Function js_std_file_readAs

deps/quickjs/quickjs-libc.c:1629–1673

XXX: could use less memory and go faster */

/* XXX: could use less memory and go faster */
static JSValue js_std_file_readAs(JSContext *ctx, JSValueConst this_val,
                                  int argc, JSValueConst *argv, int magic)
{
    FILE *f = js_std_file_get(ctx, this_val);
    int c;
    DynBuf dbuf;
    JSValue obj;
    uint64_t max_size64;
    size_t max_size;
    JSValueConst max_size_val;

    if (!f)
        return JS_EXCEPTION;

    if (argc >= 1)
        max_size_val = argv[0];
    else
        max_size_val = JS_UNDEFINED;
    max_size = (size_t)-1;
    if (!JS_IsUndefined(max_size_val)) {
        if (JS_ToIndex(ctx, &max_size64, max_size_val))
            return JS_EXCEPTION;
        if (max_size64 < max_size)
            max_size = max_size64;
    }

    js_std_dbuf_init(ctx, &dbuf);
    while (max_size != 0) {
        c = fgetc(f);
        if (c == EOF)
            break;
        if (dbuf_putc(&dbuf, c)) {
            dbuf_free(&dbuf);
            return JS_EXCEPTION;
        }
        max_size--;
    }
    if (magic) {
        obj = JS_NewStringLen(ctx, (const char *)dbuf.buf, dbuf.size);
    } else {
        obj = JS_NewArrayBufferCopy(ctx, dbuf.buf, dbuf.size);
    }
    dbuf_free(&dbuf);
    return obj;
}

static JSValue js_std_file_getByte(JSContext *ctx, JSValueConst this_val,
                                   int argc, JSValueConst *argv)