Difficulties adjusting to different versions of HDFEOS2 library for HDF4 files

[captainkirk99]

The HDFEOS2 library is for NASA HDF4 files, like MODIS.

As discussed in this issue (SpatioTemporal/STAREmaster#111), there are two different versions of HDFEOS2 that should be accomodated, 2.19 and 2.20. Unfortunately there is some const changes which interact badly with the hdf4_handler file HDFEOS2.cc.

In HDFEOS2.cc there is code that passes some of the HDFEOS2 functions as function pointers to a function that calls the HDFEOS2 function. For example:

    vector<string> gridlist;
    if (!Utility::ReadNamelist(file->path.c_str(), GDinqgrid, gridlist)) {
        delete file;
        throw1("Grid ReadNamelist failed.");
    }

This is calling the Utility::ReadNamelist() function, which is also in HDFEOS2.cc:

// Read name list from the EOS2 APIs and store names into a vector
bool Utility::ReadNamelist(const char *path,
                           int32 (*inq)(const char *, char *, int32 *),
                           vector<string> &names)
{
    char *fname = const_cast<char *>(path);
    int32 bufsize;
    int numobjs;

    if ((numobjs = inq(fname, NULL, &bufsize)) == -1) return false;
    if (numobjs > 0) {
        vector<char> buffer;
        buffer.resize(bufsize + 1);
        if (inq(fname, &buffer[0], &bufsize) == -1) return false;
        HDFCFUtil::Split(&buffer[0], bufsize, ',', names);
    }
    return true;
}

Note that the second (unnamed) parameter to ReadNamelis() is a function pointer.

This ReadNamelist function is called only 3 times, for functions GDinqgrid(), SWinqswath(), and PTinqpoint().

The challenge here is that one of these functions, SWinqswath(), has a different first parameter in 2.19 and 2.20. In 2.20 it adds a const.

[jgallagher59701]

On Mon, Dec 7, 2020 at 7:03 AM Captain James Tiberius Kirk < ***@***.***> wrote: The HDFEOS2 library is for NASA HDF4 files, like MODIS. As discussed in this issue (SpatioTemporal/STAREmaster#111 <SpatioTemporal/STAREmaster#111>), there are two different versions of HDFEOS2 that should be accomodated, 2.19 and 2.20.

We should not support 2.20 according to THG. Kent told me that release should be ignored. So we don't need to support both; just 2.19. James

…

Unfortunately there is some const changes which interact badly with the hdf4_handler file HDFEOS2.cc. In HDFEOS2.cc there is code that passes some of the HDFEOS2 functions as function pointers to a function that calls the HDFEOS2 function. For example: vector<string> gridlist; if (!Utility::ReadNamelist(file->path.c_str(), GDinqgrid, gridlist)) { delete file; throw1("Grid ReadNamelist failed."); } This is calling the Utility::ReadNamelist() function, which is also in HDFEOS2.cc: // Read name list from the EOS2 APIs and store names into a vector bool Utility::ReadNamelist(const char *path, int32 (*inq)(const char *, char *, int32 *), vector<string> &names) { char *fname = const_cast<char *>(path); int32 bufsize; int numobjs; if ((numobjs = inq(fname, NULL, &bufsize)) == -1) return false; if (numobjs > 0) { vector<char> buffer; buffer.resize(bufsize + 1); if (inq(fname, &buffer[0], &bufsize) == -1) return false; HDFCFUtil::Split(&buffer[0], bufsize, ',', names); } return true; } Note that the second (unnamed) parameter to ReadNamelis() is a function pointer. This ReadNamelist function is called only 3 times, for functions GDinqgrid(), SWinqswath(), and PTinqpoint(). The challenge here is that one of these functions, SWinqswath(), has a different first parameter in 2.19 and 2.20. In 2.20 it adds a const. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#447>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AB7Q4KTP6W6VO5ASLBCC76TSTTOBVANCNFSM4UQQBF2Q> .

-- -- James Gallagher jgalagher@opendap.org

[captainkirk99]

OK, roger that!