Introduce FastRandomContext::randbool()

sipa · sipa · commit c21cbe61c624 · 2017-03-29T00:40:17.000-07:00
diff --git a/src/random.h b/src/random.h
@@ -42,6 +42,10 @@ class FastRandomContext {
         return (Rw << 16) + Rz;
     }
 
+    bool randbool() {
+        return rand32() & 1;
+    }
+
     uint32_t Rz;
     uint32_t Rw;
 };
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
@@ -2048,7 +2048,7 @@ static void ApproximateBestSubset(const std::vector<std::pair<CAmount, std::pair
                 //that the rng is fast. We do not use a constant random sequence,
                 //because there may be some privacy improvement by making
                 //the selection random.
-                if (nPass == 0 ? insecure_rand.rand32()&1 : !vfIncluded[i])
+                if (nPass == 0 ? insecure_rand.randbool() : !vfIncluded[i])
                 {
                     nTotal += vValue[i].first;
                     vfIncluded[i] = true;

Original file line number	Diff line number	Diff line change
`@@ -2048,7 +2048,7 @@ static void ApproximateBestSubset(const std::vector<std::pair<CAmount, std::pair`
`2048`	`2048`	`//that the rng is fast. We do not use a constant random sequence,`
`2049`	`2049`	`//because there may be some privacy improvement by making`
`2050`	`2050`	`//the selection random.`
`2051`		`- if (nPass == 0 ? insecure_rand.rand32()&1 : !vfIncluded[i])`
	`2051`	`+ if (nPass == 0 ? insecure_rand.randbool() : !vfIncluded[i])`
`2052`	`2052`	`{`
`2053`	`2053`	`nTotal += vValue[i].first;`
`2054`	`2054`	`vfIncluded[i] = true;`