/*
   Copyright (c) 2003, 2014, Oracle and/or its affiliates. All rights reserved.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License, version 2.0,
   as published by the Free Software Foundation.

   This program is also distributed with certain software (including
   but not limited to OpenSSL) that is licensed under separate terms,
   as designated in a particular file or component or in included license
   documentation.  The authors of MySQL hereby grant you an additional
   permission to link the program and your derivative works with the
   separately licensed software that they have included with MySQL.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License, version 2.0, for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA
*/


#include <ndb_global.h>

#include "SHM_Transporter.hpp"
#include "TransporterInternalDefinitions.hpp"
#include <TransporterCallback.hpp>
#include <NdbSleep.h>
#include <NdbOut.hpp>

#include <InputStream.hpp>
#include <OutputStream.hpp>

extern int g_ndb_shm_signum;

SHM_Transporter::SHM_Transporter(TransporterRegistry &t_reg,
				 const char *lHostName,
				 const char *rHostName, 
				 int r_port,
				 bool isMgmConnection_arg,
				 NodeId lNodeId,
				 NodeId rNodeId,
				 NodeId serverNodeId,
				 bool checksum, 
				 bool signalId,
				 key_t _shmKey,
				 Uint32 _shmSize) :
  Transporter(t_reg, tt_SHM_TRANSPORTER,
	      lHostName, rHostName, r_port, isMgmConnection_arg,
	      lNodeId, rNodeId, serverNodeId,
	      0, false, checksum, signalId, 
              4096 + MAX_SEND_MESSAGE_BYTESIZE),
  shmKey(_shmKey),
  shmSize(_shmSize)
{
#ifndef NDB_WIN32
  shmId= 0;
#endif
  _shmSegCreated = false;
  _attached = false;

  shmBuf = 0;
  reader = 0;
  writer = 0;
  
  setupBuffersDone=false;
#ifdef DEBUG_TRANSPORTER
  printf("shm key (%d - %d) = %d\n", lNodeId, rNodeId, shmKey);
#endif
  m_signal_threshold = 4096;
}


bool
SHM_Transporter::configure_derived(const TransporterConfiguration* conf)
{
  if ((key_t)conf->shm.shmKey == shmKey &&
      (int)conf->shm.shmSize == shmSize &&
      conf->shm.signum == g_ndb_shm_signum)
    return true; // No change
  return false; // Can't reconfigure
}


SHM_Transporter::~SHM_Transporter(){
  doDisconnect();
}

bool 
SHM_Transporter::initTransporter(){
  if (g_ndb_shm_signum)
    return true;
  return false;
}
    
void
SHM_Transporter::setupBuffers(){
  Uint32 sharedSize = 0;
  sharedSize += 28; //SHM_Reader::getSharedSize();
  sharedSize += 28; //SHM_Writer::getSharedSize();

  const Uint32 slack = MAX(MAX_RECV_MESSAGE_BYTESIZE,
                           MAX_SEND_MESSAGE_BYTESIZE);

  /**
   *  NOTE: There is 7th shared variable in Win2k (sharedCountAttached).
   */
  Uint32 sizeOfBuffer = shmSize;
  sizeOfBuffer -= 2*sharedSize;
  sizeOfBuffer /= 2;

  Uint32 * base1 = (Uint32*)shmBuf;

  Uint32 * sharedReadIndex1 = base1;
  Uint32 * sharedWriteIndex1 = base1 + 1;
  serverStatusFlag = base1 + 4;
  char * startOfBuf1 = shmBuf+sharedSize;

  Uint32 * base2 = (Uint32*)(shmBuf + sizeOfBuffer + sharedSize);
  Uint32 * sharedReadIndex2 = base2;
  Uint32 * sharedWriteIndex2 = base2 + 1;
  clientStatusFlag = base2 + 4;
  char * startOfBuf2 = ((char *)base2)+sharedSize;
  
  if(isServer){
    * serverStatusFlag = 0;
    reader = new SHM_Reader(startOfBuf1, 
			    sizeOfBuffer,
			    slack,
			    sharedReadIndex1,
			    sharedWriteIndex1);

    writer = new SHM_Writer(startOfBuf2, 
			    sizeOfBuffer,
			    slack,
			    sharedReadIndex2,
			    sharedWriteIndex2);

    * sharedReadIndex1 = 0;
    * sharedWriteIndex1 = 0;

    * sharedReadIndex2 = 0;
    * sharedWriteIndex2 = 0;
    
    reader->clear();
    writer->clear();
    
    * serverStatusFlag = 1;

