func() {
+				fmt.Println("disconnect")
+				conn.Close()
+			}()
+
+			scn := bufio.NewScanner(conn)
+			scn.Split(bufio.ScanLines)
+
+			for scn.Scan() {
+				fout := &bytes.Buffer{}
+				fin := bytes.NewBuffer(scn.Bytes())
+
+				fmt.Println("<", fin.String())
+
+				name := strconv.Itoa(rand.Int())
+				config := wazero.NewModuleConfig().WithStdout(fout).WithStdin(fin).WithArgs("mastosan").WithName(name)
+
+				mod, err := r.InstantiateModule(ctx, code, config)
+				if err != nil {
+					ln.Error(ctx, err, ln.F{"remote_host": conn.RemoteAddr().String()})
+					return
+				}
+				defer mod.Close(ctx)
+
+				fmt.Print(">", fout.String())
+
+				conn.Write(fout.Bytes())
+				conn.Close()
+			}
+		}(conn)
+	}
+}
diff --git a/wasm/wasip1/echoclient.rs b/wasm/wasip1/echoclient.rs
new file mode 100644
index 0000000..8f8e1ed
--- /dev/null
+++ b/wasm/wasip1/echoclient.rs
@@ -0,0 +1,24 @@
+use std::{io, fs::File, str, thread, time};
+use std::io::prelude::*;
+
+fn main() -> io::Result<()> {
+    let stdin = io::stdin(); // We get `Stdin` here.
+    let mut fout = File::create("localhost:1997")?;
+    
+    print!("input> ");
+    io::stdout().lock().flush()?;
+    let mut buf = String::new();
+    stdin.read_line(&mut buf)?;
+    write!(fout, "{}", buf)?;
+
+    let ten_millis = time::Duration::from_millis(10);
+    thread::sleep(ten_millis);
+
+    let mut buf = Vec::new();
+    fout.read_to_end(&mut buf)?;
+    let buf = unsafe { str::from_utf8_unchecked(&buf) };
+    print!("{}", buf);
+    io::stdout().lock().flush()?;
+
+    Ok(())
+}
diff --git a/wasm/wasip1/hello.rs b/wasm/wasip1/hello.rs
new file mode 100644
index 0000000..b4998a8
--- /dev/null
+++ b/wasm/wasip1/hello.rs
@@ -0,0 +1,3 @@
+fn main() {
+    println!("hello, world!")
+}
diff --git a/wasm/wasip1/promptreply.rs b/wasm/wasip1/promptreply.rs
new file mode 100644
index 0000000..09d29db
--- /dev/null
+++ b/wasm/wasip1/promptreply.rs
@@ -0,0 +1,9 @@
+use std::io;
+
+fn main() -> io::Result<()> {
+    let mut buffer = String::new();
+    let stdin = io::stdin(); // We get `Stdin` here.
+    stdin.read_line(&mut buffer)?;
+    println!("{}", buffer.trim());
+    Ok(())
+}