runtime.js

Module.STDWEB_PRIVATE = {};

// This is based on code from Emscripten's preamble.js.
Module.STDWEB_PRIVATE.to_utf8 = function to_utf8( str, addr ) {
    var HEAPU8 = Module.HEAPU8;
    for( var i = 0; i < str.length; ++i ) {
        // Gotcha: charCodeAt returns a 16-bit word that is a UTF-16 encoded code unit, not a Unicode code point of the character! So decode UTF16->UTF32->UTF8.
        // See http://unicode.org/faq/utf_bom.html#utf16-3
        // For UTF8 byte structure, see http://en.wikipedia.org/wiki/UTF-8#Description and https://www.ietf.org/rfc/rfc2279.txt and https://tools.ietf.org/html/rfc3629
        var u = str.charCodeAt( i ); // possibly a lead surrogate
        if( u >= 0xD800 && u <= 0xDFFF ) {
            u = 0x10000 + ((u & 0x3FF) << 10) | (str.charCodeAt( ++i ) & 0x3FF);
        }

        if( u <= 0x7F ) {
            HEAPU8[ addr++ ] = u;
        } else if( u <= 0x7FF ) {
            HEAPU8[ addr++ ] = 0xC0 | (u >> 6);
            HEAPU8[ addr++ ] = 0x80 | (u & 63);
        } else if( u <= 0xFFFF ) {
            HEAPU8[ addr++ ] = 0xE0 | (u >> 12);
            HEAPU8[ addr++ ] = 0x80 | ((u >> 6) & 63);
            HEAPU8[ addr++ ] = 0x80 | (u & 63);
        } else if( u <= 0x1FFFFF ) {
            HEAPU8[ addr++ ] = 0xF0 | (u >> 18);
            HEAPU8[ addr++ ] = 0x80 | ((u >> 12) & 63);
            HEAPU8[ addr++ ] = 0x80 | ((u >> 6) & 63);
            HEAPU8[ addr++ ] = 0x80 | (u & 63);
        } else if( u <= 0x3FFFFFF ) {
            HEAPU8[ addr++ ] = 0xF8 | (u >> 24);
            HEAPU8[ addr++ ] = 0x80 | ((u >> 18) & 63);
            HEAPU8[ addr++ ] = 0x80 | ((u >> 12) & 63);
            HEAPU8[ addr++ ] = 0x80 | ((u >> 6) & 63);
            HEAPU8[ addr++ ] = 0x80 | (u & 63);
        } else {
            HEAPU8[ addr++ ] = 0xFC | (u >> 30);
            HEAPU8[ addr++ ] = 0x80 | ((u >> 24) & 63);
            HEAPU8[ addr++ ] = 0x80 | ((u >> 18) & 63);
            HEAPU8[ addr++ ] = 0x80 | ((u >> 12) & 63);
            HEAPU8[ addr++ ] = 0x80 | ((u >> 6) & 63);
            HEAPU8[ addr++ ] = 0x80 | (u & 63);
        }
    }
};

Module.STDWEB_PRIVATE.noop = function() {};
Module.STDWEB_PRIVATE.to_js = function to_js( address ) {
    var kind = Module.HEAPU8[ address + 12 ];
    if( kind === 0 ) {
        return undefined;
    } else if( kind === 1 ) {
        return null;
    } else if( kind === 2 ) {
        return Module.HEAP32[ address / 4 ];
    } else if( kind === 3 ) {
        return Module.HEAPF64[ address / 8 ];
    } else if( kind === 4 ) {
        var pointer = Module.HEAPU32[ address / 4 ];
        var length = Module.HEAPU32[ (address + 4) / 4 ];
        return Module.STDWEB_PRIVATE.to_js_string( pointer, length );
    } else if( kind === 5 ) {
        return false;
    } else if( kind === 6 ) {
        return true;
    } else if( kind === 7 ) {
        var pointer = Module.STDWEB_PRIVATE.arena + Module.HEAPU32[ address / 4 ];
        var length = Module.HEAPU32[ (address + 4) / 4 ];
        var output = [];
        for( var i = 0; i < length; ++i ) {
            output.push( Module.STDWEB_PRIVATE.to_js( pointer + i * 16 ) );
        }
        return output;
    } else if( kind === 8 ) {
        var arena = Module.STDWEB_PRIVATE.arena;
        var value_array_pointer = arena + Module.HEAPU32[ address / 4 ];
        var length = Module.HEAPU32[ (address + 4) / 4 ];
        var key_array_pointer = arena + Module.HEAPU32[ (address + 8) / 4 ];
        var output = {};
        for( var i = 0; i < length; ++i ) {
            var key_pointer = Module.HEAPU32[ (key_array_pointer + i * 8) / 4 ];
            var key_length = Module.HEAPU32[ (key_array_pointer + 4 + i * 8) / 4 ];
            var key = Module.STDWEB_PRIVATE.to_js_string( key_pointer, key_length );
            var value = Module.STDWEB_PRIVATE.to_js( value_array_pointer + i * 16 );
            output[ key ] = value;
        }
        return output;
    } else if( kind === 9 ) {
        return Module.STDWEB_PRIVATE.acquire_js_reference( Module.HEAP32[ address / 4 ] );
    } else if( kind === 10 || kind === 12 || kind === 13 ) {
        var adapter_pointer = Module.HEAPU32[ address / 4 ];
        var pointer = Module.HEAPU32[ (address + 4) / 4 ];
        var deallocator_pointer = Module.HEAPU32[ (address + 8) / 4 ];
        var num_ongoing_calls = 0;
        var drop_queued = false;
        var output = function() {
            if( pointer === 0 || drop_queued === true ) {
                if (kind === 10) {
                    throw new ReferenceError( "Already dropped Rust function called!" );
                } else if (kind === 12) {
                    throw new ReferenceError( "Already dropped FnMut function called!" );
                } else {
                    throw new ReferenceError( "Already called or dropped FnOnce function called!" );
                }
            }

