1 /**

     2  * Relational pipes (library)

     3  * Copyright © 2018 František Kučera (Frantovo.cz, GlobalCode.info)

     4  *

     5  * This program is free software: you can redistribute it and/or modify

     6  * it under the terms of the:

     7  *  - GNU Lesser General Public License as published by the Free Software Foundation;

     8  *    version 3 of the License or (at your option)

     9  *  - GNU General Public License as published by the Free Software Foundation;

    10  *    version 2 of the License.

    11  *

    12  * This program is distributed in the hope that it will be useful,

    13  * but WITHOUT ANY WARRANTY; without even the implied warranty of

    14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

    15  * GNU General Public License for more details.

    16  *

    17  * You should have received a copy of the GNU General Public License

    18  * along with this program. If not, see <http://www.gnu.org/licenses/>.

    19  */

    20 #pragma once

    21 

    22 #include <string>

    23 #include <iostream>

    24 #include <cassert>

    25 #include <limits>

    26 

    27 #include <relpipe/protocol/constants.h>

    28 

    29 #include "../../include/relpipe/reader/RelpipeReaderException.h"

    30 #include "../../include/relpipe/reader/typedefs.h"

    31 #include "../DataTypeReader.h"

    32 

    33 namespace relpipe {

    34 namespace reader {

    35 namespace types {

    36 

    37 using namespace relpipe::protocol;

    38 using namespace relpipe::reader;

    39 

    40 /**

    41  * Unsigned variable-length integer.

    42  * ULEB128

    43  */

    44 class IntegerDataTypeReader : public DataTypeReader<integer_t> { // FIXME: relpipe::common::type::UnsignedInteger

    45 private:

    46 

    47 	octet_t readNextOctet(std::istream &input) {

    48 		octet_t value = input.get();

    49 		if (input.good()) return value;

    50 		else throw RelpipeReaderException(L"Unable to read next octet of the integer.");

    51 	}

    52 

    53 public:

    54 

    55 	IntegerDataTypeReader() : DataTypeReader<integer_t>(TypeId::INTEGER, DATA_TYPE_CODE_INTEGER) {

    56 	}

    57 

    58 	integer_t readValue(std::istream &input) override {

    59 		integer_t value = 0;

    60 		integer_t shift = 0;

    61 		octet_t octet;

    62 		do {

    63 			octet = readNextOctet(input);

    64 			value += integer_t(octet & 0x7F) << shift;

    65 			shift += 7;

    66 		} while (octet >= 128);

    67 		return value;

    68 	}

    69 

    70 	string_t toString(const integer_t &value) override {

    71 		return std::to_wstring(value);

    72 	}

    73 

    74 };

    75 

    76 }

    77 }

    78 }