#ifdef DEBUG_TRANSPORTER 
    printf("-- (%d - %d) - Server -\n", localNodeId, remoteNodeId);
    printf("Reader at: %ld (%p)\n", startOfBuf1 - shmBuf, startOfBuf1);
    printf("sharedReadIndex1 at %ld (%p) = %d\n", 
	   (char*)sharedReadIndex1-shmBuf, 
	   sharedReadIndex1, *sharedReadIndex1);
    printf("sharedWriteIndex1 at %ld (%p) = %d\n", 
	   (char*)sharedWriteIndex1-shmBuf, 
	   sharedWriteIndex1, *sharedWriteIndex1);

    printf("Writer at: %ld (%p)\n", startOfBuf2 - shmBuf, startOfBuf2);
    printf("sharedReadIndex2 at %ld (%p) = %d\n", 
	   (char*)sharedReadIndex2-shmBuf, 
	   sharedReadIndex2, *sharedReadIndex2);
    printf("sharedWriteIndex2 at %ld (%p) = %d\n", 
	   (char*)sharedWriteIndex2-shmBuf, 
	   sharedWriteIndex2, *sharedWriteIndex2);

    printf("sizeOfBuffer = %d\n", sizeOfBuffer);
#endif
  } else {
    * clientStatusFlag = 0;
    reader = new SHM_Reader(startOfBuf2, 
			    sizeOfBuffer,
			    slack,
			    sharedReadIndex2,
			    sharedWriteIndex2);
    
    writer = new SHM_Writer(startOfBuf1, 
			    sizeOfBuffer,
			    slack,
			    sharedReadIndex1,
			    sharedWriteIndex1);
    
    * sharedReadIndex2 = 0;
    * sharedWriteIndex1 = 0;
    
    reader->clear();
    writer->clear();
    * clientStatusFlag = 1;
#ifdef DEBUG_TRANSPORTER
    printf("-- (%d - %d) - Client -\n", localNodeId, remoteNodeId);
    printf("Reader at: %ld (%p)\n", startOfBuf2 - shmBuf, startOfBuf2);
    printf("sharedReadIndex2 at %ld (%p) = %d\n", 
	   (char*)sharedReadIndex2-shmBuf, 
	   sharedReadIndex2, *sharedReadIndex2);
    printf("sharedWriteIndex2 at %ld (%p) = %d\n", 
	   (char*)sharedWriteIndex2-shmBuf, 
	   sharedWriteIndex2, *sharedWriteIndex2);

    printf("Writer at: %ld (%p)\n", startOfBuf1 - shmBuf, startOfBuf1);
    printf("sharedReadIndex1 at %ld (%p) = %d\n", 
	   (char*)sharedReadIndex1-shmBuf, 
	   sharedReadIndex1, *sharedReadIndex1);
    printf("sharedWriteIndex1 at %ld (%p) = %d\n", 
	   (char*)sharedWriteIndex1-shmBuf, 
	   sharedWriteIndex1, *sharedWriteIndex1);
    
    printf("sizeOfBuffer = %d\n", sizeOfBuffer);
#endif
  }
#ifdef DEBUG_TRANSPORTER
  printf("Mapping from %p to %p\n", shmBuf, shmBuf+shmSize);
#endif
}

bool
SHM_Transporter::connect_server_impl(NDB_SOCKET_TYPE sockfd)
{
  DBUG_ENTER("SHM_Transporter::connect_server_impl");
  SocketOutputStream s_output(sockfd);
  SocketInputStream s_input(sockfd);
  char buf[256];

  // Create
  if(!_shmSegCreated){
    if (!ndb_shm_create()) {
      make_error_info(buf, sizeof(buf));
      report_error(TE_SHM_UNABLE_TO_CREATE_SEGMENT, buf);
      NDB_CLOSE_SOCKET(sockfd);
      DBUG_RETURN(false);
    }
    _shmSegCreated = true;
  }

  // Attach
  if(!_attached){
    if (!ndb_shm_attach()) {
      make_error_info(buf, sizeof(buf));
      report_error(TE_SHM_UNABLE_TO_ATTACH_SEGMENT, buf);
      NDB_CLOSE_SOCKET(sockfd);
      DBUG_RETURN(false);
    }
    _attached = true;
  }

  // Send ok to client
  s_output.println("shm server 1 ok: %d", 
		   m_transporter_registry.m_shm_own_pid);
  
