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1 #pragma once |
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2 |
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3 #include <string> |
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4 #include <iostream> |
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5 #include <cassert> |
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6 #include <limits> |
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7 |
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8 #include "common.h" |
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9 #include "DataType.h" |
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10 #include "RelpipeException.h" |
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11 |
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12 using namespace std; |
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13 |
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14 namespace rp_prototype { |
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15 |
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16 /** |
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17 * The prototype does not have various integer and other numeric data types, |
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18 * it just works with one type of integer. |
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19 * But this integer has variable length -- smaller values occupy only one byte, bigger ones, more bytes 1,2,4,8 + first byte (contains length signalization). |
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20 * In the real implementation of relational pipes, there will be DataTypes for particular numeric types. |
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21 * |
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22 * TODO: support also big endian architectures. |
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23 * TODO: throw exception if a value was stored in bigger type than needed (while reading – there should be only one supported way how to encode a single value) |
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24 * |
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25 * Example of encoded values: |
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26 * ------------------------------------------------------------------------------------------------- |
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27 * $ for n in 0 1 10 250 251 252 65535 65536 4294967295 4294967296 18446744073709551615; do printf '%20s = ' $n; dist/Debug/GNU-Linux/rp-prototype write integer $n | hd | head -n 1; done |
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28 * 0 = 00000000 00 |.| |
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29 * 1 = 00000000 01 |.| |
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30 * 10 = 00000000 0a |.| |
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31 * 250 = 00000000 fa |.| |
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32 * 251 = 00000000 fb fb |..| |
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33 * 252 = 00000000 fb fc |..| |
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34 * 65535 = 00000000 fc ff ff |...| |
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35 * 65536 = 00000000 fd 00 00 01 00 |.....| |
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36 * 4294967295 = 00000000 fd ff ff ff ff |.....| |
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37 * 4294967296 = 00000000 fe 00 00 00 00 01 00 00 00 |.........| |
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38 * 18446744073709551615 = 00000000 fe ff ff ff ff ff ff ff ff |.........| |
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39 * ------------------------------------------------------------------------------------------------- |
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40 * |
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41 * Example of decoded values: |
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42 * ------------------------------------------------------------------------------------------------- |
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43 * $ for n in 0 1 10 250 251 252 65535 65536 4294967295 4294967296 18446744073709551615; do dist/Debug/GNU-Linux/rp-prototype write integer $n | dist/Debug/GNU-Linux/rp-prototype read integer; done; |
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44 * 0 |
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45 * 1 |
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46 * 10 |
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47 * 250 |
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48 * 251 |
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49 * 252 |
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50 * 65535 |
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51 * 65536 |
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52 * 4294967295 |
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53 * 4294967296 |
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54 * 18446744073709551615 |
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55 * ------------------------------------------------------------------------------------------------- |
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56 * |
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57 * Note: similar format as original idea: https://en.wikipedia.org/wiki/X.690#Length_octets |
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58 * |
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59 */ |
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60 class IntegerDataType : public DataType<integer_t> { |
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61 private: |
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62 static const uint8_t INTEGER_TYPE_UINT8 = 251; |
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63 static const uint8_t INTEGER_TYPE_UINT16 = 252; |
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64 static const uint8_t INTEGER_TYPE_UINT32 = 253; |
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65 static const uint8_t INTEGER_TYPE_UINT64 = 254; |
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66 static const uint8_t INTEGER_TYPE_RESERVED = 255; |
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67 |
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68 template<typename T> integer_t read(istream &input) { |
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69 T value = 0; |
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70 input.read(reinterpret_cast<char *> (&value), sizeof (value)); |
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71 return value; |
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72 } |
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73 |
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74 template<typename T> void write(ostream &output, const integer_t &value) { |
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75 assert(sizeof (T) <= sizeof (value)); |
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76 output.write(reinterpret_cast<const char *> (&value), sizeof (T)); |
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77 } |
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78 |
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79 template<typename T> void write(ostream &output, const uint8_t type, const integer_t &value) { |
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80 write<uint8_t>(output, type); |
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81 write<T>(output, value); |
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82 } |
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83 |
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84 template<typename T> bool fits(const integer_t &value) { |
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85 return value <= numeric_limits<T>::max(); |
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86 } |
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87 |
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88 public: |
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89 |
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90 IntegerDataType() : DataType<integer_t>(DATA_TYPE_ID_INTEGER, DATA_TYPE_CODE_INTEGER) { |
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91 } |
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92 |
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93 integer_t readValue(istream &input) override { |
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94 uint8_t first; |
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95 input.read(reinterpret_cast<char *> (&first), sizeof (first)); |
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96 if (input.good()) { |
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97 |
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98 if (first < INTEGER_TYPE_UINT8) return first; |
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99 else if (first == INTEGER_TYPE_UINT8) return read<uint8_t>(input); |
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100 else if (first == INTEGER_TYPE_UINT16) return read<uint16_t>(input); |
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101 else if (first == INTEGER_TYPE_UINT32) return read<uint32_t>(input); |
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102 else if (first == INTEGER_TYPE_UINT64) return read<uint64_t>(input); |
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103 else throw RelpipeException(L"Error while parsing integer type: unsupported type", EXIT_CODE_DATA_ERROR); |
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104 } else { |
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105 throw RelpipeException(L"Error while reading integer from the stream.", EXIT_CODE_DATA_ERROR); |
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106 } |
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107 } |
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108 |
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109 void writeValue(ostream &output, const integer_t &value) override { |
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110 // output << value; // by zapsalo číslo jako ASII text |
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111 |
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112 if (value < INTEGER_TYPE_UINT8) write<uint8_t>(output, value); |
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113 else if (fits<uint8_t>(value)) write<uint8_t>(output, INTEGER_TYPE_UINT8, value); |
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114 else if (fits<uint16_t>(value)) write<uint16_t>(output, INTEGER_TYPE_UINT16, value); |
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115 else if (fits<uint32_t>(value)) write<uint32_t>(output, INTEGER_TYPE_UINT32, value); |
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116 else if (fits<uint64_t>(value)) write<uint64_t>(output, INTEGER_TYPE_UINT64, value); |
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117 else throw RelpipeException(L"Error while writing integer type: value too long", EXIT_CODE_DATA_ERROR); |
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118 } |
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119 |
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120 integer_t toValue(const wstring &stringValue) override { |
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121 // throws „terminate called after throwing an instance of 'std::invalid_argument'“ SIGABRT, core dumped on invalid number |
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122 return stoul(stringValue); |
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123 } |
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124 |
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125 wstring toString(const integer_t &value) override { |
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126 return to_wstring(value); |
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127 } |
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128 |
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129 }; |
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130 |
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131 } |