Add --stream-piece-selector=random

1 files changed, 76 insertions, 0 deletions

diff --git a/src/RandomStreamPieceSelector.cc b/src/RandomStreamPieceSelector.cc
new file mode 100644
index 00000000..a14c2c2b
--- /dev/null
+++ b/src/RandomStreamPieceSelector.cc
@@ -0,0 +1,76 @@
+/* <!-- copyright */
+/*
+ * aria2 - The high speed download utility
+ *
+ * Copyright (C) 2015 Tatsuhiro Tsujikawa
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ * In addition, as a special exception, the copyright holders give
+ * permission to link the code of portions of this program with the
+ * OpenSSL library under certain conditions as described in each
+ * individual source file, and distribute linked combinations
+ * including the two.
+ * You must obey the GNU General Public License in all respects
+ * for all of the code used other than OpenSSL.  If you modify
+ * file(s) with this exception, you may extend this exception to your
+ * version of the file(s), but you are not obligated to do so.  If you
+ * do not wish to do so, delete this exception statement from your
+ * version.  If you delete this exception statement from all source
+ * files in the program, then also delete it here.
+ */
+/* copyright --> */
+#include "RandomStreamPieceSelector.h"
+#include "BitfieldMan.h"
+#include "SimpleRandomizer.h"
+
+namespace aria2 {
+
+RandomStreamPieceSelector::RandomStreamPieceSelector
+(BitfieldMan* bitfieldMan)
+  : bitfieldMan_(bitfieldMan)
+{}
+
+RandomStreamPieceSelector::~RandomStreamPieceSelector() {}
+
+bool RandomStreamPieceSelector::select
+(size_t& index,
+ size_t minSplitSize,
+ const unsigned char* ignoreBitfield,
+ size_t length)
+{
+  size_t start = SimpleRandomizer::getInstance()->getRandomNumber
+    (bitfieldMan_->countBlock());
+
+  auto rv = bitfieldMan_->getInorderMissingUnusedIndex
+    (index, start, bitfieldMan_->countBlock(), minSplitSize, ignoreBitfield,
+     length);
+  if (rv) {
+    return true;
+  }
+  rv = bitfieldMan_->getInorderMissingUnusedIndex(index, 0, start, minSplitSize,
+                                                  ignoreBitfield, length);
+  if (rv) {
+    return true;
+  }
+  // Fall back to inorder search because randomized search may fail
+  // because of |minSplitSize| constraint.
+  return bitfieldMan_->getInorderMissingUnusedIndex(index, minSplitSize,
+                                                    ignoreBitfield, length);
+}
+
+void RandomStreamPieceSelector::onBitfieldInit() {}
+
+} // namespace aria2