Implement fd_advice, fd_allocate and fd_filestat_set_size

src/fd.ts

@@ -3,7 +3,7 @@ import * as wasi from "./wasi_defs.js";
 
 export abstract class Fd {
   fd_advise(offset: bigint, len: bigint, advice: number): number {
-    return wasi.ERRNO_NOTSUP;
+    return wasi.ERRNO_SUCCESS;
   }
   fd_allocate(offset: bigint, len: bigint): number {
     return wasi.ERRNO_NOTSUP;

src/fs_core.ts

@@ -11,10 +11,37 @@ export class OpenFile extends Fd {
     this.file = file;
   }
 
+  fd_allocate(offset: bigint, len: bigint): number {
+    if (this.file.size > offset + len) {
+      // already big enough
+    } else {
+      // extend
+      let new_data = new Uint8Array(Number(offset + len));
+      new_data.set(this.file.data, 0);
+      this.file.data = new_data;
+    }
+    return wasi.ERRNO_SUCCESS;
+  }
+
   fd_fdstat_get(): { ret: number; fdstat: wasi.Fdstat | null } {
     return { ret: 0, fdstat: new wasi.Fdstat(wasi.FILETYPE_REGULAR_FILE, 0) };
   }
 
+  fd_filestat_set_size(size: bigint): number {
+    if (this.file.size > size) {
+      // truncate
+      this.file.data = new Uint8Array(
+        this.file.data.buffer.slice(0, Number(size)),
+      );
+    } else {
+      // extend
+      let new_data = new Uint8Array(Number(size));
+      new_data.set(this.file.data, 0);
+      this.file.data = new_data;
+    }
+    return wasi.ERRNO_SUCCESS;
+  }
+
   fd_read(
     view8: Uint8Array,
     iovs: Array<wasi.Iovec>,
@@ -147,6 +174,16 @@ export class OpenSyncOPFSFile extends Fd {
     this.file = file;
   }
 
+  fd_allocate(offset: bigint, len: bigint): number {
+    if (BigInt(this.file.handle.getSize()) > offset + len) {
+      // already big enough
+    } else {
+      // extend
+      this.file.handle.truncate(Number(offset + len));
+    }
+    return wasi.ERRNO_SUCCESS;
+  }
+
   fd_fdstat_get(): { ret: number; fdstat: wasi.Fdstat | null } {
     return { ret: 0, fdstat: new wasi.Fdstat(wasi.FILETYPE_REGULAR_FILE, 0) };
   }
@@ -161,6 +198,11 @@ export class OpenSyncOPFSFile extends Fd {
     };
   }
 
+  fd_filestat_set_size(size: bigint): number {
+    this.file.handle.truncate(0);
+    return wasi.ERRNO_SUCCESS;
+  }
+
   fd_read(
     view8: Uint8Array,
     iovs: Array<wasi.Iovec>,

test/skip.json

@@ -10,7 +10,6 @@
   "WASI Rust tests": {
     "sched_yield": "not implemented yet",
     "path_rename": "fail",
-    "fd_advise": "fail",
     "path_exists": "fail",
     "path_open_dirfd_not_dir": "fail",
     "fd_filestat_set": "fail",