tabindnode.cpp

linux下一款GIS程序源码

                return -1;
            }
            delete poTmpNode;
        }

        m_nPrevNodePtr = poNewNode->GetNodeBlockPtr();

        // Move half the entries to the new block
        m_poDataBlock->GotoByteInBlock(12 + 0);

        if (poNewNode->SetNodeBufferDirectly(numInNode1, 
                                        m_poDataBlock->GetCurDataPtr()) != 0)
            return -1;

        // Shift the second half of the entries to beginning of buffer
        memmove (m_poDataBlock->GetCurDataPtr(),
                 m_poDataBlock->GetCurDataPtr()+numInNode1*(m_nKeyLength+4),
                 numInNode2*(m_nKeyLength+4));

#ifdef DEBUG
        // Just in case, reset space previously used by moved entries
        memset(m_poDataBlock->GetCurDataPtr()+numInNode2*(m_nKeyLength+4),
               0, numInNode1*(m_nKeyLength+4));
#endif

        // And update current node members
        m_numEntriesInNode = numInNode2;
        m_nCurIndexEntry -= numInNode1;

        // Update parent node with new children info
        if (m_poParentNodeRef)
        {
            if (m_poParentNodeRef->UpdateSplitChild(poNewNode->GetNodeKey(),
                                                  poNewNode->GetNodeBlockPtr(),
                                                    GetNodeKey(),
                                                    GetNodeBlockPtr(), 2) != 0)
                return -1;
        }

    }

    /*-----------------------------------------------------------------
     * Update current node header
     *----------------------------------------------------------------*/
    m_poDataBlock->GotoByteInBlock(0);
    m_poDataBlock->WriteInt32(m_numEntriesInNode);
    m_poDataBlock->WriteInt32(m_nPrevNodePtr);
    m_poDataBlock->WriteInt32(m_nNextNodePtr);

    /*-----------------------------------------------------------------
     * Flush and destroy temporary node
     *----------------------------------------------------------------*/
    if (poNewNode->CommitToFile() != 0)
        return -1;

    delete poNewNode;

    return 0;
}


/**********************************************************************
 *                   TABINDNode::SplitRootNode()
 *
 * (private method)
 *
 * Split a Root Node.
 * First, a level of nodes must be added to the tree, then the contents
 * of what used to be the root node is moved 1 level down and then that
 * node is split like a regular node.
 *
 * Returns 0 on success, -1 on error
 **********************************************************************/
int TABINDNode::SplitRootNode()
{
    /*-----------------------------------------------------------------
     * Since a root note cannot be split, we add a level of nodes
     * under it and we'll do the split at that level.
     *----------------------------------------------------------------*/
    TABINDNode *poNewNode = new TABINDNode(m_eAccessMode);

    if (poNewNode->InitNode(m_fp, 0, m_nKeyLength, 
                            m_nSubTreeDepth, m_bUnique, m_poBlockManagerRef, 
                            this, 0, 0)!= 0 ||
        poNewNode->SetFieldType(m_eFieldType) != 0)
    {
        return -1;
    }

    // Move all entries to the new child
    m_poDataBlock->GotoByteInBlock(12 + 0);
    if (poNewNode->SetNodeBufferDirectly(m_numEntriesInNode, 
                                         m_poDataBlock->GetCurDataPtr(),
                                         m_nCurIndexEntry,
                                         m_poCurChildNode) != 0)
    {
        return -1;
    }

#ifdef DEBUG
    // Just in case, reset space previously used by moved entries
    memset(m_poDataBlock->GetCurDataPtr(), 0,
           m_numEntriesInNode*(m_nKeyLength+4));
#endif

    /*-----------------------------------------------------------------
     * Rewrite current node. (the new root node)
     *----------------------------------------------------------------*/
    m_numEntriesInNode = 0;
    m_nSubTreeDepth++;

    m_poDataBlock->GotoByteInBlock(0);
    m_poDataBlock->WriteInt32(m_numEntriesInNode);

    InsertEntry(poNewNode->GetNodeKey(), poNewNode->GetNodeBlockPtr());

    /*-----------------------------------------------------------------
     * Keep a reference to the new child
     *----------------------------------------------------------------*/
    m_poCurChildNode = poNewNode;
    m_nCurIndexEntry = 0;

    /*-----------------------------------------------------------------
     * And finally force the child to split itself
     *----------------------------------------------------------------*/
    return m_poCurChildNode->SplitNode();
}



/**********************************************************************
 *                   TABINDNode::SetNodeBufferDirectly()
 *
 * (private method)
 *
 * Set the key/value part of the nodes buffer and the pointers to the
 * current child direclty.  This is used when copying info to a new node
 * in SplitNode() and SplitRootNode()
 *
 * Returns 0 on success, -1 on error
 **********************************************************************/
int TABINDNode::SetNodeBufferDirectly(int numEntries, UGKByte *pBuf,
                                      int nCurIndexEntry/*=0*/, 
                                      TABINDNode *poCurChild/*=NULL*/)
{
    m_poDataBlock->GotoByteInBlock(0);
    m_poDataBlock->WriteInt32(numEntries);

    m_numEntriesInNode = numEntries;

    m_poDataBlock->GotoByteInBlock(12);
    if ( m_poDataBlock->WriteBytes(numEntries*(m_nKeyLength+4), pBuf) != 0)
    {
        return -1; // An error msg should have been reported already
    }

    m_nCurIndexEntry = nCurIndexEntry;
    m_poCurChildNode = poCurChild;
    if (m_poCurChildNode)
        m_poCurChildNode->m_poParentNodeRef = this;

