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

src/shared/Communication.cpp

Index: src/shared/Communication.cpp
===================================================================
--- a/src/shared/Communication.cpp
+++ b/src/shared/Communication.cpp
@@ -1,104 +1,121 @@
-#include <Windows.h>
-#include <Lmcons.h>
-#include <Sddl.h>
-
-#include "Communication.h"
-
-namespace
-{
-  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();
-
-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);
-    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();
-
-  DWORD pipeMode = PIPE_READMODE_MESSAGE | PIPE_WAIT;
-  if (!SetNamedPipeHandleState(pipe, &pipeMode, 0, 0))
-    throw std::runtime_error("SetNamedPipeHandleState failed: error " + GetLastError());
-
-  if (mode == MODE_CREATE && !ConnectNamedPipe(pipe, 0))
-    throw std::runtime_error("Client failed to connect: error " + GetLastError());
-}
-
-Communication::Pipe::~Pipe()
-{
-  CloseHandle(pipe);
-}
-
-Communication::InputBuffer Communication::Pipe::ReadMessage()
-{
-  std::stringstream stream;
-  std::auto_ptr<char> buffer(new char[bufferSize]);
-  bool doneReading = false;
-  while (!doneReading)
-  {
-    DWORD bytesRead;
-    if (ReadFile(pipe, buffer.get(), bufferSize * sizeof(char), &bytesRead, 0))
-      doneReading = true;
-    else if (GetLastError() != ERROR_MORE_DATA)
-    {
-      std::stringstream stream;
-      stream << "Error reading from pipe: " << GetLastError();
-      throw std::runtime_error(stream.str());
-    }
-    stream << std::string(buffer.get(), bytesRead);
-  }
-  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");
-}
+#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, 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();
+
+  DWORD pipeMode = PIPE_READMODE_MESSAGE | PIPE_WAIT;
+  if (!SetNamedPipeHandleState(pipe, &pipeMode, 0, 0))
+    throw std::runtime_error("SetNamedPipeHandleState failed: error " + GetLastError());
+
+  if (mode == MODE_CREATE && !ConnectNamedPipe(pipe, 0))
+    throw std::runtime_error("Client failed to connect: error " + GetLastError());
+}
+
+Communication::Pipe::~Pipe()
+{
+  CloseHandle(pipe);
+}
+
+Communication::InputBuffer Communication::Pipe::ReadMessage()
+{
+  std::stringstream stream;
+  std::auto_ptr<char> buffer(new char[bufferSize]);
+  bool doneReading = false;
+  while (!doneReading)
+  {
+    DWORD bytesRead;
+    if (ReadFile(pipe, buffer.get(), bufferSize * sizeof(char), &bytesRead, 0))
+      doneReading = true;
+    else if (GetLastError() != ERROR_MORE_DATA)
+    {
+      std::stringstream stream;
+      stream << "Error reading from pipe: " << GetLastError();
+      throw std::runtime_error(stream.str());
+    }
+    stream << std::string(buffer.get(), bytesRead);
+  }
+  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");
+}