gecko/ipc/glue/IPCMessageUtils.h

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set sw=2 ts=8 et tw=80 : */
/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Mozilla IPC.
 *
 * The Initial Developer of the Original Code is
 *   Ben Turner <bent.mozilla@gmail.com>.
 * Portions created by the Initial Developer are Copyright (C) 2009
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

#ifndef __IPC_GLUE_IPCMESSAGEUTILS_H__
#define __IPC_GLUE_IPCMESSAGEUTILS_H__

#include "chrome/common/ipc_message_utils.h"

#include "prtypes.h"
#include "nsStringGlue.h"
#include "nsTArray.h"
#include "gfxMatrix.h"

#ifdef _MSC_VER
#pragma warning( disable : 4800 )
#endif


namespace mozilla {

// XXX there are out of place and might be generally useful.  Could
// move to nscore.h or something.
struct void_t {
  bool operator==(const void_t&) const { return true; }
};
struct null_t {
  bool operator==(const null_t&) const { return true; }
};

} // namespace mozilla

namespace IPC {

template<>
struct ParamTraits<PRInt8>
{
  typedef PRInt8 paramType;

  static void Write(Message* aMsg, const paramType& aParam)
  {
    aMsg->WriteBytes(&aParam, sizeof(aParam));
  }

  static bool Read(const Message* aMsg, void** aIter, paramType* aResult)
  {
    const char* outp;
    if (!aMsg->ReadBytes(aIter, &outp, sizeof(*aResult)))
      return false;

    *aResult = *reinterpret_cast<const paramType*>(outp);
    return true;
  }
};

template<>
struct ParamTraits<PRUint8>
{
  typedef PRUint8 paramType;

  static void Write(Message* aMsg, const paramType& aParam)
  {
    aMsg->WriteBytes(&aParam, sizeof(aParam));
  }

  static bool Read(const Message* aMsg, void** aIter, paramType* aResult)
  {
    const char* outp;
    if (!aMsg->ReadBytes(aIter, &outp, sizeof(*aResult)))
      return false;

    *aResult = *reinterpret_cast<const paramType*>(outp);
    return true;
  }
};

template <>
struct ParamTraits<nsACString>
{
  typedef nsACString paramType;

  static void Write(Message* aMsg, const paramType& aParam)
  {
    bool isVoid = aParam.IsVoid();
    aMsg->WriteBool(isVoid);

    if (isVoid)
      // represents a NULL pointer
      return;

    PRUint32 length = aParam.Length();
    WriteParam(aMsg, length);
    aMsg->WriteBytes(aParam.BeginReading(), length);
  }

  static bool Read(const Message* aMsg, void** aIter, paramType* aResult)
  {
    bool isVoid;
    if (!aMsg->ReadBool(aIter, &isVoid))
      return false;

    if (isVoid) {
      aResult->SetIsVoid(PR_TRUE);
      return true;
    }

    PRUint32 length;
    if (ReadParam(aMsg, aIter, &length)) {
      const char* buf;
      if (aMsg->ReadBytes(aIter, &buf, length)) {
        aResult->Assign(buf, length);
        return true;
      }
    }
    return false;
  }

  static void Log(const paramType& aParam, std::wstring* aLog)
  {
    if (aParam.IsVoid())
      aLog->append(L"(NULL)");
    else
      aLog->append(UTF8ToWide(aParam.BeginReading()));
  }
};

template <>
struct ParamTraits<nsAString>
{
  typedef nsAString paramType;

  static void Write(Message* aMsg, const paramType& aParam)
  {
    bool isVoid = aParam.IsVoid();
    aMsg->WriteBool(isVoid);

    if (isVoid)
      // represents a NULL pointer
      return;

    PRUint32 length = aParam.Length();
    WriteParam(aMsg, length);
    aMsg->WriteBytes(aParam.BeginReading(), length * sizeof(PRUnichar));
  }

  static bool Read(const Message* aMsg, void** aIter, paramType* aResult)
  {
    bool isVoid;
    if (!aMsg->ReadBool(aIter, &isVoid))
      return false;

    if (isVoid) {
      aResult->SetIsVoid(PR_TRUE);
      return true;
    }

    PRUint32 length;
    if (ReadParam(aMsg, aIter, &length)) {
      const PRUnichar* buf;
      if (aMsg->ReadBytes(aIter, reinterpret_cast<const char**>(&buf),
                       length * sizeof(PRUnichar))) {
        aResult->Assign(buf, length);
        return true;
      }
    }
    return false;
  }

