SQLite

      [
        'bigIntEnabled'
      ].forEach(function(k){
        if(Object.getOwnPropertyDescriptor(src, k)) rc[k] = src[k];
      });
      rc.version = sqlite3.version;
      rc.vfsList = sqlite3.capi.sqlite3_js_vfs_list();
      rc.opfsEnabled = !!sqlite3.opfs;
      return rc;
    },

    /**
       Exports the database to a byte array, as per
       sqlite3_serialize(). Response is an object:

      };
      wState.xfer.push(response.byteArray.buffer);
      return response;
    }/*export()*/,

    toss: function(ev){
      toss("Testing worker exception");
    },

    'opfs-tree': async function(ev){
      if(!sqlite3.opfs) toss("OPFS support is unavailable.");
      const response = await sqlite3.opfs.treeList();
      return response;
    }
  }/*wMsgHandler*/;

  globalThis.onmessage = async function(ev){
    ev = ev.data;
    let result, dbId = ev.dbId, evType = ev.type;
    const arrivalTime = performance.now();

   - The counterpart Worker (see below) could not be loaded.

   - The environment does not support OPFS. That includes when
     this function is called from the main window thread.

  Significant notes and limitations:

  - As of this writing, OPFS is still very much in flux and only
    available in bleeding-edge versions of Chrome (v102+, noting that
    that number will increase as the OPFS API matures).

  - The OPFS features used here are only available in dedicated Worker
    threads. This file tries to detect that case, resulting in a
    rejected Promise if those features do not seem to be available.

  - It requires the SharedArrayBuffer and Atomics classes, and the
    former is only available if the HTTP server emits the so-called
    COOP and COEP response headers. These features are required for
    proxying OPFS's synchronous API via the synchronous interface
    required by the sqlite3_vfs API.

  - This function may only be called a single time. When called, this
    function removes itself from the sqlite3 object.

  All arguments to this function are for internal/development purposes
  only. They do not constitute a public API and may change at any
  time.

  The argument may optionally be a plain object with the following
  configuration options:

  - proxyUri: as described above

  - verbose (=2): an integer 0-3. 0 disables all logging, 1 enables
    logging of errors. 2 enables logging of warnings and errors. 3
    additionally enables debugging info.


  - sanityChecks (=false): if true, some basic sanity tests are
    run on the OPFS VFS API after it's initialized, before the
    returned Promise resolves.


  On success, the Promise resolves to the top-most sqlite3 namespace
  object and that object gets a new object installed in its
  `opfs` property, containing several OPFS-specific utilities.
*/
const installOpfsVfs = function callee(options){
  if(!globalThis.SharedArrayBuffer

      }catch(e){
        //sqlite3.config.warn("mkdir(",absDirName,") failed:",e);
        return false;
      }
    };
    /**
       Checks whether the given OPFS filesystem entry exists,
       returning true if it does, false if it doesn't.


    */
    opfsUtil.entryExists = async function(fsEntryName){
      try {
        const [dh, fn] = await opfsUtil.getDirForFilename(fsEntryName);
        await dh.getFileHandle(fn);
        return true;
      }catch(e){

          });
        }
        return false;
      }
    };

    /**
       Traverses the OPFS filesystem, calling a callback for each one.
       The argument may be either a callback function or an options object
       with any of the following properties:

       - `callback`: function which gets called for each filesystem
         entry.  It gets passed 3 arguments: 1) the
         FileSystemFileHandle or FileSystemDirectoryHandle of each
         entry (noting that both are instanceof FileSystemHandle). 2)
         the FileSystemDirectoryHandle of the parent directory. 3) the
         current depth level, with 0 being at the top of the tree

       If this function is passed a function, it is assumed to be the
       callback.

       Returns a promise because it has to (by virtue of being async)
       but that promise has no specific meaning: the traversal it
       performs is synchronous. The promise must be used to catch any
       exceptions propagated by the callback, however.

       TODO: add an option which specifies whether to traverse
       depth-first or breadth-first. We currently do depth-first but
       an incremental file browsing widget would benefit more from
       breadth-first.
    */
    opfsUtil.traverse = async function(opt){
      const defaultOpt = {
        recursive: true,
        directory: opfsUtil.rootDirectory
      };
      if('function'===typeof opt){