            var function_pointer = pointer;
            if (kind === 13) {
                output.drop = Module.STDWEB_PRIVATE.noop;
                pointer = 0;
            }

            if (num_ongoing_calls !== 0) {
                if (kind === 12 || kind === 13) {
                    throw new ReferenceError( "FnMut function called multiple times concurrently!" );
                }
            }

            var args = Module.STDWEB_PRIVATE.alloc( 16 );
            Module.STDWEB_PRIVATE.serialize_array( args, arguments );

            try {
                num_ongoing_calls += 1;
                Module.STDWEB_PRIVATE.dyncall( "vii", adapter_pointer, [function_pointer, args] );
                var result = Module.STDWEB_PRIVATE.tmp;
                Module.STDWEB_PRIVATE.tmp = null;
            } finally {
                num_ongoing_calls -= 1;
            }

            if( drop_queued === true && num_ongoing_calls === 0 ) {
                output.drop();
            }

            return result;
        };

        output.drop = function() {
            if (num_ongoing_calls !== 0) {
                drop_queued = true;
                return;
            }

            output.drop = Module.STDWEB_PRIVATE.noop;
            var function_pointer = pointer;
            pointer = 0;

            if (function_pointer != 0) {
                Module.STDWEB_PRIVATE.dyncall( "vi", deallocator_pointer, [function_pointer] );
            }
        };

        return output;
    } else if( kind === 14 ) {
        var pointer = Module.HEAPU32[ address / 4 ];
        var length = Module.HEAPU32[ (address + 4) / 4 ];
        var array_kind = Module.HEAPU32[ (address + 8) / 4 ];
        var pointer_end = pointer + length;

        switch( array_kind ) {
            case 0:
                return Module.HEAPU8.subarray( pointer, pointer_end );
            case 1:
                return Module.HEAP8.subarray( pointer, pointer_end );
            case 2:
                return Module.HEAPU16.subarray( pointer, pointer_end );
            case 3:
                return Module.HEAP16.subarray( pointer, pointer_end );
            case 4:
                return Module.HEAPU32.subarray( pointer, pointer_end );
            case 5:
                return Module.HEAP32.subarray( pointer, pointer_end );
            case 6:
                return Module.HEAPF32.subarray( pointer, pointer_end );
            case 7:
                return Module.HEAPF64.subarray( pointer, pointer_end );
        }
    } else if( kind === 15 ) {
        return Module.STDWEB_PRIVATE.get_raw_value( Module.HEAPU32[ address / 4 ] );
    }
};

Module.STDWEB_PRIVATE.serialize_object = function serialize_object( address, value ) {
    var keys = Object.keys( value );
    var length = keys.length;
    var key_array_pointer = Module.STDWEB_PRIVATE.alloc( length * 8 );
    var value_array_pointer = Module.STDWEB_PRIVATE.alloc( length * 16 );
    Module.HEAPU8[ address + 12 ] = 8;
    Module.HEAPU32[ address / 4 ] = value_array_pointer;
    Module.HEAPU32[ (address + 4) / 4 ] = length;
    Module.HEAPU32[ (address + 8) / 4 ] = key_array_pointer;
    for( var i = 0; i < length; ++i ) {
        var key = keys[ i ];
        var key_address = key_array_pointer + i * 8;
        Module.STDWEB_PRIVATE.to_utf8_string( key_address, key );

