sqlite/ext/wasm/api/pre-js.c-pp.js

/**
   BEGIN FILE: api/pre-js.js

   This file is intended to be prepended to the sqlite3.js build using
   Emscripten's --pre-js=THIS_FILE flag (or equivalent). It is run
   from inside of sqlite3InitModule(), after Emscripten's Module is
   defined, but early enough that we can ammend, or even outright
   replace, Module from here.

   Because this runs in-between Emscripten's own bootstrapping and
   Emscripten's main work, we must be careful with file-local symbol
   names. e.g. don't overwrite anything Emscripten defines and do not
   use 'const' for local symbols which Emscripten might try to use for
   itself. i.e. try to keep file-local symbol names obnoxiously
   collision-resistant.
*/
const sIMS =
      globalThis.sqlite3InitModuleState/*from extern-post-js.c-pp.js*/
      || Object.assign(Object.create(null),{
        debugModule: ()=>{}
      });
delete globalThis.sqlite3InitModuleState;
sIMS.debugModule('pre-js.js sqlite3InitModuleState =',sIMS);

//#ifnot target=es6-bundler-friendly
/**
   This custom locateFile() tries to figure out where to load `path`
   from. The intent is to provide a way for foo/bar/X.js loaded from a
   Worker constructor or importScripts() to be able to resolve
   foo/bar/X.wasm (in the latter case, with some help):

   1) If URL param named the same as `path` is set, it is returned.

   2) If sqlite3InitModuleState.sqlite3Dir is set, then (thatName + path)
   is returned (it's assumed to end with '/').

   3) If this code is running in the main UI thread AND it was loaded
   from a SCRIPT tag, the directory part of that URL is used
   as the prefix. (This form of resolution unfortunately does not
   function for scripts loaded via importScripts().)

   4) If none of the above apply, (prefix+path) is returned.

   None of the above apply in ES6 builds.
*/
Module['locateFile'] = function(path, prefix) {
//#if target=es6-module
  return new URL(path, import.meta.url).href;
//#else
  'use strict';
  let theFile;
  const up = this.urlParams;
  if(up.has(path)){
    theFile = up.get(path);
  }else if(this.sqlite3Dir){
    theFile = this.sqlite3Dir + path;
  }else if(this.scriptDir){
    theFile = this.scriptDir + path;
  }else{
    theFile = prefix + path;
  }
  this.debugModule(
    "locateFile(",arguments[0], ',', arguments[1],")",
    'sqlite3InitModuleState.scriptDir =',this.scriptDir,
    'up.entries() =',Array.from(up.entries()),
    "result =", theFile
  );
  return theFile;
//#endif target=es6-module
}.bind(sIMS);
//#endif ifnot target=es6-bundler-friendly

//#if custom-Module.instantiateWasm
/**
   Override Module.instantiateWasm().

   Bug warning: a custom Module.instantiateWasm() does not work
   in WASMFS builds:

   https://github.com/emscripten-core/emscripten/issues/17951

   In such builds we must disable this.
*/
Module[
//#if wasmfs
  'emscripten-bug-17951'
//#else
  'instantiateWasm'
  /* This works, but it does not have the testing coverage in
     the wild which Emscripten's default impl does, so we'll
     save this option until we really need a custom
     Module.instantiateWasm(). */
//#endif
] = function callee(imports,onSuccess){
  const sims = this;
  const uri = Module.locateFile(
    sims.wasmFilename, (
      ('undefined'===typeof scriptDirectory/*var defined by Emscripten glue*/)
        ? "" : scriptDirectory)
  );
  sims.debugModule("instantiateWasm() uri =", uri, "sIMS =",this);
  const wfetch = ()=>fetch(uri, {credentials: 'same-origin'});
  const loadWasm = WebAssembly.instantiateStreaming
        ? async ()=>
        WebAssembly
        .instantiateStreaming(wfetch(), imports)
        .then((arg)=>{
          arg.imports = imports;
          sims.instantiateWasm = arg /* used by extern-post-js.c-pp.js */;
          onSuccess(arg.instance, arg.module);
        })
        : async ()=>// Safari < v15
        wfetch()
        .then(response => response.arrayBuffer())
        .then(bytes => WebAssembly.instantiate(bytes, imports))
        .then((arg)=>{
          arg.imports = imports;
          sims.instantiateWasm = arg;
          onSuccess(arg.instance, arg.module);
        })
  ;
  return loadWasm();
}.bind(sIMS);
/*
  It is literally impossible to reliably get the name of _this_
  script at runtime, so impossible to derive X.wasm from script name
  X.js. Thus we need, at build-time, to redefine
  sIMS.uri by appending it to a build-specific
  copy of this file with the name of the wasm file. This is
  apparently why Emscripten hard-codes the name of the wasm file
  into their glue scripts.
*/
sIMS.wasmFilename = 'sqlite3.wasm';
//#endif custom-Module.instantiateWasm
/*
  END FILE: api/pre-js.js, noting that the build process may append
  "sIMS.wasmFilename = x;" to this file, for some value of x.
*/