ext/wasm/api/extern-post-js.js

   1 /* extern-post-js.js must be appended to the resulting sqlite3.js
   2    file. It gets its name from being used as the value for the
   3    --extern-post-js=... Emscripten flag. Note that this code, unlike
   4    most of the associated JS code, runs outside of the
   5    Emscripten-generated module init scope, in the current
   6    global scope. */
   7 (function(){
   8   /**
   9      In order to hide the sqlite3InitModule()'s resulting Emscripten
  10      module from downstream clients (and simplify our documentation by
  11      being able to elide those details), we rewrite
  12      sqlite3InitModule() to return the sqlite3 object.
  13
  14      Unfortunately, we cannot modify the module-loader/exporter-based
  15      impls which Emscripten installs at some point in the file above
  16      this.
  17   */
  18   const originalInit = self.sqlite3InitModule;
  19   if(!originalInit){
  20     throw new Error("Expecting self.sqlite3InitModule to be defined by the Emscripten build.");
  21   }
  22   /**
  23      We need to add some state which our custom Module.locateFile()
  24      can see, but an Emscripten limitation currently prevents us from
  25      attaching it to the sqlite3InitModule function object:
  26
  27      https://github.com/emscripten-core/emscripten/issues/18071
  28
  29      The only(?) current workaround is to temporarily stash this state
  30      into the global scope and delete it when sqlite3InitModule()
  31      is called.
  32   */
  33   const initModuleState = self.sqlite3InitModuleState = Object.assign(Object.create(null),{
  34     moduleScript: self?.document?.currentScript,
  35     isWorker: ('undefined' !== typeof WorkerGlobalScope),
  36     location: self.location,
  37     urlParams: new URL(self.location.href).searchParams
  38   });
  39   initModuleState.debugModule =
  40     (new URL(self.location.href).searchParams).has('sqlite3.debugModule')
  41     ? (...args)=>console.warn('sqlite3.debugModule:',...args)
  42     : ()=>{};
  43
  44   if(initModuleState.urlParams.has('sqlite3.dir')){
  45     initModuleState.sqlite3Dir = initModuleState.urlParams.get('sqlite3.dir') +'/';
  46   }else if(initModuleState.moduleScript){
  47     const li = initModuleState.moduleScript.src.split('/');
  48     li.pop();
  49     initModuleState.sqlite3Dir = li.join('/') + '/';
  50   }
  51
  52   self.sqlite3InitModule = (...args)=>{
  53     //console.warn("Using replaced sqlite3InitModule()",self.location);
  54     return originalInit(...args).then((EmscriptenModule)=>{
  55       if(self.window!==self &&
  56          (EmscriptenModule['ENVIRONMENT_IS_PTHREAD']
  57           || EmscriptenModule['_pthread_self']
  58           || 'function'===typeof threadAlert
  59           || self.location.pathname.endsWith('.worker.js')
  60          )){
  61         /** Workaround for wasmfs-generated worker, which calls this
  62             routine from each individual thread and requires that its
  63             argument be returned. All of the criteria above are fragile,
  64             based solely on inspection of the offending code, not public
  65             Emscripten details. */
  66         return EmscriptenModule;
  67       }
  68       EmscriptenModule.sqlite3.scriptInfo = initModuleState;
  69       //console.warn("sqlite3.scriptInfo =",EmscriptenModule.sqlite3.scriptInfo);
  70       const f = EmscriptenModule.sqlite3.asyncPostInit;
  71       delete EmscriptenModule.sqlite3.asyncPostInit;
  72       return f();
  73     }).catch((e)=>{
  74       console.error("Exception loading sqlite3 module:",e);
  75       throw e;
  76     });
  77   };
  78   self.sqlite3InitModule.ready = originalInit.ready;
  79
  80   if(self.sqlite3InitModuleState.moduleScript){
  81     const sim = self.sqlite3InitModuleState;
  82     let src = sim.moduleScript.src.split('/');
  83     src.pop();
  84     sim.scriptDir = src.join('/') + '/';
  85   }
  86   initModuleState.debugModule('sqlite3InitModuleState =',initModuleState);
  87   if(0){
  88     console.warn("Replaced sqlite3InitModule()");
  89     console.warn("self.location.href =",self.location.href);
  90     if('undefined' !== typeof document){
  91       console.warn("document.currentScript.src =",
  92                    document?.currentScript?.src);
  93     }
  94   }
  95   /* Replace the various module exports performed by the Emscripten
  96      glue... */
  97   if (typeof exports === 'object' && typeof module === 'object')
  98     module.exports = sqlite3InitModule;
  99   else if (typeof exports === 'object')
 100     exports["sqlite3InitModule"] = sqlite3InitModule;
 101   /* AMD modules get injected in a way we cannot override,
 102      so we can't handle those here. */
 103 })();