avc_e00read.c

用于读取TAB、MIF、SHP文件的类

     *----------------------------------------------------------------*/
    nCoverPrecision = _AVCE00ReadBuildSqueleton(psInfo, papszCoverDir);

    /* Ignore warnings produced while building squeleton */
    CPLErrorReset();

    CSLDestroy(papszCoverDir);
    papszCoverDir = NULL;

    psInfo->iCurSection = 0;
    psInfo->iCurStep = AVC_GEN_NOTSTARTED;
    psInfo->bReadAllSections = TRUE;

    /*-----------------------------------------------------------------
     * Init the E00 generator.
     *----------------------------------------------------------------*/
    psInfo->hGenInfo = AVCE00GenInfoAlloc(nCoverPrecision);

    /*-----------------------------------------------------------------
     * Init multibyte encoding info
     *----------------------------------------------------------------*/
    psInfo->psDBCSInfo = AVCAllocDBCSInfo();

    /*-----------------------------------------------------------------
     * If an error happened during the open call, cleanup and return NULL.
     *----------------------------------------------------------------*/
    if (CPLGetLastErrorNo() != 0)
    {
        AVCE00ReadClose(psInfo);
        psInfo = NULL;
    }

    return psInfo;
}

/**********************************************************************
 *                          AVCE00ReadOpenE00()
 *
 * Open a E00 file for reading.
 *
 * Returns a new AVCE00ReadE00Ptr handle or NULL if the file could
 * not be opened or if it does not appear to be a valid E00 file.
 *
 * The handle will eventually have to be released with
 * AVCE00ReadCloseE00().
 **********************************************************************/
AVCE00ReadE00Ptr AVCE00ReadOpenE00(const char *pszE00FileName)
{
    AVCE00ReadE00Ptr psRead;
    VSIStatBuf       sStatBuf;
    FILE             *fp;
    char             *p;

    CPLErrorReset();

    /*-----------------------------------------------------------------
     * pszE00FileName must be a valid file that can be opened for
     * reading
     *----------------------------------------------------------------*/
    if (pszE00FileName == NULL || strlen(pszE00FileName) == 0 ||
        VSIStat(pszE00FileName, &sStatBuf) == -1 ||
        VSI_ISDIR(sStatBuf.st_mode))
    {
        CPLError(CE_Failure, CPLE_OpenFailed, 
                 "Invalid E00 file path: %s.", 
                 pszE00FileName?pszE00FileName:"(NULL)");
        return NULL;
    }

    if (NULL == (fp = fopen(pszE00FileName, "r")))
        return NULL;

    /*-----------------------------------------------------------------
     * Alloc the AVCE00ReadE00Ptr handle
     *----------------------------------------------------------------*/
    psRead = (AVCE00ReadE00Ptr)CPLCalloc(1,
            sizeof(struct AVCE00ReadInfoE00_t));

    psRead->hFile = fp;
    psRead->pszCoverPath = CPLStrdup(pszE00FileName);
    psRead->eCurFileType = AVCFileUnknown;

    /*-----------------------------------------------------------------
     * Extract the coverage name from the coverage path.
     *----------------------------------------------------------------*/
    if (NULL != (p = strrchr(psRead->pszCoverPath, '/')) ||
        NULL != (p = strrchr(psRead->pszCoverPath, '\\')) ||
        NULL != (p = strrchr(psRead->pszCoverPath, ':')))
    {
        psRead->pszCoverName = CPLStrdup(p + 1);
    }
    else
    {
        psRead->pszCoverName = CPLStrdup(psRead->pszCoverPath);
    }
    if (NULL != (p = strrchr(psRead->pszCoverName, '.')))
    {
        *p = '\0';
    }

    /*-----------------------------------------------------------------
     * Make sure there was no error until now before we scan file.
     *----------------------------------------------------------------*/
    if (CPLGetLastErrorNo() != 0)
    {
        AVCE00ReadCloseE00(psRead);
        return NULL;
    }

    psRead->hParseInfo = AVCE00ParseInfoAlloc();

    /*-----------------------------------------------------------------
     * Scan the E00 file for sections
     *----------------------------------------------------------------*/
    _AVCE00ReadScanE00(psRead);
    AVCE00ReadRewindE00(psRead);
    CPLErrorReset();

    if (psRead->numSections < 1)
    {
        AVCE00ReadCloseE00(psRead);
        return NULL;
    }

    psRead->bReadAllSections = TRUE;

    /*-----------------------------------------------------------------
     * If an error happened during the open call, cleanup and return NULL.
     *----------------------------------------------------------------*/
    if (CPLGetLastErrorNo() != 0)
    {
        AVCE00ReadCloseE00(psRead);
        psRead = NULL;
    }

    return psRead;
}

/**********************************************************************
 *                          AVCE00ReadClose()
 *
 * Close a coverage and release all memory used by the AVCE00ReadPtr
 * handle.
 **********************************************************************/
void AVCE00ReadClose(AVCE00ReadPtr psInfo)
{
    CPLErrorReset();

    if (psInfo == NULL)
        return;

    CPLFree(psInfo->pszCoverPath);
    CPLFree(psInfo->pszInfoPath);
    CPLFree(psInfo->pszCoverName);

    if (psInfo->hFile)
        AVCBinReadClose(psInfo->hFile);

    if (psInfo->hGenInfo)
        AVCE00GenInfoFree(psInfo->hGenInfo);

    if (psInfo->pasSections)
    {
        int i;
        for(i=0; i<psInfo->numSections; i++)
        {
            CPLFree(psInfo->pasSections[i].pszName);
            CPLFree(psInfo->pasSections[i].pszFilename);
        }
        CPLFree(psInfo->pasSections);
    }

