GeoTiffTransmitter.cc

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// GeoTiffTransmitter.cc

// This file is part of BES GDAL File Out Module

// Copyright (c) 2012 OPeNDAP, Inc.
// Author: James Gallagher <jgallagher@opendap.org>
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
//
// You can contact University Corporation for Atmospheric Research at
// 3080 Center Green Drive, Boulder, CO 80301

#include "config.h"

#include <unistd.h>

#include <cstdio>
#include <cstdlib>

#include <sys/types.h>                  // For umask
#include <sys/stat.h>

#include <iostream>
#include <fstream>

#include <DataDDS.h>
#include <BaseType.h>
#include <escaping.h>

using namespace libdap;

#include "GeoTiffTransmitter.h"
#include "FONgTransform.h"

#include <BESInternalError.h>
#include <BESContextManager.h>
#include <BESDataDDSResponse.h>
#include <BESDapNames.h>
#include <BESDataNames.h>
#include <BESDebug.h>

#include <TheBESKeys.h>

#define FONG_TEMP_DIR "/tmp"
#define FONG_GCS "WGS84"

string GeoTiffTransmitter::temp_dir;
string GeoTiffTransmitter::default_gcs;

GeoTiffTransmitter::GeoTiffTransmitter() :  BESBasicTransmitter()
{
    // DATA_SERVICE == "dods"
    add_method(DATA_SERVICE, GeoTiffTransmitter::send_data_as_geotiff);

    if (GeoTiffTransmitter::temp_dir.empty()) {
        // Where is the temp directory for creating these files
        bool found = false;
        string key = "FONg.Tempdir";
        TheBESKeys::TheKeys()->get_value(key, GeoTiffTransmitter::temp_dir, found);
        if (!found || GeoTiffTransmitter::temp_dir.empty()) {
            GeoTiffTransmitter::temp_dir = FONG_TEMP_DIR;
        }
        string::size_type len = GeoTiffTransmitter::temp_dir.length();
        if (GeoTiffTransmitter::temp_dir[len - 1] == '/') {
            GeoTiffTransmitter::temp_dir = GeoTiffTransmitter::temp_dir.substr(0, len - 1);
        }
    }

    if (GeoTiffTransmitter::default_gcs.empty()) {
        // Use what as the default Geographic coordinate system?
        bool found = false;
        string key = "FONg.Default_GCS";
        TheBESKeys::TheKeys()->get_value(key, GeoTiffTransmitter::default_gcs, found);
        if (!found || GeoTiffTransmitter::default_gcs.empty()) {
            GeoTiffTransmitter::default_gcs = FONG_GCS;
        }
    }
}

void GeoTiffTransmitter::send_data_as_geotiff(BESResponseObject *obj, BESDataHandlerInterface &dhi)
{
    BESDataDDSResponse *bdds = dynamic_cast<BESDataDDSResponse *>(obj);
    if (!bdds)
        throw BESInternalError("cast error", __FILE__, __LINE__);

    DataDDS *dds = bdds->get_dds();
    if (!dds)
        throw BESInternalError("No DataDDS has been created for transmit", __FILE__, __LINE__);

    ostream &strm = dhi.get_output_stream();
    if (!strm)
        throw BESInternalError("Output stream is not set, cannot return as", __FILE__, __LINE__);

    BESDEBUG("fong2", "GeoTiffTransmitter::send_data - parsing the constraint" << endl);

    // ticket 1248 jhrg 2/23/09
    string ce = www2id(dhi.data[POST_CONSTRAINT], "%", "%20%26");
    try {
        bdds->get_ce().parse_constraint(ce, *dds);
    }
    catch (Error &e) {
        throw BESInternalError("Failed to parse the constraint expression: " + e.get_error_message(), __FILE__, __LINE__);
    }
    catch (...) {
        throw BESInternalError("Failed to parse the constraint expression: Unknown exception caught", __FILE__, __LINE__);
    }

