forked from lix-project/lix-website
398 lines
10 KiB
JavaScript
398 lines
10 KiB
JavaScript
|
var Chainsaw = require('chainsaw');
|
||
|
|
var EventEmitter = require('events').EventEmitter;
|
||
|
|
var Buffers = require('buffers');
|
||
|
|
var Vars = require('./lib/vars.js');
|
||
|
|
var Stream = require('stream').Stream;
|
||
|
|
|
||
|
|
exports = module.exports = function (bufOrEm, eventName) {
|
||
|
|
if (Buffer.isBuffer(bufOrEm)) {
|
||
|
|
return exports.parse(bufOrEm);
|
||
|
|
}
|
||
|
|
|
||
|
|
var s = exports.stream();
|
||
|
|
if (bufOrEm && bufOrEm.pipe) {
|
||
|
|
bufOrEm.pipe(s);
|
||
|
|
}
|
||
|
|
else if (bufOrEm) {
|
||
|
|
bufOrEm.on(eventName || 'data', function (buf) {
|
||
|
|
s.write(buf);
|
||
|
|
});
|
||
|
|
|
||
|
|
bufOrEm.on('end', function () {
|
||
|
|
s.end();
|
||
|
|
});
|
||
|
|
}
|
||
|
|
return s;
|
||
|
|
};
|
||
|
|
|
||
|
|
exports.stream = function (input) {
|
||
|
|
if (input) return exports.apply(null, arguments);
|
||
|
|
|
||
|
|
var pending = null;
|
||
|
|
function getBytes (bytes, cb, skip) {
|
||
|
|
pending = {
|
||
|
|
bytes : bytes,
|
||
|
|
skip : skip,
|
||
|
|
cb : function (buf) {
|
||
|
|
pending = null;
|
||
|
|
cb(buf);
|
||
|
|
},
|
||
|
|
};
|
||
|
|
dispatch();
|
||
|
|
}
|
||
|
|
|
||
|
|
var offset = null;
|
||
|
|
function dispatch () {
|
||
|
|
if (!pending) {
|
||
|
|
if (caughtEnd) done = true;
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
if (typeof pending === 'function') {
|
||
|
|
pending();
|
||
|
|
}
|
||
|
|
else {
|
||
|
|
var bytes = offset + pending.bytes;
|
||
|
|
|
||
|
|
if (buffers.length >= bytes) {
|
||
|
|
var buf;
|
||
|
|
if (offset == null) {
|
||
|
|
buf = buffers.splice(0, bytes);
|
||
|
|
if (!pending.skip) {
|
||
|
|
buf = buf.slice();
|
||
|
|
}
|
||
|
|
}
|
||
|
|
else {
|
||
|
|
if (!pending.skip) {
|
||
|
|
buf = buffers.slice(offset, bytes);
|
||
|
|
}
|
||
|
|
offset = bytes;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (pending.skip) {
|
||
|
|
pending.cb();
|
||
|
|
}
|
||
|
|
else {
|
||
|
|
pending.cb(buf);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
function builder (saw) {
|
||
|
|
function next () { if (!done) saw.next() }
|
||
|
|
|
||
|
|
var self = words(function (bytes, cb) {
|
||
|
|
return function (name) {
|
||
|
|
getBytes(bytes, function (buf) {
|
||
|
|
vars.set(name, cb(buf));
|
||
|
|
next();
|
||
|
|
});
|
||
|
|
};
|
||
|
|
});
|
||
|
|
|
||
|
|
self.tap = function (cb) {
|
||
|
|
saw.nest(cb, vars.store);
|
||
|
|
};
|
||
|
|
|
||
|
|
self.into = function (key, cb) {
|
||
|
|
if (!vars.get(key)) vars.set(key, {});
|
||
|
|
var parent = vars;
|
||
|
|
