Moved all pipe functionality into a self-containing Communication::Pipe class

src/shared/Communication.cpp

 #include <Windows.h>
 #include <Lmcons.h>
 #include <Sddl.h>
 
 #include "Communication.h"
 
 namespace
 {
+  const int bufferSize = 1024;
+
   std::string AppendErrorCode(const std::string& message)
   {
     std::stringstream stream;
     stream << message << " (Error code: " << GetLastError() << ")";
     return stream.str();
   }
 
   std::wstring GetUserName()
   {
     const DWORD maxLength = UNLEN + 1;
     std::auto_ptr<wchar_t> buffer(new wchar_t[maxLength]);
     DWORD length = maxLength;
     if (!::GetUserNameW(buffer.get(), &length))
       throw std::runtime_error(AppendErrorCode("Failed to get the current user's name"));
     return std::wstring(buffer.get(), length);
   }
 }
 
 const std::wstring Communication::pipeName = L"\\\\.\\pipe\\adblockplusengine_" + GetUserName();
 
+void Communication::InputBuffer::CheckType(Communication::ValueType expectedType)
+{
+  if (!hasType)
+    ReadBinary(currentType);
+
+  if (currentType != expectedType)
+  {
+    // Make sure we don't attempt to read the type again
+    hasType = true;
+    throw new std::runtime_error("Unexpected type found in input buffer");
+  }
+  else
+    hasType = false;
+}
+
 Communication::PipeConnectionError::PipeConnectionError()
     : std::runtime_error(AppendErrorCode("Unable to connect to a named pipe"))
 {
 }
 
 Communication::Pipe::Pipe(const std::wstring& pipeName, Communication::Pipe::Mode mode)
 {
   pipe = INVALID_HANDLE_VALUE;
   if (mode == MODE_CREATE)
   {
     SECURITY_ATTRIBUTES sa;
     memset(&sa, 0, sizeof(SECURITY_ATTRIBUTES));
     sa.nLength = sizeof(SECURITY_ATTRIBUTES);
 
     // Low mandatory label. See http://msdn.microsoft.com/en-us/library/bb625958.aspx
     LPCWSTR accessControlEntry = L"S:(ML;;NW;;;LW)";
     PSECURITY_DESCRIPTOR securitydescriptor;
     ConvertStringSecurityDescriptorToSecurityDescriptorW(accessControlEntry, SDDL_REVISION_1, &securitydescriptor, 0);
 
     sa.lpSecurityDescriptor = securitydescriptor;
     sa.bInheritHandle = TRUE;
 
     pipe = CreateNamedPipeW (pipeName.c_str(), PIPE_ACCESS_DUPLEX, PIPE_TYPE_MESSAGE | PIPE_READMODE_MESSAGE | PIPE_WAIT,
-                                  PIPE_UNLIMITED_INSTANCES, Communication::bufferSize, Communication::bufferSize, 0, &sa);
+                                  PIPE_UNLIMITED_INSTANCES, bufferSize, bufferSize, 0, &sa);
     LocalFree(securitydescriptor);
   }
   else
   {
     if (WaitNamedPipeW(pipeName.c_str(), 5000))
       pipe = CreateFileW(pipeName.c_str(), GENERIC_READ | GENERIC_WRITE, 0, 0, OPEN_EXISTING, 0, 0);
   }
 
   if (pipe == INVALID_HANDLE_VALUE)
     throw PipeConnectionError();
@@ skipping 32 matching lines @@
   return Communication::InputBuffer(stream.str());
 }
 
 void Communication::Pipe::WriteMessage(Communication::OutputBuffer& message)
 {
   DWORD bytesWritten;
   std::string data = message.Get();
   if (!WriteFile(pipe, data.c_str(), data.length(), &bytesWritten, 0))
     throw std::runtime_error("Failed to write to pipe");
 }