tabindfile.cpp

linux下一款GIS程序源码

        {
            /*---------------------------------------------------------
             * NULL Root Node: This index has likely been deleted
             *--------------------------------------------------------*/
            poHeaderBlock->WriteZeros( 16 );
        }
    }

    /*-----------------------------------------------------------------
     * OK, we won't need the header block any more... write and free it.
     *----------------------------------------------------------------*/
    if (poHeaderBlock->CommitToFile() != 0)
        return -1;

    delete poHeaderBlock;

    return 0;
}



/**********************************************************************
 *                   TABINDFile::ValidateIndexNo()
 *
 * Private method to validate the index no parameter of some methods...
 * returns 0 if index no. is OK, or produces an error ands returns -1
 * if index no is not valid. 
 **********************************************************************/
int TABINDFile::ValidateIndexNo(int nIndexNumber)
{
    if (m_fp == NULL)
    {
        UGKError(ET_Failure, UGKErr_AssertionFailed,
                 "TABINDFile: File has not been opened yet!");
        return -1;
    }

    if (nIndexNumber < 1 || nIndexNumber > m_numIndexes ||
        m_papoIndexRootNodes == NULL || 
        m_papoIndexRootNodes[nIndexNumber-1] == NULL)
    {
        UGKError(ET_Failure, UGKErr_AssertionFailed,
                 "No field index number %d in %s: Valid range is [1..%d].",
                 nIndexNumber, m_pszFname, m_numIndexes);
        return -1;
    }

    return 0;  // Index seems valid
}




/**********************************************************************
 *                   TABINDFile::SetIndexFieldType()
 *
 * Sets the field type for the specified index.
 * This information will then be used in building the key values, etc.
 *
 * Returns 0 on success, -1 on error.
 **********************************************************************/
int TABINDFile::SetIndexFieldType(int nIndexNumber, TABFieldType eType)
{
    if (ValidateIndexNo(nIndexNumber) != 0)
        return -1;

    return m_papoIndexRootNodes[nIndexNumber-1]->SetFieldType(eType);
}


/**********************************************************************
 *                   TABINDFile::SetIndexUnique()
 *
 * Indicate that an index's keys are unique.  This allows for some 
 * optimization with read access.  By default, an index is treated as if
 * its keys could have duplicates.
 *
 * Returns 0 on success, -1 on error.
 **********************************************************************/
int TABINDFile::SetIndexUnique(int nIndexNumber, UGKBool bUnique/*=TRUE*/)
{
    if (ValidateIndexNo(nIndexNumber) != 0)
        return -1;

    m_papoIndexRootNodes[nIndexNumber-1]->SetUnique(bUnique);

    return 0;
}



/**********************************************************************
 *                   TABINDFile::BuildKey()
 *
 * Encode a field value in the form required to be compared with index
 * keys in the specified index.
 * 
 * Note that index numbers are positive values starting at 1.
 *
 * Returns a reference to an internal buffer that is valid only until the
 * next call to BuildKey().  (should not be freed by the caller).
 * Returns NULL if field index is invalid.
 *
 * The first flavour of the function handles integer type of values, this
 * corresponds to MapInfo types: integer, smallint, logical and date
 **********************************************************************/
UGKByte *TABINDFile::BuildKey(int nIndexNumber, UGKInt32 nValue)
{
    if (ValidateIndexNo(nIndexNumber) != 0)
        return NULL;

    int nKeyLength = m_papoIndexRootNodes[nIndexNumber-1]->GetKeyLength();
    
    /*-----------------------------------------------------------------
     * Convert all int values to MSB using the right number of bytes
     * Note:
     * The most significant bit has to be unset for negative values,
     * and to be set for positive ones... that's the reverse of what it
     * should usually be.  Adding 0x80 to the MSB byte will do the job.
     *----------------------------------------------------------------*/
    switch(nKeyLength)
    {
      case 1:
        m_papbyKeyBuffers[nIndexNumber-1][0] = (UGKByte)(nValue & 0xff)+0x80;
        break;
      case 2:
        m_papbyKeyBuffers[nIndexNumber-1][0] = 
                                       (UGKByte)(nValue/0x100 & 0xff)+0x80;
        m_papbyKeyBuffers[nIndexNumber-1][1] = (UGKByte)(nValue & 0xff);
        break;
      case 4:
        m_papbyKeyBuffers[nIndexNumber-1][0] = 
                                       (UGKByte)(nValue/0x1000000 &0xff)+0x80;
        m_papbyKeyBuffers[nIndexNumber-1][1] = (UGKByte)(nValue/0x10000 & 0xff);
        m_papbyKeyBuffers[nIndexNumber-1][2] = (UGKByte)(nValue/0x100 &0xff);
        m_papbyKeyBuffers[nIndexNumber-1][3] = (UGKByte)(nValue & 0xff);
        break;
      default:
        UGKError(ET_Failure, UGKErr_AssertionFailed,
                 "BuildKey(): %d bytes integer key length not supported",
                 nKeyLength);
        break;
    }