        Module.STDWEB_PRIVATE.from_js( value_array_pointer + i * 16, value[ key ] );
    }
};

Module.STDWEB_PRIVATE.serialize_array = function serialize_array( address, value ) {
    var length = value.length;
    var pointer = Module.STDWEB_PRIVATE.alloc( length * 16 );
    Module.HEAPU8[ address + 12 ] = 7;
    Module.HEAPU32[ address / 4 ] = pointer;
    Module.HEAPU32[ (address + 4) / 4 ] = length;
    for( var i = 0; i < length; ++i ) {
        Module.STDWEB_PRIVATE.from_js( pointer + i * 16, value[ i ] );
    }
};

// New browsers and recent Node
var cachedEncoder = ( typeof TextEncoder === "function"
    ? new TextEncoder( "utf-8" )
    // Old Node (before v11)
    : ( typeof util === "object" && util && typeof util.TextEncoder === "function"
        ? new util.TextEncoder( "utf-8" )
        // Old browsers
        : null ) );

if ( cachedEncoder != null ) {
    Module.STDWEB_PRIVATE.to_utf8_string = function to_utf8_string( address, value ) {
        var buffer = cachedEncoder.encode( value );
        var length = buffer.length;
        var pointer = 0;

        if ( length > 0 ) {
            pointer = Module.STDWEB_PRIVATE.alloc( length );
            Module.HEAPU8.set( buffer, pointer );
        }

        Module.HEAPU32[ address / 4 ] = pointer;
        Module.HEAPU32[ (address + 4) / 4 ] = length;
    };

} else {
    Module.STDWEB_PRIVATE.to_utf8_string = function to_utf8_string( address, value ) {
        var length = Module.STDWEB_PRIVATE.utf8_len( value );
        var pointer = 0;

        if ( length > 0 ) {
            pointer = Module.STDWEB_PRIVATE.alloc( length );
            Module.STDWEB_PRIVATE.to_utf8( value, pointer );
        }

        Module.HEAPU32[ address / 4 ] = pointer;
        Module.HEAPU32[ (address + 4) / 4 ] = length;
    };
}

Module.STDWEB_PRIVATE.from_js = function from_js( address, value ) {
    var kind = Object.prototype.toString.call( value );
    if( kind === "[object String]" ) {
        Module.HEAPU8[ address + 12 ] = 4;
        Module.STDWEB_PRIVATE.to_utf8_string( address, value );
    } else if( kind === "[object Number]" ) {
        if( value === (value|0) ) {
            Module.HEAPU8[ address + 12 ] = 2;
            Module.HEAP32[ address / 4 ] = value;
        } else {
            Module.HEAPU8[ address + 12 ] = 3;
            Module.HEAPF64[ address / 8 ] = value;
        }
    } else if( value === null ) {
        Module.HEAPU8[ address + 12 ] = 1;
    } else if( value === undefined ) {
        Module.HEAPU8[ address + 12 ] = 0;
    } else if( value === false ) {
        Module.HEAPU8[ address + 12 ] = 5;
    } else if( value === true ) {
        Module.HEAPU8[ address + 12 ] = 6;
    } else if( kind === "[object Symbol]" ) {
        var id = Module.STDWEB_PRIVATE.register_raw_value( value );
        Module.HEAPU8[ address + 12 ] = 15;
        Module.HEAP32[ address / 4 ] = id;
    } else {
        var refid = Module.STDWEB_PRIVATE.acquire_rust_reference( value );
        Module.HEAPU8[ address + 12 ] = 9;
        Module.HEAP32[ address / 4 ] = refid;
    }
};

// New browsers and recent Node
var cachedDecoder = ( typeof TextDecoder === "function"
    ? new TextDecoder( "utf-8" )
    // Old Node (before v11)
    : ( typeof util === "object" && util && typeof util.TextDecoder === "function"
        ? new util.TextDecoder( "utf-8" )
        // Old browsers
        : null ) );

if ( cachedDecoder != null ) {
    Module.STDWEB_PRIVATE.to_js_string = function to_js_string( index, length ) {
        return cachedDecoder.decode( Module.HEAPU8.subarray( index, index + length ) );
    };

