Allow inlining random number generator most of the time.

Signed-off-by: Stefan Westerfeld <stefan@space.twc.de>

src/TODO

 key:
-- multiple values per block
 - avoid reroll in up_down generation
 - move shuffle function to Random class
 

src/random.cc

@@ -102,28 +102,23 @@ Random::get_start_counter (uint64_t seed, Stream stream)
   return cipher_text;
 }
 
-uint64_t
-Random::operator()()
+void
+Random::refill_buffer()
 {
-  if (buffer_pos == buffer.size())
-    {
-      const size_t block_size = 256;
-      unsigned char zeros[block_size] = { 0, };
-      unsigned char cipher_text[block_size];
+  const size_t block_size = 256;
+  unsigned char zeros[block_size] = { 0, };
+  unsigned char cipher_text[block_size];
 
-      gcry_error_t gcry_ret = gcry_cipher_encrypt (aes_ctr_cipher, cipher_text, block_size, zeros, block_size);
-      die_on_error ("gcry_cipher_encrypt", gcry_ret);
+  gcry_error_t gcry_ret = gcry_cipher_encrypt (aes_ctr_cipher, cipher_text, block_size, zeros, block_size);
+  die_on_error ("gcry_cipher_encrypt", gcry_ret);
 
-      // print ("AES OUT", {cipher_text, cipher_text + block_size});
+  // print ("AES OUT", {cipher_text, cipher_text + block_size});
 
-      buffer.clear();
-      for (size_t i = 0; i < block_size; i += 8)
-        buffer.push_back (uint64_from_buffer (cipher_text + i));
+  buffer.clear();
+  for (size_t i = 0; i < block_size; i += 8)
+    buffer.push_back (uint64_from_buffer (cipher_text + i));
 
-      buffer_pos = 0;
-    }
-  assert (buffer_pos < buffer.size());
-  return buffer[buffer_pos++];
+  buffer_pos = 0;
 }
 
 void

src/random.hh

@@ -26,7 +26,16 @@ private:
 public:
   Random (uint64_t seed, Stream stream);
   ~Random();
-  uint64_t operator()();
+
+  uint64_t
+  operator()()
+  {
+    if (buffer_pos == buffer.size())
+      refill_buffer();
+
+    return buffer[buffer_pos++];
+  }
+  void refill_buffer();
 
   static void        set_global_test_key (uint64_t seed);
   static void        load_global_key (const std::string& key_file);