Initial commit

src/systemData/tcpPackage.js

@@ -0,0 +1,86 @@
+var uuid = require('uuid');
+
+var createBufferSegment = require('../common/bufferSegment');
+var TcpFlags = require('./tcpFlags');
+
+const CommandOffset = 0;
+const FlagsOffset = CommandOffset + 1;
+const CorrelationOffset = FlagsOffset + 1;
+const AuthOffset = CorrelationOffset + 16;
+const MandatorySize = AuthOffset;
+
+function TcpPackage(command, flags, correlationId, login, password, data) {
+  this.command = command;
+  this.flags = flags;
+  this.correlationId = correlationId;
+  this.login = login || null;
+  this.password = password || null;
+  this.data = data || null;
+}
+
+TcpPackage.fromBufferSegment = function(data) {
+  if (data.length < MandatorySize)
+    throw new Error("ArraySegment too short, length: " + data.length);
+
+  var command = data.buffer[data.offset + CommandOffset];
+  var flags = data.buffer[data.offset + FlagsOffset];
+
+  var correlationId = uuid.unparse(data.buffer, data.offset + CorrelationOffset);
+
+  var headerSize = MandatorySize;
+  var login = null, pass = null;
+  if ((flags & TcpFlags.Authenticated) != 0)
+  {
+    var loginLen = data.buffer[data.offset + AuthOffset];
+    if (AuthOffset + 1 + loginLen + 1 >= data.count)
+        throw new Error("Login length is too big, it doesn't fit into TcpPackage.");
+    login = data.buffer.toString('utf8', data.offset + AuthOffset + 1, data.offset + AuthOffset + 1 + loginLen);
+
+    var passLen = data.buffer[data.offset + AuthOffset + 1 + loginLen];
+    if (AuthOffset + 1 + loginLen + 1 + passLen > data.count)
+        throw new Error("Password length is too big, it doesn't fit into TcpPackage.");
+    headerSize += 1 + loginLen + 1 + passLen;
+    pass = data.buffer.toString('utf8', data.offset + AuthOffset + 1 + loginLen + 1, data.offset + headerSize);
+  }
+  return new TcpPackage(
+      command, flags, correlationId, login, pass,
+      createBufferSegment(data.buffer, data.offset + headerSize, data.count - headerSize));
+};
+
+TcpPackage.prototype.asBuffer = function() {
+  if ((this.flags & TcpFlags.Authenticated) != 0) {
+    var loginBytes = new Buffer(this.login);
+    if (loginBytes.length > 255) throw new Error("Login serialized length should be less than 256 bytes.");
+    var passwordBytes = new Buffer(this.password);
+    if (passwordBytes.length > 255) throw new Error("Password serialized length should be less than 256 bytes.");
+
+    var res = new Buffer(MandatorySize + 2 + loginBytes.length + passwordBytes.length + (this.data ? this.data.count : 0));
+    res[CommandOffset] = this.command;
+    res[FlagsOffset] = this.flags;
+    uuid.parse(this.correlationId, res, CorrelationOffset);
+
+    res[AuthOffset] = loginBytes.length;
+    loginBytes.copy(res, AuthOffset + 1);
+    res[AuthOffset + 1 + loginBytes.length] = passwordBytes.length;
+    passwordBytes.copy(res, AuthOffset + 2 + loginBytes.length);
+
+    if (this.data)
+      this.data.copyTo(res, res.length - this.data.count);
+
+    return res;
+  } else {
+    var res = new Buffer(MandatorySize + (this.data ? this.data.count : 0));
+    res[CommandOffset] = this.command;
+    res[FlagsOffset] = this.flags;
+    uuid.parse(this.correlationId, res, CorrelationOffset);
+    if (this.data)
+      this.data.copyTo(res, AuthOffset);
+    return res;
+  }
+};
+
+TcpPackage.prototype.asBufferSegment = function() {
+  return createBufferSegment(this.asBuffer());
+};
+
+module.exports = TcpPackage;