    return m_papbyKeyBuffers[nIndexNumber-1];
}


/**********************************************************************
 *                   TABINDFile::BuildKey()
 *
 * BuildKey() for string fields
 **********************************************************************/
UGKByte *TABINDFile::BuildKey(int nIndexNumber, const char *pszStr)
{
    if (ValidateIndexNo(nIndexNumber) != 0 || pszStr == NULL)
        return NULL;

    int nKeyLength = m_papoIndexRootNodes[nIndexNumber-1]->GetKeyLength();

    /*-----------------------------------------------------------------
     * Strings keys are all in uppercase, and padded with '\0'
     *----------------------------------------------------------------*/
    int i=0;
    for (i=0; i<nKeyLength && pszStr[i] != '\0'; i++)
    {
        m_papbyKeyBuffers[nIndexNumber-1][i] = (UGKByte)toupper(pszStr[i]);
    }

    /* Pad the end of the buffer with '\0' */
    for( ; i<nKeyLength; i++)
    {   
        m_papbyKeyBuffers[nIndexNumber-1][i] = '\0';
    }
        
    return m_papbyKeyBuffers[nIndexNumber-1];
}



/**********************************************************************
 *                   TABINDFile::BuildKey()
 *
 * BuildKey() for float and decimal fields
 **********************************************************************/
UGKByte *TABINDFile::BuildKey(int nIndexNumber, double dValue)
{
    if (ValidateIndexNo(nIndexNumber) != 0)
        return NULL;

    int nKeyLength = m_papoIndexRootNodes[nIndexNumber-1]->GetKeyLength();
    assert(nKeyLength == 8 && sizeof(double) == 8);

    /*-----------------------------------------------------------------
     * Convert double and decimal values... 
     * Reverse the sign of the value, and convert to MSB
     *----------------------------------------------------------------*/
    dValue = -dValue;

    memcpy(m_papbyKeyBuffers[nIndexNumber-1], (UGKByte*)(&dValue), nKeyLength);

    return m_papbyKeyBuffers[nIndexNumber-1];
}


/**********************************************************************
 *                   TABINDFile::FindFirst()
 *
 * Search one of the indexes for a key value.  
 *
 * Note that index numbers are positive values starting at 1.
 *
 * Return value:
 *  - the key's corresponding record number in the .DAT file (greater than 0)
 *  - 0 if the key was not found
 *  - or -1 if an error happened
 **********************************************************************/
UGKInt32 TABINDFile::FindFirst(int nIndexNumber, UGKByte *pKeyValue)
{
    if (ValidateIndexNo(nIndexNumber) != 0)
        return -1;

    return m_papoIndexRootNodes[nIndexNumber-1]->FindFirst(pKeyValue);
}


/**********************************************************************
 *                   TABINDFile::FindNext()
 *
 * Continue the Search for pKeyValue previously initiated by FindFirst().  
 * NOTE: FindFirst() MUST have been previously called for this call to
 *       work...
 *
 * Note that index numbers are positive values starting at 1.
 *
 * Return value:
 *  - the key's corresponding record number in the .DAT file (greater than 0)
 *  - 0 if the key was not found
 *  - or -1 if an error happened
 **********************************************************************/
UGKInt32 TABINDFile::FindNext(int nIndexNumber, UGKByte *pKeyValue)
{
    if (ValidateIndexNo(nIndexNumber) != 0)
        return -1;

    return m_papoIndexRootNodes[nIndexNumber-1]->FindNext(pKeyValue);
}



/**********************************************************************
 *                   TABINDFile::CreateIndex()
 *
 * Create a new index with the specified field type and size.
 * Field size applies only to char field type... the other types have a
 * predefined key length.
 *
 * Key length is limited to 128 chars. char fields longer than 128 chars
 * will have their key truncated to 128 bytes.
 *
 * Note that a .IND file can contain only a maximum of 29 indexes.
 *
 * Returns the new field index on success (greater than 0), or -1 on error.
 **********************************************************************/
int TABINDFile::CreateIndex(TABFieldType eType, int nFieldSize)
{
    int i, nNewIndexNo = -1;

    if (m_fp == NULL || 
        (m_eAccessMode != TABWrite && m_eAccessMode != TABReadWrite))
        return -1;

