Alexandre Lision | ddd731e | 2014-01-31 11:50:08 -0500 | [diff] [blame] | 1 | // Copyright (C) 2006-2010 David Sugar, Tycho Softworks. |
| 2 | // |
| 3 | // This file is part of GNU uCommon C++. |
| 4 | // |
| 5 | // GNU uCommon C++ is free software: you can redistribute it and/or modify |
| 6 | // it under the terms of the GNU Lesser General Public License as published |
| 7 | // by the Free Software Foundation, either version 3 of the License, or |
| 8 | // (at your option) any later version. |
| 9 | // |
| 10 | // GNU uCommon C++ is distributed in the hope that it will be useful, |
| 11 | // but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | // GNU Lesser General Public License for more details. |
| 14 | // |
| 15 | // You should have received a copy of the GNU Lesser General Public License |
| 16 | // along with GNU uCommon C++. If not, see <http://www.gnu.org/licenses/>. |
| 17 | |
| 18 | /** |
| 19 | * Support for various automatic counting objects. |
| 20 | * This header defines templates for various kinds of automatic counting |
| 21 | * and sequencing objects. Templates are used to allow manipulation of |
| 22 | * various numerical-like types. |
| 23 | * @file ucommon/counter.h |
| 24 | */ |
| 25 | |
| 26 | #ifndef _UCOMMON_COUNTER_H_ |
| 27 | #define _UCOMMON_COUNTER_H_ |
| 28 | |
| 29 | #ifndef _UCOMMON_CONFIG_H_ |
| 30 | #include <ucommon/platform.h> |
| 31 | #endif |
| 32 | |
| 33 | NAMESPACE_UCOMMON |
| 34 | |
| 35 | /** |
| 36 | * Automatic integer counting class. This is an automatic counting object |
| 37 | * that is used to retrieve a new integer value between 0 and n each time |
| 38 | * the object is referenced. When reaching the last n value, the object |
| 39 | * restarts at 0, and so is used to retrieve a sequence of values in order. |
| 40 | * @author David Sugar <dyfet@gnutelephony.org> |
| 41 | */ |
| 42 | class __EXPORT counter |
| 43 | { |
| 44 | private: |
| 45 | unsigned value, cycle; |
| 46 | |
| 47 | public: |
| 48 | /** |
| 49 | * Initialize integer counter of unknown size. |
| 50 | */ |
| 51 | counter(); |
| 52 | |
| 53 | /** |
| 54 | * Initialize integer counter for a range of values. |
| 55 | * @param limit before recycling to zero. |
| 56 | */ |
| 57 | counter(unsigned limit); |
| 58 | |
| 59 | /** |
| 60 | * Get the next counter value. |
| 61 | * @return next counter value. |
| 62 | */ |
| 63 | unsigned get(void); |
| 64 | |
| 65 | /** |
| 66 | * Get the range of values before recycling. |
| 67 | * @return counter limit. |
| 68 | */ |
| 69 | inline unsigned range(void) |
| 70 | {return cycle;}; |
| 71 | |
| 72 | /** |
| 73 | * Reference next counter value through pointer operation. |
| 74 | * @return next counter value. |
| 75 | */ |
| 76 | inline unsigned operator*() |
| 77 | {return get();}; |
| 78 | |
| 79 | /** |
| 80 | * Reference next counter value by casting to integer. |
| 81 | * @return next counter value. |
| 82 | */ |
| 83 | inline operator unsigned() |
| 84 | {return get();}; |
| 85 | |
| 86 | /** |
| 87 | * Assign the value of the counter. |
| 88 | * @param value to assign. |
| 89 | */ |
| 90 | void operator=(unsigned value); |
| 91 | }; |
| 92 | |
| 93 | /** |
| 94 | * Automatically return a sequence of untyped objects. This is an automatic |
| 95 | * counter based class which returns the next pointer in an array of pointers |
| 96 | * and restarts the list when reaching the end. This is used to support the |
| 97 | * sequence template. |
