js: load games using FileReader.readAsArrayBuffer()

Using .readAsText() meant that trying to load a non-text file (for
instance something that's not a save file at all) would generate an
"RuntimeError: index out of bounds".  This would then leave the
Emscripten runtime in a broken state.

It might even be possible for a real save file not to be valid UTF-8,
for instance if it came from a platform that used a different character
encoding for random seeds.

There's still a problem with opening very large files, apparently
because Emscripten tries to stuff the entire file onto the C stack.
That will probably have to be fixed by properly exposing the incremental
file-loading API to JavaScript.
This commit is contained in:
Ben Harris
2023-04-02 20:58:30 +01:00
parent 2499eb47fa
commit 8d3a93ce47

View File

@ -423,7 +423,7 @@ function initPuzzle() {
// 'number' is used for C pointers
var get_save_file = Module.cwrap('get_save_file', 'number', []);
var free_save_file = Module.cwrap('free_save_file', 'void', ['number']);
var load_game = Module.cwrap('load_game', 'void', ['string', 'number']);
var load_game = Module.cwrap('load_game', 'void', ['array', 'number']);
if (save_button) save_button.onclick = function(event) {
if (dlg_dimmer === null) {
@ -457,10 +457,10 @@ function initPuzzle() {
var file = input.files.item(0);
var reader = new FileReader();
reader.addEventListener("loadend", function() {
var string = reader.result;
load_game(string, string.length);
var array = new Uint8Array(reader.result);
load_game(array, array.length);
});
reader.readAsText(file);
reader.readAsArrayBuffer(file);
}
});
input.click();