1 #pragma once

     2 

     3 #include <string>

     4 #include <sstream>

     5 #include <iostream>

     6 #include <vector>

     7 #include <locale>

     8 #include <codecvt>

     9 

    10 #include "DataType.h"

    11 #include "RelpipeException.h"

    12 #include "IntegerDataType.h"

    13 

    14 using namespace std;

    15 

    16 namespace rp_prototype {

    17 

    18 /**

    19  * The prototype does not recognize any encoding,

    20  * it just works with c++ strings in encoding default to given platform. 

    21  * In the real implementation of relational pipes, there will be DataTypes for particular encodings.

    22  */

    23 class StringDataType : public DataType<wstring> {

    24 private:

    25 	IntegerDataType integerType;

    26 	wstring_convert<codecvt_utf8<wchar_t>> convertor; // TODO: support also other encodings.

    27 public:

    28 

    29 	StringDataType() : DataType<wstring>(DATA_TYPE_ID_STRING, DATA_TYPE_CODE_STRING) {

    30 	}

    31 

    32 	wstring readValue(istream &input) override {

    33 		integer_t length = integerType.readValue(input);

    34 		// TODO: check maximum length of single field

    35 		// if (length > 4000) throw RelpipeException("data too long", EXIT_CODE_DATA_ERROR);

    36 		vector<char> buf(length);

    37 		input.read(buf.data(), length);

    38 		if (input.good()) {

    39 			return convertor.from_bytes(string(buf.data(), length));

    40 		} else {

    41 			throw RelpipeException(L"Error while reading string from the stream.", EXIT_CODE_DATA_ERROR);

    42 		}

    43 	}

    44 

    45 	void writeValue(ostream &output, const wstring &value) override {

    46 		string s = convertor.to_bytes(value);

    47 		integerType.writeValue(output, s.length());

    48 		output << s.c_str();

    49 	}

    50 

    51 	wstring toValue(const wstring &stringValue) override {

    52 		return stringValue;

    53 	}

    54 

    55 	wstring toString(const wstring &value) override {

    56 		return value;

    57 	}

    58 

    59 };

    60 

    61 }