Merge pull request #67 from amesgen/console-stdout

Add `ConsoleStdout`
bjorn3 · Jan 13, 2024 · bea3870 · bea3870
2 parents b18b2da + b150eba
commit bea3870
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Showing 4 changed files with 57 additions and 34 deletions.
diff --git a/README.md b/README.md
@@ -9,14 +9,14 @@ npm install @bjorn3/browser_wasi_shim --save
 ```
 
 ```javascript
-import { WASI, File, OpenFile, PreopenDirectory } from "@bjorn3/browser_wasi_shim";
+import { WASI, File, OpenFile, ConsoleStdout, PreopenDirectory } from "@bjorn3/browser_wasi_shim";
 
 let args = ["bin", "arg1", "arg2"];
 let env = ["FOO=bar"];
 let fds = [
     new OpenFile(new File([])), // stdin
-    new OpenFile(new File([])), // stdout
-    new OpenFile(new File([])), // stderr
+    ConsoleStdout.lineBuffered(msg => console.log(`[WASI stdout] ${msg}`)),
+    ConsoleStdout.lineBuffered(msg => console.warn(`[WASI stderr] ${msg}`)),
     new PreopenDirectory(".", {
         "example.c": new File(new TextEncoder("utf-8").encode(`#include "a"`)),
         "hello.rs": new File(new TextEncoder("utf-8").encode(`fn main() { println!("Hello World!"); }`)),

diff --git a/src/fs_core.ts b/src/fs_core.ts
@@ -588,3 +588,55 @@ export class Directory {
     return entry;
   }
 }
+
+export class ConsoleStdout extends Fd {
+  write: (buffer: Uint8Array) => void;
+
+  constructor(write: (buffer: Uint8Array) => void) {
+    super();
+    this.write = write;
+  }
+
+  fd_filestat_get(): { ret: number; filestat: wasi.Filestat } {
+    const filestat = new wasi.Filestat(
+      wasi.FILETYPE_CHARACTER_DEVICE,
+      BigInt(0),
+    );
+    return { ret: 0, filestat };
+  }
+
+  fd_fdstat_get(): { ret: number; fdstat: wasi.Fdstat | null } {
+    const fdstat = new wasi.Fdstat(wasi.FILETYPE_CHARACTER_DEVICE, 0);
+    fdstat.fs_rights_base = BigInt(wasi.RIGHTS_FD_WRITE);
+    return { ret: 0, fdstat };
+  }
+
+  fd_write(
+    view8: Uint8Array,
+    iovs: Array<wasi.Ciovec>,
+  ): { ret: number; nwritten: number } {
+    let nwritten = 0;
+    for (const iovec of iovs) {
+      const buffer = view8.slice(iovec.buf, iovec.buf + iovec.buf_len);
+      this.write(buffer);
+      nwritten += iovec.buf_len;
+    }
+    return { ret: 0, nwritten };
+  }
+
+  static lineBuffered(write: (line: string) => void): ConsoleStdout {
+    const dec = new TextDecoder("utf-8", { fatal: false });
+    let line_buf = "";
+    return new ConsoleStdout((buffer) => {
+      line_buf += dec.decode(buffer, { stream: true });
+      const lines = line_buf.split("\n");
+      for (const [i, line] of lines.entries()) {
+        if (i < lines.length - 1) {
+          write(line);
+        } else {
+          line_buf = line;
+        }
+      }
+    });
+  }
+}
diff --git a/src/index.ts b/src/index.ts
@@ -10,6 +10,7 @@ export {
   OpenDirectory,
   OpenSyncOPFSFile,
   PreopenDirectory,
+  ConsoleStdout,
 } from "./fs_core.js";
 export { strace } from "./strace.js";
 export * as wasi from "./wasi_defs.js";
diff --git a/test/adapters/browser/run-test.html b/test/adapters/browser/run-test.html
@@ -1,36 +1,6 @@
 <html>
 <script type="module">
-    import { WASI, OpenFile, File, Fd, Directory, PreopenDirectory, wasi } from "/dist/index.js";
-    class ConsoleStdout extends Fd {
-        constructor(write) {
-            super();
-            this.write = write;
-        }
-
-        fd_filestat_get() {
-            const filestat = new wasi.Filestat(
-                wasi.FILETYPE_CHARACTER_DEVICE,
-                BigInt(0),
-            );
-            return { ret: 0, filestat };
-        }
-
-        fd_fdstat_get() {
-            const fdstat = new wasi.Fdstat(wasi.FILETYPE_CHARACTER_DEVICE, 0);
-            fdstat.fs_rights_base = BigInt(wasi.RIGHTS_FD_WRITE);
-            return { ret: 0, fdstat };
-        }
-
-        fd_write(view8, iovs) {
-            let nwritten = 0;
-            for (let iovec of iovs) {
-                let buffer = view8.slice(iovec.buf, iovec.buf + iovec.buf_len);
-                this.write(buffer);
-                nwritten += iovec.buf_len;
-            }
-            return { ret: 0, nwritten };
-        }
-    }
+    import { WASI, ConsoleStdout, OpenFile, File, Directory, PreopenDirectory } from "/dist/index.js";
 
     async function derivePreopens(dirs) {
         const rawPreopens = await window.bindingDerivePreopens(dirs)