  static void Log(const paramType& aParam, std::wstring* aLog)
  {
    if (aParam.IsVoid())
      aLog->append(L"(NULL)");
    else {
#ifdef WCHAR_T_IS_UTF16
      aLog->append(reinterpret_cast<const wchar_t*>(aParam.BeginReading()));
#else
      PRUint32 length = aParam.Length();
      for (PRUint32 index = 0; index < length; index++) {
        aLog->push_back(std::wstring::value_type(aParam[index]));
      }
#endif
    }
  }
};

template <>
struct ParamTraits<nsCString> : ParamTraits<nsACString>
{
  typedef nsCString paramType;
};

template <>
struct ParamTraits<nsString> : ParamTraits<nsAString>
{
  typedef nsString paramType;
};

template <typename E>
struct ParamTraits<nsTArray<E> >
{
  typedef nsTArray<E> paramType;

  static void Write(Message* aMsg, const paramType& aParam)
  {
    PRUint32 length = aParam.Length();
    WriteParam(aMsg, length);
    for (PRUint32 index = 0; index < length; index++) {
      WriteParam(aMsg, aParam[index]);
    }
  }

  static bool Read(const Message* aMsg, void** aIter, paramType* aResult)
  {
    PRUint32 length;
    if (!ReadParam(aMsg, aIter, &length)) {
      return false;
    }

    for (PRUint32 index = 0; index < length; index++) {
      E* element = aResult->AppendElement();
      if (!(element && ReadParam(aMsg, aIter, element))) {
        return false;
      }
    }

    return true;
  }

  static void Log(const paramType& aParam, std::wstring* aLog)
  {
    for (PRUint32 index = 0; index < aParam.Length(); index++) {
      if (index) {
        aLog->append(L" ");
      }
      LogParam(aParam[index], aLog);
    }
  }
};

template<>
struct ParamTraits<float>
{
  typedef float paramType;

  static void Write(Message* aMsg, const paramType& aParam)
  {
    aMsg->WriteBytes(&aParam, sizeof(paramType));
  }

  static bool Read(const Message* aMsg, void** aIter, paramType* aResult)
  {
    const char* outFloat;
    if (!aMsg->ReadBytes(aIter, &outFloat, sizeof(float)))
      return false;
    *aResult = *reinterpret_cast<const float*>(outFloat);
    return true;
  }

  static void Log(const paramType& aParam, std::wstring* aLog)
  {
    aLog->append(StringPrintf(L"%g", aParam));
  }
};

template<>
struct ParamTraits<gfxMatrix>
{
  typedef gfxMatrix paramType;

  static void Write(Message* aMsg, const paramType& aParam)
  {
    WriteParam(aMsg, aParam.xx);
    WriteParam(aMsg, aParam.xy);
    WriteParam(aMsg, aParam.yx);
    WriteParam(aMsg, aParam.yy);
    WriteParam(aMsg, aParam.x0);
    WriteParam(aMsg, aParam.y0);
  }

  static bool Read(const Message* aMsg, void** aIter, paramType* aResult)
  {
    if (ReadParam(aMsg, aIter, &aResult->xx) &&
        ReadParam(aMsg, aIter, &aResult->xy) &&
        ReadParam(aMsg, aIter, &aResult->yx) &&
        ReadParam(aMsg, aIter, &aResult->yy) &&
        ReadParam(aMsg, aIter, &aResult->x0) &&
        ReadParam(aMsg, aIter, &aResult->y0))
      return true;

    return false;
  }

  static void Log(const paramType& aParam, std::wstring* aLog)
  {
    aLog->append(StringPrintf(L"[[%g %g] [%g %g] [%g %g]]", aParam.xx, aParam.xy, aParam.yx, aParam.yy,
	  						    aParam.x0, aParam.y0));
  }
};

template<>
struct ParamTraits<mozilla::void_t>
{
  typedef mozilla::void_t paramType;
  static void Write(Message* aMsg, const paramType& aParam) { }
  static bool
  Read(const Message* aMsg, void** aIter, paramType* aResult)
  {
    *aResult = paramType();
    return true;
  }
};

template<>
struct ParamTraits<mozilla::null_t>
{
  typedef mozilla::null_t paramType;
  static void Write(Message* aMsg, const paramType& aParam) { }
  static bool
  Read(const Message* aMsg, void** aIter, paramType* aResult)
  {
    *aResult = paramType();
    return true;
  }
};

} /* namespace IPC */

#endif /* __IPC_GLUE_IPCMESSAGEUTILS_H__ */