1 files changed, 186 insertions, 0 deletions
diff --git a/host/lib/utils/gain_group.cpp b/host/lib/utils/gain_group.cpp
new file mode 100644
index 000000000..85f4977a6
--- /dev/null
+++ b/host/lib/utils/gain_group.cpp
@@ -0,0 +1,186 @@
+//
+// Copyright 2010-2011 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#include <uhd/utils/gain_group.hpp>
+#include <uhd/utils/log.hpp>
+#include <uhd/types/dict.hpp>
+#include <uhd/utils/algorithm.hpp>
+#include <uhd/exception.hpp>
+#include <boost/foreach.hpp>
+#include <boost/bind.hpp>
+#include <algorithm>
+#include <vector>
+
+using namespace uhd;
+
+static const bool verbose = false;
+
+static bool compare_by_step_size(
+    const size_t &rhs, const size_t &lhs, std::vector<gain_fcns_t> &fcns
+){
+    return fcns.at(rhs).get_range().step() > fcns.at(lhs).get_range().step();
+}
+
+/*!
+ * Get a multiple of step with the following relation:
+ *     result = step*floor(num/step)
+ *
+ * Due to small doubleing-point inaccuracies:
+ *     num = n*step + e, where e is a small inaccuracy.
+ * When e is negative, floor would yeild (n-1)*step,
+ * despite that n*step is really the desired result.
+ * This function is designed to mitigate that issue.
+ *
+ * \param num the number to approximate
+ * \param step the step size to round with
+ * \param e the small inaccuracy to account for
+ * \return a multiple of step approximating num
+ */
+template <typename T> static T floor_step(T num, T step, T e = T(0.001)){
+    return step*int(num/step + e);
+}
+
+/***********************************************************************
+ * gain group implementation
+ **********************************************************************/
+class gain_group_impl : public gain_group{
+public:
+    gain_group_impl(void){
+        /*NOP*/
+    }
+
+    gain_range_t get_range(const std::string &name){
+        if (not name.empty()) return _name_to_fcns[name].get_range();
+
+        double overall_min = 0, overall_max = 0, overall_step = 0;
+        BOOST_FOREACH(const gain_fcns_t &fcns, get_all_fcns()){
+            const gain_range_t range = fcns.get_range();
+            overall_min += range.start();
+            overall_max += range.stop();
+            //the overall step is the min (zero is invalid, first run)
+            if (overall_step == 0) overall_step = range.step();
+            overall_step = std::min(overall_step, range.step());
+        }
+        return gain_range_t(overall_min, overall_max, overall_step);
+    }
+
+    double get_value(const std::string &name){
+        if (not name.empty()) return _name_to_fcns[name].get_value();
+
+        double overall_gain = 0;
+        BOOST_FOREACH(const gain_fcns_t &fcns, get_all_fcns()){
+            overall_gain += fcns.get_value();
+        }
+        return overall_gain;
+    }
+
+    void set_value(double gain, const std::string &name){
+        if (not name.empty()) return _name_to_fcns[name].set_value(gain);
+
+        std::vector<gain_fcns_t> all_fcns = get_all_fcns();
+        if (all_fcns.size() == 0) return; //nothing to set!
+
+        //get the max step size among the gains
+        double max_step = 0;
+        BOOST_FOREACH(const gain_fcns_t &fcns, all_fcns){
+            max_step = std::max(max_step, fcns.get_range().step());
+        }
+
+        //create gain bucket to distribute power
+        std::vector<double> gain_bucket;
+
+        //distribute power according to priority (round to max step)
+        double gain_left_to_distribute = gain;
+        BOOST_FOREACH(const gain_fcns_t &fcns, all_fcns){
+            const gain_range_t range = fcns.get_range();
+            gain_bucket.push_back(floor_step(uhd::clip(
+                gain_left_to_distribute, range.start(), range.stop()
+            ), max_step));
+            gain_left_to_distribute -= gain_bucket.back();
+        }
+
+        //get a list of indexes sorted by step size large to small
+        std::vector<size_t> indexes_step_size_dec;
+        for (size_t i = 0; i < all_fcns.size(); i++){
+            indexes_step_size_dec.push_back(i);
+        }
+        std::sort(
+            indexes_step_size_dec.begin(), indexes_step_size_dec.end(),
+            boost::bind(&compare_by_step_size, _1, _2, all_fcns)
+        );
+        UHD_ASSERT_THROW(
+            all_fcns.at(indexes_step_size_dec.front()).get_range().step() >=
+            all_fcns.at(indexes_step_size_dec.back()).get_range().step()
+        );
+
+        //distribute the remainder (less than max step)
+        //fill in the largest step sizes first that are less than the remainder
+        BOOST_FOREACH(size_t i, indexes_step_size_dec){
+            const gain_range_t range = all_fcns.at(i).get_range();
+            double additional_gain = floor_step(uhd::clip(
+                gain_bucket.at(i) + gain_left_to_distribute, range.start(), range.stop()
+            ), range.step()) - gain_bucket.at(i);
+            gain_bucket.at(i) += additional_gain;
+            gain_left_to_distribute -= additional_gain;
+        }
+        UHD_LOGV(often) << "gain_left_to_distribute " << gain_left_to_distribute << std::endl;
+
+        //now write the bucket out to the individual gain values
+        for (size_t i = 0; i < gain_bucket.size(); i++){
+            UHD_LOGV(often) << i << ": " << gain_bucket.at(i) << std::endl;
+            all_fcns.at(i).set_value(gain_bucket.at(i));
+        }
+    }
+
+    const std::vector<std::string> get_names(void){
+        return _name_to_fcns.keys();
+    }
+
+    void register_fcns(
+        const std::string &name,
+        const gain_fcns_t &gain_fcns,
+        size_t priority
+    ){
+        if (name.empty() or _name_to_fcns.has_key(name)){
+            //ensure the name name is unique and non-empty
+            return register_fcns(name + "_", gain_fcns, priority);
+        }
+        _registry[priority].push_back(gain_fcns);
+        _name_to_fcns[name] = gain_fcns;
+    }
+
+private:
+    //! get the gain function sets in order (highest priority first)
+    std::vector<gain_fcns_t> get_all_fcns(void){
+        std::vector<gain_fcns_t> all_fcns;
+        BOOST_FOREACH(size_t key, uhd::sorted(_registry.keys())){
+            const std::vector<gain_fcns_t> &fcns = _registry[key];
+            all_fcns.insert(all_fcns.begin(), fcns.begin(), fcns.end());
+        }
+        return all_fcns;
+    }
+
+    uhd::dict<size_t, std::vector<gain_fcns_t> > _registry;
+    uhd::dict<std::string, gain_fcns_t> _name_to_fcns;
+};
+
+/***********************************************************************
+ * gain group factory function
+ **********************************************************************/
+gain_group::sptr gain_group::make(void){
+    return sptr(new gain_group_impl());
+}