    AVCFreeDBCSInfo(psInfo->psDBCSInfo);

    CPLFree(psInfo);
}

/**********************************************************************
 *                          AVCE00ReadCloseE00()
 *
 * Close a coverage and release all memory used by the AVCE00ReadE00Ptr
 * handle.
 **********************************************************************/
void AVCE00ReadCloseE00(AVCE00ReadE00Ptr psRead)
{
    CPLErrorReset();

    if (psRead == NULL)
        return;

    CPLFree(psRead->pszCoverPath);
    CPLFree(psRead->pszCoverName);

    if (psRead->hFile)
    {
        fclose(psRead->hFile);
        psRead->hFile = 0;
    }

    if (psRead->pasSections)
    {
        int i;
        for(i=0; i<psRead->numSections; i++)
        {
            CPLFree(psRead->pasSections[i].pszName);
            CPLFree(psRead->pasSections[i].pszFilename);
        }
        CPLFree(psRead->pasSections);
    }

    /* These Free calls handle NULL's */
    AVCE00ParseInfoFree(psRead->hParseInfo);
    psRead->hParseInfo = NULL;

    CPLFree(psRead);
}


/**********************************************************************
 *                          _AVCIncreaseSectionsArray()
 *
 * Add a number of structures to the Sections array and return the
 * index of the first one that was added.  Note that the address of the
 * original array (*pasArray) is quite likely to change!
 *
 * The value of *pnumItems will be updated to reflect the new array size.
 **********************************************************************/
static int _AVCIncreaseSectionsArray(AVCE00Section **pasArray, int *pnumItems,
                                    int numToAdd)
{
    int i;

    *pasArray = (AVCE00Section*)CPLRealloc(*pasArray, 
                                           (*pnumItems+numToAdd)*
                                                    sizeof(AVCE00Section));

    for(i=0; i<numToAdd; i++)
    {
        (*pasArray)[*pnumItems+i].eType = AVCFileUnknown;
        (*pasArray)[*pnumItems+i].pszName = NULL;
        (*pasArray)[*pnumItems+i].pszFilename = NULL;
        (*pasArray)[*pnumItems+i].nLineNum = 0;
        (*pasArray)[*pnumItems+i].nFeatureCount = -1;
    }

    i = *pnumItems;
    (*pnumItems) += numToAdd;

    return i;
}

/**********************************************************************
 *                         _AVCE00ReadFindCoverType()
 *
 * This functions tries to establish the coverage type by looking
 * at the coverage directory listing passed as argument.
 *
 * Returns one of AVCCoverV7 for Arc/Info V7 (Unix) coverages, or
 *                AVCCoverPC for PC Arc/Info coverages.
 *                AVCCoverWeird for an hybrid between V7 and PC
 *
 * If coverage type cannot be established then AVCCoverTypeUnknown is 
 * returned.
 **********************************************************************/
static AVCCoverType _AVCE00ReadFindCoverType(char **papszCoverDir)
{
    int         i, nLen;
    GBool       bFoundAdfFile=FALSE, bFoundArcFile=FALSE, 
                bFoundTableFile=FALSE, bFoundDbfFile=FALSE;

    /*-----------------------------------------------------------------
     * Scan the list of files, looking for well known filenames.
     * Start with the funky types first...
     *----------------------------------------------------------------*/
    for(i=0; papszCoverDir && papszCoverDir[i]; i++)
    {
        nLen = strlen(papszCoverDir[i]);
        if (nLen > 4 && EQUAL(papszCoverDir[i]+nLen-4, ".adf") )
        {
            bFoundAdfFile = TRUE;
        }
        else if (nLen > 4 && EQUAL(papszCoverDir[i]+nLen-4, ".dbf") )
        {
            bFoundDbfFile = TRUE;
        }
        else if (EQUAL(papszCoverDir[i], "arc") ||
                 EQUAL(papszCoverDir[i], "cnt") ||
                 EQUAL(papszCoverDir[i], "pal") ||
                 EQUAL(papszCoverDir[i], "lab") ||
                 EQUAL(papszCoverDir[i], "prj") ||
                 EQUAL(papszCoverDir[i], "tol") )
        {
            bFoundArcFile = TRUE;
        }
        else if (EQUAL(papszCoverDir[i], "aat") ||
                 EQUAL(papszCoverDir[i], "pat") ||
                 EQUAL(papszCoverDir[i], "bnd") ||
                 EQUAL(papszCoverDir[i], "tic") )
        {
            bFoundTableFile = TRUE;
        }

    }

    /*-----------------------------------------------------------------
     * Check for PC Arc/Info coverage - variant 1.
     * These PC coverages have files with no extension (e.g. "ARC","PAL",...)
     * and their tables filenames are in the form "???.dbf"
     *----------------------------------------------------------------*/
    if (bFoundArcFile && bFoundDbfFile)
        return AVCCoverPC;

    /*-----------------------------------------------------------------
     * Check for PC Arc/Info coverage - variant 2.
     * looks like a hybrid between AVCCoverPC and AVCCoverV7
     * These PC coverages have files with .adf extension (e.g."ARC.ADF"),
     * and their tables filenames are in the form "???.dbf"
     *----------------------------------------------------------------*/
    if (bFoundAdfFile && bFoundDbfFile)
        return AVCCoverPC2;

    /*-----------------------------------------------------------------
     * Check for the weird coverages.
     * Their coverage files have no extension just like PC Coverages, 
     * and their tables have 3 letters filenames with no extension
     * either (e.g. "AAT", "PAT", etc.)
     * They also have a ../info directory, but we don't really need
     * to check that (not yet!).