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libsql/libsql-sqlite3/ext/wasm/api/pre-js.c-pp.js
2023-10-16 13:58:16 +02:00

111 lines
3.8 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 = globalThis.sqlite3InitModuleState
|| Object.assign(Object.create(null),{
debugModule: ()=>{}
});
delete globalThis.sqlite3InitModuleState;
sqlite3InitModuleState.debugModule('globalThis.location =',globalThis.location);
//#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 (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) {
//#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;
}
sqlite3InitModuleState.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(sqlite3InitModuleState);
//#endif ifnot target=es6-bundler-friendly
/**
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.
*/
const xNameOfInstantiateWasm = false
? 'instantiateWasm'
: 'emscripten-bug-17951';
Module[xNameOfInstantiateWasm] = function callee(imports,onSuccess){
imports.env.foo = function(){};
const uri = Module.locateFile(
callee.uri, (
('undefined'===typeof scriptDirectory/*var defined by Emscripten glue*/)
? "" : scriptDirectory)
);
sqlite3InitModuleState.debugModule(
"instantiateWasm() uri =", uri
);
const wfetch = ()=>fetch(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[xNameOfInstantiateWasm].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[xNameOfInstantiateWasm].uri = 'sqlite3.wasm';
/* END FILE: api/pre-js.js, noting that the build process may add a
line after this one to change the above .uri to a build-specific
one. */