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sqlite/ext/wasm/api/extern-post-js.js
stephan f7d98ac764 More work towards creation of a ES6 JS module.
FossilOrigin-Name: 6b826e700f6849eebfbba38e5948b96be245994e3e03ea30743114d3f5689c42
2022-11-19 02:51:41 +00:00

116 lines
4.5 KiB
JavaScript

/* extern-post-js.js must be appended to the resulting sqlite3.js
file. It gets its name from being used as the value for the
--extern-post-js=... Emscripten flag. Note that this code, unlike
most of the associated JS code, runs outside of the
Emscripten-generated module init scope, in the current
global scope. */
//#if SQLITE_JS_ESM
const toexport =
//#endif
(function(){
/**
In order to hide the sqlite3InitModule()'s resulting Emscripten
module from downstream clients (and simplify our documentation by
being able to elide those details), we rewrite
sqlite3InitModule() to return the sqlite3 object.
Unfortunately, we cannot modify the module-loader/exporter-based
impls which Emscripten installs at some point in the file above
this.
*/
const originalInit =
/*Maintenance reminde: DO NOT use `self.` here. It's correct
for non-ES6 Module cases but wrong for ES6 modules because those
resolve this symbol differently! */ sqlite3InitModule;
if(!originalInit){
throw new Error("Expecting self.sqlite3InitModule to be defined by the Emscripten build.");
}
/**
We need to add some state which our custom Module.locateFile()
can see, but an Emscripten limitation currently prevents us from
attaching it to the sqlite3InitModule function object:
https://github.com/emscripten-core/emscripten/issues/18071
The only(?) current workaround is to temporarily stash this state
into the global scope and delete it when sqlite3InitModule()
is called.
*/
const initModuleState = self.sqlite3InitModuleState = Object.assign(Object.create(null),{
moduleScript: self?.document?.currentScript,
isWorker: ('undefined' !== typeof WorkerGlobalScope),
location: self.location,
urlParams: new URL(self.location.href).searchParams
});
initModuleState.debugModule =
(new URL(self.location.href).searchParams).has('sqlite3.debugModule')
? (...args)=>console.warn('sqlite3.debugModule:',...args)
: ()=>{};
if(initModuleState.urlParams.has('sqlite3.dir')){
initModuleState.sqlite3Dir = initModuleState.urlParams.get('sqlite3.dir') +'/';
}else if(initModuleState.moduleScript){
const li = initModuleState.moduleScript.src.split('/');
li.pop();
initModuleState.sqlite3Dir = li.join('/') + '/';
}
self.sqlite3InitModule = (...args)=>{
//console.warn("Using replaced sqlite3InitModule()",self.location);
return originalInit(...args).then((EmscriptenModule)=>{
if(self.window!==self &&
(EmscriptenModule['ENVIRONMENT_IS_PTHREAD']
|| EmscriptenModule['_pthread_self']
|| 'function'===typeof threadAlert
|| self.location.pathname.endsWith('.worker.js')
)){
/** Workaround for wasmfs-generated worker, which calls this
routine from each individual thread and requires that its
argument be returned. All of the criteria above are fragile,
based solely on inspection of the offending code, not public
Emscripten details. */
return EmscriptenModule;
}
EmscriptenModule.sqlite3.scriptInfo = initModuleState;
//console.warn("sqlite3.scriptInfo =",EmscriptenModule.sqlite3.scriptInfo);
const f = EmscriptenModule.sqlite3.asyncPostInit;
delete EmscriptenModule.sqlite3.asyncPostInit;
return f();
}).catch((e)=>{
console.error("Exception loading sqlite3 module:",e);
throw e;
});
};
self.sqlite3InitModule.ready = originalInit.ready;
if(self.sqlite3InitModuleState.moduleScript){
const sim = self.sqlite3InitModuleState;
let src = sim.moduleScript.src.split('/');
src.pop();
sim.scriptDir = src.join('/') + '/';
}
initModuleState.debugModule('sqlite3InitModuleState =',initModuleState);
if(0){
console.warn("Replaced sqlite3InitModule()");
console.warn("self.location.href =",self.location.href);
if('undefined' !== typeof document){
console.warn("document.currentScript.src =",
document?.currentScript?.src);
}
}
/* Replace the various module exports performed by the Emscripten
glue... */
if (typeof exports === 'object' && typeof module === 'object')
module.exports = sqlite3InitModule;
else if (typeof exports === 'object')
exports["sqlite3InitModule"] = sqlite3InitModule;
/* AMD modules get injected in a way we cannot override,
so we can't handle those here. */
//#if SQLITE_JS_ESM
return self.sqlite3InitModule;
//#endif
})();
//#if SQLITE_JS_ESM
export default toexport;
//#endif