vars = Vars(parent.get(key));
|
||
|
|
|
||
|
|
saw.nest(function () {
|
||
|
|
cb.apply(this, arguments);
|
||
|
|
this.tap(function () {
|
||
|
|
vars = parent;
|
||
|
|
});
|
||
|
|
}, vars.store);
|
||
|
|
};
|
||
|
|
|
||
|
|
self.flush = function () {
|
||
|
|
vars.store = {};
|
||
|
|
next();
|
||
|
|
};
|
||
|
|
|
||
|
|
self.loop = function (cb) {
|
||
|
|
var end = false;
|
||
|
|
|
||
|
|
saw.nest(false, function loop () {
|
||
|
|
this.vars = vars.store;
|
||
|
|
cb.call(this, function () {
|
||
|
|
end = true;
|
||
|
|
next();
|
||
|
|
}, vars.store);
|
||
|
|
this.tap(function () {
|
||
|
|
if (end) saw.next()
|
||
|
|
else loop.call(this)
|
||
|
|
}.bind(this));
|
||
|
|
}, vars.store);
|
||
|
|
};
|
||
|
|
|
||
|
|
self.buffer = function (name, bytes) {
|
||
|
|
if (typeof bytes === 'string') {
|
||
|
|
bytes = vars.get(bytes);
|
||
|
|
}
|
||
|
|
|
||
|
|
getBytes(bytes, function (buf) {
|
||
|
|
vars.set(name, buf);
|
||
|
|
next();
|
||
|
|
});
|
||
|
|
};
|
||
|
|
|
||
|
|
self.skip = function (bytes) {
|
||
|
|
if (typeof bytes === 'string') {
|
||
|
|
bytes = vars.get(bytes);
|
||
|
|
}
|
||
|
|
|
||
|
|
getBytes(bytes, function () {
|
||
|
|
next();
|
||
|
|
});
|
||
|
|
};
|
||
|
|
|
||
|
|
self.scan = function find (name, search) {
|
||
|
|
if (typeof search === 'string') {
|
||
|
|
search = new Buffer(search);
|
||
|
|
}
|
||
|
|
else if (!Buffer.isBuffer(search)) {
|
||
|
|
throw new Error('search must be a Buffer or a string');
|
||
|
|
}
|
||
|
|
|
||
|
|
var taken = 0;
|
||
|
|
pending = function () {
|
||
|
|
var pos = buffers.indexOf(search, offset + taken);
|
||
|
|
var i = pos-offset-taken;
|
||
|
|
if (pos !== -1) {
|
||
|
|
pending = null;
|
||
|
|
if (offset != null) {
|
||
|
|
vars.set(
|
||
|
|
name,
|
||
|
|
buffers.slice(offset, offset + taken + i)
|
||
|
|
);
|
||
|
|
offset += taken + i + search.length;
|
||
|
|
}
|
||
|
|
else {
|
||
|
|
vars.set(
|
||
|
|
name,
|
||
|
|
buffers.slice(0, taken + i)
|
||
|
|
);
|
||
|
|
buffers.splice(0, taken + i + search.length);
|
||
|
|
}
|
||
|
|
next();
|
||
|
|
dispatch();
|
||
|
|
} else {
|
||
|
|
i = Math.max(buffers.length - search.length - offset - taken, 0);
|
||
|
|
}
|
||
|
|
taken += i;
|
||
|
|
};
|
||
|
|
dispatch();
|
||
|
|
};
|
||
|
|
|
||
|
|
self.peek = function (cb) {
|
||
|
|
offset = 0;
|
||
|
|
saw.nest(function () {
|
||
|
|
cb.call(this, vars.store);
|
||
|
|
this.tap(function () {
|
||
|
|
offset = null;
|
||
|
|
});
|
||
|
|
});
|
||
|
|
};
|
||
|
|
|
||
|
|
return self;
|
||
|
|
};
|
||
|
|
|
||
|
|
var stream = Chainsaw.light(builder);
|
||
|
|
stream.writable = true;
|
||
|
|
|
||
|
|