| 98 | * @author David Sugar <dyfet@gnutelephony.org> |
| 99 | */ |
| 100 | class __EXPORT SeqCounter : protected counter |
| 101 | { |
| 102 | private: |
| 103 | void *item; |
| 104 | size_t offset; |
| 105 | |
| 106 | protected: |
| 107 | SeqCounter(void *start, size_t size, unsigned count); |
| 108 | |
| 109 | void *get(void); |
| 110 | |
| 111 | void *get(unsigned idx); |
| 112 | |
| 113 | public: |
| 114 | /** |
| 115 | * Used to directly assign sequence position in template. |
| 116 | * @param inc_offset in sequence to reset sequencing to. |
| 117 | */ |
| 118 | inline void operator=(unsigned inc_offset) |
| 119 | {counter::operator=(inc_offset);}; |
| 120 | }; |
| 121 | |
| 122 | /** |
| 123 | * Automatically toggle a bool on each reference. |
| 124 | * @author David Sugar <dyfet@gnutelephony.org> |
| 125 | */ |
| 126 | class __EXPORT toggle |
| 127 | { |
| 128 | private: |
| 129 | bool value; |
| 130 | |
| 131 | public: |
| 132 | inline toggle() |
| 133 | {value = false;}; |
| 134 | |
| 135 | bool get(void); |
| 136 | |
| 137 | inline bool operator*() |
| 138 | {return get();}; |
| 139 | |
| 140 | inline void operator=(bool v) |
| 141 | {value = v;}; |
| 142 | |
| 143 | inline operator bool() |
| 144 | {return get();}; |
| 145 | |
| 146 | }; |
| 147 | |
| 148 | /** |
| 149 | * A template to return a sequence of objects of a specified type. |
| 150 | * This is used to return a different member in a sequence of objects of |
| 151 | * a specified type during each reference to the sequencer. |
| 152 | * @author David Sugar <dyfet@gnutelephony.org> |
| 153 | */ |
| 154 | template <class T> |
| 155 | class sequence : public SeqCounter |
| 156 | { |
| 157 | protected: |
| 158 | inline T *get(unsigned idx) |
| 159 | {return static_cast<T *>(SeqCounter::get(idx));}; |
| 160 | |
| 161 | public: |
| 162 | /** |
| 163 | * Create a template auto-sequence from a list of typed pointers. |
| 164 | * @param array of typed values to sequence on reference. |
| 165 | * @param size of list of typed values. |
| 166 | */ |
| 167 | inline sequence(T *array, unsigned size) : |
| 168 | SeqCounter(array, sizeof(T), size) {}; |
| 169 | |
| 170 | /** |
| 171 | * Return next typed member of the sequence. |
| 172 | * @return next typed member of sequence. |
| 173 | */ |
| 174 | inline T* get(void) |
| 175 | {return static_cast<T *>(SeqCounter::get());}; |
| 176 | |
| 177 | /** |
| 178 | * Return next typed member of the sequence by pointer reference. |
| 179 | * @return next typed member of sequence. |
| 180 | */ |
| 181 | inline T& operator*() |
| 182 | {return *get();}; |
| 183 | |
| 184 | /** |
| 185 | * Return next typed member of the sequence by casted reference. |
| 186 | * @return next typed member of sequence. |
| 187 | */ |
| 188 | inline operator T&() |
| 189 | {return *get();}; |
| 190 | |
| 191 | /** |
| 192 | * Return a specific typed member from the sequence list. |
| 193 | * @param offset of member to return. |
| 194 | * @return typed value at the specified offset. |
| 195 | */ |
| 196 | inline T& operator[](unsigned offset) |
| 197 | {return *get(offset);}; |
| 198 | }; |
| 199 | |
| 200 | /** |
| 201 | * A convenience typecast for integer counters. |
| 202 | */ |
| 203 | typedef counter counter_t; |
| 204 | |
| 205 | /** |
| 206 | * A convenience typecast for auto-toggled bools. |
| 207 | */ |
| 208 | typedef toggle toggle_t; |
| 209 | |
| 210 | END_NAMESPACE |
| 211 | |
| 212 | #endif |