} else {
    // This is ported from Rust's stdlib; it's faster than
    // the string conversion from Emscripten.
    Module.STDWEB_PRIVATE.to_js_string = function to_js_string( index, length ) {
        var HEAPU8 = Module.HEAPU8;
        index = index|0;
        length = length|0;
        var end = (index|0) + (length|0);
        var output = "";
        while( index < end ) {
            var x = HEAPU8[ index++ ];
            if( x < 128 ) {
                output += String.fromCharCode( x );
                continue;
            }
            var init = (x & (0x7F >> 2));
            var y = 0;
            if( index < end ) {
                y = HEAPU8[ index++ ];
            }
            var ch = (init << 6) | (y & 63);
            if( x >= 0xE0 ) {
                var z = 0;
                if( index < end ) {
                    z = HEAPU8[ index++ ];
                }
                var y_z = ((y & 63) << 6) | (z & 63);
                ch = init << 12 | y_z;
                if( x >= 0xF0 ) {
                    var w = 0;
                    if( index < end ) {
                        w = HEAPU8[ index++ ];
                    }
                    ch = (init & 7) << 18 | ((y_z << 6) | (w & 63));

                    output += String.fromCharCode( 0xD7C0 + (ch >> 10) );
                    ch = 0xDC00 + (ch & 0x3FF);
                }
            }
            output += String.fromCharCode( ch );
            continue;
        }
        return output;
    };
}

Module.STDWEB_PRIVATE.id_to_ref_map = {};
Module.STDWEB_PRIVATE.id_to_refcount_map = {};
Module.STDWEB_PRIVATE.ref_to_id_map = new WeakMap();
// Not all types can be stored in a WeakMap
Module.STDWEB_PRIVATE.ref_to_id_map_fallback = new Map();
Module.STDWEB_PRIVATE.last_refid = 1;

Module.STDWEB_PRIVATE.id_to_raw_value_map = {};
Module.STDWEB_PRIVATE.last_raw_value_id = 1;

Module.STDWEB_PRIVATE.acquire_rust_reference = function( reference ) {
    if( reference === undefined || reference === null ) {
        return 0;
    }

    var id_to_refcount_map = Module.STDWEB_PRIVATE.id_to_refcount_map;
    var id_to_ref_map = Module.STDWEB_PRIVATE.id_to_ref_map;
    var ref_to_id_map = Module.STDWEB_PRIVATE.ref_to_id_map;
    var ref_to_id_map_fallback = Module.STDWEB_PRIVATE.ref_to_id_map_fallback;

    var refid = ref_to_id_map.get( reference );
    if( refid === undefined ) {
        refid = ref_to_id_map_fallback.get( reference );
    }
    if( refid === undefined ) {
        refid = Module.STDWEB_PRIVATE.last_refid++;
        try {
            ref_to_id_map.set( reference, refid );
        } catch (e) {
            ref_to_id_map_fallback.set( reference, refid );
        }
    }

    if( refid in id_to_ref_map ) {
        id_to_refcount_map[ refid ]++;
    } else {
        id_to_ref_map[ refid ] = reference;
        id_to_refcount_map[ refid ] = 1;
    }

    return refid;
};

Module.STDWEB_PRIVATE.acquire_js_reference = function( refid ) {
    return Module.STDWEB_PRIVATE.id_to_ref_map[ refid ];
};

Module.STDWEB_PRIVATE.increment_refcount = function( refid ) {
    Module.STDWEB_PRIVATE.id_to_refcount_map[ refid ]++;
};

Module.STDWEB_PRIVATE.decrement_refcount = function( refid ) {
    var id_to_refcount_map = Module.STDWEB_PRIVATE.id_to_refcount_map;
    if( 0 == --id_to_refcount_map[ refid ] ) {
        var id_to_ref_map = Module.STDWEB_PRIVATE.id_to_ref_map;
        var ref_to_id_map_fallback = Module.STDWEB_PRIVATE.ref_to_id_map_fallback;
        var reference = id_to_ref_map[ refid ];
        delete id_to_ref_map[ refid ];
        delete id_to_refcount_map[ refid ];
        ref_to_id_map_fallback.delete(reference);
    }
};

Module.STDWEB_PRIVATE.register_raw_value = function( value ) {
    var id = Module.STDWEB_PRIVATE.last_raw_value_id++;
    Module.STDWEB_PRIVATE.id_to_raw_value_map[ id ] = value;
    return id;
};

Module.STDWEB_PRIVATE.unregister_raw_value = function( id ) {
    delete Module.STDWEB_PRIVATE.id_to_raw_value_map[ id ];
};

Module.STDWEB_PRIVATE.get_raw_value = function( id ) {
    return Module.STDWEB_PRIVATE.id_to_raw_value_map[ id ];
};