    // now we need to read the data
    BESDEBUG("fong2", "GeoTiffTransmitter::send_data - reading data into DataDDS" << endl);

    try {
        // Handle *functional* constraint expressions specially
        if (bdds->get_ce().function_clauses()) {
            BESDEBUG("fonc", "processing a functional constraint clause(s)." << endl);
            DataDDS *tmp_dds = bdds->get_ce().eval_function_clauses(*dds);
            bdds->set_dds(tmp_dds);
            delete dds;
            dds = tmp_dds;
        }
        else {
            // Iterate through the variables in the DataDDS and read
            // in the data if the variable has the send flag set.
            for (DDS::Vars_iter i = dds->var_begin(); i != dds->var_end(); i++) {
                if ((*i)->send_p()) {
                    (*i)->intern_data(bdds->get_ce(), *dds);
                }
            }
        }
    }
    catch (Error &e) {
        throw BESInternalError("Failed to read data: " + e.get_error_message(), __FILE__, __LINE__);
    }
    catch (...) {
        throw BESInternalError("Failed to read data: Unknown exception caught", __FILE__, __LINE__);
    }

    // Huh? Put the template for the temp file name in a char array. Use vector<char>
    // to avoid using new/delete.
    string temp_file_name = GeoTiffTransmitter::temp_dir + '/' + "geotiffXXXXXX";
    vector<char> temp_file(temp_file_name.length() + 1);
    string::size_type len = temp_file_name.copy(&temp_file[0], temp_file_name.length());
    temp_file[len] = '\0';

    // cover the case where older versions of mkstemp() create the file using
    // a mode of 666.
    mode_t original_mode = umask(077);

    // Make and open (an atomic operation) the temporary file. Then reset the umask
    int fd = mkstemp(&temp_file[0]);
    umask(original_mode);

    if (fd == -1)
        throw BESInternalError("Failed to open the temporary file: " + temp_file_name, __FILE__, __LINE__);

    // transform the OPeNDAP DataDDS to the geotiff file
    BESDEBUG("fong2", "GeoTiffTransmitter::send_data - transforming into temporary file " << &temp_file[0] << endl);

    try {
        FONgTransform ft(dds, bdds->get_ce(), &temp_file[0]);

        // transform() opens the temporary file, dumps data to it and closes it.
        ft.transform_to_geotiff();

        BESDEBUG("fong2", "GeoTiffTransmitter::send_data - transmitting temp file " << &temp_file[0] << endl );

        GeoTiffTransmitter::return_temp_stream(&temp_file[0], strm);
    }
    catch (BESError &e) {
        close(fd);
        (void) unlink(&temp_file[0]);
        throw;
    }
    catch (Error &e) {
        close(fd);
        (void) unlink(&temp_file[0]);
        throw BESInternalError(e.get_error_message(), __FILE__, __LINE__);
    }

    catch (...) {
        close(fd);
        (void) unlink(&temp_file[0]);
        throw BESInternalError("Fileout GeoTiff, was not able to transform to geotiff, unknown error", __FILE__, __LINE__);
    }

    close(fd);
    (void) unlink(&temp_file[0]);

    BESDEBUG("fong2", "GeoTiffTransmitter::send_data - done transmitting to geotiff" << endl);
}

void GeoTiffTransmitter::return_temp_stream(const string &filename, ostream &strm)
{
    ifstream os;
    os.open(filename.c_str(), ios::binary | ios::in);
    if (!os)
        throw BESInternalError("Cannot connect to data source", __FILE__, __LINE__);

    char block[4096];
    os.read(block, sizeof block);
    int nbytes = os.gcount();
    if (nbytes == 0) {
        os.close();
        throw BESInternalError("Internal server error, got zero count on stream buffer.", __FILE__, __LINE__);
    }

    bool found = false;
    string context = "transmit_protocol";
    string protocol = BESContextManager::TheManager()->get_context(context, found);
    if (protocol == "HTTP") {
        strm << "HTTP/1.0 200 OK\n";
        strm << "Content-type: application/octet-stream\n";
        strm << "Content-Description: " << "BES dataset" << "\n";
        strm << "Content-Disposition: filename=" << filename << ".tif;\n\n";
        strm << flush;
    }
    strm.write(block, nbytes);

    while (os) {
        os.read(block, sizeof block);
        nbytes = os.gcount();
        strm.write(block, nbytes);
    }

    os.close();
}