tabrelation.cpp

linux下一款GIS程序源码

// tabrelation.cpp: implementation of the TABRelation class.
//
//////////////////////////////////////////////////////////////////////

#include "tabrelation.h"

#include "ugk_errhandle.h"
#include "ugk_memopr.h"
#include "ugk_string.h"


/**********************************************************************
 *                   TABRelation::TABRelation()
 *
 * Constructor.
 **********************************************************************/
TABRelation::TABRelation()
{
    m_poMainTable = NULL;
    m_pszMainFieldName = NULL;
    m_nMainFieldNo = -1;

    m_poRelTable = NULL;
    m_pszRelFieldName = NULL;
    m_nRelFieldNo = -1;
    m_nRelFieldIndexNo = -1;
    m_poRelINDFileRef = NULL;

    m_nUniqueRecordNo = 0;

    m_panMainTableFieldMap = NULL;
    m_panRelTableFieldMap = NULL;

    m_poDefn = NULL;
}


/**********************************************************************
 *                   TABRelation::~TABRelation()
 *
 * Destructor.
 **********************************************************************/
TABRelation::~TABRelation()
{
    ResetAllMembers();
}


/**********************************************************************
 *                   TABRelation::ResetAllMembers()
 *
 * Reset all class members.
 **********************************************************************/
void TABRelation::ResetAllMembers()
{
    m_poMainTable = NULL;
    UGK_Free(m_pszMainFieldName);
    m_pszMainFieldName = NULL;
    m_nMainFieldNo = -1;

    m_poRelTable = NULL;
    UGK_Free(m_pszRelFieldName);
    m_pszRelFieldName = NULL;
    m_nRelFieldNo = -1;
    m_nRelFieldIndexNo = -1;

    m_nUniqueRecordNo = 0;

    // No need to close m_poRelINDFileRef since we only got a ref. to it
    m_poRelINDFileRef = NULL;

    UGK_Free(m_panMainTableFieldMap);
    m_panMainTableFieldMap = NULL;
    UGK_Free(m_panRelTableFieldMap);
    m_panRelTableFieldMap = NULL;

    /*-----------------------------------------------------------------
     * Note: we have to check the reference count before deleting m_poDefn
     *----------------------------------------------------------------*/
    if (m_poDefn && m_poDefn->Dereference() == 0)
        delete m_poDefn;
    m_poDefn = NULL;

}


/**********************************************************************
 *                   TABRelation::Init()
 *
 * Set the details of the relation: the main and related tables, the fields
 * through which they will be connected, and the list of fields to select.
 * After this call, we are ready to read data records.
 *
 * For write access, Init() is called with pszMain/RelFieldName and
 * **papszSelectedFields passed as NULL.  They will have to be set through
 * other methods before a first feature can be written.
 *
 * A new UGKFeatureDefn is also built for the combined tables.
 *
 * Returns 0 on success, or -1 or error.
 **********************************************************************/
int  TABRelation::Init(const char *pszViewName,
                       TABFile *poMainTable, TABFile *poRelTable,
                       const char *pszMainFieldName,
                       const char *pszRelFieldName,
                       char **papszSelectedFields)
{
    if (poMainTable == NULL || poRelTable == NULL)
        return -1;

    // We'll need the feature Defn later...
    UGKFeatureDefn *poMainDefn, *poRelDefn;

    poMainDefn = poMainTable->GetLayerDefn();
    poRelDefn = poRelTable->GetLayerDefn();

    /*-----------------------------------------------------------------
     * Keep info for later use about source tables, etc.
     *----------------------------------------------------------------*/
    ResetAllMembers();

    m_poMainTable = poMainTable;
    if (pszMainFieldName)
    {
        m_pszMainFieldName = UGKStrdup(pszMainFieldName);
        m_nMainFieldNo = poMainDefn->GetFieldIndex(pszMainFieldName);
    }

    m_poRelTable = poRelTable;
    if (pszRelFieldName)
    {
        m_pszRelFieldName = UGKStrdup(pszRelFieldName);
        m_nRelFieldNo = poRelDefn->GetFieldIndex(pszRelFieldName);
        m_nRelFieldIndexNo = poRelTable->GetFieldIndexNumber(m_nRelFieldNo);
        m_poRelINDFileRef = poRelTable->GetINDFileRef();

        if (m_nRelFieldIndexNo >= 0 && m_poRelINDFileRef == NULL)
        {
            UGKError(ET_Failure, UGKErr_FileIO,
                      "Field %s is indexed but the .IND file is missing.",
                      pszRelFieldName);
            return -1;
        }
    }

    /*-----------------------------------------------------------------
     * Init field maps.  For each field in each table, a -1 means that
     * the field is not selected, and a value >=0 is the index of the 
     * field in the view's FeatureDefn
     *----------------------------------------------------------------*/
    int i;
    int numFields1 = (poMainDefn?poMainDefn->GetFieldCount():0);
    int numFields2 = (poRelDefn?poRelDefn->GetFieldCount():0);

    m_panMainTableFieldMap = (int*)UGK_Malloc((numFields1+1)*sizeof(int));
    for(i=0; i<numFields1; i++)
        m_panMainTableFieldMap[i] = -1;
    m_panRelTableFieldMap = (int*)UGK_Malloc((numFields2+1)*sizeof(int));
    for(i=0; i<numFields2; i++)
        m_panRelTableFieldMap[i] = -1;

