pcjs/my_modules/pcjs-client/lib/defines.js
2014-09-28 18:18:53 -07:00

121 lines
5 KiB
JavaScript

/**
* @fileoverview PCjs-specific compile-time definitions.
* @author <a href="mailto:Jeff@pcjs.org">Jeff Parsons</a>
* @version 1.0
* Created 2014-May-08
*
* Copyright © 2012-2014 Jeff Parsons <Jeff@pcjs.org>
*
* This file is part of PCjs, which is part of the JavaScript Machines Project (aka JSMachines)
* at <http://jsmachines.net/> and <http://pcjs.org/>.
*
* PCjs is free software: you can redistribute it and/or modify it under the terms of the
* GNU General Public License as published by the Free Software Foundation, either version 3
* of the License, or (at your option) any later version.
*
* PCjs is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
* even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along with PCjs. If not,
* see <http://www.gnu.org/licenses/gpl.html>.
*
* You are required to include the above copyright notice in every source code file of every
* copy or modified version of this work, and to display that copyright notice on every screen
* that loads or runs any version of this software (see Computer.sCopyright).
*
* Some PCjs files also attempt to load external resource files, such as character-image files,
* ROM files, and disk image files. Those external resource files are not considered part of the
* PCjs program for purposes of the GNU General Public License, and the author does not claim
* any copyright as to their contents.
*/
"use strict";
/**
* APP_PCJS collects all PCjs application globals in one convenient place
*/
if (DEBUG) {
var APP_PCJS = {Component: null};
if (typeof Component === 'function') APP_PCJS.Component = Component;
}
/**
* @define {string}
*/
var PCJSCLASS = "pcjs"; // this @define is the default application class (formerly APPCLASS) to use for PCjs
/**
* @define {boolean}
*
* WARNING: DEBUGGER needs to accurately reflect whether or not the Debugger component is (or will be) loaded.
* In the compiled case, we rely on the Closure Compiler to override DEBUGGER as appropriate. When it's *false*,
* nearly all of debugger.js will be conditionally removed by the compiler, reducing it to little more than a
* "type skeleton", which also solves some type-related warnings we would otherwise have if we tried to remove
* debugger.js from the compilation process altogether.
*
* However, when we're in "development mode" and running uncompiled code in debugger-less configurations,
* I would like to skip loading debugger.js altogether. When doing that, we must ALSO arrange for an additional file
* (nodebugger.js) to be loaded immediately after this file, which *explicitly* overrides DEBUGGER with *false*.
*/
var DEBUGGER = true; // this @define is overridden by the Closure Compiler to remove Debugger-related support
/**
* @define {boolean}
*
* PREFETCH enables the use of a prefetch queue.
*
* See the Bus component for details.
*/
var PREFETCH = false;
/**
* @define {boolean}
*
* FASTDISABLE turns on memory-function switching to dynamically disable memory accesses whenever the CPU wants
* to disable spurious memory reads (which are mostly harmless) or stale memory writes (which tend to be destructive
* and are NOT mostly harmless).
*
* If FASTDISABLE is false, then the code falls back to setting/testing internal OP_NOREAD and OP_NOWRITE opFlags
* as needed.
*
* At the moment, it seems that FASTDISABLE is a bit slower than relying on the OP_NOREAD/OP_NOWRITE flags, so it's
* turned off; apparently, I was a bit too optimistic calling it "FAST". But your mileage may vary, depending on the
* browser and its version.
*
* See the X86CPU component for details, since it is the CPU, not the underlying Bus or Memory components, that needs
* to be able to do this.
*/
var FASTDISABLE = false;
/**
* @define {boolean}
*
* FATARRAYS is a Closure Compiler compile-time option that allocates 1 number per byte for Memory blocks;
* wasteful, but potentially slightly faster.
*
* See the Memory component for details.
*/
var FATARRAYS = false;
/**
* TYPEDARRAYS enables use of typed arrays for Memory blocks. This used to be a compile-time * option, but since I've
* added memory access functions for typed arrays (see Memory.afnTArray), I can turn the support on dynamically now.
* Originally, I didn't see much of a speed increase over the original (non-typed) implementation, but that will probably
* change over time.
*
* See the Memory component for details.
*/
var TYPEDARRAYS = (typeof window.ArrayBuffer !== 'undefined');
if (typeof module !== 'undefined') {
global.PCJSCLASS = PCJSCLASS;
global.DEBUGGER = DEBUGGER;
global.PREFETCH = PREFETCH;
global.FASTDISABLE = FASTDISABLE;
global.FATARRAYS = FATARRAYS;
global.TYPEDARRAYS = TYPEDARRAYS;
/*
* TODO: When we're "required" by Node, should we return anything via module.exports?
*/
}