gzip_file_reader.h

// Copyright (c) 2018 Coronis Computing S.L. (Spain)
// All rights reserved.
//
// This file is part of EMODnet Quantized Mesh Generator for Cesium.
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <https://www.gnu.org/licenses/>.
//
// Author: Ricard Campos (ricardcd@gmail.com)

#ifndef EMODNET_QMGC_GZIP_FILE_READER_H
#define EMODNET_QMGC_GZIP_FILE_READER_H

#include <zlib.h>
#include <string>
#include <cstring>

class GZipFileReader {

public:
    // Typedefs
    typedef unsigned char Byte;

    GZipFileReader( const std::string &filePath );

    bool isFileOpen() { return m_file != NULL; }

    Byte readByte();

    void skipBytes(int numBytes);

    double readDouble();

    float readFloat();

    int readInt();

    unsigned int readUInt();

    short readShort();

    unsigned short readUShort();

    char readChar();

    unsigned char readUChar();

    template <typename T>
    T read() {
        // Size of the type used
        int sz = sizeof(T);

        // Read from the GZip file
        Byte buffer[sz];
        int bytesRead = gzread(m_file, buffer, sz);
        T ret;
        memcpy(&ret, &buffer[0], sz);

        // Update the position of the pointer in the file
        m_pos += sz;

        return ret;
    }

    int getPos() { return m_pos; }

    bool close() { return gzclose(m_file); }

    bool eof() { return gzeof(m_file); }

private:
    gzFile m_file; 
    int m_pos;     
};


#endif //EMODNET_QMGC_GZIP_FILE_READER_H