Function truncatePath

packages/computerd/src/fuse/driver.ts:390–438

(path: string, size: number, cb: StatusCallback)

  };

  const truncatePath = (path: string, size: number, cb: StatusCallback): void => {
    if (!exists(path)) {
      cb(ERRNO.ENOENT);
      return;
    }
    let entry = files.get(path);
    if (entry === undefined) {
      if (hasDirectWrites) {
        if (size > MAX_FILE_BYTES) {
          cb(ERRNO.EFBIG);
          return;
        }
        try {
          directWriteVfs.truncateFileSync?.(toVfs(path), size);
          cb(0);
        } catch (error) {
          cb(toErrno(error));
        }
        return;
      }
      try {
        const data = vfs.readFileSync(toVfs(path));
        entry = {
          buf: data,
          size: data.length,
          dirty: false,
          dirtyRanges: [],
          pendingCreate: false,
          mode: modeFromVfs(path),
          pendingMtime: new Date(),
        };
        files.set(path, entry);
      } catch (error) {
        cb(toErrno(error));
        return;
      }
    }
    if (size > entry.size) {
      if (!ensureCapacity(entry, size)) {
        cb(ERRNO.EFBIG);
        return;
      }
      entry.buf.fill(0, entry.size, size);
    }
    const previousSize = entry.size;
    entry.size = size;
    markDirty(entry, Math.min(previousSize, size), Math.max(previousSize, size));
    cb(0);
  };

  const warnedOperations = new Set<string>();
  const notImplemented = (operation: string): NotImplementedOperation => {