    /*-----------------------------------------------------------------
     * If selectedFields = "*" then select all fields from both tables
     *----------------------------------------------------------------*/
    if (CountOfList(papszSelectedFields) == 1 && 
        EQUAL(papszSelectedFields[0], "*") )
    {
        FreeStrList(papszSelectedFields);
        papszSelectedFields = NULL;

        for(i=0; i<numFields1; i++)
        {
            UGKFieldDefn *poFieldDefn = poMainDefn->GetFieldDefn(i);

            papszSelectedFields = AddStringToList(papszSelectedFields, 
                                               poFieldDefn->GetNameRef());
        }

        for(i=0; i<numFields2; i++)
        {
            UGKFieldDefn *poFieldDefn = poRelDefn->GetFieldDefn(i);

            if (FindStrInList(papszSelectedFields, 
                              poFieldDefn->GetNameRef()) != -1)
                continue;  // Avoid duplicate field name in view

            papszSelectedFields = AddStringToList(papszSelectedFields, 
                                               poFieldDefn->GetNameRef());
        }

    }

    /*-----------------------------------------------------------------
     * Create new FeatureDefn and copy selected fields definitions
     * while updating the appropriate field maps.
     *----------------------------------------------------------------*/
    int nIndex, numSelFields = CountOfList(papszSelectedFields);
    UGKFieldDefn *poFieldDefn;

    m_poDefn = new UGKFeatureDefn(pszViewName);
    // Ref count defaults to 0... set it to 1
    m_poDefn->Reference();

    for(i=0; i<numSelFields ; i++)
    {
        if (poMainDefn &&
            (nIndex=poMainDefn->GetFieldIndex(papszSelectedFields[i])) >=0)
        {
            /* Field from the main table
             */
            poFieldDefn = poMainDefn->GetFieldDefn(nIndex);
            m_poDefn->AddFieldDefn(poFieldDefn);
            m_panMainTableFieldMap[nIndex] = m_poDefn->GetFieldCount()-1;
        }
        else if (poRelDefn &&
                 (nIndex=poRelDefn->GetFieldIndex(papszSelectedFields[i]))>=0)
        {
            /* Field from the related table
             */
            poFieldDefn = poRelDefn->GetFieldDefn(nIndex);
            m_poDefn->AddFieldDefn(poFieldDefn);
            m_panRelTableFieldMap[nIndex] = m_poDefn->GetFieldCount()-1;
        }
        else
        {
            // Hummm... field does not exist... likely an unsupported feature!
            // At least send a warning and ignore the field.
            UGKError(ET_Warning, UGKErr_IllegalArg,
                      "Selected Field %s not found in source tables %s and %s",
                      papszSelectedFields[i], 
                      poMainDefn->GetName(), poRelDefn->GetName());
        }
    }

    return 0;
}



/**********************************************************************
 *                   TABRelation::CreateRelFields()
 *
 * For write access, create the integer fields in each table that will
 * link them, and setup everything to be ready to write the first feature.
 *
 * This function should be called just before writing the first feature.
 *
 * Returns 0 on success, or -1 or error.
 **********************************************************************/
int  TABRelation::CreateRelFields()
{
    int i;

    /*-----------------------------------------------------------------
     * Create the field in each table.  
     * The default name is "MI_refnum" but if a field with the same name
     * already exists then we'll try to generate a unique name.
     *----------------------------------------------------------------*/
    m_pszMainFieldName = UGKStrdup("MI_Refnum      ");
    strcpy(m_pszMainFieldName, "MI_Refnum");
    i = 1;
    while(m_poDefn->GetFieldIndex(m_pszMainFieldName) >= 0)
    {
        sprintf(m_pszMainFieldName, "MI_Refnum_%d", i++);
    }
    m_pszRelFieldName = UGKStrdup(m_pszMainFieldName);

    m_nMainFieldNo = m_nRelFieldNo = -1;
    if (m_poMainTable->AddFieldNative(m_pszMainFieldName,
                                      TABFInteger, 0, 0) == 0)
        m_nMainFieldNo = m_poMainTable->GetLayerDefn()->GetFieldCount()-1;

    if (m_poRelTable->AddFieldNative(m_pszRelFieldName,
                                     TABFInteger, 0, 0) == 0)
        m_nRelFieldNo = m_poRelTable->GetLayerDefn()->GetFieldCount()-1;

    if (m_nMainFieldNo == -1 || m_nRelFieldNo == -1)
        return -1;

    if (m_poMainTable->SetFieldIndexed(m_nMainFieldNo) == -1)
        return -1;

    if ((m_nRelFieldIndexNo=m_poRelTable->SetFieldIndexed(m_nRelFieldNo)) ==-1)
        return -1;

    m_poRelINDFileRef = m_poRelTable->GetINDFileRef();

