src/base/sat_counter.hh

53  * Implements an n bit saturating counter and provides methods to
63      * Constructor for the counter. The explicit keyword is used to make
64      * sure the user does not assign a number to the counter thinking it
65      * will be used as a counter value when it is in fact used as the number
68      * @param bits How many bits the counter will have.
69      * @param initial_val Starting value for the counter.
73           counter(initial_val)
76                  "Number of bits exceeds counter size");
78                  "Saturating counter's Initial value exceeds max value.");
84           counter(other.counter)
102         counter = other.counter;
112             counter = other.counter;
130         std::swap(counter, other.counter);
137         if (counter < maxVal) {
138             ++counter;
156         if (counter > 0) {
157             --counter;
175         this->counter >>= shift;
183         this->counter <<= shift;
184         if (this->counter > maxVal) {
185             this->counter = maxVal;
194         if (maxVal - this->counter >= value) {
195             this->counter += value;
197             this->counter = maxVal;
206         if (this->counter > value) {
207             this->counter -= value;
209             this->counter = 0;
215      * Read the counter's value.
217     operator uint8_t() const { return counter; }
219     /** Reset the counter to its initial value. */
220     void reset() { counter = initialVal; }
223      * Calculate saturation percentile of the current counter's value
229     double calcSaturation() const { return (double) counter / maxVal; }
232      * Whether the counter has achieved its maximum value or not.
234      * @return True if the counter saturated.
236     bool isSaturated() const { return counter == maxVal; }
239      * Saturate the counter.
241      * @return The value added to the counter to reach saturation.
245         const uint8_t diff = maxVal - counter;
246         counter = maxVal;
253     uint8_t counter;