    return 0;
}


/**********************************************************************
 *                   TABINDNode::GetNodeKey()
 *
 * Returns a reference to the key for the first entry in the node, which
 * is also the key for this node at the level above it in the tree.
 *
 * Returns NULL if node is empty.
 **********************************************************************/
UGKByte* TABINDNode::GetNodeKey()
{
    if (m_poDataBlock == NULL || m_numEntriesInNode == 0)
        return NULL;

    m_poDataBlock->GotoByteInBlock(12);

    return m_poDataBlock->GetCurDataPtr();
}



/**********************************************************************
 *                   TABINDNode::SetPrevNodePtr()
 *
 * Update the m_nPrevNodePtr member.
 *
 * Returns 0 on success, -1 on error.
 **********************************************************************/
int TABINDNode::SetPrevNodePtr(UGKInt32 nPrevNodePtr)
{
    if ((m_eAccessMode != TABWrite && m_eAccessMode != TABReadWrite) ||
        m_poDataBlock == NULL)
        return -1;

    if (m_nPrevNodePtr == nPrevNodePtr)
        return 0;  // Nothing to do.

    m_poDataBlock->GotoByteInBlock(4);
    return m_poDataBlock->WriteInt32(nPrevNodePtr);
}


/**********************************************************************
 *                   TABINDNode::SetNextNodePtr()
 *
 * Update the m_nNextNodePtr member.
 *
 * Returns 0 on success, -1 on error.
 **********************************************************************/
int TABINDNode::SetNextNodePtr(UGKInt32 nNextNodePtr)
{
    if ((m_eAccessMode != TABWrite && m_eAccessMode != TABReadWrite) ||
        m_poDataBlock == NULL)
        return -1;

    if (m_nNextNodePtr == nNextNodePtr)
        return 0;  // Nothing to do.

    m_poDataBlock->GotoByteInBlock(8);
    return m_poDataBlock->WriteInt32(nNextNodePtr);
}



/**********************************************************************
 *                   TABINDNode::Dump()
 *
 * Dump block contents... available only in DEBUG mode.
 **********************************************************************/
void TABINDNode::Dump(FILE *fpOut /*=NULL*/)
{
    if (fpOut == NULL)
        fpOut = stdout;

    fprintf(fpOut, "----- TABINDNode::Dump() -----\n");

    if (m_fp == NULL)
    {
        fprintf(fpOut, "Node is not initialized.\n");
    }
    else
    {
        fprintf(fpOut, "   m_numEntriesInNode   = %d\n", m_numEntriesInNode);
        fprintf(fpOut, "   m_nCurDataBlockPtr   = %d\n", m_nCurDataBlockPtr);
        fprintf(fpOut, "   m_nPrevNodePtr       = %d\n", m_nPrevNodePtr);
        fprintf(fpOut, "   m_nNextNodePtr       = %d\n", m_nNextNodePtr);
        fprintf(fpOut, "   m_nSubTreeDepth      = %d\n", m_nSubTreeDepth);
        fprintf(fpOut, "   m_nKeyLength         = %d\n", m_nKeyLength);
        fprintf(fpOut, "   m_eFieldtype         = %s\n", 
                                        TABFIELDTYPE_2_STRING(m_eFieldType) );
        if (m_nSubTreeDepth > 0)
        {
            UGKByte  aKeyValBuf[255];
            UGKInt32 nRecordPtr, nValue;
            TABINDNode oChildNode;

            if (m_nKeyLength > 254)
            {
                UGKError(ET_Failure, UGKErr_NotSupported,
                          "Dump() cannot handle keys longer than 254 chars.");
                return;
            }

            fprintf(fpOut, "\n");
            for (int i=0; i<m_numEntriesInNode; i++)
            {
              if (m_nSubTreeDepth > 1)
              {
                fprintf(fpOut, "   >>>> Child %d of %d <<<<<\n", i, 
                                                         m_numEntriesInNode);
              }
              else
              {
                fprintf(fpOut, "   >>>> Record (leaf) %d of %d <<<<<\n", i, 
                                                         m_numEntriesInNode);
              }

              if (m_eFieldType == TABFChar)
              {
                  nRecordPtr = ReadIndexEntry(i, aKeyValBuf);
                  fprintf(fpOut, "   nRecordPtr = %d\n", nRecordPtr);
                  fprintf(fpOut, "   Char Val= \"%s\"\n", (char*)aKeyValBuf);
              }
              else if (m_nKeyLength != 4)
              {
                nRecordPtr = ReadIndexEntry(i, aKeyValBuf);
                fprintf(fpOut, "   nRecordPtr = %d\n", nRecordPtr);
                fprintf(fpOut, "   Int Value = %d\n", *(UGKInt32*)aKeyValBuf);
                fprintf(fpOut, "   Int16 Val= %d\n",*(UGKInt16*)(aKeyValBuf+2));
                fprintf(fpOut, "   Hex Val= 0x%8.8x\n",*(UGKUInt32*)aKeyValBuf);
              }
              else
              {
                nRecordPtr = ReadIndexEntry(i, (UGKByte*)&nValue);
                fprintf(fpOut, "   nRecordPtr = %d\n", nRecordPtr);
                fprintf(fpOut, "   Int Value = %d\n", nValue);
                fprintf(fpOut, "   Hex Value = 0x%8.8x\n",nValue);
              }

              if (m_nSubTreeDepth > 1)
              {
                oChildNode.InitNode(m_fp, nRecordPtr, m_nKeyLength, 
                                    m_nSubTreeDepth - 1, FALSE);
                oChildNode.SetFieldType(m_eFieldType);
                oChildNode.Dump(fpOut);
              }
            }
        }
    }

    fflush(fpOut);
}