    /*-----------------------------------------------------------------
     * Update field maps
     *----------------------------------------------------------------*/
    UGKFeatureDefn *poMainDefn, *poRelDefn;

    poMainDefn = m_poMainTable->GetLayerDefn();
    poRelDefn = m_poRelTable->GetLayerDefn();

    m_panMainTableFieldMap = (int*)UGK_Realloc(m_panMainTableFieldMap,
                                      poMainDefn->GetFieldCount()*sizeof(int));
    m_panMainTableFieldMap[poMainDefn->GetFieldCount()-1] = -1;

    m_panRelTableFieldMap = (int*)UGK_Realloc(m_panRelTableFieldMap,
                                      poRelDefn->GetFieldCount()*sizeof(int));
    m_panRelTableFieldMap[poRelDefn->GetFieldCount()-1] = -1;

    /*-----------------------------------------------------------------
     * Make sure the first unique field (in poRelTable) is indexed since
     * it is the one against which we will try to match records.
     *----------------------------------------------------------------*/
    if ( m_poRelTable->SetFieldIndexed(0) == -1)
        return -1;

    return 0;
}


/**********************************************************************
 *                   TABRelation::GetFeature()
 *
 * Fill and return a TABFeature object for the specified feature id.
 *
 * The retuned pointer is a new TABFeature that will have to be freed
 * by the caller.
 *
 * Returns NULL if the specified feature id does not exist of if an
 * error happened.  In any case, CPLError() will have been called to
 * report the reason of the failure.
 *
 * __TODO__ The current implementation fetches the features from each table
 * and creates a 3rd feature to merge them.  There would be room for 
 * optimization, at least by avoiding the duplication of the geometry 
 * which can be big sometimes... but this would imply changes at the
 * lower-level in the lib. and we won't go there yet.
 **********************************************************************/
TABFeature *TABRelation::GetFeature(int nFeatureId)
{
    TABFeature *poMainFeature;
    TABFeature *poCurFeature;

    /*-----------------------------------------------------------------
     * Make sure init() has been called
     *----------------------------------------------------------------*/
    if (m_poMainTable == NULL || m_poRelTable == NULL)
    {
        UGKError(ET_Failure, UGKErr_IllegalArg,
                  "GetFeatureRef() failed: object not initialized yet!");
        return NULL;
    }

    /*-----------------------------------------------------------------
     * Read main feature and create a new one of the right type
     *----------------------------------------------------------------*/
    if ((poMainFeature = m_poMainTable->GetFeatureRef(nFeatureId)) == NULL)
    {
        // Feature cannot be read from main table... 
        // an error has already been reported.
        return NULL;
    }

    poCurFeature = poMainFeature->CloneTABFeature(m_poDefn);

    /*-----------------------------------------------------------------
     * Keep track of FID and copy the geometry 
     *----------------------------------------------------------------*/
    poCurFeature->SetFID(nFeatureId);

    if (poCurFeature->GetFeatureClass() != TABFCNoGeomFeature)
    {
        UGKGeometry *poGeom;
        poGeom = poMainFeature->GetGeometryRef();
        poCurFeature->SetGeometry(poGeom);
    }

    /*-----------------------------------------------------------------
     * Fetch feature from related table
     *
     * __TODO__ Right now we support only many-to-1 relationships, but
     *          it might be possible to have several related entries
     *          for a single key, and in this case we should return
     *          one new feature for each of them.
     *----------------------------------------------------------------*/
    TABFeature *poRelFeature=NULL;
    UGKByte *pKey = BuildFieldKey(poMainFeature, m_nMainFieldNo,
                            m_poMainTable->GetNativeFieldType(m_nMainFieldNo),
                                m_nRelFieldIndexNo);
    int i;
    int nRelFeatureId = m_poRelINDFileRef->FindFirst(m_nRelFieldIndexNo, pKey);
    
    if (nRelFeatureId > 0)
        poRelFeature = m_poRelTable->GetFeatureRef(nRelFeatureId);

    /*-----------------------------------------------------------------
     * Copy fields from poMainFeature
     *----------------------------------------------------------------*/
    for(i=0; i<poMainFeature->GetFieldCount(); i++)
    {
        if (m_panMainTableFieldMap[i] != -1)
        {
            poCurFeature->SetField(m_panMainTableFieldMap[i], 
                                     poMainFeature->GetRawFieldRef(i));
        }
    }

    /*-----------------------------------------------------------------
     * Copy fields from poRelFeature...
     *
     * NOTE: For now, if no corresponding feature is found in RelTable
     *       then we will just leave the corresponding fields unset.
     *----------------------------------------------------------------*/
    for(i=0; poRelFeature && i<poRelFeature->GetFieldCount(); i++)
    {
        if (m_panRelTableFieldMap[i] != -1)
        {
            poCurFeature->SetField(m_panRelTableFieldMap[i], 
                                     poRelFeature->GetRawFieldRef(i));
        }
    }

    return poCurFeature;
}


/**********************************************************************
 *                   TABRelation::BuildFieldKey()