consolidate throttling

src/math/lp/nla_throttle.cpp

@@ -0,0 +1,24 @@
+/*++
+  Copyright (c) 2017 Microsoft Corporation
+
+  Author:
+    Lev Nachmanson (levnach)
+
+  --*/
+#include "math/lp/nla_throttle.h"
+#include "util/trace.h"
+
+namespace nla {
+
+bool nla_throttle::insert_new_impl(const signature& sig) {
+    if (m_seen.contains(sig)) {
+        TRACE(nla_solver, tout << "throttled lemma generation\n";);
+        return true;  // Already seen, throttle
+    }
+    
+    m_seen.insert(sig);
+    m_trail.push(insert_map(m_seen, sig));
+    return false;     // New, don't throttle
+}
+
+} // namespace nla