var buffers = Buffers();
|
||
|
|
|
||
|
|
stream.write = function (buf) {
|
||
|
|
buffers.push(buf);
|
||
|
|
dispatch();
|
||
|
|
};
|
||
|
|
|
||
|
|
var vars = Vars();
|
||
|
|
|
||
|
|
var done = false, caughtEnd = false;
|
||
|
|
stream.end = function () {
|
||
|
|
caughtEnd = true;
|
||
|
|
};
|
||
|
|
|
||
|
|
stream.pipe = Stream.prototype.pipe;
|
||
|
|
Object.getOwnPropertyNames(EventEmitter.prototype).forEach(function (name) {
|
||
|
|
stream[name] = EventEmitter.prototype[name];
|
||
|
|
});
|
||
|
|
|
||
|
|
return stream;
|
||
|
|
};
|
||
|
|
|
||
|
|
exports.parse = function parse (buffer) {
|
||
|
|
var self = words(function (bytes, cb) {
|
||
|
|
return function (name) {
|
||
|
|
if (offset + bytes <= buffer.length) {
|
||
|
|
var buf = buffer.slice(offset, offset + bytes);
|
||
|
|
offset += bytes;
|
||
|
|
vars.set(name, cb(buf));
|
||
|
|
}
|
||
|
|
else {
|
||
|
|
vars.set(name, null);
|
||
|
|
}
|
||
|
|
return self;
|
||
|
|
};
|
||
|
|
});
|
||
|
|
|
||
|
|
var offset = 0;
|
||
|
|
var vars = Vars();
|
||
|
|
self.vars = vars.store;
|
||
|
|
|
||
|
|
self.tap = function (cb) {
|
||
|
|
cb.call(self, vars.store);
|
||
|
|
return self;
|
||
|
|
};
|
||
|
|
|
||
|
|
self.into = function (key, cb) {
|
||
|
|
if (!vars.get(key)) {
|
||
|
|
vars.set(key, {});
|
||
|
|
}
|
||
|
|
var parent = vars;
|
||
|
|
vars = Vars(parent.get(key));
|
||
|
|
cb.call(self, vars.store);
|
||
|
|
vars = parent;
|
||
|
|
return self;
|
||
|
|
};
|
||
|
|
|
||
|
|
self.loop = function (cb) {
|
||
|
|
var end = false;
|
||
|
|
var ender = function () { end = true };
|
||
|
|
while (end === false) {
|
||
|
|
cb.call(self, ender, vars.store);
|
||
|
|
}
|
||
|
|
return self;
|
||
|
|
};
|
||
|
|
|
||
|
|
self.buffer = function (name, size) {
|
||
|
|
if (typeof size === 'string') {
|
||
|
|
size = vars.get(size);
|
||
|
|
}
|
||
|
|
var buf = buffer.slice(offset, Math.min(buffer.length, offset + size));
|
||
|
|
offset += size;
|
||
|
|
vars.set(name, buf);
|
||
|
|
|
||
|
|
return self;
|
||
|
|
};
|
||
|
|
|
||
|
|
self.skip = function (bytes) {
|
||
|
|
if (typeof bytes === 'string') {
|
||
|
|
bytes = vars.get(bytes);
|
||
|
|
}
|
||
|
|
offset += bytes;
|
||
|
|
|
||
|
|
return self;
|
||
|
|
};
|
||
|
|
|
||
|
|
self.scan = function (name, search) {
|
||
|
|
if (typeof search === 'string') {
|
||
|
|
search = new Buffer(search);
|
||
|
|
}
|
||
|
|
else if (!Buffer.isBuffer(search)) {
|
||
|
|
throw new Error('search must be a Buffer or a string');
|
||
|
|
}
|
||
|
|
vars.set(name, null);
|
||
|
|
|
||
|
|
// simple but slow string search
|
||
|
|
for (var i = 0; i + offset <= buffer.length - search.length + 1; i++) {
