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

89 lines
3.2 KiB
JavaScript

/**
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).
*/
// See notes in extern-post-js.js
const sqlite3InitModuleState = self.sqlite3InitModuleState || Object.create(null);
delete self.sqlite3InitModuleState;
/**
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 (note that 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.
*/
Module['locateFile'] = function(path, prefix) {
let theFile;
const up = this.urlParams;
if(0){
console.warn("locateFile(",arguments[0], ',', arguments[1],")",
'self.location =',self.location,
'sqlite3InitModuleState.scriptDir =',this.scriptDir,
'up.entries() =',Array.from(up.entries()));
}
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;
}
return theFile;
}.bind(sqlite3InitModuleState);
/**
Bug warning: this xInstantiateWasm bit must remain disabled
until this bug is resolved or wasmfs won't work:
https://github.com/emscripten-core/emscripten/issues/17951
*/
const xInstantiateWasm = 1
? 'emscripten-bug-17951'
: 'instantiateWasm';
Module[xInstantiateWasm] = function callee(imports,onSuccess){
imports.env.foo = function(){};
console.warn("instantiateWasm() uri =",callee.uri, self.location.href);
const wfetch = ()=>fetch(callee.uri, {credentials: 'same-origin'});
const loadWasm = WebAssembly.instantiateStreaming
? async ()=>{
return WebAssembly.instantiateStreaming(wfetch(), imports)
.then((arg)=>onSuccess(arg.instance, arg.module));
}
: async ()=>{ // Safari < v15
return wfetch()
.then(response => response.arrayBuffer())
.then(bytes => WebAssembly.instantiate(bytes, imports))
.then((arg)=>onSuccess(arg.instance, arg.module));
};
loadWasm();
return {};
};
/*
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
Module[xInstantiateWasm].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.
*/
Module[xInstantiateWasm].uri = 'sqlite3.wasm';
/* END FILE: api/pre-js.js */