activestack-gateway
Version:
Socket server for ActiveStack
297 lines (238 loc) • 7.26 kB
JavaScript
var fs = require("fs");
function Iterator(text) {
var pos = 0, length = text.length;
this.peek = function(num) {
num = num || 0;
if(pos + num >= length) { return null; }
return text.charAt(pos + num);
};
this.next = function() {
if(pos >= length) { return null; }
return text.charAt(pos++);
};
this.pos = function() {
return pos;
};
}
var rWhitespace = /\s/;
function isWhitespace(chr) {
return rWhitespace.test(chr);
}
function consumeWhiteSpace(iter) {
var start = iter.pos();
while(isWhitespace(iter.peek())) { iter.next(); }
return { type: "whitespace", start: start, end: iter.pos() };
}
function startsComment(chr) {
return chr === "!" || chr === "#";
}
function isEOL(chr) {
return chr == null || chr === "\n" || chr === "\r";
}
function consumeComment(iter) {
var start = iter.pos();
while(!isEOL(iter.peek())) { iter.next(); }
return { type: "comment", start: start, end: iter.pos() };
}
function startsKeyVal(chr) {
return !isWhitespace(chr) && !startsComment(chr);
}
function startsSeparator(chr) {
return chr === "=" || chr === ":" || isWhitespace(chr);
}
function startsEscapedVal(chr) {
return chr === "\\";
}
function consumeEscapedVal(iter) {
var start = iter.pos();
iter.next(); // move past "\"
var curChar = iter.next();
if(curChar === "u") { // encoded unicode char
iter.next();iter.next();iter.next();iter.next(); // Read in the 4 hex values
}
return { type: "escaped-value", start: start, end: iter.pos() };
}
function consumeKey(iter) {
var start = iter.pos(), children = [];
var curChar;
while((curChar = iter.peek()) !== null) {
if(startsSeparator(curChar)) { break; }
if(startsEscapedVal(curChar)) { children.push(consumeEscapedVal(iter)); continue; }
iter.next();
}
return { type: "key", start: start, end: iter.pos(), children: children };
}
function consumeKeyValSeparator(iter) {
var start = iter.pos();
var seenHardSep = false, curChar;
while((curChar = iter.peek()) !== null) {
if(isEOL(curChar)) { break; }
if(isWhitespace(curChar)) { iter.next(); continue; }
if(seenHardSep) { break; }
seenHardSep = (curChar === ":" || curChar === "=");
if(seenHardSep) { iter.next(); continue; }
break; // curChar is a non-separtor char
}
return { type: "key-value-separator", start: start, end: iter.pos() };
}
function startsLineBreak(iter) {
return iter.peek() === "\\" && isEOL(iter.peek(1));
}
function consumeLineBreak(iter) {
var start = iter.pos();
iter.next(); // consume \
if(iter.peek() === "\r") { iter.next(); }
iter.next(); // consume \n
var curChar;
while((curChar = iter.peek()) !== null) {
if(isEOL(curChar)) { break; }
if(!isWhitespace(curChar)) { break; }
iter.next();
}
return { type: "line-break", start: start, end: iter.pos() };
}
function consumeVal(iter) {
var start = iter.pos(), children = [];
var curChar;
while((curChar = iter.peek()) !== null) {
if(startsLineBreak(iter)) { children.push(consumeLineBreak(iter)); continue; }
if(startsEscapedVal(curChar)) { children.push(consumeEscapedVal(iter)); continue; }
if(isEOL(curChar)) { break; }
iter.next();
}
return { type: "value", start: start, end: iter.pos(), children: children };
}
function consumeKeyVal(iter) {
return {
type: "key-value",
start: iter.pos(),
children: [
consumeKey(iter),
consumeKeyValSeparator(iter),
consumeVal(iter)
],
end: iter.pos()
};
}
var renderChild = {
"escaped-value": function(child, text) {
var type = text.charAt(child.start + 1);
if(type === "t") { return "\t"; }
if(type === "r") { return "\r"; }
if(type === "n") { return "\n"; }
if(type === "f") { return "\f"; }
if(type !== "u") { return type; }
return String.fromCharCode(parseInt(text.substr(child.start + 2, 4), 16));
},
"line-break": function (child, text) {
return "";
}
};
function rangeToBuffer(range, text) {
var start = range.start, buffer = [];
for(var i = 0; i < range.children.length; i++) {
var child = range.children[i];
buffer.push(text.substring(start, child.start));
buffer.push(renderChild[child.type](child, text));
start = child.end;
}
buffer.push(text.substring(start, range.end));
return buffer;
}
function rangesToObject(ranges, text) {
var obj = Object.create(null); // Creates to a true hash map
for(var i = 0; i < ranges.length; i++) {
var range = ranges[i];
if(range.type !== "key-value") { continue; }
var key = rangeToBuffer(range.children[0], text).join("");
var val = rangeToBuffer(range.children[2], text).join("");
obj[key] = val;
}
return obj;
}
function stringToRanges(text) {
var iter = new Iterator(text), ranges = [];
var curChar;
while((curChar = iter.peek()) !== null) {
if(isWhitespace(curChar)) { ranges.push(consumeWhiteSpace(iter)); continue; }
if(startsComment(curChar)) { ranges.push(consumeComment(iter)); continue; }
if(startsKeyVal(curChar)) { ranges.push(consumeKeyVal(iter)); continue; }
throw Error("Something crazy happened. text: '" + text + "'; curChar: '" + curChar + "'");
}
return ranges;
}
function Editor(text, path) {
var ranges = stringToRanges(text);
var obj = rangesToObject(ranges, text);
var keyRange = Object.create(null); // Creates to a true hash map
for(var i = 0; i < ranges.length; i++) {
var range = ranges[i];
if(range.type !== "key-value") { continue; }
var key = rangeToBuffer(range.children[0], text).join("");
keyRange[key] = range;
}
this.get = function(key) { return obj[key]; }
this.put = function(key, val) {
obj[key] = val;
var range = keyRange[key];
if(range) {
range.children[2].type = "literal";
range.children[2].text = val;
range.children[2].parent = range;
} else {
ranges.push({ type: "literal", text: "\n" + key + "=" + val });
}
}
this.valueOf = this.toString = function() {
var buffer = [], stack = [].concat(ranges);
var node;
while((node = stack.shift()) != null) {
switch(node.type) {
case "literal":
buffer.push(node.text);
if(!node.parent) { buffer.push("\n"); }
else { buffer.push(text.substring(node.end, node.parent.end)); }
break;
case "key":
case "value":
case "comment":
case "whitespace":
case "key-value-separator":
case "escaped-value":
case "line-break":
buffer.push(text.substring(node.start, node.end));
break;
case "key-value":
Array.prototype.unshift.apply(stack, node.children);
break;
}
}
return buffer.join("");
},
this.save = function(callback) {
if(!path) { callback("Unknown path"); }
fs.writeFile(path, this.toString(), callback);
}
}
function createEditor(path, callback) {
fs.readFile(path, function(err, text) {
if(err) { return callback(err, null); }
text = text.toString();
return callback(null, new Editor(text, path));
});
}
function parse(text) {
text = text.toString();
var ranges = stringToRanges(text);
return rangesToObject(ranges, text);
}
function read(path, callback) {
fs.readFile(path, function(err, data) {
if(err) { return callback(err, null); }
return callback(null, parse(data));
});
}
function readSync(path) {
return parse(fs.readFileSync(path));
}
module.exports = { parse: parse, read: read, readSync: readSync, createEditor: createEditor };