  // Wait for ok from client
  DBUG_PRINT("info", ("Wait for ok from client"));
  if (s_input.gets(buf, sizeof(buf)) == 0) 
  {
    NDB_CLOSE_SOCKET(sockfd);
    DBUG_RETURN(false);
  }

  if(sscanf(buf, "shm client 1 ok: %d", &m_remote_pid) != 1)
  {
    NDB_CLOSE_SOCKET(sockfd);
    DBUG_RETURN(false);
  }

  int r= connect_common(sockfd);

  if (r) {
    // Send ok to client
    s_output.println("shm server 2 ok");
    // Wait for ok from client
    if (s_input.gets(buf, 256) == 0) {
      NDB_CLOSE_SOCKET(sockfd);
      DBUG_RETURN(false);
    }
    DBUG_PRINT("info", ("Successfully connected server to node %d",
                remoteNodeId)); 
  }

  NDB_CLOSE_SOCKET(sockfd);
  DBUG_RETURN(r);
}

bool
SHM_Transporter::connect_client_impl(NDB_SOCKET_TYPE sockfd)
{
  DBUG_ENTER("SHM_Transporter::connect_client_impl");
  SocketInputStream s_input(sockfd);
  SocketOutputStream s_output(sockfd);
  char buf[256];

  // Wait for server to create and attach
  DBUG_PRINT("info", ("Wait for server to create and attach"));
  if (s_input.gets(buf, 256) == 0) {
    NDB_CLOSE_SOCKET(sockfd);
    DBUG_PRINT("error", ("Server id %d did not attach",
                remoteNodeId));
    DBUG_RETURN(false);
  }

  if(sscanf(buf, "shm server 1 ok: %d", &m_remote_pid) != 1)
  {
    NDB_CLOSE_SOCKET(sockfd);
    DBUG_RETURN(false);
  }
  
  // Create
  if(!_shmSegCreated){
    if (!ndb_shm_get()) {
      NDB_CLOSE_SOCKET(sockfd);
      DBUG_PRINT("error", ("Failed create of shm seg to node %d",
                  remoteNodeId));
      DBUG_RETURN(false);
    }
    _shmSegCreated = true;
  }

  // Attach
  if(!_attached){
    if (!ndb_shm_attach()) {
      make_error_info(buf, sizeof(buf));
      report_error(TE_SHM_UNABLE_TO_ATTACH_SEGMENT, buf);
      NDB_CLOSE_SOCKET(sockfd);
      DBUG_PRINT("error", ("Failed attach of shm seg to node %d",
                  remoteNodeId));
      DBUG_RETURN(false);
    }
    _attached = true;
  }

  // Send ok to server
  s_output.println("shm client 1 ok: %d", 
		   m_transporter_registry.m_shm_own_pid);
  
  int r= connect_common(sockfd);
  
  if (r) {
    // Wait for ok from server
    DBUG_PRINT("info", ("Wait for ok from server"));
    if (s_input.gets(buf, 256) == 0) {
      NDB_CLOSE_SOCKET(sockfd);
      DBUG_PRINT("error", ("No ok from server node %d",
                  remoteNodeId));
      DBUG_RETURN(false);
    }
    // Send ok to server
    s_output.println("shm client 2 ok");
    DBUG_PRINT("info", ("Successfully connected client to node %d",
                remoteNodeId)); 
  }

  NDB_CLOSE_SOCKET(sockfd);
  DBUG_RETURN(r);
}

bool
SHM_Transporter::connect_common(NDB_SOCKET_TYPE sockfd)
{
  if (!checkConnected()) {
    return false;
  }
  
  if(!setupBuffersDone) 
  {
    setupBuffers();
    setupBuffersDone=true;
  }

  if(setupBuffersDone) 
  {
    NdbSleep_MilliSleep(m_timeOutMillis);
    if(*serverStatusFlag == 1 && *clientStatusFlag == 1)
      return true;
  }

  DBUG_PRINT("error", ("Failed to set up buffers to node %d",
              remoteNodeId));
  return false;
}

bool
SHM_Transporter::doSend()
{
  struct iovec iov[64];
  Uint32 cnt = fetch_send_iovec_data(iov, NDB_ARRAY_SIZE(iov));

  if (cnt == 0)
  {
    return false;
  }

  Uint32 sum = 0;
  for(Uint32 i = 0; i<cnt; i++)
  {
    assert(iov[i].iov_len);
    sum += iov[i].iov_len;
  }

  int nBytesSent = writer->writev(iov, cnt);

  if (nBytesSent > 0)
  {
    kill(m_remote_pid, g_ndb_shm_signum);
    iovec_data_sent(nBytesSent);

    if (Uint32(nBytesSent) == sum && (cnt != NDB_ARRAY_SIZE(iov)))
    {
      return false;
    }
    return true;
  }

  return true;
}
