initial implementation

src/reactor/PollingReactor.cpp

@@ -0,0 +1,88 @@
+/* @file PollingReactor.cpp */
+
+#include "PollingReactor.hpp"
+
+namespace xo {
+    using ref::brw;
+    using std::size_t;
+    using std::uint64_t;
+    using std::int64_t;
+
+    namespace reactor {
+        bool
+        PollingReactor::add_source(brw<ReactorSource> src)
+        {
+            /* make sure src does not already appear in .source_v[] */
+            for(ReactorSourcePtr const & x : this->source_v_) {
+                if(x.get() == src.get()) {
+                    throw std::runtime_error("PollingReactor::add_source; source already present");
+                    return false;
+                }
+            }
+
+            src->notify_reactor_add(this);
+
+            this->source_v_.push_back(src.get());
+
+            return true;
+        } /*add_source*/
+
+        bool
+        PollingReactor::remove_source(brw<ReactorSource> src)
+        {
+            auto ix = std::find(this->source_v_.begin(),
+                                this->source_v_.end(),
+                                src);
+
+            if(ix != this->source_v_.end()) {
+                src->notify_reactor_remove(this);
+
+                this->source_v_.erase(ix);
+
+                return true;
+            }
+
+            return false;
+        } /*remove_source*/
+
+        int64_t
+        PollingReactor::find_nonempty_source(size_t start_ix)
+        {
+            size_t z = this->source_v_.size();
+
+            /* search sources [ix .. z) */
+            for(size_t ix = start_ix; ix < z; ++ix) {
+                brw<ReactorSource> src = this->source_v_[ix];
+
+                if(src->is_nonempty())
+                    return ix;
+            }
+
+            /* search source [0 .. ix) */
+            for(size_t ix = 0, n = std::min(start_ix, z); ix < n; ++ix) {
+                brw<ReactorSource> src = this->source_v_[ix];
+
+                if(src->is_nonempty())
+                    return ix;
+            }
+
+            return -1;
+        } /*find_nonempty_source*/
+
+        uint64_t
+        PollingReactor::run_one()
+        {
+            int64_t ix = this->find_nonempty_source(this->next_ix_);
+
+            if(ix >= 0) {
+                brw<ReactorSource> src = this->source_v_[ix];
+
+                return src->deliver_one();
+            } else {
+                return 0;
+            }
+        } /*run_one*/
+    } /*namespace reactor*/
+} /*namespace xo*/
+
+/* end PollingReactor.cpp */