X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=sampling.h;h=8f80b72eca8d4982731d15a366100b5c68563ed3;hb=5d607690061273a9fca1262be1473038dc9fb3da;hp=417140395b8b78801af1808fc93bf6d3eca9d602;hpb=946f9a6adb2a82048c8453d44693cd3838d32939;p=rsem.git

diff --git a/sampling.h b/sampling.h
index 4171403..8f80b72 100644
--- a/sampling.h
+++ b/sampling.h
@@ -5,17 +5,48 @@
 #include<cstdio>
 #include<cassert>
 #include<vector>
+#include<set>
 
 #include "boost/random.hpp"
 
-boost::mt19937 rng(time(NULL));
-boost::uniform_01<boost::mt19937> rg(rng);
+typedef unsigned int seedType;
+typedef boost::mt19937 engine_type;
+typedef boost::gamma_distribution<> gamma_dist;
+typedef boost::uniform_01<engine_type> uniform01;
+typedef boost::variate_generator<engine_type&, gamma_dist> gamma_generator;
+
+class engineFactory {
+public:
+  static void init() { seedEngine = new engine_type(time(NULL)); }
+  static void init(seedType seed) { seedEngine = new engine_type(seed); }
+
+  static void finish() { if (seedEngine != NULL) delete seedEngine; }
+
+	static engine_type *new_engine() {
+		seedType seed;
+		static std::set<seedType> seedSet;			// empty set of seeds
+		std::set<seedType>::iterator iter;
+
+		do {
+			seed = (*seedEngine)();
+			iter = seedSet.find(seed);
+		} while (iter != seedSet.end());
+		seedSet.insert(seed);
+
+		return new engine_type(seed);
+	}
+
+ private:
+	static engine_type *seedEngine;
+};
+
+engine_type* engineFactory::seedEngine = NULL;
 
 // arr should be cumulative!
 // interval : [,)
 // random number should be in [0, arr[len - 1])
 // If by chance arr[len - 1] == 0.0, one possibility is to sample uniformly from 0...len-1
-int sample(std::vector<double>& arr, int len) {
+int sample(uniform01& rg, std::vector<double>& arr, int len) {
   int l, r, mid;
   double prb = rg() * arr[len - 1];