mailparser

lib/streams.js

@@ -0,0 +1,145 @@
+var Stream = require('stream').Stream,
+    utillib = require('util'),
+    mimelib = require("mimelib"),
+    encodinglib = require("encoding"),
+    crypto = require("crypto");
+
+module.exports.Base64Stream = Base64Stream;
+module.exports.QPStream = QPStream;
+module.exports.BinaryStream = BinaryStream;
+
+function Base64Stream(){
+    Stream.call(this);
+    this.writable = true;
+
+    this.checksum = crypto.createHash("md5");
+    this.length = 0;
+
+    this.current = "";
+}
+utillib.inherits(Base64Stream, Stream);
+
+Base64Stream.prototype.write = function(data){
+    this.handleInput(data);
+    return true;
+};
+
+Base64Stream.prototype.end = function(data){
+    this.handleInput(data);
+    this.emit("end");
+    return {
+        length: this.length,
+        checksum: this.checksum.digest("hex")
+    };
+};
+
+Base64Stream.prototype.handleInput = function(data){
+    if(!data || !data.length){
+        return;
+    }
+
+    data = (data || "").toString("utf-8");
+
+    var remainder = 0;
+    this.current += data.replace(/[^\w\+\/=]/g,'');
+    var buffer = new Buffer(this.current.substr(0, this.current.length - this.current.length % 4),"base64");
+    if(buffer.length){
+        this.length += buffer.length;
+        this.checksum.update(buffer);
+        this.emit("data", buffer);
+    }
+    this.current = (remainder=this.current.length % 4)?this.current.substr(- remainder):"";
+};
+
+function QPStream(charset){
+    Stream.call(this);
+    this.writable = true;
+
+    this.checksum = crypto.createHash("md5");
+    this.length = 0;
+
+    this.charset = charset || "UTF-8";
+    this.current = undefined;
+}
+utillib.inherits(QPStream, Stream);
+
+QPStream.prototype.write = function(data){
+    this.handleInput(data);
+    return true;
+};
+
+QPStream.prototype.end = function(data){
+    this.handleInput(data);
+    this.flush();
+    this.emit("end");
+    return {
+        length: this.length,
+        checksum: this.checksum.digest("hex")
+    };
+};
+
+QPStream.prototype.handleInput = function(data){
+    if(!data || !data.length){
+        return;
+    }
+
+    data = (data || "").toString("utf-8");
+    if(data.match(/^\r\n/)){
+        data = data.substr(2);
+    }
+
+    if(typeof this.current !="string"){
+        this.current = data;
+    }else{
+        this.current += "\r\n" + data;
+    }
+};
+
+QPStream.prototype.flush = function(){
+    var buffer = mimelib.decodeQuotedPrintable(this.current, false, this.charset);
+
+    if(this.charset.toLowerCase() == "binary"){
+        // do nothing
+    }else if(this.charset.toLowerCase() != "utf-8"){
+        buffer = encodinglib.convert(buffer, "utf-8", this.charset);
+    }else{
+        buffer = new Buffer(buffer, "utf-8");
+    }
+
+    this.length += buffer.length;
+    this.checksum.update(buffer);
+
+    this.emit("data", buffer);
+};
+
+function BinaryStream(charset){
+    Stream.call(this);
+    this.writable = true;
+
+    this.checksum = crypto.createHash("md5");
+    this.length = 0;
+
+    this.charset = charset || "UTF-8";
+    this.current = "";
+}
+utillib.inherits(BinaryStream, Stream);
+
+BinaryStream.prototype.write = function(data){
+    if(data && data.length){
+        this.length += data.length;
+        this.checksum.update(data);
+        this.emit("data", data);
+    }
+    return true;
+};
+
+BinaryStream.prototype.end = function(data){
+    if(data && data.length){
+        this.emit("data", data);
+    }
+    this.emit("end");
+    return {
+        length: this.length,
+        checksum: this.checksum.digest("hex")
+    };
+};