|
||
|
|
for (
|
||
|
|
var j = 0;
|
||
|
|
j < search.length && buffer[offset+i+j] === search[j];
|
||
|
|
j++
|
||
|
|
);
|
||
|
|
if (j === search.length) break;
|
||
|
|
}
|
||
|
|
|
||
|
|
vars.set(name, buffer.slice(offset, offset + i));
|
||
|
|
offset += i + search.length;
|
||
|
|
return self;
|
||
|
|
};
|
||
|
|
|
||
|
|
self.peek = function (cb) {
|
||
|
|
var was = offset;
|
||
|
|
cb.call(self, vars.store);
|
||
|
|
offset = was;
|
||
|
|
return self;
|
||
|
|
};
|
||
|
|
|
||
|
|
self.flush = function () {
|
||
|
|
vars.store = {};
|
||
|
|
return self;
|
||
|
|
};
|
||
|
|
|
||
|
|
self.eof = function () {
|
||
|
|
return offset >= buffer.length;
|
||
|
|
};
|
||
|
|
|
||
|
|
return self;
|
||
|
|
};
|
||
|
|
|
||
|
|
// convert byte strings to unsigned little endian numbers
|
||
|
|
function decodeLEu (bytes) {
|
||
|
|
var acc = 0;
|
||
|
|
for (var i = 0; i < bytes.length; i++) {
|
||
|
|
acc += Math.pow(256,i) * bytes[i];
|
||
|
|
}
|
||
|
|
return acc;
|
||
|
|
}
|
||
|
|
|
||
|
|
// convert byte strings to unsigned big endian numbers
|
||
|
|
function decodeBEu (bytes) {
|
||
|
|
var acc = 0;
|
||
|
|
for (var i = 0; i < bytes.length; i++) {
|
||
|
|
acc += Math.pow(256, bytes.length - i - 1) * bytes[i];
|
||
|
|
}
|
||
|
|
return acc;
|
||
|
|
}
|
||
|
|
|
||
|
|
// convert byte strings to signed big endian numbers
|
||
|
|
function decodeBEs (bytes) {
|
||
|
|
var val = decodeBEu(bytes);
|
||
|
|
if ((bytes[0] & 0x80) == 0x80) {
|
||
|
|
val -= Math.pow(256, bytes.length);
|
||
|
|
}
|
||
|
|
return val;
|
||
|
|
}
|
||
|
|
|
||
|
|
// convert byte strings to signed little endian numbers
|
||
|
|
function decodeLEs (bytes) {
|
||
|
|
var val = decodeLEu(bytes);
|
||
|
|
if ((bytes[bytes.length - 1] & 0x80) == 0x80) {
|
||
|
|
val -= Math.pow(256, bytes.length);
|
||
|
|
}
|
||
|
|
return val;
|
||
|
|
}
|
||
|
|
|
||
|
|
function words (decode) {
|
||
|
|
var self = {};
|
||
|
|
|
||
|
|
[ 1, 2, 4, 8 ].forEach(function (bytes) {
|
||
|
|
var bits = bytes * 8;
|
||
|
|
|
||
|
|
self['word' + bits + 'le']
|
||
|
|
= self['word' + bits + 'lu']
|
||
|
|
= decode(bytes, decodeLEu);
|
||
|
|
|
||
|
|
self['word' + bits + 'ls']
|
||
|
|
= decode(bytes, decodeLEs);
|
||
|
|
|
||
|
|
self['word' + bits + 'be']
|
||
|
|
= self['word' + bits + 'bu']
|
||
|
|
= decode(bytes, decodeBEu);
|
||
|
|
|
||
|
|
self['word' + bits + 'bs']
|
||
|
|
= decode(bytes, decodeBEs);
|
||
|
|
});
|
||
|
|
|
||
|
|
// word8be(n) == word8le(n) for all n
|
||
|
|
self.word8 = self.word8u = self.word8be;
|
||
|
|
self.word8s = self.word8bs;
|
||
|
|
|
||
|
|
return self;
|
||
|
|
}
|