Apply considerable acrobatics to get the JS/WASM deliverables building to and loadable from a directory other than the one which contains the app-level code. Requires an only-slightly-leaky abstraction of passing a URL argument when loading sqlite3.js but provides much greater flexibility in where the JS/WASM files are located.

FossilOrigin-Name: 6d468dab9eb84d4548f68014959f02fe4f66455472ff24fe729382bb2972e3d1

1 files changed, 53 insertions, 0 deletions

diff --git a/ext/wasm/api/sqlite3-worker1.js b/ext/wasm/api/sqlite3-worker1.js
new file mode 100644
index 000000000..bc860300b
--- /dev/null
+++ b/ext/wasm/api/sqlite3-worker1.js
@@ -0,0 +1,53 @@
+/*
+  2022-05-23
+
+  The author disclaims copyright to this source code.  In place of a
+  legal notice, here is a blessing:
+
+  *   May you do good and not evil.
+  *   May you find forgiveness for yourself and forgive others.
+  *   May you share freely, never taking more than you give.
+
+  ***********************************************************************
+
+  This is a JS Worker file for the main sqlite3 api. It loads
+  sqlite3.js, initializes the module, and postMessage()'s a message
+  after the module is initialized:
+
+  {type: 'sqlite3-api', result: 'worker1-ready'}
+
+  This seemingly superfluous level of indirection is necessary when
+  loading sqlite3.js via a Worker. Instantiating a worker with new
+  Worker("sqlite.js") will not (cannot) call sqlite3InitModule() to
+  initialize the module due to a timing/order-of-operations conflict
+  (and that symbol is not exported in a way that a Worker loading it
+  that way can see it).  Thus JS code wanting to load the sqlite3
+  Worker-specific API needs to pass _this_ file (or equivalent) to the
+  Worker constructor and then listen for an event in the form shown
+  above in order to know when the module has completed initialization.
+
+  This file accepts a couple of URL arguments to adjust how it loads
+  sqlite3.js:
+
+  - `sqlite3.js`, if set, is used as the URI to `sqlite3.js` and it
+    may contain path elements, e.g. `sqlite3.js=foo/bar/my-sqlite3.js`.
+  - `sqlite3.dir`, if set, treats the given directory name as the
+    directory from which `sqlite3.js` will be loaded.
+
+  By default is loads 'sqlite3.js'.
+*/
+"use strict";
+(()=>{
+  const urlParams = new URL(self.location.href).searchParams;
+  let theJs = 'sqlite3.js';
+  if(urlParams.has('sqlite3.js')){
+    theJs = urlParams.get('sqlite3.js');
+  }else if(urlParams.has('sqlite3.dir')){
+    theJs = urlParams.get('sqlite3.dir') + '/' + theJs;
+  }
+  importScripts(theJs);
+  sqlite3InitModule().then((sqlite3)=>{
+    sqlite3.capi.sqlite3_wasmfs_opfs_dir();
+    sqlite3.initWorker1API();
+  });
+})();