    /*-----------------------------------------------------------------
     * Look for an empty slot in the current array, if there is none
     * then extend the array.
     *----------------------------------------------------------------*/
    for(i=0; m_papoIndexRootNodes && i<m_numIndexes; i++)
    {
        if (m_papoIndexRootNodes[i] == NULL)
        {
            nNewIndexNo = i;
            break;
        }
    }

    if (nNewIndexNo == -1 && m_numIndexes >= 29)
    {
        UGKError(ET_Failure, UGKErr_AppDefined,
                 "Cannot add new index to %s.  A dataset can contain only a "
                 "maximum of 29 indexes.", m_pszFname);
        return -1;
    }

    if (nNewIndexNo == -1)
    {
        /*-------------------------------------------------------------
         * Add a slot for new index at the end of the nodes array.
         *------------------------------------------------------------*/
        m_numIndexes++;
        m_papoIndexRootNodes = (TABINDNode**)UGK_Realloc( m_papoIndexRootNodes,
                                                         m_numIndexes*
                                                         sizeof(TABINDNode*));

        m_papbyKeyBuffers = (UGKByte **)UGK_Realloc(m_papbyKeyBuffers,
                                                 m_numIndexes*sizeof(UGKByte*));

        nNewIndexNo = m_numIndexes-1;
    }

    /*-----------------------------------------------------------------
     * Alloc and init new node
     * The call to InitNode() automatically allocates storage space for
     * the node in the file.
     * New nodes are created with a subtree_depth=1 since they start as
     * leaf nodes, i.e. their entries point directly to .DAT records
     *----------------------------------------------------------------*/
    int nKeyLength = ((eType == TABFInteger)  ? 4:
                      (eType == TABFSmallInt) ? 2:
                      (eType == TABFFloat)    ? 8:
                      (eType == TABFDecimal)  ? 8:
                      (eType == TABFDate)     ? 4:
                      (eType == TABFLogical)  ? 4: MIN(128,nFieldSize));

    m_papoIndexRootNodes[nNewIndexNo] = new TABINDNode(m_eAccessMode);
    if (m_papoIndexRootNodes[nNewIndexNo]->InitNode(m_fp, 0, nKeyLength, 
                                                    1,  // subtree depth=1
                                                    FALSE, // not unique
                                                    &m_oBlockManager, 
                                                    NULL, 0, 0)!= 0)
    {
        // CPLError has already been called
        return -1;
    }

    // Alloc a temporary key buffer for this index.
    // This buffer will be used by the BuildKey() method
    m_papbyKeyBuffers[nNewIndexNo] = (UGKByte *)UGK_Calloc(nKeyLength+1,
                                                        sizeof(UGKByte));

    // Return 1-based index number
    return nNewIndexNo+1;
}



/**********************************************************************
 *                   TABINDFile::AddEntry()
 *
 * Add an .DAT record entry for pKeyValue in the specified index.
 *
 * Note that index numbers are positive values starting at 1.
 * nRecordNo is the .DAT record number, record numbers start at 1.
 *
 * Returns 0 on success, -1 on error
 **********************************************************************/
int TABINDFile::AddEntry(int nIndexNumber, UGKByte *pKeyValue, UGKInt32 nRecordNo)
{
    if ((m_eAccessMode != TABWrite && m_eAccessMode != TABReadWrite) || 
        ValidateIndexNo(nIndexNumber) != 0)
        return -1;

    return m_papoIndexRootNodes[nIndexNumber-1]->AddEntry(pKeyValue,nRecordNo);
}


/**********************************************************************
 *                   TABINDFile::Dump()
 *
 * Dump block contents... available only in DEBUG mode.
 **********************************************************************/

void TABINDFile::Dump(FILE *fpOut /*=NULL*/)
{
    if (fpOut == NULL)
        fpOut = stdout;

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

    if (m_fp == NULL)
    {
        fprintf(fpOut, "File is not opened.\n");
    }
    else
    {
        fprintf(fpOut, "File is opened: %s\n", m_pszFname);
        fprintf(fpOut, "   m_numIndexes   = %d\n", m_numIndexes);
        for(int i=0; i<m_numIndexes && m_papoIndexRootNodes; i++)
        {
            if (m_papoIndexRootNodes[i])
            {
                fprintf(fpOut, "  ----- Index # %d -----\n", i+1);
                m_papoIndexRootNodes[i]->Dump(fpOut);
            }
        }

    }

    fflush(fpOut);
}