jquery/build/js/Packer.js
2007-04-25 21:11:06 +00:00

205 lines
6.7 KiB
JavaScript

/*
Packer version 3.0 (beta 5) - copyright 2004-2007, Dean Edwards
http://www.opensource.org/licenses/mit-license
*/
eval(base2.namespace);
var IGNORE = RegGrp.IGNORE;
var REMOVE = "";
var SPACE = " ";
var WORDS = /\w+/g;
var Packer = Base.extend({
minify: function(script) {
script = script.replace(Packer.CONTINUE, "");
script = Packer.clean.exec(script);
script = Packer.whitespace.exec(script);
script = Packer.clean.exec(script); // seem to grab a few more bytes on the second pass
return script;
},
pack: function(script, base62, shrink) {
script = this.minify(script);
if (shrink) script = this._shrinkVariables(script);
if (base62) script = this._base62Encode(script);
return script;
},
_base62Encode: function(script) {
var words = new Words(script);
var encode = function(word) {
return words.fetch(word).encoded;
};
/* build the packed script */
var p = this._escape(script.replace(WORDS, encode));
var a = Math.min(Math.max(words.count(), 2), 62);
var c = words.count();
var k = words;
var e = Packer["ENCODE" + (a > 10 ? a > 36 ? 62 : 36 : 10)];
var r = a > 10 ? "e(c)" : "c";
// the whole thing
return format(Packer.UNPACK, p,a,c,k,e,r);
},
_escape: function(script) {
// single quotes wrap the final string so escape them
// also escape new lines required by conditional comments
return script.replace(/([\\'])/g, "\\$1").replace(/[\r\n]+/g, "\\n");
},
_shrinkVariables: function(script) {
// Windows Scripting Host cannot do regexp.test() on global regexps.
var global = function(regexp) {
// This function creates a global version of the passed regexp.
return new RegExp(regexp.source, "g");
};
var data = []; // encoded strings and regular expressions
var store = function(string) {
var replacement = "#" + data.length;
data.push(string);
return replacement;
};
// Base52 encoding (a-Z)
var encode52 = function(c) {
return (c < 52 ? '' : arguments.callee(parseInt(c / 52))) +
((c = c % 52) > 25 ? String.fromCharCode(c + 39) : String.fromCharCode(c + 97));
};
// identify blocks, particularly identify function blocks (which define scope)
var BLOCK = /(function\s*[\w$]*\s*\(\s*([^\)]*)\s*\)\s*)?(\{([^{}]*)\})/;
var VAR_ = /var\s+/g;
var VAR_NAME = /var\s+[\w$]{2,}/g; // > 1 char
var COMMA = /\s*,\s*/;
var blocks = []; // store program blocks (anything between braces {})
// encoder for program blocks
var encode = function(block, func, args) {
if (func) { // the block is a function block
// decode the function block (THIS IS THE IMPORTANT BIT)
// We are retrieving all sub-blocks and will re-parse them in light
// of newly shrunk variables
block = decode(block);
// create the list of variable and argument names
var vars = match(block, VAR_NAME).join(",").replace(VAR_, "");
var ids = Array2.combine(args.split(COMMA).concat(vars.split(COMMA)));
// process each identifier
var count = 0, shortId;
forEach (ids, function(id) {
id = rescape(trim(id));
if (id) {
// find the next free short name (check everything in the current scope)
do shortId = encode52(count++);
while (new RegExp("[^\\w$.]" + shortId + "[^\\w$:]").test(block));
// replace the long name with the short name
var reg = new RegExp("([^\\w$.])" + id + "([^\\w$:])");
while (reg.test(block)) block = block.replace(global(reg), "$1" + shortId + "$2");
var reg = new RegExp("([^{,])" + id + ":", "g");
block = block.replace(reg, "$1" + shortId + ":");
}
});
}
var replacement = "~" + blocks.length;
blocks.push(block);
return replacement;
};
// decoder for program blocks
var ENCODED = /~(\d+)/;
var decode = function(script) {
while (ENCODED.test(script)) {
script = script.replace(global(ENCODED), function(match, index) {
return blocks[index];
});
}
return script;
};
// encode strings and regular expressions
script = Packer.data.exec(script, store);
// remove closures (this is for base2 namespaces only)
script = script.replace(/new function\(_\)\s*\{/g, "{;#;");
// encode blocks, as we encode we replace variable and argument names
while (BLOCK.test(script)) {
script = script.replace(global(BLOCK), encode);
}
// put the blocks back
script = decode(script);
// put back the closure (for base2 namespaces only)
script = script.replace(/\{;#;/g, "new function(_){");
// put strings and regular expressions back
script = script.replace(/#(\d+)/g, function(match, index) {
return data[index];
});
return script;
}
}, {
CONTINUE: /\\\r?\n/g,
ENCODE10: "String",
ENCODE36: "function(c){return c.toString(a)}",
ENCODE62: "function(c){return(c<a?'':e(parseInt(c/a)))+((c=c%a)>35?String.fromCharCode(c+29):c.toString(36))}",
UNPACK: "eval(function(p,a,c,k,e,r){e=%5;if(!''.replace(/^/,String)){while(c--)r[%6]=k[c]" +
"||%6;k=[function(e){return r[e]}];e=function(){return'\\\\w+'};c=1};while(c--)if(k[c])p=p." +
"replace(new RegExp('\\\\b'+e(c)+'\\\\b','g'),k[c]);return p}('%1',%2,%3,'%4'.split('|'),0,{}))",
init: function() {
this.data = reduce(this.data, new RegGrp, function(data, replacement, expression) {
data.store(this.javascript.exec(expression), replacement);
return data;
}, this);
this.clean = this.data.union(this.clean);
this.whitespace = this.data.union(this.whitespace);
},
clean: {
";;;[^\\n]*": REMOVE, // triple semi-colons treated like line comments
"\\(\\s*;\\s*;\\s*\\)": "(;;)", // for (;;) loops
"throw[^};]+[};]": IGNORE, // a safari 1.3 bug
";+\\s*([};])": "$1"
},
data: {
// strings
"STRING1": IGNORE,
'STRING2': IGNORE,
"CONDITIONAL": IGNORE, // conditional comments
"(COMMENT1)\\n\\s*(REGEXP)?": "\n$2",
"(COMMENT2)\\s*(REGEXP)?": " $3",
"COMMENT1$": REMOVE,
"([\\[(\\^=,{}:;&|!*?])\\s*(REGEXP)": "$1$2"
},
javascript: new RegGrp({
COMMENT1: /\/\/[^\n]*/.source,
COMMENT2: /\/\*[^*]*\*+([^\/][^*]*\*+)*\//.source,
CONDITIONAL: /\/\*@|@\*\/|\/\/@[^\n]*\n/.source,
REGEXP: /\/(\\\/|[^*\/])(\\.|[^\/\n\\])*\//.source,
STRING1: /'(\\.|[^'\\])*'/.source,
STRING2: /"(\\.|[^"\\])*"/.source
}),
whitespace: {
"(\\d)\\s+(\\.\\s*[a-z\\$_\\[(])": "$1 $2", // http://dean.edwards.name/weblog/2007/04/packer3/#comment84066
"([+-])\\s+([+-])": "$1 $2", // c = a++ +b;
"\\b\\s+\\$\\s+\\b": " $ ", // var $ in
"\\$\\s+\\b": "$ ", // object$ in
"\\b\\s+\\$": " $", // return $object
"\\b\\s+\\b": SPACE,
"\\s+": REMOVE
}
});